| Baltimore Gabbro | |
|---|---|
| Stratigraphic range: Late Precambrian | |
| Type | Igneous |
| Location | |
| Region | Piedmont of Maryland |
| Extent | Howard and Baltimore Counties |
| Type section | |
| Named for | Baltimore, Maryland |
| Named by | G. H. Williams 1866 |
Baltimore Gabbro Complex is a hypersthene gabbro with subordinate amounts of olivine gabbro, norite, anorthositic gabbro, and pyroxenite. Igneous minerals and textures are well preserved in some rocks, and other rocks exhibit varying degrees of alteration and recrystallization with a new metamorphic mineral assemblage.[1]