Map Unit Properties Table Map Unit Erosion Suitability for Paleontologic Cultural Mineral Mineral Global Age Unit Description Hazards Karst Issues Habitat Recreation (Symbol) Resistance Development Resources Resources Specimens Resources Significance Wells in these units Unit Qcm report sufficient Unconsolidated gravel, sand, silt, and clay in represents the water for domestic floodplain deposits and along streams and low Unit is highly Habitat for cliff- Good for most paleolake levels of needs (high Fe and terraces, some cobbles present. Unit Qcm susceptible to slides, May contain Gravel, sand, dwelling birds use unless Ancient Lake Mn, low pH); acid Perched terraces record Alluvium (Qal); contains lacustrine deposits of unconsolidated rockfall, slumping, Native silt, clay, and burrowing undercut along a Monongahela and mine drainage may be paleolake levels and may None Carmichaels Formation clay, silt, sand, gravel, cobbles, and boulders of Low and mass movement American None cobbles, some animals on slope or records the glacial a concern for contain remains from documented. (Qcm. sandstone (silica- cemented quartzarenite), some if exposed on bare artifacts and sandstone terraces, adjacent to a setting during the development of wells. Pleistocene Ice Ages. small limonite nodules. Deposits in abandoned and/or undercut campsites. boulders. riparian habitat waterway; avoid Pleistocene; Avoid for waste QUATERNARY channels and on rock terraces in the eastern half slopes. along rivers. bare slopes. boulders in unit facility development of Fayette County. Qcm are from due to high Pottsville Group. permeability. Sold as May have been kimberlite; may Unit is the only Present on surface in Fayette County as the only Rockfall potential if source of stone Present only contain olivine, Jurassic Gates- Adah dike (Jk.) igneous rock found there, swarm of three or High Present only locally. unit is exposed on None prized for None Kimberlite None locally; good for pyroxene, (Mesozoic) rock more mica- peridotite dikes. slope. Native most uses. amphibole, and in the area. JURASSIC American trade. mica. Unit Pg consists of shale, sandstone, siltstone, thin limestone beds, claystone, carbonaceous Unit is suitable for Slides and slumps are shale, and impure coal interbeds (Ten Mile coal most development a hazard for claystone is less than 24 in. thick). Most units are Ten Mile coal is Low to medium unless exposed on and shale- rich Represent micaceous with variable thickness and Not enough impure and Good for most in shale- rich undercut or members; Siderite Units support Permian Period Greene Formation (Pg); crossbeds. Unit Pw contains an upper olive to Nodules may massive lenticular; uses unless beds, medium to unvegetated slope; heterogeneous Freshwater ostracodes, (ironstone) and forests in middle with dateable coal Washington Formation dark- gray limestone member; a middle shale, have provided carbonate Jollytown coal highly fractured high in massive poor aquifer with layering may prove Spirorbis, and fish remains. limestone to upper parts of horizons and (Pw) siltstone, and micaceous, olive- gray sandstone tool material. units present and Washington and exposed on sandstone- hard to very hard unstable on slopes; nodules. stream basins. fresh- water PERMIAN member; and a lower argillaceous limestone for karst. coals are bare slopes. limestone beds. water (high barium, rockfall hazard exists fossils. member that is 0.5−2 ft thick and contains shale impure. Fe, and Mn, when resistant beds interbeds. Jollytown coal beds are less than 24 in. moderate pH). are undercut. thick, and the Washington coal is impure and shaly and is close to 48 in. thick Mined areas pose Unit is between 85 and 210 ft thick. Upper Suitable for most Thin and impure safety hazards and member is predominantly gray to black shale development except Little acid- mine- drainage containing some calcareous layers and gray near unremediated Washington problems. Slides and Good for most Records sandstone interbeds, and a basal layer of impure mined areas. Several coal, thin and slumps are a hazard Not enough Units support uses unless near depositional Little Washington coal. Middle member consists wells record elevated Previously believed to be locally impure for shale- rich Nodules may massive forests and mine- altered environments Waynesburg Formation of medium- gray shale, sandstone, and light- gray Fe, Mn, chloride, and wholly Permian, but Waynesburg B Medium members; have provided Siderite nodules. carbonate riparian habitat areas, or highly during (PPNw). siltstone with the shaly, impure Waynesburg B hydrogen sulfide Pennsylvanian fossils were and A coals; heterogeneous tool material. units present in lower parts of fractured and Pennsylvanian to and A coals as much as 84 in. thick locally. Lower (10% of wells showed recently found in this unit. viable PERMIAN - layering may prove for karst. stream basins. exposed on bare Permian member comprises shale, light- gray, massive, high Ca, Mg, Pb, Al); Waynesburg unstable on slopes; slopes. transition. PENNSYLVANIAN crossbedded sandstone, and siltstone. The viable where mines are coal mined in rockfall hazard exists Waynesburg coal is at the base of the formation present, low pH and eastern map when resistant beds and is as much as 84 in. thick. high dissolved solids. areas. are undercut. Unit PNm consists of black to light- gray, Suitable for most Records massive limestone and some argillaceous development except Thin and impure depositional Rockfall hazard exists limestone containing thin- bedded to massive, near areas of Little environments in when resistant beds Some gray sandstone, carbonaceous shale, and coal extensive mining, Artifacts Waynesburg Good for most the long- standing (such as massive dissolution Unit supports interbeds. Unit is dominated by repetitive Medium to high, where subsidence is relevant to the coal, Uniontown uses unless Appalachian Monongahela Group limestone and None possible in forests on bluffs sequences (cyclothems) of shale, mudstone, lower in shale- possible. Ground- Pennsylvanian fossils. land- use history bony coal beds; highly fractured Basin. Source (PNm). sandstone) are documented. massive and low- level claystone, sandstone, coal, and limestone. rich beds. water is hard to very at the Gallatin massive and exposed on areas include the undercut by erosion limestone terraces. Continental (fresh- water) cyclothems are hard with dissolved House . limestone may bare slopes. equatorial of shale and friable units. present in this unit. Group contains the solids, Fe, Mn, Ca, provide building Allegheny PENNSYLVANIAN claystone. Uniontown and Pittsburgh formations, which Mn; chloride material. Mountains in an have well- documented coal horizons. commonly high. arid climate. FONE Geologic Resources Inventory Report 23 Map Unit Erosion Suitability for Paleontologic Cultural Mineral Mineral Global Age Unit Description Hazards Karst Issues Habitat Recreation (Symbol) Resistance Development Resources Resources Specimens Resources Significance Upper formations contain sequence of thin- bedded, green and red calcareous claystone; gray siltstone; massive, gray sandstone; and impure limestone. Scant coal beds are present locally. Four prominent clay, shale, or limestone marine Cyclothems in Marine fossils, plant fossils. horizons in Glenshaw (including Ames units represent Units yield very hard Unit PNcg contains vertical Native Limestone) with some coarse- grained sandstone Coal (Freeport, Good for most arid conditions Casselman Formation water with excessive Ledge- forming burrows, biogenic mounds, American sites, Dissolution and minor fresh- water limestone. Lower Low to medium Some Kittanning, and recreation with a river (PNcc); Glenshaw iron, manganese, and sandstone may be crinoids, trilobites, and artifacts Nodular features may formations include sequences of olive to dark- in upper beds, dissolution in Brookville- unless soft shale floodplain and Formation (PNcg); sulfate. undercut in softer foraminifera, fusulinids, relevant to the limestone, provide burrow gray claystone, thin to massive sandstone, medium in limestone Clarion), high- units are wetlands of a Allegheny Group (PNa); Heterogeneity of shale units, posing bryozoans, brachiopods, land- use history siderite. and nesting nodules of limestone, gray siltstone, and coal lower beds. interbeds. alumina clay exposed along foreland basin at Pottsville Group (PNp). layers may lead to rockfall hazard. fish fragments. Unit PNcc at the Gallatin habitat. beds. Unit is dominated by repetitive sequences deposits. slopes. equatorial instability on slopes. contains bivalves, House . PENNSYLVANIAN (cyclothems) of shale, mudstone, claystone, latitudes. Classic myriapods. sandstone, coal, and limestone. Fresh- water coal deposits. cyclothems are present in unit PNa. Lowermost unit is gray, crossbedded sandstone and quartz- pebble conglomerate containing some thin beds of carbonaceous black shale, siltstone, claystone, and thin, nonpersistent coal. Upper beds consist of grayish- red shale, siltstone, sandstone and several limestone Plant fossils. Unit Mmc members (Wymps Gap, Deer Valley, and highly Iron- rich ground contains fish fragments, Good for most crossbedded, gray, siliceous Loyalhanna), water from these Rockfall is possible if worm burrows, corals, Mauch Chunk Some recreation containing some conglomerate. Middle beds Medium, units. Suitable for units are undercut on conularids, bryozoans, Formation (Mmc); None None dissolution in None unless soft