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.

Petersburg granite virginia geology. The granite contains xenoliths of biotite gneiss and amphibolite. 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. Multiple intrusive phases are present. Light to dark gray to pink fine to coarse grained equigranular to porphyritic foliated to nonfoliated ranges from granite to granodiorite in composition.

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. The granite contains xenoliths of biotite gneiss and amphibolite. From the earliest investigations of the batholith it was recognized that multiple intrusive phases are present. 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.

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. 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. The batholith is primarily composed of granite including massive and foliated both magmatic and solid state fabrics varieties. Jonas 1927 1929 formally named the peterbsurg granite.

Multiple intrusive phases are present. 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. 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. Ct chopawamsic terrane gt goochland terrane rt raleigh terrane rrt roanoke rapids terrane.

Multiple intrusive phases are present. Multiple intrusive phases are present. 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. Generalized geologic map of the petersburg batholith in east central virginia.

Step back and look at virginia from space and we see a certain degree of complexity.