Cs
Sykesville Formation (Early Cambrian) Diamictite
Ogh
Georgetown Intrusive Suite (Early Ordovician) Biotite-hornblende tonalite
Ogl
Granite (Ordovician (?))
Ok
Kensington Tonalite (Middle Ordovician)
Odm
Dalecarlia Intrusive Suite (Early and Middle Ordovician) Biotite monzogranite and lesser granodiorite
Csp
Sykesville Formation (Early Cambrian) Chlorite-sericite phyllonite
CZa
Metavolcanic and meta-igneous rocks of uncertain origin (Lower Cambrian and Neoproterozoic) Amphibolite
CZg
Metavolcanic and meta-igneous rocks of uncertain origin (Lower Cambrian and Neoproterozoic) Metagabbro and metapyroxenite
Ogg
Georgetown Intrusive Suite (Early Ordovician) Quartz gabbro
Ogus
Georgetown Intrusive Suite (Early Ordovician) Soapstone and talc schist
Ogr
Georgetown Intrusive Suite (Early Ordovician) Garnetiferous biotite-hornblende tonalite
Ogp
Pyroxenite
Csg
Sykesville Formation (Early Cambrian) Metagraywacke and schist
Pzq
Vein Quartz bodies (Paleozoic)
Ogb
Georgetown Intrusive Suite (Early Ordovician) Biotite tonalite
CZt
Metavolcanic and meta-igneous rocks of uncertain origin (Lower Cambrian & Neoproterozoic) Soapstone, talc schist, actinolite schist
Odt
Dalecarlia Intrusive Suite (Early and Middle Ordovician) Muscovite trondhjemite
CZu
Metavolcanic and meta-igneous rocks of uncertain origin (Lower Cambrian and Neoproterozoic) Ultramafic rocks
CZms
Mather Gorge Formation (Early Cambrian and(or) Neoproterozoic) Schist
DI
Lamprophyre dike (Late Devonian)
CZmg
Mather Gorge Formation (Early Cambrian and(or) Neoproterozoic) Metagraywacke
Ob
Bear Island Granodiorite (Early Ordovician (?))
CZmms
Mather Gorge Formation (Early Cambrian and(or) Neoproterozoic) Migmatitic Schist
CZmmg
Mather Gorge Formation (Early Cambrian and(or) Neoproterozoic) Migmatitic Metagraywacke
CZd
Diamictite (Lower Cambrian and(or) Neoproterozoic)
CZmmp
Mather Gorge Formation (Early Cambrian and(or) Neoproterozoic) Migmatitic Phyllonite
CZmss
Mather Gorge Formation (Early Cambrian and(or) Neoproterozoic) Sheared migmatitic schist and migmatitic phyllonite
Ogu
Georgetown Intrusive Suite (Early Ordovician) Ultramafic rocks
Oc
Clarendon Granite (Middle Ordovician)
Cst
Sykesville Formation (Early Cambrian) Diamictite Tectonite
Op
Pegmatite (Ordovician)
Cl
Laurel Formation (Lower Cambrian)