Jonestown Volcanic Suite

Andesite extrusives and dark-greenish-gray metadiabase. Metadiabase weathers medium gray to brown, forming rounded cobbles and boulders.
State Pennsylvania
Name Jonestown Volcanic Suite
Geologic age Ordovician
Lithologic constituents
Major
Igneous > Volcanic > Mafic-volcanic > Andesiteandesite extrusives
Metamorphic > Metaigneous > Metaintrusive > Metadiabasedark-greenish-gray metadiabase. Metadiabase weathers medium gray to brown, forming rounded cobbles and boulders.
Comments Digital map differences from 1980 printed map: name and map symbols changed from Ohe (Andesite extrusives) and Od (Metadiabase) of Hamburg sequence.
References

Berg, T.M., Edmunds, W.E., Geyer, A.R., and others, compilers, 1980, Geologic map of Pennsylvania: Pennsylvania Geological Survey, 4th ser., Map 1, 2nd ed., 3 sheets, scale 1:250,000.

Pennsylvania Bureau of Topographic and Geologic Survey, Department of Conservation and Natural Resources, Miles, C.E., and Whitfield, T.G., compilers, 2001, Bedrock Geology of Pennsylvania, edition: 1.0, digital map, scale 1:250,000.

NGMDB product
Counties Lebanon