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Alkaline & Carbonatite Database – Search
Total localities: 3097
Plotted on map: 3040
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"V" Intrusive
United States of America · Arkansas · 174-00-118
A complex system of dykes known as the "V" Intrusive lies about 1.2 km south of the Potash Sulfur Springs complex (No. 117) (Erickson and Blade, 1963, Fig. 4). …
Abercrombie, Grabben Gullen And Southern Highlands
Australia · New South Wales · 011-00-068
Age: K-Ar age determinations for fourteen separate flows ranged from 38.8 to 14.6 Ma (Wellman & McDougall, 1974).
These three volcanic provinces lie close to each other, are aligned east-west and extend over about 150 km. The Abercrombie rocks comprise isolated basaltic flo…
Abontorok (Adrar Pinto)
Niger · 121-00-010
Age: A Rb-Sr whole-rock isochron for the syenite-granite-breccia suite gave 399(10 Ma (Brown et al., 1989).
The circular, funnel-shaped Abontorok intrusion is 2.6 km in diameter and has a low central hill of quartz syenites and syenite breccias surrounded by an arcuat…
Abu Dom
Sudan · 155-00-041
Age: Rb-Sr analyses of two peralkaline granites from Abu Dom are compatible with an eight point isochron for Sultaniyat (No. 155-00-039) and Ras Ed Dom (No. 155-00-040) of 236(3 Ma and thus Abu Dom is considered to be the same age (Barth et al., 1983).
This complex is emplaced mainly in Precambrian biotite gneisses and is overlain in places by thin remnant patches of Nubian Sandstone. A small area (0.1 km2) of…
Abu Durba
Egypt · 049-00-005
This is an intrusion of peralkaline granite. No other details have been traced. A paper describing a riebeckite granite lying to the south of Abu Durba was only…
Abu Handal
Sudan · 155-00-044
Age: A Rb-Sr isochron on four peralkaline granites and five peralkaline rhyolites gave 432(3 Ma (Barth et al., 1983).
A central granite ring complex about 10 km in diameter lies within a zone of about 25x20 km containing peralkaline rhyolites and rhyolitic dykes. The central co…
Abu Homr And Abu Dalf (Gabal Abu Homr And Gabal Abu Dalf)
Egypt · 049-00-011
Granites consisting of perthite, quartz and riebeckite form the Abu Homr pluton and the western part of the Gabal Abu Dalf intrusion.
Abu Kharif
Egypt · 049-00-012
Riebeckite-bearing granites in the Abu Kharif area are referred to by Abdel-Maksoud et al. (1978).
Abu Khruq (Gabal Abu Khruq)
Egypt · 049-00-017
Age: K-Ar whole rock detarminations on nepheline syenite and gabbro gave 89(2 and 90(2 Ma (Serencsits et al., 1979) and on nepheline syenite 86(15 Ma and 83(3 Ma, while biotite from the same rock gave 93.5(1.5 Ma (Meneisy and Kreuzer, 1974b). A range of 87-91 Ma by Rb-Sr was obtained by El Ramly and Hussein (1982). Omar et al. (1987) report fission-track ages on apatite and zircon from syenite, tinguaite and essexitic gabbro of 75.8 - 89.9 Ma with an average apatite age of 82.5 Ma. Rb-Sr determinations on minerals from a quartz syenite and two nepheline syenites yielded dates of 92(2, 88(2 and 93(6 Ma (Lutz et al., 1988); these authors tabulate and discuss the previous data.
Economic: A preliminary assessment has been made of the nepheline syenites for the production of aluminium and alkali carbonates. 25-30 million tons of suitable material was proved (El Ramly et al., 1969a).
Gabal Abu Khruq is a conspicuous peak surrounded by semi-annular ridges and wadis. The complex cuts basement gneisses and schists and is partly overlain by lava…
Abu Ramla (Abu Ramlu)
Ethiopia · 054-00-025
Abu Ramla is a multiple intrusion of ring dykes. According to Vail (1985) it contains nepheline syenite but details have not been traced.
Acahay
Paraguay · Paraguari · 130-00-016
Acahay forms an annular ridge rising 300 m above the surrounding plain and has a deep central basin. Milton and Eckel (1959) distinguish on air photographs nume…
Acheron
New Zealand · 119-00-010
Age: Probably late Cretaceous.
Southeast of Lake Coleridge along the banks of the Acheron River for about 1.5 km outcrop three sills and three laccoliths which comprise the Acheron igneous co…
Adare Peninsula
Antarctica · 006-00-057
Age: K-Ar dates on 12 samples from the western edge of the Peninsula ranged between 6.77±0.05 and 13.24±0.12 Ma with a single date of 1.14±0.05 Ma (Kreuzer et al., 1981).
The Adare Peninsula is about 50 km in length with a width at its base of some 15 km and comprises a series of fragments of overlapping shield volcanoes with fiv…
Aden
Yemen · 179-00-015
Age: K-Ar dating of whole-rock samples of rhyolite and trachyte gave 6.5±0.6 and 5.0±0.5 Ma (Dickinson et al., 1969).
Aden is the most easterly of the line of six volcanoes that extend eastwards along the coast from the entrance to the Red Sea. It forms a peninsula that is join…
Adiounedj (Adiounedj)
Mali · 105-00-006
The major rock type of this very irregular complex is fenite with a substantial area of rodbergite and lesser areas of foid syenite and carbonatite (Sauvage and…
Ado Ale
Ethiopia · 054-00-018
This is a rhyolitic volcanic centre which is of peralkaline composition. There are spatter cones and associated basaltic flows. Analyses of two pantelleritic ob…
Adrar Bous (Bous, Adrar Bouss)
Niger · 121-00-001
Age: Karche and Vachette (1978) give a Rb-Sr date of 470(5 Ma. A Rb-Sr whole rock and alkali feldspar isochron age of 429(4 Ma was determined by Bowden et al. (1976), and Moreau et al. (1994) give a Rb-St isochron age, based on six granites, of 406(11 Ma..
The most northerly of the alkaline complexes of Air, Adrar Bous has an elliptical form of 20x12 km. It comprises three units (Husch and Moreau, 1982), a western…
Adrar N'Ajjer
Algeria · 003-00-004
The most northeasterly of the Hoggar volcanic fields Adrar n'Ajjer extends over about 90x40 km. No detailed accounts have been located but Fabre (1976) describe…
Adrar Tadhak (Tadhak)
Mali · 105-00-003
Age: U-Pb isochrons on eight whole rocks yielded ages of 271(32 and 254(18 Ma (Weis et al., 1987) and a 13 point Rb-Sr isochron 262(7 Ma (Liegeois et al., 1983).
The northern part of this complex, which is 15 km from east to west, is obscured by Quaternary sediments. An outer incomplete ring and the arcuate disposition o…
Adzharo-Trialetskaya
Georgia · 059-00-001
In this region Palaeogene volcanic rocks increase in alkalinity from east to west. Among the alkaline effusive rocks there are leucite tephrites, leucite basalt…
Affara Dara
Ethiopia · 054-00-017
Age: A K-Ar determination on granite gave 25(0.9 Ma (Barberi et al., 1972a).
The Affara Dara peralkaline granite is exposed over 35x25 km but to the west is partially covered by younger basalts that emanated from the Alayta and Boina eru…
Afrikanda
Russia · Kola and Karelia · 136-12-020
Age: K-Ar on biotite gave ages from 344 to 426 Ma (Kukharenko et al., 1965) and a Rb-Sr mineral isochron 364_+3.1 Ma (Kramm et al., 1993).
Economic: Titanomagnetite-perovskite ores form an oval pipe-like body which has been drilled to 400 m. The principal ore types are ore olivinites, ore pyroxenites and ore-amphibole pyroxenites. The perovskite content of the ores varies from 18 to 48% and titanomagnetite from 20 to 76% (Gorbunov et al., 1981).
This complex has an isometric shape, an area of some 7 km2, and lies on an east-west-trending fracture system. The country rocks are granite gneisses. Four zone…
Agamenticus
United States of America · Maine · 174-00-131
Age: K-Ar on biotite from granite gave 228 ±5 Ma(Foland and Faul, 1977) and a Rb-Sr whole rock isochron 227 ±3 Ma (Hoefs, 1967).
An approximately circular complex some 9 km in diameter, Agamenticus is intruded into Silurian sedimentary rocks and Late Devonian quartz monzonites. The wester…
Agardak (Bayan-Erdenet)
Mongolia · 111-00-004
In the Agardak region is a chain of small volcanic fields in which the volcanic rocks are interspersed with red beds. The total thickness of the volcanic rocks …
Agash
Russia · East Tuva · 136-08-032
This symmetrical stock of 4x3.5 km cuts Proterozoic marbles and schists. Lower Proterozoic gabbro and diorite containing xenoliths of marble are also present. T…
Agate Mountain
Namibia · 116-00-005
Age: Post early Cretaceous.
This complex is located in a range of low hills almost totally surrounded by salt pans 6.5 km east-southeast of Cape Fria in a half graben parallel to the coast…
Agoro
Uganda · 170-00-009
Age: “preliminary and tentative” K-Ar ages of the Agoro phonolite and a related intrusion of 424 and 336 Ma are given in a footnote in Nixon and Clark (1967).
Agoro is an intrusion of eudialyte phonolite lying close to the border with Sudan (P. Nixon, pers.comm., 1990) No other details have been traced.
Agua Emendada
Brazil · Goias · 025-00-053
This is a small eroded volcanic neck cutting Carboniferous sandstones and consisting principally of breccias and tuffs, but with some flows. The central part is…
Aguapety
Paraguay · Caaguazu · 130-00-022
A shonkinite plug forms a conical hill 500 m in diameter. A modal analysis gave alkali feldspar 26%, nepheline 29.7%, augite 31.6%, olivine 4.5% and ore 8.2%; a…
Ahmirah
Saudi Arabia · 143-00-034
This is a 20 km long intrusion of peralkaline granite that is only some three kilometres wide. The most southerly four kilometres are separated from the rest of…
Aikel
Kyrgyzstan · 086-00-023
Age: Permian.
Aikel is a symmetrical intrusion of about 14 km2 lying near Lake Aikel. It is composed of subalkaline gabbroids (monzonites and syenodiorites) and syenites. It …
Ailagir
Kyrgyzstan · 086-00-009
Ailagir lies within upper Silurian limestones and schists and upper Carboniferous biotite-amphibole granites and granosyenites. It is a northeasterly-trending e…
Aillik
Canada · Labrador · 031-00-154
Age: K-Ar on biotite gave 570 Ma (Currie, 1976a, p. 115).
In the vicinity of Cape Aillik and Cape Makkovik on the Labrador coast and on offshore islands occur numerous gently dipping dykes (? cone sheets) possibly rela…
Ailsa Craig
United Kingdom And Channel Islands · 173-00-022
Age: A Rb-Sr isochron age of 61.5±0.5 Ma for eight samples of microgranite was obtained by Harrison et al. (1987).
Economic: The island was once famous for the production of curling stones, certain facies of the microgranite being particularly tough and taking a high polish. In the 1890s 1,000 pairs were produced and exported annually from a quarry at the north end of the island. The quarry eventually closed but was re-opened in 1961. However, it proved to be uneconomical and was closed in 1973. The granite has also been worked for road setts and was utilised for a number of famous memorials in Scotland.
Ailsa Craig is an imposing, precipitous rock in the Firth of Clyde 20 km south of Arran. It is approximately circular, 1.2 km in diameter and has steep cliffs r…
Aiotsdzor
Armenia · 009-00-006
This volcanic complex lies in the southwestern part of central Armenia within the Western Aiotsdzor district and extends over an area of about 150 km2. The volc…
Aitutaki
Pacific Ocean · Cook Islands · 125-14-001
Age: K-Ar dating of numerous specimens of lava, tuff breccia and boulders support a scenario of initial volcanism up to 8 Ma followed by a 6 Ma hiatus then continuous volcanism from about 1.9 Ma until the building of the Maungapu tuff ring at less than 0.7 Ma – the youngest known volcanism in the Cook Islands (Turner & Jarrard, 1982).
The most northerly of the volcanic Cook islands Aitutaki is a near-atoll consisting of a volcanic island – Aitutaki itself some eight kilometres in length –…
Ajjipuram (Kollegal Taluk)
India · 072-00-091
Anantharamu et al. (1995) have described carbonatites and fenitized charnockites and granulites from the triangular area between Ajjipuram, Hanur and Kaudalli. …
Akbiik
Kazakhstan · 084-00-032
The Akbiik intrusion cuts through Carboniferous volcanic rocks and small intrusive bodies of early upper Palaeozoic age. The massif is 18x4 km and composed of i…
Akhbasai
Tajikistan · 162-00-002
Age: K-Ar on foyaite gave 275-209 Ma (Abdusalomov and Dusmatov, 1978).
This occurrence is situated on the southern slope of the Zeravshansky mountain ridge and takes the form of a stratified body extending in a northeasterly direct…
Akitskii
Russia · Baikal · 136-03-010
Age: K-Ar on biotite from peralkaline syenite gave 199 Ma (Arkhangelskaya, 1974).
The Akitskii occurrence of 4.5 km2 cuts Lower Palaeozoic granites and granosyenites. Arkhangelskaya (1974) determined the order of intrusion as peralkaline trac…
Akjoujt
Mauritania · 107-00-006
Referred to as carbonatite by Van Alstine and Schruben (1980), but source of this information not found.
Akkoitas
Kazakhstan · 084-00-041
A granite intrusion of 9x3.5-4 km Akkoitas possibly is sill-like in form. Biotite granites are the most abundant rocks with less abundant areas of riebeckite an…
Akobo
Ethiopia · 054-00-055
Akongo
Cameroon · 030-00-033
Braun et al. (1993) describe a lateritic profile overlying ‘the Akongo syenite’ with aegirine-augite being present in the fresh syenite. This locality is no…
Aksai
Tajikistan · 162-00-001
The 2 km2 Aksai intrusion lies within Carboniferous sediments and consists of nepheline, nepheline-analcime and cancrinite syenites and syenite porphyries. The …
Aksug
Russia · East Tuva · 136-08-003
Age: The Pb method on euxenite gave 430±60 Ma (Zykov et al., 1961).
This small stock of only 0.2 km2 cuts lower Palaeozoic gabbro-diorites. The rocks belong to two intrusive phases the younger of which consists of amphibole syen…
Aksum-Adwa (Axum-Adua)
Ethiopia · 054-00-001
Age: Possibly Pliocene (Abbate and Sagri, in Merla et al., 1979).
In an area east and west of Aksum and Adwa and extending for some 230 km about 20 occurrences of peralkaline trachytic lavas are found, several of which are mor…
Al Ajarda (Lakatah Complex)
Saudi Arabia · 143-00-054
Age: K-Ar dating of biotite from syenite gave an age of 557±8 Ma (Stoeser, 1986).
This is a layered complex with a core of gabbro passing into pyroxenite with an external rim of peralkaline syenite, described as a ring dyke by Greenwood (1979…
Al Aybah
Saudi Arabia · 143-00-050
This occurrence is depicted on the 1:1,000,000 geological map (Stoeser et al., 1986) as an approximately circular, 15 km diameter complex of alkali granite in c…
Al Ghab
Syria · 160-00-003
Age: K-Ar and 40Ar/39Ar dating of the lavas gave ages ranging from 4.0 to 1.1 Ma with the majority being <2 Ma (Ma et al., 2011).
The Al Ghab volcanic field comprises about 40 cinder and lava cones from which have issued lava flows and scoriaceous materials, the whole field extending over …
Al Harrah (Harrat Ash Shama)
Saudi Arabia · 143-00-001
Age: Five K-Ar whole-rock age determinations gave 11.4 to 13.4 Ma.
The Al Harrah volcanic field is the continuation southwards in Saudi Arabia of the Ash Shaam field in Jordan (No. 1), and the most northerly of the harrats (vol…
Al Haruj Al Aswad
Libya · 097-00-005
Age: K-Ar whole rock determinations on seven samples ranged from 6.0(0.2 to 0.41(0.2 Ma, but the rocks are probably in the age range 0.4-2.2 Ma (Ade-Hall, 1974).
By far the most voluminous volcanic province in Libya, Al Haruj covers over 45,000 km2. The province is essentially basaltic with all rocks analysed so far (Alm…
Al Ulub
Saudi Arabia · 143-00-041
This is an arcuate intrusion of peralkaline granite 24 km in length and up to four kilometres wide, for which no further details have been gleaned.
Al-Ashkahara (Al Ashkharah, Batain Area, Jebel Faya)
Oman · 124-00-005
Age: 40Ar/39Ar ages of 39.77±0.26, 37.63±0.46 and 36.51±0.21 Ma are given by Worthing & Wilde (2002).
Six basanitic intrusions are aligned north-south close to the coast of northeastern Oman. They are mostly plugs but one appears to be a dyke and another a plug …
Alcsútdoboz-2 (Ad-2) Borehole
Hungary · 071-00-002
Age: Cretaceous (Guzmics et al., 2008).
The Alcsútdoboz-2 (Ad-2) borehole is located in the Transdanubian Central Range and penetrated Triassic sediments which are cut by 11 lamprophyre dykes and a s…
Alexander Island (Mount Pinafore, Debussy Heights, Hornpipe Heights)
Antarctica · 006-00-005
Age: Six K-Ar age determinations on lava flow rocks from the Mount Pinafore area range from 7.7±0.6 to 3.9±0.4 Ma, a single sample from Debussy Heights gave 6.0±0.2 and 6.3±0.2 Ma and two basanite flows from Hornpipe Heights 2.5±0.8 and 2.7±0.2 Ma (Hole & Thomson, 1990).
These localities are located in the north of Alexander Island just to the southeast of Rothschild Island. Widely scattered exposures of volcanic rocks occur ove…
Algarve Area
Portugal · 133-00-008
Age: Martins (1999) states that the Algarve suite lies in the range 72±2 to 75±2 Ma but no details of method or rocks dated are given.
In a broad east-west zone along the southern, Algarve, coast of Portugal is a suite of mostly minor intrusions including dykes, sills, small irregular intrusion…
Ali Mela Ale
Ethiopia · 054-00-012
This is a small rhyolitic volcanic centre which is probably of peralkaline composition.
Ali Sabieh (Aysha)
Djibouti · 045-00-005
Age: K-Ar age determinations on the Ali Adde rhyolites gave 25-19 Ma and on the Mablas rhyolites 15-10 Ma (Chessex et al., 1975; Gadalia and Varet, 1983).
The Ali Sabieh-Aysha horst extends southwards into Ethiopia and along its northwestern and eastern margins are rhyolitic rocks which are correlated with the Mab…
Aliağa-Foça Area
Turkey · 168-00-003
Age: Miocene. For discussion of stratigraphic evidence pertaining to the age of the volcanism see Akay & Erdoğan (2004).
In the area lying between Bergama and Izmir and extending westwards to the coast approximately between Aliağa and Foça, is an extensive area of volcanic rocks…
Alid
Eritrea · 052-00-003
The Alid volcano lies at the northern end of the Danakil Depression. Three units are distinguished by Barberi et al. (1973): a central silicic complex and north…
Alimamas
Mali · 105-00-016
The 8x2 km intrusion of Alimamas cuts Tiralrur rhyolites and ignimbrites. It consists of peralkaline granites similar to those of Ebrhoren (No. 105-00-015).
Aljorra
Spain · 153-00-020
Age: Pellicer (1973) reports the presence of xenoliths of Miocene limestone within the pipe.
Two kilometres west of the village of Aljorra occurs a vertical lamproitic pipe of approximately 600x350 m (Pellicer, 1973). Two specimens described by Venturel…
Alkhain
Mongolia · 111-00-016
Allard Stock (La Plata)
United States of America · Colorado · 174-00-080
Age: K-Ar on porphyritic quartz diorite gave 120 ± 4 Ma (McDowell, 1971) but McDowell noted that this is unusually high for San Juan Mountain volcanics. Cunningham et al. (1977 - reported by Werle et al., 1984, p. 631) give emplacement ages of 65-70 Ma.
Economic: A general review of the ore deposits of the La Plata district is given by Eckel (1949). Concentrations of Cu, Ag, Au, Bi and Te occur throughout the mineralized part of the Allard stock, and there is significant enrichment in Pt metals. A brief summary of the types of mineralization will be found in Werle et al. (1984, p. 636).
Within the La Plata Mountains of southwest Colorado are a number of syenitic stocks (see Eckel, 1949, Plate 2), only one of which, the Allard stock, has been de…
Alligator Rivers (Mudginberri, Maningkorrirr)
Australia · Northern Territory · 011-00-018
Age: Rb-Sr dating of a Mudginberri phonolite gave an age of 1,316±40 Ma (Page et al., 1980).
Two separate clusters of phonolite dykes occur in the vicinity of the Alligator Rivers. They intrude Archaean and early Proterozoic granitic rocks of the North …
Allihies
Ireland · 077-00-006
A ferrocarbonatite breccia has been recovered from the historic dressing plant of the Mountain Mine in Allihies (Moore, 2013; K.R. Moore, pers. comm., 2016). Th…
Almadén
Spain · 153-00-008
Age: The volcanic-sedimentary rocks range from Lower Ordovician to Upper Devonian in age. Hall et al. (1997) suggest the Hg mineralization was active between 360 and 427 Ma, based on 40Ar/39Ar determinations on illite and biotite, while Higueras et al. (2000) obtained a Rb-Sr isochron age of 365±17 Ma on mineralized basic volcanic rocks.
Economic: The mercury deposit of Almadén is the largest in the world the metal being present as cinnabar. Mining was almost continuous from Roman Times until the year 2,000 AD when all mining activity ceased.
The Almadén Syncline contains a Palaeozoic succession of detrital rocks associated with which are lava flows, tuffs, dykes, sills and diatremes that are intima…
Almi Guenfalabo (Gwenfalabo, Halmi)
Cameroon · 030-00-013
This is a large complex, with a diameter of nearly 20 km, comprising both plutonic and extrusive volcanic rocks. Few details on the volcanic rocks are available…
Almunge
Sweden · 158-00-008
Age: K-Ar determinations on biotite from nepheline syenite pegmatite in canadite and from nepheline syenite yielded 1,780 Ma (Gorbatshev, 1970) and 1,580 Ma (Doig, 1970). It is likely that the intrusion has been metamorphosed to some degree and consequently Rb-Sr determinations would yield older dates.
The Almunge complex has an oval outline of about 5x3 km and is emplaced in Svecofennian Archaean igneous and metamorphic rocks. The complex comprises three prin…
Alnö
Sweden · 158-00-005
Age: Phlogopite from a sövite ring dyke 500 m southwest of Hartung gave a K-Ar date of 537±16 Ma (Kresten et al., 1977) and Brueckner & Rex (1980) obtained a Rb-Sr whole-rock isochron age for silicate rocks of 553±6 Ma. 40Ar/39Ar dating of biotite and K-feldspar from a carbonatite dyke gave a mean age of 584±7 Ma (Meert et al., 2007).
The occurrence of alkaline rocks and associated limestones on the island of Alnö in the Baltic has been known since the 19th century, but it was the detailed s…
Aloatra (Amparafaravola)
Madagascar · 102-00-010
West of Lac Aloatra, and close to Amparafaravola, a melilite-bearing flow overlies Precambrian migmatites. Three other occurrences lie in a line to the northeas…
Alphard Banks
South Africa · 151-00-044
Age: K40/Ar40 determinations on sanidine gave a date of 58(2.4 Ma (Dingle and Gentle, 1972).
Alkaline rocks have been dredged from the Alphard Banks, which lie off the coast south and east of Cape Agulhas. The area is underlain by Mesozoic sediments wit…
Altan Hulyn Nuruu (Altan Holiin Nuruu)
(no coordinates, not on the map)
Mongolia · 111-00-060
Age: Early Devonian.
Lying close to the Mongolia-Russia border, where it cuts sedimentary rocks of probable Devonian age, the Altan Hulyn Nuruu intrusion consists of a peralkaline s…
Altanskii
Russia · Baikal · 136-03-038
Nepheline syenites and aegirine-augite syenites are present in the form of talus blocks over an area of 1 km2.
Alto Alentejo
Portugal · 133-00-002
Age: A whole-rock Rb-Sr isochron, based on six samples from the Alto Alentejo area, gave an age of 466±12 Ma (Priem et al., 1970).
In an area trending northwest-southeast of about 60x40 km in the Province of Haut Alentejo, including the towns and villages of Alter do Chão, Monforte, Arronc…
Aluchinskie
Russia · Omolon · 136-15-003
Age: Holocene.
These volcanoes are accompanied by lava flows which extend for about 70 km. Two stages of effusive activity are separated by an interval that is indicated by th…
Alutu
Ethiopia · 054-00-044
The Alutu volcanic centre lies immediately south of Lake Zwai (Ziway), covers some 90 km2 and rises 650 m above the surrounding lake deposits and tuffs. The vol…
Amalat
Russia · Baikal · 136-03-026
This is a group of lens- and sheet-like bodies within an area of about 1.0 x 1.5 km which cut Upper Proterozoic marbles. Geophysical data indicate that at depth…
Amasya
Turkey · 168-00-016
Age: 40Ar/39Ar dating of biotite from two leucitites gave ages of 70.5±2.3 and 67.9±3.6 Ma (Eyuboglu et al., 2011).
Ultrapotassic volcanic rocks, similar to those of the Bayburt area (No. 26), occur in the Amasya area in the southwestern part of the Eastern Pontides orogenic …
Amba Dongar (Ambadungar, Ambadonger)
India · 072-00-019
Age: Deans et al. (1973) reported K-Ar dates on feldspar from fenites of 61±2 and 76±2 Ma and Ray & Pande (1999) obtained identical 40Ar/39Ar dates of 65 Ma for samples of carbonatite and silicate rock
Economic: Fluorite veins and replacement deposits occur in both the sövites and ankeritic carbonatites and are the largest fluorite deposits in India. They have been worked since 1970 and reserves were originally estimated at 11.6 million tonnes at an average 30 wt% CaF2 (Notholt et al., 1990). There are also potential deposits of barite.
Amba Dongar was the first carbonatite to be recognised in India and has subsequently become the most thoroughly studied. The complex intrudes Bagh sandstones (C…
Ambalavayal
India · 072-00-079
Age: Nair et al. (1985) reported a K-Ar age on biotite of 560±30 Ma, Santosh et al. (1986) a seven point whole-rock Rb-Sr age of 595±20 Ma and Santosh et al. (1994) a Re-Os age for molybdenite from granite of 567±28 Ma.
Ambalavayal is a granite intrusion of approximately 8x3 km that is emplaced into Archaean migmatitic biotite- and hornblende-bearing gneisses. A brief, general …
Ambariccio (Bobija, Data)
Ethiopia · 054-00-049
No details have been traced but this occurrence is shown on an unpublished map of Di Paola (1976) and Di Paola (1973) as being pantelleritic.
Ambatofinandrahana
Madagascar · 102-00-015
Nepheline syenite dykes are indicated on the 1:500,000 geological map (Besairie, 1969a) as occurring at three localities in the Ambatofinandrahana igneous compl…
Ambondrona And Ankaizina
Madagascar · 102-00-006
Age: Oligocene to Recent (Jourde, 1963).
Under the general name Ankaizina are included several extensive and a number of smaller volcanic fields lying to the east and southeast of the Ampasindava provi…
Amboseli Area
Kenya · 085-00-073
Age: Upper Pliocene to Recent. Williams (1972b) quotes ages of about one million years for two earlier flows and notes that the youngest flows are post glaciation.
The southern half of the Amboseli area, which lies adjacent to the border with Tanzania, is covered extensively by lavas of the Kilimanjaro volcano, (see Tanzan…
Ambre
Madagascar · 102-00-001
Age: Emerick and Duncan (1982) give K-Ar ages of 0.85(0.02 Ma for a flow from Massif d’Ambre, 9.61(0.45 and 9.32(0.57 Ma for a flow from Diego Suarez (just south of Cap d’Ambre.
The northernmost part of Madagascar is extensively covered with volcanic rocks the Massif d’Ambre being approximately circular and 85 km in diameter, extendin…
Ames Range (Mount Andrus, Mount Kosciusko, Mount Kauffman)
Antarctica · 006-00-022
Age: Eleven K-Ar dates are available and range between 14.7 and <0.1 Ma (LeMasurier & Rex, 1989).
The Ames Range comprises three aligned and coalescing volcanoes with an overall length of 35 km. Mount Andrus, the most southerly, is the best exposed, has a su…
Amethyst And Gribble Mountain
United States of America · Colorado · 174-00-085
Within an area of 1000x300 m about 10 silico-carbonatite dykes up to 10 m thick, trending north-northwest-south-southeast, cut the Precambrian Pikes Peak granit…
Amo And Rukuba
Nigeria · 122-00-033
Age: A Rb-Sr isochron on riebeckite-arfvedsonite-biotite granite gave 165(3 Ma (van Breemen et al., 1975).
Economic: Small alluvial deposits derived from biotite granite have been worked for cassiterite (Buchanan et al., 1971).
Amo is perhaps the best example of a ring-complex in the Nigerian Younger granite province, being built of a succession of granite ring-dykes and plutons. The c…
Amorinopolis
Brazil · Goias · 025-00-052
Amorinopolis is a volcanic vent of the Ipora Group standing 250 m above the surrounding Devonian sandstones. It consists of a central plug surrounded by a serie…
Ampan
Nigeria · 122-00-039
This is an approximately circular, 3 km diameter intrusion lying east of the Pankshin syenite. It is a fayalite-hedenbergite-calcic-sodic amphibole syenite and …
Amparihy (Ahi Bori, Ahy Bory, Ambohi Bory)
Madagascar · 102-00-007
Age: Post-Liassic.
In the area lying between the Amparihy and Manampatrana Rivers there are numerous occurrences of phonolite and nepheline syenite, extending over an area of abou…
Ampasindava Area
Madagascar · 102-00-004
Economic: Traces of molybdenite are reported from the Bekolosy granite (Donnot, 1963).
The Ampasindava Province was defined by Lacroix (1922a, Fig. 5) and includes several areas of igneous rocks on the Ampasindava Peninsula, a number of volcanic f…
Ampipal (Gorkha-Ampipal Area)
Nepal · 117-00-001
Age: On structural grounds Lasserre ( 1977) postulated that emplacement of the Ampipal body probably took place in the late Eocene to early Oligocene but preliminary Rb-Sr dating seems to indicate a much older age (Bordet et al., 1981).
Ampipal is a nepheline syenite intrusion of about 7.5x2 km emplaced in rocks of the Kuncha Formation, which comprises essentially phyllites and quartzites. The …
Amreit (Amreit-Akab El Nugum)
Egypt · 049-00-037
The Amreit complex (Robertson et al., 1990) comprises peralkaline granite and quartz syenite at Gebel Amreit and, to the south, granite and gabbro at Gebel Akab…
An Nimar (An Namar, An Nammar)
Saudi Arabia · 143-00-029
Age: Rb-Sr dating gave an apparent age of 604±26 Ma (Stuckless et al., 1985).
This is an approximately square-shaped intrusion of sodic amphibole-bearing granite with margins of about 6 km (Delfour, 1977; Stoeser et al., 1986), but Stuckl…
Anahef (Amadror)
Algeria · 003-00-006
Age: Probably Tertiary and Quaternary.
The Anahef region, referred to as Amadror by Remy (1967), lies between the volcanic fields of Adrar n'Ajjer and Atakor and differs from the rest of the Hoggar v…
Andrahary
Madagascar · 102-00-005
A volcanic field comprising basalt, rhyolite and trachyte and extending for 30 km in a northeasterly-southwesterly direction is shown on the 1:500,000 geologica…
Andriyanovka
Russia · Kamchatka-Anadyr' · 136-10-005
Age: K-Ar on leucite gave 20±3 Ma.
Trachybasalts are dominant at the Andriyanovka occurrence but alkali basalts, tephrites and trachyandesite-basalts are also present with occasional occurrences …
Androy
Madagascar · 102-00-020
Age: K-Ar dating of two dykes gave 90.5(9 and 123.2(12 Ma (Andriamirado, 1971).
The large volcanic complex of Androy consists predominantly of basalts and rhyolites with, according to Besairie (1957), late dykes of ankaratrite (nephelinite)…
Andryushkina Rechka
Russia · Kuznetsk-Minusinsk · 136-13-008
Age: K-Ar on nepheline gave 444±20 Ma (Kononova and Shanin, 1973).
Bereshite (see locality 2) sheets and cross-cutting dykes have been observed among nappes of diabase porphyry and basalt in the northwestern part of the Minusin…
Anezrouf
Mali · 105-00-008
An approximately circular complex 2 km in diameter, Anezrouf is composed dominantly of nepheline syenites with smaller intrusions of other igneous rocks scatter…
Angadimagar
India · 072-00-076
Age: A Rb-Sr isochron age, based on five rocks, of 638±24 Ma is given by Santosh et al. (1989).
Angadimogar is an intrusion of syenite emplaced into migmatitic gneisses close to the village of that name. The 18x9 km intrusion has sharp contacts with the co…
Angarkhain
Mongolia · 111-00-029
Angarkhaingolski Massiv
(no coordinates, not on the map)
Mongolia · 111-00-077
Angidritovyi
Russia · Taimyr Peninsula · 136-19-004
Age: 199-205 Ma by the K-Ar method
This occurrence is situated in the southern part of the Birranga Ridge in the upper part of a small river, the Angidritovyi. It has a ring form and occupies onl…
Angidzhan
Russia · Baikal · 136-03-016
Proterozoic sandstones and schists are partly covered by talus deposits in which large blocks of nepheline syenite occur. The nepheline syenites comprise nephel…
Anitapolis
Brazil · Santa Catarina · 025-00-113
Age: A tinguaite gave 104.7 Ma, biotite from melteigite 129.2 and 127.5 Ma and alkali feldspar from fenite 131.0 Ma, all by K-Ar (Amaral et al. 1967, Table 2).
Economic: Extensive phosphate deposits are present in the deeply weathered cover and an open pit is being worked. Reserves of 53 million tons in the residuals (8.2% P2O5) and 205 million tons in fresh rock (4% P2O5) have been proved (Vergara, 1980).
Anitapolis is a partially zoned intrusion of 5 km2, the emplacement of which produced a system of radial and concentric fractures in the surrounding Precambrian…
Anjouan
Indian Ocean · Comores · 073-03-003
Age: Four K-Ar ages of lavas range from 3.9±0.3 to 0.36±0.09 (Nougier et al., 1986) but a block of syenite that gave an age of 11.1±0.5 Ma probably corresponds to an earlier and deeper magmatic phase.
The mountainous and rugged island of Anjouan covers 378 km2 and rises to the peak of N’Tingui at 1,595 m. The initial volcanic phase involved growth of a larg…
Ankaratra
Madagascar · 102-00-013
Age: Pliocene-Pleistocene from evidence of interstratified fossiliferous sediments (Bussiere, 1957a).
The Ankaratra volcanic field, which is located immediately southwest of Tananarive, covers about 3,800 km2 and extends for over 100 km in a north-south directio…
Ankasimbelona (Ankasimbelo)
Madagascar · 102-00-008
A basaltic field extending 45 km north-south and up to 18 km east-west is depicted on the 1:500,000 geological map (Besairie, 1971b). Few details have been foun…
Ankur
Sudan · 155-00-010
Age: Two samples of quartz syenite from the central stock and three of aegirine syenite from the surrounding ring-dyke define a Rb-Sr isochon of 130(4 Ma (Cavanagh, 1979).
Ankur consists of a central stock of quartz syenite and concentric rings of aegirine syenite and gabbro, the whole complex being 3 km in diameter. The gabbro of…
Anmandykanskii
Russia · Omolon · 136-15-011
Age: Palaeozoic.
The Anmandykanskii pluton occupies an area of about 310 km2 and cuts Precambrian metamorphic rocks. The complex has a concentric zonal structure with quartz sye…
Anomaly 4B Pipe
Russia · Aldan · 136-01-009
This pipe contains highly magnesian olivine-phlogopite leucitites which throughout the entire pipe are present as an autolith breccia. The cores of the autolith…
Antipodes Islands (Bollons Island)
Pacific Ocean · 125-00-022
Age: Cullen (1969) reported K-Ar ages of 0.25±0.2 and 0.50±0.4 Ma for lavas.
The Antipodes Islands are wholly volcanic and comprise the 7x4 km Antipodes Island, Bollons Island, which is less than a kilometre in length, and numerous stack…
Antonovskii
Ukraine · 171-00-004
Age: A U-Pb determination on zircon gave 2060 Ma (Sherback et al., 1989).
The alkaline rocks of this massif, which were discovered by drilling, are situated one kilometre northeast of the town of Letichev. The complex consists of olig…
Anyuiskii
Russia · Omolon · 136-15-002
Age: 0.4-0.5 million years.
Two stages of extrusive activity have been identified at this locality. The first stage is characterised by extensive lava flows of basalt, which ran along the …
Apiragua
Paraguay · Paraguari · 130-00-020
An essexite stock. A large area of alkaline rocks is shown on Plate 1 of Milton and Eckel (1959) but this is an error, most of the area being occupied by Siluri…
Apupariu
Brazil · Para · 025-00-008
Apupariu consists of three intrusions which have been identified by radar imagery, and interpreted as alkaline by comparison with known intrusions in the area, …
Aragol And Dumdakhemgol
Mongolia · 111-00-025
Arakaou (Arakao)
Niger · 121-00-008
This 20 km wide pluton has eroded to form a depression. According to Black et al. (1967) the periphery consists of a biotite-rich granite which at the outer mar…
Arasangolski Massiv
(no coordinates, not on the map)
Mongolia · 111-00-087
Araxa (Barreiro)
Brazil · Minas Gerais · 025-00-066
Age: Biotite from glimmerite gave 87.2±4.4 Ma by K-Ar (Hasui and Cordani, 1968).
Economic: The weathered mantle is worked in three separate areas. (1) In a 1 km2 area towards the centre of the complex, bariopyrochlore (pandaite) is mined for Nb in an open pit. The mined laterite contains about 5% pyrochlore and reserves are estimated at 460 million tons grading 2.5% Nb2O5. This is the largest known reserve and principal producer of Nb in the world with an annual capacity of 42 000 tons of pyrochlore concentrates (60% Nb2O5). Details of mining operations will be found in Paraiso Filho and Fuccio (1982). (2) Deposits of secondary carbonate apatite are concentrated in the northwest and southeast of the complex with estimated reserves of 560 million tons grading 11.8% P2O5. The mine has an annual capacity of 550 000 tons of apatite. (3) Rare earth deposits in the north of the complex consist of secondary earthy monazite and goyazite. Proved reserves to 15 m depth are 800 000 tons averaging 13.5% REO and 2% Nb2O5, but they are not worked at present (Sad and Torres, 1978).
A circular complex 4.5 km in diameter, Araxa cuts and domes quartzites and schists of the Proteroxoic Araxa Group. Fenitization extends up to 2.5 km from the co…
Arbarastakh
Russia · Aldan · 136-01-027
Age: K-Ar determinations on phlogopite from pyroxene-mica rocks gave 690±28, on apatite-magnetite rocks 720±28 and on carbonatites 690±28 Ma (Glagolev and Korchagin, 1974). K-Ar on phlogopite from forsterite-magnetite rocks gave 625 Ma (El'anov and Moralev, 1961).
References BORODIN, l.S., LAPIN, A.V. and CHARCHENKOV, A.G. 1973. Rare-metal camoforite. Nauka, Moscow. 176 pp. This is some extra text
Economic: There is a potentially economic apatite-magnetite deposit (Frolov, 1984).
Lying within Precambrian gneisses, granites and schists the Arbarastakh complex has a striking concentric structure. It is a 7x5 km stock which is composed domi…
Arenopolis (Areianopolis)
Brazil · Goias · 025-00-047
Age: Probably Cretaceous.
Arenopolis is an elongate intrusion of 6x2 km emplaced in Precambrian granites and Devonian Furnas sandstone. The earliest rocks are olivine pyroxenites with se…
Argor (James Bay Pyrochlore Deposit; Alpha-B Deposit; Southbluff Creek; James Bay Lowlands-North)
Canada · Ontario · 031-00-059
Age: 1635 Ma by K-Ar on biotite (Gittins et al., 1967 - 'James Bay Lowlands (North)').
Economic: Large quantities of pyrochlore have been proved by extensive drilling with 62.5 million tons averaging 0.52% Nb2O5.
The Argor body is an elongate intrusion of pyroxenite and carbonatite about 2.5 km long, although the ends were not reached in drilling, with a maximum width of…
Arnold Eschers Land
Greenland · 063-00-005
Age: K-Ar on five rocks gave 44-57 Ma, with a value of 56±1 Ma estimated as the probable time of extrusion (Brooks et al., 1979, Table 1).
Alkaline basic lavas cap a number of nunataks extending westwards from Arnold Eschers Land to Hobbs Land, with one small area further south in J. L. Mowinkels L…
Aroyan (Orayan) And Azambaradan-Tamoelet
Niger · 121-00-013
Age: A Rb-Sr whole-rock isochron gave 426(6 Ma (Karche and Vachette, 1978).
Situated between Iskou (No. 121-00-014) and Egalah (No. 121-00-012) Aroyan consists of an amphibole-biotite granite of alkali feldspar, quartz, ferrohastingsiti…
Arran Basic Sills (Dippin Sill)
United Kingdom And Channel Islands · 173-00-020
Age: Tertiary.
Several large basic alkaline sills occur in the southeastern part of the island of Arran. Brief descriptions of these sills are given by Tyrrell (1928) and Emel…
Arrua-I
Paraguay · Central · 130-00-010
Age: Probably Cretaceous.
A steep sided hill 1.2x1 km rising some 150 m from a flat alluvial plain forms a shonkinite stock emplaced in Upper Jurassic sandstones. Dykes of phonolite with…
Arsalan
Kazakhstan · 084-00-044
This granite intrusion is pear-shaped and covers 25 km2. It cuts through volcanogenic Devonian deposits and granodiorites. The inner structure of the intrusion …
Arta
Djibouti · 045-00-004
This is a small area of Mablas peralkaline rhyolites located near the south coast of the Gulf of Tadjoura (Varet, 1978). The Mablas rhyolites are described unde…
Artem
Russia · Primorye · 136-16-006
Age: Neogene.
In the Artem depression, in the vicinity of the city of Artem, lavas and sills of trachydolerite, shoshonitic absarokite and leucite and pseudoleucite shoshonit…
Arukty
Russia · East Tuva · 136-08-017
Age: K-Ar on K-feldspar gave 244±10 Ma, on biotite 226±9 Ma and on nepheline 232±9 Ma (Yashina and Borisevich, 1966). Pb from zircon gave 400±40 Ma (Zykov et al., 1961).
This intrusion, covering approximately 3 km2, cuts Upper Proterozoic dolomitic marbles and Lower Palaeozoic gabbro-diorites and granites. The massif includes ne…
Arvida (Chicoutimi)
Canada · Quebec · 031-00-146
Age: K-Ar on whole rock gave 568 Ma and on separated biotites 560 and 563 Ma (Doig and Barton, 1968, Table l).
In the vicinity of Arvida, about 30 km west-northwest of Chicoutimi, are found dykes ranging from a few cm to 1 m thick and ranging from carbonatite to calcareo…
Ary-Mas
Russia · Maimecha-Kotui · 136-14-011
This is a circular intrusion of about 200 m diameter composed of melteigite and melanephelinite.
As Sirat (Jabal As Sarat)
Saudi Arabia · 143-00-057
Age: du Bray et al. (1991) give 22 K-Ar age determinations with apparent ages ranging from 15.6 to 37.3 Ma, but they consider the true range to be 20.5 to 33.2 Ma. K-Ar determinations on a basalt and a rock described as a mugearite (the uppermost flow of the field) gave 30.1±1.0 and 25.3±Ma and on a syenite (trachyte?) 22.5±0.7 Ma (Brown et al., 1989).
As Sarat is a volcanic field that extends southwards to the border with Yemen and is probably a northerly continuation of the Yemen volcanic series (No. 1). The…
Asa Ale
Ethiopia · 054-00-007
Age: K-Ar on Asa Ale granite gave 22.0 Ma (Barberi et al., 1972a).
The Asa Ale granite lies beneath ignimbrites northwest of the Nabro volcano (see Bidu No. 6). Barberi et al. (1971b) report that the granite is similar to the i…
Ascension
Atlantic Ocean · 010-00-015
Age: A review of K-Ar and Ar-Ar dating of volcanic rocks and Rb-Sr dating of granite xenoliths is given by Kar et al. (1998). A suite of 38 samples, covering all rock types, gave 40Ar/39Ar ages ranging from 1094 to 38 ka (Jicha et al., 2013).
Ascension Island measures 14x11.5 km, reaches an elevation of 859 m at Green Mountain, and represents the summit of a submarine volcano that rises from a depth …
Askatinskii
Kazakhstan · 084-00-021
This occurrence is situated between mid-Palaeozoic sedimentary rocks and granitoids of upper Palaeozoic age. Peralkaline granites, which comprise most of the in…
Asseelah (Asseel, Asselah)
Oman · 124-00-004
Age: Ar-Ar dating of mica gave 150 Ma and zircon extracted from aillikite gave a mean age of 137+1 Ma (Nasir et al., 2011).
Carbonatite and ultramafic lamprophyre occur in a diatreme on the beach close to Asseelah village. The diatreme, which intrudes late Jurassic to early Cretaceou…
Assynt Minor Intrusions
United Kingdom And Channel Islands · 173-00-006
Age: A U-Pb (TIMS) zircon age of 437±4.8 Ma from Canisp porphyry was obtained by Goodenough et al. (2006). The Borralan and Ailsh intrusions are probably co-magmatic with the Assynt minor intrusions that are alkaline.
Within the district of Assynt in northwest Scotland, and particularly within the embayment defined by the Moine Thrust known as the Assynt Culmination, are nume…
Asuncion Area
Paraguay · Central · 130-00-009
Eight small plugs of olivine nephelinite ranging from 200-500 m diameter occur in the vicinity of Asuncion and up to 15 km distant. They comprise about 35% oliv…
Atakor
Algeria · 003-00-007
Age: Miocene to Pliocene; dates range between 19.9 and 5.7 Ma (Girod, 1971 1). Rognon et al. (1983) give further K-Ar dates and age data based on fossil wood.
The Atakor volcanic field extends over 2150 km2 and has an estimated volume of 250 km3 (Girod, 1971). It lies on a 1 km high basement dome which is 80 km in dia…
Atherton
Australia · Queensland · 011-00-029
Age: Forty seven K-Ar ages are given by Whitehead et al. (2007) which range from 7.10 to 0.64 Ma with six main periods of volcanism identified.
The Atherton volcanic province has an area of 1,800 km2 and includes 65 known eruptive centres from 54 localities (Whitehead et al., 2007). The volcanic rocks o…
Atiu
Pacific Ocean · Cook Islands · 125-14-003
Age: K-Ar dating indicates that the island was intermittently active mainly between 10 and 8.5-8.0 Ma, but younger ages determined by Turner & Jarrard (1982) they considered probably to be due to argon loss.
The island of Atiu has a fringing coral reef within which is a broad nearly kilometre-wide zone of raised coralline limestone reef. The centre of the island com…
Atkhinskii
Russia · Baikal · 136-03-056
Age: Geological evidence indicates a Permian-Triassic or Triassic age.
This occurrence is associated with a system of faults and extends over about 22 km in a zone which is roughly 4-6 km wide. Generally the main intrusion truncate…
Atlin
Canada · British Columbia · 031-00-012
Age: Late Pleistocene.
Approximately 50 km east of Atlin and 2 km north of the Mount Llangorse quartz diorite intrusion five small intrusions of nephelinite cut thermally altered Perm…
Atsumi (Atumi)
Japan · 082-00-005
Age: Probably late Miocene, on stratigraphic evidence (Kushiro, 1964).
Dolerite extends along the coast of northeastern Honshu in the vicinity of the town of Atsumi, where it is well exposed for some 15 km, is up to 4 km wide in ou…
Atsutla Range
Canada · British Columbia · 031-00-013
Several peralkaline dykes up to a metre thick have been described from the central part of the Atsutla Range. The dykes are banded and contain abundant, zoned s…
Atyrdyakh
Russia · Maimecha-Kotui · 136-14-014
Atyrdyakh was discovered in 1958 by Egorov and Surina (1961). It has an oval shape, an area of 0.5-0.6 km2 and is emplaced in upper Cambrian and Ordovician lime…
Auas Mountains
Namibia · 116-00-021
Age: Dating of phonolite by the 40Ar/39Ar age spectrum method gave 33(1 Ma (Fitch and Miller, 1984).
Economic: Soil sampling, subsequently confirmed by drilling, indicated Pb-Zn-Ag sulphide mineralization in the northeastern part of the Regenstein Vent (Ferreira et al., 1979).
In the Auas Mountains south of Windhoek numerous occurrences of alkaline rocks are scattered over an area of about 25x20 km. Gevers (1934) identified several la…
Aubrac
France · 056-00-010
Age: Activity was concentrated between 7.6 and 4.5 Ma with isolated events apparently dated to 10.3 and 3.9 Ma (Brousse & Lefevre, 1990).
Aubrac is an area of volcanic rocks covering 450 km2 and extending over 40x16 km in a northwest-southeast-trending zone immediately south of the Cantal volcano …
Auckland Province
New Zealand · 119-00-002
Age: Lindsay et al. (2011) have assessed 186 age determinations from 27 centres of the Auckland Volcanic Field. Data for the individual centres are discussed and fall in the range of ~600 years to ~250,000 years, although most dates fall in the period 10-55 ka. Kereszturi et al. (2014) list dates for all 52 centres of the Auckland field which range from 247 to 0.5 ka. K-Ar age determinations on 43 samples from the South Auckland field are given by Briggs et al. (1994) and range between 0.51 and 1.3 Ma; they also give palaeomagnetic determinations from 26 sites.
The Auckland volcanic province extends from Auckland City southwards to the lower Waikato valley and comprises the four spatially distinct fields of Auckland (A…
Augusta County
United States of America · Virginia · 174-00-142
Age: K-Ar on biotite and amphibole separated from nepheline syenite of a dyke northeast of Staunton gave 145 ±7 and 153 ±8 Ma, while Rb-Sr on the same biotite gave 114 ±12 Ma. (Zartman et al., 1967).
A suite of northwest-trending dykes injected into Palaeozoic sedimentary rocks of the Shenandoah Valley includes teschenites, camptonites, aegirine, nepheline a…
Åvike Bay
Sweden · 158-00-004
Age: K-Ar on phlogopite from an alnöite dyke on the northern shore of the bay gave 542±16 Ma (Kresten et al., 1977).
Åvike Bay is located about 17 km east of the Alnö complex and includes numerous dykes of alnöitic and carbonatitic affinities which, together with boulders o…
Avoca
Ireland · 077-00-007
Age: Ordovician (Caradoc).
In the vicinity of Avoca a sequence of basalts and rhyolites has been hydrothermally altered to produce a massive sulphide deposit. The rhyolites are associated…
Avon
United States of America · Missouri · 174-00-111
Age: Biotite separated from rock of two nearby diatremes gave 377 ± 19 and 388 ± 19 Ma by K-Ar and 399 ± 23 and 396 ± 28 Ma by Rb-Sr (Zartman et al., 1967, Tables 2 and 3).
At least 79 small diatremes and dykes occur in the counties of St Genevieve and St. Francois. The majority are of peridotite with pyroxene and phlogopite but on…
Awasib Hills
Namibia · 116-00-025
H. Martin (reported by Mathias, 1974) identified dykes of phonolite on the western side of the Awasib Hills.
Ayelu-Aabida (Ayyalu-Abida)
Ethiopia · 054-00-035
Age: Aabida is of recent age with many fumaroles within the caldera and around the volcano.
This is a large (45 km east-west) twin volcano the older and higher Ayelu centre lying west of Aabida. Ayelu is built of thick rhyolitic flows with the eastern …
Azov Sea Coast Dykes
Ukraine · 171-00-012
A belt of alkaline ultrabasic dykes occurs along the western part of the Azov Sea Coast (Glevassky and Krivdik, 1985). They have chemical compositions identical…
Azrou Area
Morocco · 113-00-004
Age: Harmand and Cantagrel (1984) give 14 K-Ar whole rock age determinations on melanephelinite, nephelinite, ijolite, basalt and basanite from localities across the whole area. Apart from the melanephelinite at Zebzat, which gives a date of 35(3 Ma, they lie in the range 14.6 to 0.5 Ma, with three dated Talzast rocks varying from 5.9 to 10.6 Ma. They tabulate previous age determinations (Harmand and Cantagrel, 1984).
Over this large region there are extensive areas of basaltic flows, notably southeast of Azrou, with numerous volcanic centres including maars and particularly …
Babba Olou
Djibouti · 045-00-003
Age: A K-Ar determination on a comendite flow gave 2.3(0.2 Ma (Barberi et al., 1975).
Babba Olou is a large silicic volcanic centre essentially comprising rhyolitic flows which are probably peralkaline but details of which have not been found. Th…
Badajoz
Spain · 153-00-007
Two small sub-circular intrusions of peralkaline granite and syenite are situated approximately 40 km northwest of Zafra (Dupont, 1978). The Sierra Vieja intrus…
Badan And Abu Safiyah (Jabal Lyaynat Al-Badan)
Saudi Arabia · 143-00-014
Age: A Rb-Sr age of 586±5 Ma is reported by Stoeser (1986).
Badan is an approximately circular, 8 km diameter peralkaline granite intrusion to the immediate north of which is the layered Abu Safiyah complex. The Badan gr…
Badda And Sagatu (Gara Badda)
Ethiopia · 054-00-043
Age: K-Ar determinations on two trachyte and one basaltic dyke ranged from 2.1 to 3.6 Ma (Mohr and Potter, 1976). Later K-Ar work on 10 samples yielded an isochron age of 1.97(0.02 Ma (Kennan et al., 1990).
Badda is a large volcano lying immediately east of, and overlapping, Chilallo (No. 42). Like Chilallo it appears to be formed predominantly of alkaline trachyte…
Baerzhe (Barzhe, Xing’An)
China · 035-00-089
Age: A whole-rock Rb-Sr isochron age determination yielded an age of 122±5 Ma (Jahn et al., 2001).
Economic: Baerzhe is a superlarge REE-Nb-Be-Zr deposit (Wang & Zhao, 1997). Lin et al. (1995) give values, in terms of grams per ton, for parisite, monazite, pyrochlore, zircon and euxenite in the West body, and for hingganite, columbite, monazite and zircon in the East body.
The Baerzhe occurrence comprises two principal granite intrusions that are emplaced into a sequence of Jurassic pyroclastic rhyolitic rocks (Jahn et al., 2001).…
Bagbe (Maho)
Sierra Leone · 146-00-002
Age: Hurley et al. (1971) obtained a Rb-Sr age of 2100 Ma but Culver and Williams (1979) suggest that this could be a relict Archaean age of fenitized basement rocks. Andrews-Jones (1968 - reference not seen) is quoted by Culver and Williams (1979) as suggesting that the Songo (No. 1) and Bagbe complexes are coeval.
Economic: Nepheline syenite has been investigated as a feedstock for glass and ceramic manufacture, but contains too much iron, even after beneficiation, to be acceptable (Allen and Charsley, 1968).
The Bagbe complex is an elongate body extending in a northeasterly direction over 13 km. It is closely associated with the major Maho fault which appears to hav…
Bagham And Ar Rumayh (Ba’Gham, Jabal Al-Raud, Al Rumayh)
Saudi Arabia · 143-00-019
The Bagham granite intrusion is about 17 km from north to south with a maximum width of five kilometres and is expressed as rugged hills (Quick, 1983). It is a …
Bagzane (Baguezans)
Niger · 121-00-017
An oval complex of 20x40 km Bagzane forms a plateau some 700 m high. The volcanic nature of the complex is attested by the presence of a vestigial patch of rhyo…
Bahçedam Volcanics
Turkey · 168-00-021
Age: Maastrichtian.
The Bahçedam volcanics are located in central-eastern Anatolia in the vicinity of Bahçedam and comprise a sequence of alkaline volcanic rocks that includes la…
Baie-Comeau
Canada · Quebec · 031-00-144
Currie (1976a, p. 135) reports the presence of carbonatite dykes in road-cuts along the highway west of Baie-Comeau. The country rocks are fenitized.
Baie-Des-Moutons (Mutton Bay)
Canada · Quebec · 031-00-158
Age: K-Ar on biotite gave 566 Ma (Doig and Barton, 1968, Table 1) and 577 and 562 Ma by Rb-Sr (Lalonde and Martin, 1983, p. 66).
The Baie-des-Moutons intrusion is a ring complex predominantly of syenitic composition. However, the syenites are only marginally alkaline as indicated by the p…
Baifen And Sinantang
China · 035-00-069
Age: A K-Ar age determination on phlogopite gave 475.4±7.5 Ma (Mei et al., 1998).
Two lamproite dyke swarms occur in Zhenyuan County, Guizhou: the Baifen and Sinantang swarms (Mei et al., 1998). There are 48 dykes in the Baifen swarm which ar…
Bailundo
Angola · 005-00-013
Economic: Small-scale mining of magnetite from the central carbonatite was formerly undertaken and preliminary assessment made for exploiting the superficial deposits and the central carbonatite. Accessories in these deposits include pyrochlore, apatite and barite.
A circular pattern of hills of fenite define a 6 km-diameter ring in the centre of which is a complex of carbonatites of lower relief. The country rocks are poo…
Baima (Cida)
China · 035-00-052
Age: SHRIMP zircon U-Pb dating of a gabbro gave 261±2 Ma and of two syenites 259±5 and 258± 4 Ma (Shellnutt et al., 2009a). U-Pb dating of zircons from six rocks, including syenite, granite gabbro and mafic enclaves, ranged from 256.2 to 259.5 Ma (Zhong et al., 2011).
Figs 39 and 44 The Baima complex is located within the central part of the Panxi region, which lies within the Emeishan large igneous province (Shellnutt et al.…
Baiñas-Mazaricos (Sierra De Corzón)
Spain · 153-00-002
Between Malpica and Noya in the province of La Coruña extends a zone of Precambrian biotite and hornblende gneisses in the central part of which, between Baiñ…
Bairro Da Cruz
Brazil · Parana · 025-00-108
Age: K-Ar on amphibole plus pyroxene from gabbro gave 230±17 Ma.
An oval-shaped complex of about 1 km diameter. Olivine gabbro and phonolite are present but little information is available.
Baishilagi (Baishilazi, Biashileizi)
China · 035-00-111
Age: U-Pb dating of four zircon crystals gave an age of 123±3 Ma (Wu et al., 2002).
This peralkaline granite with an area of only 1 km2 comprises perthite, a little albite, quartz and 2-3% of arfvedsonite; accessory minerals include ilmenite, z…
Baiyinula (Bayan Ul)
China · 035-00-083
Age: Hong et al. (1994) give a Rb-Sr isochron age of 286±3 Ma.
Baiyinula is a complex with margins of biotite syenogranite and a centre of aegirine granite. There are abundant peralkaline granite dykes and porphyries. The g…
Bakanasskaya
Kazakhstan · 084-00-052
Age: Geological evidence indicates a Permian age.
This approximately circular, 30 km diameter extrusive-intrusive complex has been emplaced into extrusive volcanic and sedimentary formations of late Palaeozoic …
Bakhatgarh-Phulmahal (Chhaktalao Area)
India · 072-00-018
To the east of the towns of Bakhatgarh and Phulmahal over an area of about 10x10 km is the densest concentration of dykes in the Chhota Udaipur subprovince (Gwa…
Bakony-Balaton Highlands
Hungary · 071-00-004
Age: Balogh et al. (1986) present a large number of K-Ar dates for the basaltic rocks of Hungary. For the Bakony-Balaton area these range from ~2.3 to 6.7 Ma. Wijbrans et al. (2007) give 40Ar/39Ar isochron ages f or 16 samples from 13 localities which range from 8.01±0.07 to 2.52± 0.08 Ma.
To the west and north of Lake Balaton there are numerous volcanic centres a number of which form spectacular edifices (e.g. Trunkó, 1996, Photo 55), with just …
Balagan-Tas
Russia · Omolon · 136-15-006
Age: Upper Pleistocene.
This volcano takes the form of an almost symmetrical cone about 190 m high which is composed of lavas similar in composition to those of peripheral lava flows. …
Balcones Province (Uvalde County; Balcones Fault Zone)
United States of America · Texas · 174-00-109
Age: Some 20 samples, principally from the Uvalde area, but also from intrusions further east including Pilot Knob near Austen, and representing all the major rock types were dated by K-Ar on whole rocks and indicated a minimum range of from 63-86 Ma (Baldwin and Adams, 1971).
Economic: Oil has been produced from at least 60 buried igneous centres in the Balcones province, either from reservoirs in altered pyroclastic rocks or from structural and stratigraphic traps in sedimentary rocks flanking and overlying the volcanoes (Barker and Young, 1979).
More than 200 plugs, sills and volcanic remnants extend northeast-southwest over some 300 km from east of Austin to west of Uvalde. Many of the plugs form hills…
Balleny Islands
Antarctica · 006-00-059
Age: There have been no isotopic age determinations but probably late Cenozoic with a maximum age of 10 Ma, based on seafloor magnetic patterns (Wright & Kyle, 1990j). There are reported sightings of volcanic activity during the 19th century.
The Balleny Islands, together with a series of seamounts, form a chain >300 km long with three larger islands, of which Sturge Island, the largest, covers appro…
Balombo And Nonga
Angola · 005-00-016
Andrade (1954) describes essexite, nepheline monzonite and nepheline syenite from the Balombo centre. The essexite and monzonite contain oligoclase-andesine wit…
Baltata
Ethiopia · 054-00-046
The Baltata volcano is located immediately northwest of Cacca (No. 47). No details of the petrology have been found but Baltata is shown on an unpublished map o…
Bamaoqiongzong (Huochetoushan, Huochetou)
China · 035-00-025
Age: K-Ar ages of 20.0, 27.8, 28.0, 28.3 and 28.6 Ma are quoted by Guo et al. (2006).
This is an area of ultrapotassic lavas having, according to Guo et al. (2006), a thickness of 50 m, an area of 300 km2 and volume of 15 km3. Seven samples, clas…
Bambouto
Cameroon · 030-00-023
Age: K-Ar dating indicates that the basaltic activity took place between 14.9 and 5.8 Ma and that the more evolved rocks were extruded between 22.7 and 15.9 Ma (Gouhier et al., 1974; Fitton and Dunlop, 1985). Marzoli et al. (1997) obtained dates of 17.8-15.1 Ma by 40Ar/39Ar on feldspar.
This large volcanic complex, which extends in a northeast-southwesterly direction for over 50 km, has not been mapped in detail but it is clearly depicted on th…
Bambui
Brazil · Minas Gerais · 025-00-065
Economic: Concentrations of Th and U in which Th>U occur.
At least 12 of a much larger number of radioactive anomalies in the Bambui area prove to be pipes up to about 100 km in diameter, which are usually filled with …
Bambuiskii
Russia · Baikal · 136-03-017
The Bambuiskii massif consists of two bodies divided by the Bambu’ river valley. They cut Lower Cambrian dolomites and dolomite-bearing limestones, which occu…
Ban Huai Sai
Laos · 092-00-001
Age: U-Pb isotope (SHRIMP) determinations on three zircon inclusions gave ages of 1.2-1.3±0.3 Ma (Sutherland et al., 2002).
Ban Huai Sai is a town on the Laos side of the Mekong River, close to the town of Chiang Kong in Thailand where basanite occurs (Thailand No. 1). Sapphire-beari…
Bang Phuc (Bac Kan)
Vietnam · 178-00-005
Age: Sm-Nd dating ofijolite whole-rock gave an age of 220±1 (Chi & Flower, 2014).
This is an elongate complex consisting dominantly of alkaline and nepheline syenites with lesser amounts of ijolitic rocks (Chi & Flower, 2014). The ijolitic ro…
Bangala
Malawi · 103-00-034
On the northeast slopes of Bangala Hill occurs a thin dyke of sovite about 6 m long and up to 60 cm thick. It consists of calcite, barite and orthoclase. Small …
Bangs Havn
Greenland · 063-00-035
At Bangs Havn, northeast of the Nunarssuit intrusion, dykes of the Gardar swarm coalesce to form a small complex with a gabbro envelope around a core of layered…
Banhadao
Brazil · Parana · 025-00-101
Age: Biotite from malignite gave 118±4 Ma by K-Ar and anorthoclase from foyaite 68±1 Ma (Hama et al. 1977).
Economic: Geochemical work on soils has proved high concentrations of Nb, Ti, Zr and Al.
Banhadao is a multiple intrusion of some 11 km2 intruding the Tres Corregos granitic complex. Nepheline syenites are predominant and variable, aegirine-augite/a…
Bani Amr (Jabal Adh Dhur As Saghir, Jabal Adh Dhur)
Saudi Arabia · 143-00-053
The two syenite intrusions of Jabal adh Dhur (1 km in diameter) and Jabal adh Dhur as Saghir (2.3x1.4 km), referred to by Stoeser (1986) as the Bani Amr syenite…
Banke
Nigeria · 122-00-014
Age: Ages of 173(2 and 173(3 Ma have been obtained by Rb-Sr on biotite granite (Rahaman et al., 1984).
Economic: Cassiterite has been won from alluvial gravels derived from greisen in basement rocks adjacent to the biotite granite (Jacobson and MacLeod, 1977). The mineralization is discussed in the light of trace element data by Ekwere (1985).
The 17.5x15 km Banke complex is bounded by a ring-fault but one third of the enclosed area is occupied by basement rocks. The northern part of the complex is mo…
Banks Peninsula
New Zealand · 119-00-011
Age: 40Ar/39Ar dating of 15 rocks are given by Timm et al. (2009) and for the Lyttelton volcano range from 12.3 to 10.7 Ma and for Akaroa from 9.4 to 8.8 Ma. A Rb-Sr isochron age of 10.79±0.01 Ma for dacites and rhyolites of the Governors Bay Volcanics was obtained by Barley et al. (1988). K-Ar dating by Stipp & McDougall (1968) gave ages of 11.9 to 8.83 Ma for the Lyttelton volcano, 9.23 to 7.50 Ma for Akaroa and 8.18 to 5.84 Ma for the Diamond Harbour Group.
The Banks Peninsula is built from the overlapping shield volcanoes of Lyttelton and Akaroa. Initially the volcanoes formed an island which was subsequently join…
Baotoudong (Baotou)
China · 035-00-076
Age: Yan et al. (1999) give a Rb-Sr isochron age of 197.7±5.6 Ma. U-Pb dating of zircon from K-feldspar syenite gave an age of 214.7±1.1 Ma (Niu et al., 2016).
This is a stock of ~14 km2 intruding Archaean gneisses and partly overlan on the eastern side by Permian tuffs (Niu et al., 2016). It comprises syenites and nep…
Bár
Hungary · 071-00-006
Age: A K-Ar age of 2.17±0.17 Ma, based on three determinations, is given by Balogh et al. (1986).
Although mainly obscured by Quaternary loess deposits three drill holes have proved the existance of a maar-like volcano, probably extending over about 0.5 km2,…
Baradangua
India · 072-00-024
Age: Probably Precambrian.
A ridge of nepheline syenite approximately 600 m in length and 100 m wide occurs amongst Precambrian amphibolite, marble, quartzite and kyanite-bearing rocks ne…
Baralaba
Australia · Queensland · 011-00-043
Age: 72 Ma (Duggan et al., 1989).
Olgers et al. (1966) mapped an intrusion of about 3x1.5 km that forms Mount Ramsay, which is 12 km southeast of Baralaba. They described the intrusion as consis…
Barchinskii
Kazakhstan · 084-00-003
Age: K-Ar gave 521-547 Ma (Nurlibayev, 1973).
This intrusion is situated to the southwest of the town of Kokchetav. It is 4.3 km long, but averages only 300-350 m in width, and is composed of pyroxenites, a…
Bardkish (Urumieh Complex)
Iran · 075-00-006
Age: K-Ar dating of arfvedsonite from syenite gave an age of 80.1±3.1 Ma (Ghalamghash et al., 2009a).
West of the southern end of Lake Urumieh is a series of intrusions of granite and diorite, known as the Urumieh complex, amongst which is the peralkaline Bardki…
Bargushatskii
Armenia · 009-00-008
Age: A K-Ar whole rock determination gave 35 Ma (Bagdasaryan, 1966).
The rocks of the Bargushatskii occurrence are located in the Bargushatskii mountain range and consist of a single 250x150 m mass as well as small lens-shaped an…
Baringo-Laikipia Area
Kenya · 085-00-032
Age: Miocene to Recent. Numerous age determinations are available for the area and will be found in Hackman (1988) under the appropriate lithological descriptions.
Running approximately north-south in the western part of this one degree square area is a complete segment of the East African (Gregory) Rift within which lie l…
Barlow Canyon
United States of America · Wyoming · 174-00-068
A small domed (?)sill is seen to intrude sandstones of the Sundance Formation over some 220 m in the bottom of the Barlow Canyon; the lower contact is not expos…
Barnavave
Ireland · 077-00-008
Nockolds (1950) has described eudyalite-bearing rocks in the Carlingford Complex, County Louth. In the vicinity of Barnavave (Baxter, 2008), limestones at the m…
Barpung
India · 072-00-026
Barpung is an almost perfectly circular, 6 km diameter, complex located in the central area of the Mikir Hills, Assam, and emplaced in metasediments of the Shil…
Barqueros
Spain · 153-00-018
Age: A lamproite lava gave a K-Ar date of 7.0 Ma (van Couvering et al., 1976).
Barqueros is a 2x1.2 km volcanic edifice which has been deeply eroded. It comprises lavas and breccias, dykes and vents, which have been mapped by Fúster & Gas…
Barra Do Itapirapua
Brazil · Sao Paulo · 025-00-104
Economic: REE-rich phosphates and carbonates occur and there is fluorite and galena mineralization.
This carbonatite intrusion is situated only 2.3 km southeast of Itapirapua (025-00-103) and forms a plug over 500 m high surrounded by precipitous cliffs; it is…
Barra Do Pirai And Dos Tomazos
Brazil · Rio de Janeiro · 025-00-085
Minor plugs and dykes of phonolite cut Precambrian gneisses; pseudoleucite-bearing rocks occur (J. G. Valenca, personal communication).
Barra Do Teixeira And Sete Quedas
Brazil · Parana · 025-00-102
Age: K-Ar on phonolite (whole rock) of Barra do Teixeira gave 72.9 Ma (Cordani and Hasui, 1968).
Barra do Teixeira is a small phonolite plug intruding the Precambrian Tres Corregos batholith. Sete Quedas is a similar phonolite plug some 10 km to the east.
Barrier Volcano (Likaiu, Likaiyo, Nagaramsainia)
Kenya · 085-00-008
Age: Dunkley et al. (1993) report eight Ar/Ar dates which range from 1.37 Ma to 1888 AD. The last reported eruption was from Teleki’s volcano in 1895 (Dodson, 1963).
The Barrier volcano stands at the southern end of Lake Turkana and is so named because it separates the lake from the Suguta valley, the site of a former lake t…
Barrington (Square Top Intrusion)
Australia · New South Wales · 011-00-059
Age: Five K-Ar ages, from three samples, range from 57.1 to 43.1 Ma (Wellman & McDougall, 1974). These authors note that 15 ages determined previously, for which references are given, fall in the range 55 to 43 Ma. McDougall & Wilkinson (1967) give a K-Ar age of 58.6±2.0 Ma for an analcime-olivine theralite from the Square Top intrusion.
Barrington was probably originally a low-angle shield volcano but the present volcanic field is estimated as having only about 20% of its former volume (Mason, …
Barsalinga
Kenya · 085-00-036
In the extreme northwest of the Isiola area occur extensive phonolite flows, one of which extends some 20 kilometres southeastwards along a former river valley …
Bartoiskoe Volcanic Field
Russia · Baikal · 136-03-040
Age: Neogene-Holocene. K-Ar determinations record activity at 27 Ma, 3 Ma and 1.4 Ma (Kononova et al., 1988).
The Bartoiskoe volcanic field is one of the numerous volcanic fields of the Baikal rift system. The maximum volcanic activity took place in the Miocene and duri…
Barun Bogdo
(no coordinates, not on the map)
Mongolia · 111-00-053
This is a peralkaline intrusion which consists, according to Kovalenko et al. (1973), of a pegmatoid arfvedsonite granite similar to the inner contact varieties…
Barun-Khasar Ula (Zeden)
Mongolia · 111-00-044
Vladykin (2008) notes that the Mongolian geologist T. Zeden found a ‘rare-metal’ carbonatite dyke 30 km west of Lugiin Gol (No. 45) close to Barun-Khasar-Ul…
Barur And El Sharif
Sudan · 155-00-034
These are two overlapping circular complexes emplaced in basement gneisses. The 12 km diameter Barur complex is composed mainly of rhyolitic lavas, ignimbrites …
Baruun Manhan (Ujig Gol, Ovor Shivleg, Doshin Gol)
(no coordinates, not on the map)
Mongolia · 111-00-065
Age: Early Devonian.
Intruding Neoproterozoic to Cambrian limestones this intrusion comprises a range of nepheline-bearing gabbroic rocks. They contain widely varying proportions of…
Barwaha
India · 072-00-020
Yellur (1968) indicates that in the Barwaha area there are nepheline-bearing dyke rocks associated with occurrences of fluorite and possible carbonatite. Deans,…
Basanites Of Southern Vietnam
(no coordinates, not on the map)
Vietnam · 178-00-009
Age: Volcanic activity commenced at about 12 Ma and has continued to the present (Barr & Macdonald, 1981).
There are a number of extensive basaltic volcanic fields in southern Vietnam notably the plateaux of Pleiku, Darlac, Haut Chhlong, Djiring and Xuan Loc. There a…
Bashisugong
(no coordinates, not on the map)
China · 035-00-020
Age: U-Pb dating of zircon from alkali syenite gave 313±12 Ma (Chen et al., 2002).
This occurrence includes biotite-amphibole syenite and aegirine-augite-amphibole syenite (X.X. Song & T. Zou, pers. comm. 2011). No other field or petrological …
Baskatong Reservoir
Canada · Quebec · 031-00-105
Currie (1976a, p. 201) reports nepheline-bearing rocks from the edges of the Baskatong Reservoir syenite. This intrusion is briefly described by Corriveau (1985…
Basören (Sofular, Kuluncak-Sofular Area, Kuluncak-Malatya, Avliya Dere, Alibeyli, )
Turkey · 168-00-022
Age: A K-Ar age of 65.2±1.6 Ma for the Avliya Dere syenite is reported by Leo et al. (1974).
Economic: Deposits containing 30,000 tons at 52% CaF2 and 1,000 tons of britholite containing 57% rare earth oxides, 2.49% Y2O3 and 2.68% ThO2 are reported by Özgenç (1999).
The basement rocks of the Basören occurrence are upper Cretaceous to lower Palaeocene limestones and ophiolites, with the former dominant. Cutting this sequenc…
Basotu Craters
Tanzania · 163-00-025
Age: Post-Miocene.
About 30 explosion craters aligned north-northeast form two parallel lines. They are seldom more than 40 m high, are up to 100 m deep and a number contain crate…
Bat-Tsengel (Altan Ovoo, Tsorgo Uul)
(no coordinates, not on the map)
Mongolia · 111-00-054
Age: Early to middle Triassic.
Cutting sediments of middle to upper Devonian age this intrusive complex includes granite, monzonite and peralkaline granite. The monzonite contains 10% biotite…
Batanaulskii
Russia · Kuznetsk-Minusinsk · 136-13-002
This sheet-like body covers an area of 5x0.6-1.5 km. It is surrounded by lower and middle Devonian volcanic rocks and is composed of theralite porphyry, nepheli…
Batbjerg
Greenland · 063-00-015
Age: Determinations by Rb-Sr and K-Ar gave ages "of around 450 myr" (Brooks et al., 1976, p. 694) and a fission-track age on sphene of 435 ±14 Ma was obtained by Gleadow and Brooks (1979, Table 4).
Situated 15 km beyond the head of Kangerdlugssuaq Fjord, Batbjerg is of Caledonian age, the other intrusions of the Kangerdlugssuaq vicinity all being Tertiary.…
Bateman No. 1 Well
United States of America · Tennessee · 174-00-114
Batpak
Kazakhstan · 084-00-046
The 30 km2 Batpak intrusion is situated in the Chingis-Tarbagatai region and is composed of peralkaline quartz syenites. These consist of microcline perthite, a…
Batu
Ethiopia · 054-00-064
Le Bas and Mohr (1968) describe melanephelinite and tinguaite, collected by Sowerbutts, from immediately north of the Batu Mountains. On the 1:2,000,000 geologi…
Batu Tara (Batoe Tara, Batu Tava, Komba)
Indonesia · Komba Island · 075-00-013
Age: The volcano erupted in 2010.
Batu Tara is a volcano forming an isolated island in the Flores Sea about 50 km north of Lembata (fomerly Lomblen) Island. The volcano is 748 m high but the bas…
Bauhinia
Australia · Queensland · 011-00-044
Age: K-Ar dating of five rocks gave ages of 24.8 to 21.3 Ma (Harding, 1969).
The rocks of the Bauhinia volcanic province are scattered over an area of approximately 500 km2 with flows filling a Tertiary drainage system incised into Trias…
Bawean
Indonesia · Bawean · 075-00-002
Age: K-Ar dating of the phonolites gave ages in the range 0.84-0.38 Ma and leucite-bearing lavas 0.67-0.26 Ma (Soeria-Atmadja et al., 1988).
Bawean is an isolated island of 17x 12 km, lying between Java and Kalimantan, in the centre of which is a volcano with a summit height of 655 m. Most of the isl…
Bayan Airag (Gegeed Tolgoi, Harmagtai Har Uul, Tayangyn Nuruu, Orog Ovoo Tolgoi)
(no coordinates, not on the map)
Mongolia · 111-00-055
Age: The complex is said to be early Carboniferous in age.
The Bayan Airag complex comprises several distinct plutons all of which contain peralkaline granite. The Gegeed tolgoi intrusion consists of peralkaline granite…
Bayan Khoshuu (Bayan Hoshuu, Bayan Hushu)
Mongolia · 111-00-037
Age: K-Ar age determinations on syenite and feldspar and biotite fractions ranged from 143 to 145 Ma (Baskina et al., 1978). A whole-rock – mineral isochron age of 130.6±9.3 Ma is given by Gerel et al. (2005a).
The Bayan Khoshuu complex consists of trachytes and trachyrhyolites, syenites and monzonites that have been emplaced into late Palaeozoic granosyenite, granite …
Bayan Obo
China · 035-00-079
Age: Eight samples from carbonatite dykes gave a Sm-Nd isochron age of 1354±59 Ma (Yang et al., 2011b) and a whole-rock Sm-Nd isochron age of 1341±160 Ma was obtained for the ore-hosting dolomite. However, there is a dating problem in so far as ages, determined by many methods, range from 2.0 to 0.4 Ga and have peaks in the middle and late Palaeoproterozoic, Caledonian and Hercynian (Yang et al., 2009; Chao et al., 1997). Problematically these ages reflect metamorphic, metasomatic and igneous events that are not easy to distinguish. U-Pb dating of zircons from H8 banded ores gave an age of 1,325±60 Ma for zircon cores and 455.6±28.3 for rims (Campbell et al., 2014). Campbell et al. (2014) also tabulate a dozen papers in which there are age values.
Economic: The ore bodies at Bayan Obo are concentrated along the southern margin of the H8 dolomite the largest being the East, Main and West but there are at least 16 smaller orebodies (Xu et al., 2012). Coarse- and fine-grained facies of the H8 dolomite are distinguished the latter being concentrated around and in the vicinity of the ore bodies. In general terms there are three broad categories of ore type, namely disseminated, banded and massive (Xu et al., 2012). Yang et al. (2011b) illustrate the Main and East orebodies as including riebeckite, aegirine, banded and massive types. The ores can also classified as REE-Nb ore and Fe ore the former mainly represented by monazite (Ce), bastnäsite (Ce) and huanghoite. A more detailed classification, based on characteristic mineral associations (Institute of Geochemistry, Chinese Academy of Sciences, 1988), is as follows: (1) massive and partly banded fluorite-magnetite-REE ore, (2) banded fluorite-magnetite-bastnäsite ore, (3) disseminated aegirine-magnetite-REE ore, (4) disseminated arfvedsonite-phlogopite-muscovite-magnetite-REE ore, (5) disseminated dolomite-magnetite-REE ore, (6) disseminated and partly banded aegirine-REE ore, (7) disseminated and partly banded dolomite-REE ore, (8) disseminated and banded diopside-phlogopite-REE ore and (9) disseminated biotite-magnetite-REE ore. The principal host rock minerals (Chao et al., 1997) are ferroan dolomite, Sr and Mn-calcite, quartz, illite, biotite, apatite and albite. The main REE ore minerals are monazite, bastnäsite, huanghoite, parisite and cebaite with Nb (±REEs) minerals columbite, aeschynite, fergusonite, fersmite, pyrochlore and Nb-rutile. Iron ore minerals include magnetite, hematite, martite, goethite and ilmenite while other carbonates are benstonite, norsethite, barytocalcite and strontianite. Common gangue and other minerals include fluorite, barite, aegirine, magnesio-arfvedsonite, magnesio-riebeckite, phlogopite, microcline, bafertisite, cerianite, pyrite, pyrrhotite, sphalerite, galena and chalopyrite. Reserves of REE minerals are estimated at 57 million tons of RE oxides with a million tons of Nb2O5, 470 million tons of iron and 130 tons of fluorite. It is, by far, the world’s largest known REE deposit, accounting for about 70% of the known reserves, and also the largest deposit of fluorite.
Figs 51 and 52 The unique Bayan Obo REE-Nb-Fe occurrence is the largest REE deposit in the world and is genetically extremely complex, which has led to consider…
Bayan-Ulan
Mongolia · 111-00-034
Age: Ar-Ar dating of amphiboles from two peralkaline granites gave ages of 220.7±0.9 and 221±5 Ma (Yarmolyuk et al., 2002).
Bayan-Ulan is a granite pluton extending over >1,000 km2 and located within a large graben (Dostal et al., 2015). The intrusion is cut by numerous aplitic and o…
Bayankol
Russia · East Tuva · 136-08-019
Age: K-Ar on nepheline gave 410±16 Ma (Yashina and Borisevich, 1966) and Pb determinations on thorite 400±80 Ma (Zykov et al., 1961).
Economic: The massif has a potential for the mining of nepheline as a raw material for alumina production.
The alkaline rocks of the Bayankol complex cut Upper Proterozoic marbles and Lower Palaeozoic granitoids. The complex is oval in outline but a deep valley divid…
Bayariya Oasis
Egypt · 049-00-001
Phonolite basanite', an analysis of which is given in Aly et al. (1983, No. 1052), occurs in the area of Bahariya oasis but few details are available.
Bayburt (Everek Hanlari Volcanics)
Turkey · 168-00-026
Age: The Everek Hanlari volcanics overlie limestones of Upper Campanian to Maastrichtian age and are overlain by late Paleocene to early Eocene flysch deposits (Altherr et al., 2008).
The Everek Hanlari volcanic leucitites, referred to as ‘plagioleucitites’ by (Altherr et al., 2008), are located four kilometres south of Maden village, whi…
Bayda Nathil
Saudi Arabia · 143-00-018
This is a large complex of some 35x20 km with peralkaline granites forming several distinct bodies associated with alkali feldspar granite, monzogranite and dio…
Bayindir And Durmuşlu (Kortundağ, Hamit)
Turkey · 168-00-014
Age: Hamit does not appear to have been dated but other members of the Central Anatolian Crystalline Complex give ages in the range 67 to 110 Ma (Ilbeyli et al., 2004)
The Kortundağ pluton is one of a series of mainly granitoid intrusions, but with some gabbroic sections, that make up the Central Anatolian Crystalline Complex…
Bayuda
Sudan · 155-00-053
Age: A Rb-Sr determination on peralkaline granite gave 365(7 Ma (Barth et al., 1983).
Situated in the extreme southwestern corner of the Bayuda Desert this 12x8 km complex is intruded into basement gneisses but partly obscured by superfical depos…
Bayuda Main Volcanic Field, Ban Gidid And El Eide
Sudan · 155-00-037
Age: Two samples of peralkaline granite, two of peralkaline syenite and two rhyolites gave a Rb-Sr isochron defining an age of 398(7 Ma (Barth et al., 1983). Barth and Meinhold (1979) report the volcanic rocks of the Bayuda Main Volcanic Field to give K-Ar ages in the range 1.7-0.9 Ma.
The Main Volcanic Field in the central Bayuda Desert occupies an area of about 50x20 km within which there is an almost continuous volcanic cover, but in the no…
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