Althaus pegmatite, Gillespie Co., Texas, USAi
| Regional Level Types | |
|---|---|
| Althaus pegmatite | Pegmatite |
| Gillespie Co. | County |
| Texas | State |
| USA | Country |
| Place | Population | Distance |
|---|---|---|
| Stonewall | 505 (2011) | 20.3km |
| Johnson City | 1,959 (2017) | 25.1km |
| Round Mountain | 181 (2011) | 26.3km |
| Horseshoe Bay | 3,560 (2017) | 27.6km |
| Sunrise Beach Village | 731 (2017) | 28.7km |
East side of county
Regions containing this locality
| North America Plate | Tectonic Plate |
Select Mineral List Type
Standard Detailed Strunz Dana Chemical ElementsMineral List
2 valid minerals.
Rock Types Recorded
Select Rock List Type
Alphabetical List Tree DiagramDetailed Mineral List:
| β Microcline Formula: K(AlSi3O8) Reference: BEG University of Texas publication 4301 |
| β Quartz Formula: SiO2 Reference: BEG University of Texas publication 4301 |
List of minerals arranged by Strunz 10th Edition classification
| Group 4 - Oxides and Hydroxides | |||
|---|---|---|---|
| β | Quartz | 4.DA.05 | SiO2 |
| Group 9 - Silicates | |||
| β | Microcline | 9.FA.30 | K(AlSi3O8) |
List of minerals arranged by Dana 8th Edition classification
| Group 75 - TECTOSILICATES Si Tetrahedral Frameworks | |||
|---|---|---|---|
| Si Tetrahedral Frameworks - SiO2 with [4] coordinated Si | |||
| β | Quartz | 75.1.3.1 | SiO2 |
| Group 76 - TECTOSILICATES Al-Si Framework | |||
| Al-Si Framework with Al-Si frameworks | |||
| β | Microcline | 76.1.1.5 | K(AlSi3O8) |
List of minerals for each chemical element
| O | Oxygen | |
|---|---|---|
| O | β Microcline | K(AlSi3O8) |
| O | β Quartz | SiO2 |
| Al | Aluminium | |
| Al | β Microcline | K(AlSi3O8) |
| Si | Silicon | |
| Si | β Microcline | K(AlSi3O8) |
| Si | β Quartz | SiO2 |
| K | Potassium | |
| K | β Microcline | K(AlSi3O8) |
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
| Paleozoic 251.902 - 541 Ma ID: 3187973 | Paleozoic sedimentary rocks Age: Phanerozoic (251.902 - 541 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] |
| Proterozoic 541 - 2500 Ma ID: 2764486 | Packsaddle Schist Age: Proterozoic (541 - 2500 Ma) Stratigraphic Name: Packsaddle Schist Description: Comstock and Dumble (1890) included unit in the Packsaddle series, described as metamorphosed shaly beds and marble (near base) forming top div. of Texan system. Barnes (1952) described the unit as mostly feldspathic amphibole and biotite schist and chiefly dark colored. (from Llano Sheet, Geol. Atlas of Texas) From top down: Click Fm.-mostly hornblende schist, underlain by leptite and qtz-feldspar-mica schist which grades into hornblende schist SE; thickness ca. 7,800 ft. Rough Rider Fm.-gray leptite, qtz-feldspar-mica schist, and biotite-cordierite gneiss local muscovite schist, biotite schist, and biotite-microcline gneiss; thickness ca. 5,200 ft. Sandy Fm.-alternating units of hornblende schist, and quartz-feldsparpmica schist and leptite; thickness ca.2,100 ft. Honey Fm.-upper part graphite schist, hornblende schist, and marble with graphite schist interbeds; middle part-muscovite schist, changes to leptite,graphite, schist, and hornblende schist toward SE, one prominent marble; lower part-hornblende schist, graphite schist, leptite, and marble; thickness ca 7,800 ft. Comments: Original map source: Stoeser, Douglas B., Shock, Nancy, Green, Gregory N., Dumonceaux, Gayle M., and Heran, William D., 2005, Geologic Map Database of Texas, USGS, DS 170, scale 1:500,000. Lithology: Major:{schist} 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] |
Data and map coding provided by Macrostrat.org, used under Creative Commons Attribution 4.0 License
