Petersburg Granite Virginia Geology
Multiple intrusive phases are present.
Petersburg granite virginia geology. Geology is fractal that is the detail and complexity of what we observe remains the same regardless of the scale of observation. Geologic units in chesterfield county virginia petersburg granite mississippian at surface covers 29 of this area light to dark gray to pink fine to coarse grained equigranular to porphyritic foliated to nonfoliated ranges from granite to granodiorite in composition. Multiple intrusive phases are present. Jonas 1927 1929 formally named the peterbsurg granite.
On the 1928 geologic map of virginia stose 1928 the petersburg granite was designated as precambrian but jonas 1932 later interpreted it to be late paleozoic. Petersburg granite mississippian at surface covers 3 of this area light to dark gray to pink fine to coarse grained equigranular to porphyritic foliated to nonfoliated ranges from granite to granodiorite in composition. Multiple intrusive phases are present. The granite contains xenoliths of biotite gneiss and amphibolite.
The 295 300 ma petersburg batholith in east central virginia forms one of the largest and northernmost of the alleghanian plutonic complexes in the southern appalachian piedmont. Generalized geologic map of the petersburg batholith in east central virginia. Multiple intrusive phases are present. Geologic unit mapped in virginia.
Petersburg granite mississippian at surface covers 24 of this area light to dark gray to pink fine to coarse grained equigranular to porphyritic foliated to nonfoliated ranges from granite to granodiorite in composition. Petersburg granite mississippian at surface covers 20 of this area light to dark gray to pink fine to coarse grained equigranular to porphyritic foliated to nonfoliated ranges from granite to granodiorite in composition. The central part of chesterfield county is underlain by the petersburg granite a large granitic pluton of mississippian age age dated to about 330 million years old. The batholith is primarily composed of granite including massive and foliated both magmatic and solid state fabrics varieties.
Multiple intrusive phases are present. Ct chopawamsic terrane gt goochland terrane rt raleigh terrane rrt roanoke rapids terrane. The petersburg granite forms the bedrock over a large area in east central virginia and one of the best places to see it is along the james river in richmond. Step back and look at virginia from space and we see a certain degree of complexity.
The granite contains xenoliths of biotite gneiss and amphibolite.