Syenite Gneiss

Light-pinkish-white- to buff-white-weathering, greenish-gray, medium-grained, moderately foliated rock consisting of two distinct phases: hornblende syenite gneiss containing microcline microperthite, oligoclase, hornblende, and opaque minerals; and pyroxene syenite gneiss containing microcline microperthite, oligoclase, clinopyroxene, accessory amounts of titanite, and opaque minerals. Despite the co-mingling of these two phases, they appear to belong respectively to the Byram and Lake Hopatcong Intrusive Suites. In Hamburg Mountain area.
State New Jersey
Name Syenite Gneiss
Geologic age Middle Proterozoic
Lithologic constituents
Major
Metamorphic > GneissLight-pinkish-white- to buff-white-weathering, greenish-gray, medium-grained, moderately foliated rock consisting of two distinct phases: hornblende syenite gneiss containing microcline microperthite, oligoclase, hornblende, and opaque minerals; and pyroxene syenite gneiss containing microcline microperthite, oligoclase, clinopyroxene, accessory amounts of titanite, and opaque minerals.
Comments Lake Hopatcong Intrusive Suite (Middle Proterozoic) (Drake and Volkert, 1991)
References
NGMDB product
Counties Sussex