Portland Mine, Bald Mountain District, Lawrence Co., South Dakota, USA
| Latitude & Longitude (WGS84): | 44° 20' 50'' North , 103° 50' 45'' West |
|---|---|
| Latitude & Longitude (decimal): | 44.34722,-103.84583 |
| Köppen climate type: | Dfb : Warm-summer humid continental climate |
A gold mine located Lead.
Commodity List
This is a list of exploitable or exploited mineral commodities recorded at this locality.Mineral List
8 valid minerals.
Regional Geology
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
| Eocene - Paleocene 33.9 - 66 Ma ID: 2749430 | Phonolitic Intrusive Rocks Age: Paleogene (33.9 - 66 Ma) Description: Gray to greenish-gray sills, laccoliths, and small stocks of phonolite, trachyphonolite, and trachyandesite. Contains phenocrysts of andesine, feldspathoids, aegirine-augite, biotite, and sphene in a finely crystalline plagioclase-biotote-feldsphoid groundmass. Lithology: Major:{hypabyssal felsic alkaline,hypabyssal trachyte} 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. [133] |
| Eocene - Paleocene 33.9 - 66 Ma ID: 2474149 | Quartz trachytic intrusive rocks Age: Paleogene (33.9 - 66 Ma) Description: Tan to gray and porphyritic or phaneritic. Locally sanidine-bearing. Forms laccolithic bodies and sills. Reference: Redden, J.A., E. DeWitt. Maps Showing Geology, Structure, and Geophysics of the Central Black Hills, South Dakota. U.S. Geological Survey Scientific Investigations Map 2777. [73] |
| Permian - Devonian 252.17 - 419.2 Ma ID: 3190647 | Paleozoic sedimentary rocks Age: Paleozoic (252.17 - 419.2 Ma) Lithology: Sedimentary rocks 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. [154] |
Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License
Portland Mine, Bald Mountain District, Lawrence Co., South Dakota, USA