Prominent rock units include granite gneiss, migmatites, schist/ quartz schist
, porphyritic granite, fine-medium grained granite and charnockite.
Hole G2P-3 0 to 150m Biotite quartz schist
with varying feldspar, garnet graphite, chlorite and pyrite, with minor pegmatites.
There are a variety of different types: clinozoisite-rich rock fragments, epidote-biotite quartz schist
, amphibole-biotite-clinozoisite-quartz schist
, biotite-clinozoisite-quartz schist
, clinozoisite-biotite-opaques-quartz schist
, biotite-rich rock fragments, amphibole-biotite-opaques-clinozoisite-quartz-titanite rock fragment, chlorite or anthophyllite-biotite schist (some possibly with accessory tourmaline?
TABLE 1 Soil Groups (5) Soil Group Parent material Chandler/Talledaga Hard talcose schist and mica schist Chester Micaceous schist; white quartzite present on uplands Edgemont Quartz schist
, quartzitic sandstone, quartzite conglomerate, pure quartzite Glenelg/Chester Micaceous schists Hagerstown/Duffield Limestone Highfield Metabasalt with considerable quartzite Linganore Hard slaty schist or phyllite Manor/Glenelg Thin, platty schistose rock Myersville/Fauquier Metabasalt Penn/Readington/Croton Red, Triassic-age sandstone and shale
These schistose rocks are mainly quartz schist and amphibole schist.
The Modal composition of the quartz schist and amphibole schist are shown in tables 1and 2.
Seven unaltered and fresh samples each of quartz schist and amphibole schist were analyzed for both major oxide and trace element concentrations at the Activation Laboratories, Canada, using the inductively coupled plasma analytical technique.
However, for the quartz schist they are within limits for metasedimentary rocks (Okonkwo and Winchester, 1992.
2] for the quartz schist are low (both less than 0.
4) (Garrels and McKenzie, 1971) shows the entire quartz schist samples plot in the sedimentary/metasedimentary field while the amphibole schists plot in the igneous /metaigneous field.
Tectonically, the quartz schist samples plots as passive margin rocks on a discriminant function diagram after Bhatia (1983).
1966; De Swardt, 1953; Dempster, 1967; Caby and Boesse, 2001) comprises quartzites, quartz schists
and granulites which occur largely east of Ilesha and run for nearly 180 km in a NNE-SSW direction.