USGS - science for a changing world

Mineral Resources On-Line Spatial Data

Mineral Resources > Online Spatial Data > Geology > by state > South Dakota

Phonolitic Intrusive Rocks

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.
StateSouth Dakota
NamePhonolitic Intrusive Rocks
Geologic agePhanerozoic | Cenozoic | Tertiary | Paleocene Eocene
Original map labelTp
Primary rock typephonolite
Secondary rock typetrachyte
Other rock types
Lithologic constituents
Major
Igneous > Hypabyssal > Felsic-hypabyssal > Hypabyssal-trachyte (Laccolith)
Igneous > Hypabyssal > Felsic-hypabyssal > Hypabyssal-felsic-alkaline (Dike or sill)Phonolite
Map references
Martin, J. E., Sawyer, J. F., Fahrenbach, M. D., Tomhave, D. W., and Schulz, L. D., 2004, Geologic Map of South Dakota: South Dakota Geological Survey
Unit references
Martin, J. E., Sawyer, J. F., Fahrenbach, M. D., Tomhave, D. W., and Schulz, L. D., 2004, Geologic Map of South Dakota: South Dakota Geological Survey
Geographic coverageLawrence

Show this information as [XML] - [JSON]

AccessibilityFOIAPrivacyPolicies and Notices

Take Pride in America logoUSA.gov logoU.S. Department of the Interior | U.S. Geological Survey
URL: http://mrdata.usgs.gov/geology/state/sgmc-unit.php?unit=SDTp;0
Page Contact Information: Peter Schweitzer