| OBJECTID | MapUnit | Name | FullName | Age | Description | HierarchyKey | ParagraphStyle | Label | Symbol | AreaFillRGB | AreaFillPatternDescription | DescriptionSourceID | GeoMaterial | GeoMaterialConfidence | DescriptionOfMapUnits_ID |
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| 1 | Qal | Alluvium | Alluvium | Quaternary | Pebbles, cobbles and boulders in a sandy matrix. Clasts weather yellowish orange and orange-brown. These deposits are present along both modern and ancient streams and may have a thick humic component near the top. Finer alluvium such as sand, silt and gravel underlies the stream channel where it is lower gradient, while steeper stream reaches are frequently floored by bedrock or locally derived cobbles and boulders. The thickness of alluvium varies from a thin veneer to more than 30 feet. These thicker accumulations tend to be concentrated where colluvium at the edge of valleys overlaps the alluvium. | 01-01 | DMU Unit 1 | Qal | 40 | 255,255,179 | None | MGS_OAKLA2025.1 | Alluvial sediment | High | DMU001 |
| 2 | Qps | Peatland and swamp deposits | Peatland and swamp deposits | Quaternary | Unconsolidated, light to dark gray, organic-rich, sandy clay to fibrous peat. These materials accumulated in boggy, low-lying, poorly drained areas, and many are remnants of late Pleistocene glades or lakes. These histic sediments are water-logged during part or most of the year and are poor agricultural lands. Thickness ranges from less than three feet to nearly 10 feet. | 01-02 | DMU Unit 1 | Qps | 120 | 235,255,222 | None | MGS_OAKLA2025.1 | Peat and muck | High | DMU002 |
| 3 | Qcl | Colluvium/Landslide | Colluvium/Landslide | Quaternary | Unconsolidated and unsorted boulders and cobbles present on steep slopes, or at the base of steep slopes, below outcrops of sandstone units. These deposits are largely the result of frost wedging or mass movement (i.e., landslide). Topographically, these accumulations exhibit an irregular upper surface, thin upslope and rarely have soil cover. Thickness ranges from several feet on steep slopes to more than 50 feet. | 01-03 | DMU Unit 1 | Qcl | 62 | 255,222,128 | None | MGS_OAKLA2025.1 | Colluvium and other widespread mass-movement sediment | High | DMU003 |
| 4 | None | Conemaugh Group | Conemaugh Group | None | Interbedded sandstone, shale, siltstone and nonmarine limestone. The aggregate thickness of the Conemaugh Group is as much as 800 feet in the Oakland quadrangle (Swartz, 1922). The Conemaugh Group is divided into the Glenshaw and Casselman Formations as named by Flint (1965). | 02 | DMU-Heading1 | None | None | None | None | MGS_OAKLA2025.1|MGS_v11_35|PAGS_CR_SO1965 | None | None | DMU004 |
| 5 | Pcc | Casselman Formation | Conemaugh Group, Casselman Formation | Pennsylvanian | Interbedded, tan, medium- to coarse-grained, locally conglomeratic, cross-bedded sandstone, gray to reddish gray mudstone, medium gray, silty shale, siltstone and light-gray to grayish brown, buff-weathering, non-marine limestone. The base of the Casselman Formation is considered the top of the Ames marine horizon. Less than 100 feet of the Casselman Formation are preserved in the Oakland Quadrangle. | 02-01 | DMU Unit 1 | *cc | 312 | 204,222,235 | None | MGS_OAKLA2025.1 | Sandstone and mudstone | High | DMU005 |
| 6 | Pcg | Glenshaw Formation | Conemaugh Group, Glenshaw Formation | Pennsylvanian | Gray, tan-weathering, micaceous, medium- to coarse-grained, cross-bedded sandstone containing abundant coaly plant fragments; interbedded with gray, reddish gray, and locally reddish brown, silty shale, siltstone, light gray, bioturbated, non-marine limestone, and brittle, dark gray, fossiliferous, marine shale. The base of the Glenshaw Formation is placed at the top of the Upper Freeport coal bed. Coal beds locally mined from the Glenshaw Formation include the Brush Creek (bc) and Lower Bakerstown (lb). The Glenshaw Formation is approximately 350 feet thick. | 02-02 | DMU Unit 1 | *cg | 421 | 179,235,222 | None | MGS_OAKLA2025.1 | Sandstone and mudstone | High | DMU006 |
| 7 | Pa | Allegheny Formation | Allegheny Formation | Pennsylvanian | Interbedded, medium to dark gray shale and siltstone, and tan to light gray, coarse-grained, cross-bedded sandstone, with thin, light-gray claystones. The top of the formation is at the top of the Upper Freeport (uf) coal bed, and the base of the formation is the top of the white, massive, conglomeratic Homewood Member of the underlying Pottsville Formation. The Lower (lk) and Upper Kittanning (uk) coal beds are locally mined and mapped in the quadrangle based on previous coal bed investigations (Baker-Wibberly and Associates, Inc., 1977). The Allegheny Formation is approximately 250 to 300 feet thick. | 03 | DMU Unit 1 | *a | 521 | 153,235,222 | None | MGS_OAKLA2025.1|BWA_1977 | Mostly sandstone | High | DMU007 |
| 8 | Pp | Pottsville Formation | Pottsville Formation | Pennsylvanian | Dominantly tan to light grayish brown, medium- to coarse-grained, cross-bedded sandstone and conglomeratic sandstone with abundant coaly plant fragments and thin intervals of dark gray, coaly shale, siltstone, or coal beds. The massive, pebbly to granular, light gray, highly cross-bedded Homewood Member constitutes a resistant, mappable sandstone layer at the top of the formation whose top demarcates the top of the formation. Total thickness for the unit is 200 to 250 feet. | 04 | DMU Unit 1 | *p | 733 | 102,204,204 | None | MGS_OAKLA2025.1 | Mostly sandstone | High | DMU008 |
| 9 | Mmc | Mauch Chunk Formation | Mauch Chunk Formation | Mississippian | Interbedded, reddish brown shale, variegated mudstone and siltstone, and reddish brown to greenish gray, medium-grained, micaceous sandstone. Sandstone intervals are lenticular, cross-bedded, exhibit sharp bases, and fine upsection. Several thin, greenish gray, marine calcareous shale to argillaceous limestone units are present near the base of the formation. The Mauch Chunk Formation is approximated at 400 feet in thickness in the Oakland Quadrangle. | 05 | DMU Unit 1 | Mmc | 603 | 128,204,255 | None | MGS_OAKLA2025.1 | Sandstone and mudstone | High | DMU009 |
| 10 | Mg | Greenbrier Formation | Greenbrier Formation | Mississippian | Interbedded, gray to reddish brown sandstone, fossiliferous and variegated shale, and fossiliferous limestone. The light gray, cross-bedded, sandy limestone (Loyalhanna Member) is at the base and is overlain by interbedded, reddish, fossiliferous mudstone, white to tan and reddish brown, fine-grained sandstone, and reddish brown siltstone and variegated shale (Savage Dam Member). The Savage Dam Member is overlain by thin- to medium-bedded, light to medium gray, argillaceous, fossiliferous limestone at the top of the formation (Wymps Gap Member). The Greenbrier Formation is 150 to 200 feet thick. | 06 | DMU Unit 1 | Mg | 501 | 153,235,255 | None | MGS_OAKLA2025.1 | Limestone | High | DMU010 |
| 11 | Mp | Purslane Formation | Purslane Formation | Mississippian | Tan to light gray, coarse-grained sandstone to conglomerate. Thick-bedded, pebbly conglomerate occurs near the base and at the top of the formation. Thin beds of gray shale and coaly shale are locally interbedded with the sandstone intervals. The Purslane Formation is 250 to 300 feet thick in southern Garrett County. | 07 | DMU Unit 1 | Mp | 301 | 204,235,255 | None | MGS_OAKLA2025.1 | Mostly sandstone | High | DMU011 |
| 12 | MDr | Rockwell Formation | Rockwell Formation | Devonian-Mississippian | Interbedded, greenish gray, tan-weathering, argillaceous, bioturbated sandstone, and reddish gray to gray, coaly siltstone and shale. The greenish gray bioturbated sandstones at the base of the formation (Oswayo Member) are locally interbedded with the reddish strata of the upper Hampshire Formation. These basal marine strata are overlain by light gray to tan, thin- to medium- bedded, cross-bedded, lenticular sandstone, and rooted, gray mudstone. The top of the formation consists of well-sorted, burrowed, locally fossiliferous, buff sandstone of the Riddlesburg Member. The Rockwell Formation is between 100 and 200 feet thick in the Oakland Quadrangle. | 08 | DMU Unit 1 | MDr | 614 | 128,179,235 | None | MGS_OAKLA2025.1 | Sandstone and mudstone | High | DMU012 |
| 13 | Dh | Hampshire Formation | Hampshire Formation | Devonian | Interbedded, reddish brown to reddish gray, and brownish red, locally greenish gray, cross-bedded, upward-fining, lenticular sandstone; reddish brown micaceous siltstone, shale, and red-brown rooted claystone. The Hampshire Formation is approximately 1,500 feet thick in the Oakland Quadrangle. | 09 | DMU Unit 1 | Dh | 414 | 179,179,235 | None | MGS_OAKLA2025.1 | Sandstone and mudstone | High | DMU013 |
| 14 | Df | Foreknobs Formation | Foreknobs Formation | Devonian | Interbedded, olive gray, tan-weathering, medium- to coarse-grained, cross-bedded, bioturbated sandstone; greenish gray to dusky red, fossiliferous shale and siltstone. Top of the formation is mapped at the top of the medium- to thick-bedded, cross-bedded, light gray to white (>30 feet) sandstone considered equivalent to the Pound Sandstone Member of the Valley and Ridge Province (Dennison, 1970). The middle part of the formation is characterized by intervals of thinly interbedded greenish gray, silty shale and bioturbated sandstone. The lower contact of the formation is mapped approximately 1,600 feet below the top of the formation (Flint, 1965) at the base of a conglomeratic interval correlated with the Park Head Sandstone of eastern Allegany County (Stose and Swartz, 1912; Brezinski, 2019). The Foreknobs Formation is 1,600 feet thick in Garrett County. | 10 | DMU Unit 1 | Df | 303 | 204,204,255 | None | MGS_OAKLA2025.1|PAGS_CR_SO1965|USGS_GEOATL_1912_179|MGS_DEER_PARK2019.OF.2|SEGEO_12.1.54 | Sandstone and mudstone | High | DMU014 |
| 15 | Dfp | Foreknobs Formation, Parkhead Sandstone | Foreknobs Formation, Parkhead Sandstone | Devonian | Interbedded greenish gray, silty shale and thick-bedded, light gray, coarse-grained sandstone and quartz-pebble conglomerates. At least two separate conglomerate layers are identified and where possible, mapped. Thickness of the member is 50 to 75 feet. | 10-01 | DMU Unit 2 | Dfp | 533 | 153,204,204 | None | MGS_OAKLA2025.1 | Sandstone and mudstone | High | DMU015 |
| 16 | Ds | Scherr Formation | Scherr Formation | Devonian | Interbedded gray to greenish gray, fissile shale, gray, planar-bedded siltstones, and light gray, tan-weathering, thin-bedded, fine-grained, bioturbated sandstone. The Sherr Formation of the Deer Park Anticline is considered correlative with the Brallier Formation of the Valley and Ridge Physiographic Province (Dennison, 1970). Thickness of the exposed part of this formation in the Oakland Quadrangle may be up to 1,000 feet. | 11 | DMU Unit 1 | Ds | 604 | 128,179,255 | None | MGS_OAKLA2025.1|SEGEO_12.1.54 | Mostly mudstone | High | DMU016 |