Spizzicatore Hill, Allumiere, Tolfa Mts District, Rome Province, Latium, Italy
|Latitude & Longitude (WGS84):||42° 10' 8'' North , 11° 50' 33'' East|
|Latitude & Longitude (decimal):||42.16886,11.84251|
|Köppen climate type:||Csa : Hot-summer Mediterranean climate|
|Name(s) in local language(s):||Colle dello Spizzicatore, Allumiere, Distretto dei Monti della Tolfa, Roma, Italia|
The Spizzicatore hill (Colle dello Spizzicatore) is partly occupied by a quarry, where the ignimbrite rocks are occasionally extracted for road construction and servicing. Several types of rocks occur in this pyroclastic deposit (known in literature as “tufi caotici"): there are fragments of ignimbrites which show a glassy groundmass with K feldspar (sanidine), labradoritic plagioclase, biotite, ortho- and clino-pyroxene as main phenocrystals. Other holocrystalline tephra have a syenitic appearance and are constituted by dominant K feldspar (sanidine) and plagioclase, with minor pyroxene and biotite; common accessories are rutile and zircon (Negretti, 1962).
Cordierite ha been found in blocks with a very fine-grained holocrystalline texture. Cordierite crystal cores often enclose euhedral spinel, ilmenite, and quartz, often coexisting with monazite and pyrrhotite droplets. The ignimbrite can include volcanic rocks in which one can find different minerals. The fine-grained matrix is composed of plagioclase, abundant graphite flakes, accessory minerals (ilmenite) and numerous vugs and vesicles coated with smectite group minerals.
[GPS coordinates to be confirmed.]
14 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
|Pliocene - Miocene|
2.588 - 23.03 Ma
|Miocene-Pliocene sedimentary rocks|
Della Ventura, G., Bellatreccia, F., Cámara, F., Oberti, R., Lorand, J.P., Parodi, G.C., Carlier, G., Di Domenico, D. (2006): Carbon-bearing cordierite from Allumiere (Tolfa volcanic center, Latium, Italy): occurrence, crystal-structure and FTIR microspectroscopy. Periodico di Mineralogia, 75, 113–126. [http://www.dst.uniroma1.it/riviste/permin/testi/V75/14.pdf]