Tishomingo and Troy Granites (OKpCAt;0)

State	Oklahoma
Name	Tishomingo and Troy Granites
Geologic age	Middle Proterozoic
Lithologic constituents	Major Igneous > Plutonic > Granitic > Granite (Batholith)
Comments	TISHOMINGO:Named for Tishomingo, capital of Chickasaw Nation, Indian Territory, Midcontinent region, Johnston Co, OK. No type locality designated. Occurs in Tishomingo quad Is a coarse-grained, pink or reddish, microcline-rich granite with numerous basic dikes. Biotite is always present. Accessory minerals are zircon, apatite, magnetite, and sometimes garnet. Quartz monzonite occurs in intimate association with the granite and appears as phases of it. (Taff, 1902). TROY: Probably named for town of Troy, Johnston Co, OK, in Arbuckle Mountains district. Present on the southeastern flank of the exposed portion of the Arbuckle uplift, in Johnston Co (S. Oklahoma folded belt province) and Atoka Co (Ouachita tectonic belt province). Probably part of same intrusive body as Tishomingo granite, which is also present in this area. When unaltered, Troy is a medium- to fine-grained gray granite, speckled with black. It shows cleavage surfaces of a gray feldspar usually less than .5 mm broad, with occasionally a pinkish individual more than 1 cm across, rounded grains of colorless quartz, and many small black specks of biotite evenly distributed. There are 2 or 3 nearly vertical joint systems, spaced 2-40 ft apart, usually at right angles to each other. There are also strong sheet joints parallel or nearly parallel to the slopes of the granite hills, usually spaced 10-25 ft apart. (Taylor,1915).
References	Heran, W.D., Green, G. and Stoeser, D.B., 2003, A Digital Geologic Map Database of Oklahoma: USGS Open File Report 03-247, scale 1:250,000. https://pubs.er.usgs.gov/publication/ofr03247 Hart, D.L., 1974, Reconnaissance of the water resources of the Ardmore and Sherman quadrangles, southern Oklahoma: Oklahoma Geological Survey, Hydrologic Atlas 3, scale 1:250,000, 4 sheets. (Geology on sheet 1 compiled by D.L. Hart, and R.O. Fay, in 1970.) Cederstrand, J.R., 1996a, Digital geologic map of Ardmore-Sherman quadrangles, south-central Oklahoma: U.S. Geological Survey Open-File Report 96-370, (3 diskettes), URL address is: http://ok.water.usgs.gov/gis/geology https://pubs.er.usgs.gov/publication/ofr96370 Taff, J.A., 1902, Description of the Atoka quadrangle [Indian Territory]: U.S. Geological Survey Geologic Atlas of the United States, Folio 79. https://pubs.er.usgs.gov/publication/gf79 Taylor, C.H., 1915, Granites of Oklahoma: Oklahoma Geological Survey Bulletin 20.
NGMDB product	NGMDB product page for 55294
Counties	Atoka - Johnston

State

Oklahoma

Name

Tishomingo and Troy Granites

Geologic age

Middle Proterozoic

Lithologic constituents

Major

Igneous > Plutonic > Granitic > Granite (Batholith)

Comments

TISHOMINGO:Named for Tishomingo, capital of Chickasaw Nation, Indian Territory, Midcontinent region, Johnston Co, OK. No type locality designated. Occurs in Tishomingo quad Is a coarse-grained, pink or reddish, microcline-rich granite with numerous basic dikes. Biotite is always present. Accessory minerals are zircon, apatite, magnetite, and sometimes garnet. Quartz monzonite occurs in intimate association with the granite and appears as phases of it. (Taff, 1902). TROY: Probably named for town of Troy, Johnston Co, OK, in Arbuckle Mountains district. Present on the southeastern flank of the exposed portion of the Arbuckle uplift, in Johnston Co (S. Oklahoma folded belt province) and Atoka Co (Ouachita tectonic belt province). Probably part of same intrusive body as Tishomingo granite, which is also present in this area. When unaltered, Troy is a medium- to fine-grained gray granite, speckled with black. It shows cleavage surfaces of a gray feldspar usually less than .5 mm broad, with occasionally a pinkish individual more than 1 cm across, rounded grains of colorless quartz, and many small black specks of biotite evenly distributed. There are 2 or 3 nearly vertical joint systems, spaced 2-40 ft apart, usually at right angles to each other. There are also strong sheet joints parallel or nearly parallel to the slopes of the granite hills, usually spaced 10-25 ft apart. (Taylor,1915).

References

Heran, W.D., Green, G. and Stoeser, D.B., 2003, A Digital Geologic Map Database of Oklahoma: USGS Open File Report 03-247, scale 1:250,000.

https://pubs.er.usgs.gov/publication/ofr03247

Hart, D.L., 1974, Reconnaissance of the water resources of the Ardmore and Sherman quadrangles, southern Oklahoma: Oklahoma Geological Survey, Hydrologic Atlas 3, scale 1:250,000, 4 sheets. (Geology on sheet 1 compiled by D.L. Hart, and R.O. Fay, in 1970.)

Cederstrand, J.R., 1996a, Digital geologic map of Ardmore-Sherman quadrangles, south-central Oklahoma: U.S. Geological Survey Open-File Report 96-370, (3 diskettes), URL address is: http://ok.water.usgs.gov/gis/geology

https://pubs.er.usgs.gov/publication/ofr96370

Taff, J.A., 1902, Description of the Atoka quadrangle [Indian Territory]: U.S. Geological Survey Geologic Atlas of the United States, Folio 79.

https://pubs.er.usgs.gov/publication/gf79

Taylor, C.H., 1915, Granites of Oklahoma: Oklahoma Geological Survey Bulletin 20.

NGMDB product

NGMDB product page for 55294

Counties

Atoka - Johnston