Crater of Diamonds State Park (Arkansas Diamond Corp. Mine; Mauney Mine; Ozark Mine; Prairie Creek Lamproite), Murfreesboro, Pike Co., Arkansas, USA
|Latitude & Longitude (WGS84):||34° 1' 59'' North , 93° 40' 21'' West|
|Latitude & Longitude (decimal):||34.03333,-93.67250|
|Köppen climate type:||Cfa : Humid subtropical climate|
Diamonds were discovered at this location in 1906. Now a fee-based collecting site.
Four major rock types occur: magmatic lamproite (with mantle and crust-derived xenoliths); marr epiclastics (largely sandstone); lamproite lapilli tuff (phlogopite-rich); and lamproite breccia tuff. These last two types are the source of most of the diamonds recovered in the visitor area.
Haggertyite is present as microscopic hexagonal plates in the alteration zones of xenoliths in Prairie Creek lamproite.
The Prairie Creek Lamproite is Early Cretaceous (106 mya) in age.
Mindat Articles5. Diamonds R Waiting 4U At The Crater of Diamonds State Park by Frank Festa
TGMS 2008 - The Crater of Diamonds by Jolyon & Katya Ralph
Mineral ListMineral list contains entries from the region specified including sub-localities
26 valid minerals. 1 (TL) - type locality of valid minerals.
Rock Types Recorded
Rock list contains entries from the region specified including sub-localities
Select Rock List TypeAlphabetical List Tree Diagram
Entries shown in red are rocks recorded for this region.
GeochronologyMineralization age: Cretaceous : 106 ± 3 Ma to 92 ± 2 Ma
Important note: This table is based only on rock and mineral ages recorded below and is not necessarily a complete representation of the geochronology, but does give an indication of possible mineralization events relevant to this locality. As more age information is added this table may expand in the future. A break in the table simply indicates a lack of data entered here, not necessarily a break in the geologic sequence. Grey background entries are from different, related, localities.
|Geologic Time||Rocks, Minerals and Events|
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
66 - 145 Ma
Age: Cretaceous (66 - 145 Ma)
Description: Includes undifferentiated altered sedimentary rocks of Paleozoic age at Granite Mountain, Pulaski County, and Mufreesboro, Pike County. Acid to intermediate - Nepheline syenite complexes at Magnet Cove and Potash Sulfur Springs, stocks at Granite Mtn., explosion breccias, and dikes and sills (principally trachyte,tinguaite, phonolite, some ranging from syenite to diabase). Basic to ultrabasic - Lamproite pipes (Murfreesboro, Pike County) and dikes and sills (principally lamprophyres of fourchite, ouachitite, and monchiquite).
Comments: Alkalic ring dike igneous complexes: Magnet Cove (Hot Spring County)-core of carbonatite-ijolite, inner ring of alkalic extrusives and outer ring of nepheline syenite; Potash Sulfur Springs (Garland County)-mafic alkalic rocks, carbonatite, nepheline syenite and syenite. Both intruded during Mesozoic time into Paleozoic shale, sandstone and novaculite.
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. 
100.5 - 145 Ma
|Mesozoic sedimentary rocks|
Age: Early Cretaceous (100.5 - 145 Ma)
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529.