fe: garnet-biotite-quartz-plagioclase gneiss, and amphibolite; fd: sillimanite-garnet schistose gneiss, quartzite; fc: biotite-hornblende-quartz-plagioclase gneiss, quartz-feldspar lenses, amphibolite, biotite and/or hornblende-quartz-feldspar gneiss; fb: amphibolite, biotite and/or hornblende-garnet-quartz-plagioclase gneiss; fa: garnet-biotite-quartz-plagioclase gneiss, amphibolite, biotite-hornblende-quartz-plagioclase gneiss, quartz-feldspar granulite.
Pelitic schists, amphibolite; Units ?Omb, ?Omc, and ?Omd may be Cambrian eugeosynclinal rocks thrust upon Oma; ?Omd - sillimanite-garnet-muscovite-biotite-plagioclase-quartz gneiss; ?Omc - sillimanite-garnet-muscovite-biotite-quartz-plagioclase schistose gneiss, sillimanite nodules, local quartz-rich layers; ?Omb - discontinous unit of amphibolite and ?Omc-type schist.
fc: biotite-hornblende-quartz-plagioclase gneiss, quartz-feldspar lenses, amphibolite, biotite and/or hornblende-quartz-feldspar gneiss; fd: sillimanite-garnet schistose gneiss, quartzite.
Dolomite marble, calc-schist, granulite, and quartzite, overlain by calcite marble; grades into underlying patchy Lowerre Quartzite of Early Cambrian age.
Basal amphibolite overlain by pelitic schists.
With subordinate biotite granitic gneiss, amphibolite, calcsilicate rock.
Biotite-quartz-plagioclase gneiss and interlayered amphibolite; in part with augen of andesine and microcline.
Overprint signifies inequigranular texture.
Harrison Gneiss - in New York and Connecticut, Brookfield diorite gneiss in Connecticut, and Ravenswood Gneiss in Brooklyn - biotite-hornblende-quartz-plagioclase gneiss with accessory garnet and sphene; plagioclase commonly occurs as augen.
Biotite and/or hornblende-quartz-feldspar gneiss.
Hornblende is poikilitic.
fb: amphibolite, biotite and/or hornblende-garnet- quartz-plagioclase gneiss.
Biotite augite norite
Pyroxenite
fe: garnet-biotite-quartz-plagioclase gneiss, and amphibolite.
In part with poikilitic hornblende; local peridotite.
Muscovite-biotite granodiorite - of Peekskill Pluton.
Sillimanite-garnet-muscovite-biotite-quartz- plagioclase schists; calcite marble and calcsilicate rock at base.
Biotite and/or hornblende-quartz-feldspar gneiss, similar to Yonkers Gneiss and parts of Fordham C member.
Diorite with hornblende and/or biotite.
fa: garnet-biotite-quartz-plagioclase gneiss, amphibolite, biotite-hornblende-quartz-plagioclase gneiss, quartz-feldspar granulite.
Contains varying amounts of biotite, garnet, sillimanite; minor marble, amphibolite, rusty paragneiss.
Pyroxenic amphibolite, hornblende gneiss, commonly biotitic, garnetiferous; subordinate calcsilicate rock.
Muscovite-biotite granite - of Peekskill Pluton.
(includes local Dalton Formation at base)-locally conglomeratic.
Underlying bedrock geology unknown.
Rock complex with minor pyroxenite; Croton Falls and Peach Lake complexes in New York, and Mt. Prospect Complex in Connecticut.
Rusty facies contains variable amounts of garnet, sillimanite, cordierite, graphite, sulfides; minor marble and calcsilicate rock.
Serpentinite.
Balmville Limestone
Variably siliceous; in part with calcsilicate rock and amphibolite.
With subordinate leucogranite.
Quartzite, quartz-feldspar gneiss, calcsilicate rock.
(KÂmmel, 1897) - Light-gray, light-grayishbrown, yellowish- to pinkish-gray, or violet-gray to reddish-brown, medium- to coarse-grained arkosic sandstone and reddish- to purplish-brown mudstone, silty mudstone, argillaceous siltstone, and shale. Mudstone, siltstone and shale beds thicker and more numerous in central Newark basin west of Round Valley Reservoir. Sandstones mostly planar-bedded, with scoured bases containing pebble lags and mudstone rip-ups. Unit is coarser near Newark basin border fault, where poorly exposed, reddish-brown to pinkish-white, medium- to coarse-grained, feldspathic pebbly sandstone and conglomerate (Trss) and pebble to cobble quartzite conglomerate (Trscq). Maximum thickness of formation about 1,240 m (4,070 ft).