The document summarizes the geology of Chester County, South Carolina based on the author's synthesis of detailed data from 1:2400 scale geologic maps. The earliest rocks are Proterozoic amphibolites, gneisses and quartzites that have been intruded by metagranites, gabbro and granite. This synthesis is based on the study of 125 samples and 172 thin sections collected across 13 USGS 7.5 minute quadrangles within the county. The dominant rock types described include metagranites, metagabbros, quartzites, and mafic dikes. Structural features mentioned include folds, faults, and shear zones.

1. Geology Chester County, SC

2. geologic map at a scale 1:250,000 and depicts my synthesis of
the detailed data presented on open file 1:2400 maps

3. THE GEOLOGY OF CHESTER COUNTY, SC.
The area has a long history of sedimentation, tectonism and erosion.
The earliest Proterozoic host amphibolites, gneiss and quartzites are
cut by metagranites (Great Falls), gabbro (Chester), granite.(Lowery)
This synthesis come from study of apx 125 samples 172 thin sections.The 7.5 minute
quadrangles with the number of collected samples are: Lockhart -1, Leeds - 2, Carslile –
2, Carslile SE- 9, Baton Rouge - 3, Chester- 19, Blackstock- 6, Richburg- 11, Stover 11
Catawba 1, Fort Lawn 9,Grea t Falls - 24, Flint Hill 6, Lancaster - 4 Lancaster SE 10

5. Metagranites and Metadiorites

6. Older metadiorite intrudded by metagranite.

7. Completely saprolotized metadiorites
(red orange) and metagranite.

10. Mafic and felsic saprolite

11. Metadiorite xenoliths

16. 618 26

18. Metagranite/Metadiorite
complexoff St. Hwy. 97

19. Metagranite/Metadiorite complex
off St. Hwy. 97

20. Metagranite/Metadiorite complex
off St. Hwy. 97

21. Lockhart metadiorite.
Medium- to coarse-grained,
relatively uniform biotite-
hornblende metadiorite, that
locally grades into metagabbro
and metatonalite. Part of a large
pluton that lies mainly in Union
County, South Carolina, in the
vicinity of the city of Lockhart.

23. Gabbro

24. Great Falls Metagranite

25. QUARTZITE

26. Quartzite thin sectionNo.119

28. Fold in quartz mica scist

31. Orbicular Diorite

35. 1/13/2006 303
9/11/2003 133
Geologic map of the Metagranite
Generalized geologic map of the Great Falls metagranite and surrounding rocks.
Explanation: MGR- Great Falls metagranite, GN -gneiss complex, GB -gabbro,
ƒ- sheared rocks, dd -diabase dikes, M -mafic dike concentration, z -zeolite
mineralization, s - skarn. From Privett, 1984.

37. Folds and faults

38. Shear Zones

39. Northsouthstrikingverticalmaficdike.
Maficdikecuttingmassivemetagranite.
North-southmaficdikeoffsetbynearlyeastwestdike.
Close-up.
GreatFallsoftheCatawba.GeneralAerialView
ThisspillwaydamwasbuiltatoptheGreatFallsoftheCatawba.
Eastsideoftheriver,priortodiversiontheriverhadcutdeeplyinto
unjointedmetagranite.Polishedmetagraniteatbaseofthefalls.Pothole
inpolishedmetagranite.

40. Bibliography