PALEOZOIC STRATIGRAPHIC COLUMN of Central Pennsylvania

PALEOZOIC STRATIGRAPHIC COLUMN of Central Pennsylvania _____________________________________________________________________*Ridge Makers System & Series Formation and Members General Description Llewellyn Formation Cycles of conglomerate or sandstone; underclay coal, shale Pnn. L & N 2000’+ Pottsville Formation* Cycles of conglomerate or sandstone; underclay coal, shale L & M 1400’ Mauch Chunk Grayish red and gray shale M 5000’ Miss. Pocono* Mount Carbon Gray to buff, medium grained, cross-bedded sandstone 1600’ 940’ Beckville Gray to buff, medium grained, cross-bedded sandstone Lower 225’ Spechty Kopf Gray, fine and medium grained sandstone conglomerate 435’ near middle and base Catskill Duncannon Asymmetric, upward-fining fluvial cycles, basal nonred, locally 7250’ 2000’ conglomeratic sandstone is overlain by grayish red sandstone and siltstones Sherman Creek Interbedded grayish red claystone and fine grained, cross- 2400’ bedded sandstone Upper Irish Valley Interbedded, grayish red and olive gray sandstone, siltstone, 2850’ shale, overlain upward-fining cyclic deposits of gray sandstone and red siltstone Trimmers Rock Medium gray siltstone and shale, with fine grained sandstone in 2000’ upper part; graded bedding common Harrell Olive and medium light gray shale 200’ Mahantango Sherman Ridge* Olive gray, fossiliferous, claystone with interbedded fine 1600’ 600’ sandstones which coarsen upward Montebello Olive gray, medium grained, locally conglomeratic, fossiliferous 600’ sandstone, interbedded with siltstone and claystone in upward- Dev. coarsening cycles Fisher Ridge* Laminated gray silty shale Middle 700’ Dalmatia Light olive gray sandstone 300’ Turkey Ridge Light gray, fine to medium grained sandstone 100’ Marcellus Highly fissile, dark gray to black shale; weathers yellowish 106’ orange Onondaga Selinsgrove Medium to dark gray, fossiliferous argillaceous fine grained 165’ 80’ limestone Needmore Medium gray, fissile shale 85’ Lower Old Port* Dark gray, whitish weathering chert, underlain by shale limestone 100’ beds, and locally overlain medium to coarse grained sandstone Keyser Medium gray, fossiliferous, lumpy, fine to coarse grained 200’ limestone Upper Tonoloway Medium gray, laminated thin-bedded, fine grained limestone 600’ Wills Creek Gray calcareous shale with interbedded light gray, calcareous, fine Sil. 700’ grained sandstone, limestone and red silty claystone Bloomsburg* Red claystone shale with fine grained, argillaceous, hematitic Middle 500’ sandstone at base and near top Mifflintown Dark gray, silty, calcareous shale; bioclastic, f. grain, thin bedded, 160’ limestone Middle Keefer* Gray, fine to coarse grained, fossiliferous, sandstone which is 40’ locally hematitic Sil. Rose Hill Light olive gray, shale, calcareous in upper part; grayish red, fine 950’ to coarse grained, hematitic sandstone near top Tuscarora* Light gray, fine to medium grained quartz sandstone L 600’ Juniata Grayish red, fine to medium grained, cross-bedded, graywacke 750’ sandstone; grayish red siltstone Upper Bald Eagle* Gray, cross bedded, medium to coarse grained sandstone, quartz 730’ pebble conglomerate Reedsville Olive gray silty shale, with increasing interbeds of graded gray 900’ sandstone in upper part Antes Gap Shale Very dark gray fissile, carbonaceous shale graptolite trilobite 200’ fauna Coburn Limestone Well-bedded, dark gray, fine to medium grained fossiliferous 275’ limestone with very dark shale interbeds Salona Limestone Dark gray fine grained limestone, less fossiliferous than Coburn 175’ and containing five or more metabentonite Middle Nealmont Limestone Medium gray, coarse grained highly fossiliferous (crinoids, 70’ bryozoans) limestone “Quarry Limestone” including: Linden Hall Medium gray, thick bedded, fine grained pure limestone 150’ Ord. Snyder Light gray, mudcracked, fine to coarse grained, thin bedded 70’ commonly fossiliferous and dolomitic limestone Loysburg Medium gray, fine grained, 1 footbedded “striped” limestone 400’ and dolomite Bellefonte Dolomite Yellowish gray, fine grained microcrystalline dolomite 1200’ Axeman Limestone Gray, slightly fossiliferous, fine grained, limestone with layers Lower 400’ of dolomite Nittany Dolomite Dark gray, cherty, coarsely crystallite dolomite 1200’ Stonehenge Limestone Gray, well bedded limestone 600’ Mines Dolomite Thick bedded, cherty, oolitic dolomite 250’ Upper Gatesburg Sandstone & Dolomite* Dolomitic sandstone or sandy dolomite Dolomite 1600’___ Warrior Limestone Thin bedded, gray limestone Cam. 1200’ M Pleasant Hill Limestone BLUE RIDGE-GREAT VALLEY SEQUENCE 250’ Elbrook Limestone Waynesboro Formation Waynesboro Formation L Tomstown Dolomite Antietam Quartzite* Eo- Harpers Formation (Montalto Quartzite Member) Cam. Weverton Quartzite* London Conglomerate U Catocton Volcanics Pre- Swift Run Formation Cam. L Gneissic Basement .

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