Read on Twitter
two days ago I shared a photo of an outcrop ( https://twitter.com/clasticdetritus/status/1264301063676493826) and then I posted a slightly zoomed-out photo of the same exposure ( https://twitter.com/clasticdetritus/status/1264522377402241024) — I posted w/out any context and people replied w/ observations/interpretations — so, now, here's some context!
this is from an outcrop along the Virginia-Kentucky border known as Pound Gap — for those that want it, here are the lat/long coordinates: -82.6470, 37.1570
Pound Gap is an absolute jewel of an outcrop in this region — it's a huge roadcut that intersects the Pine Mountain Thrust Fault, which brings Devonian through Pennsylvanian (upper Carboniferous) sedimentary rocks up to the surface
here's a GoogleEarth view of Pound Gap (looking to the SE)
here's zoomed-in GoogleEarth view, the yellow arrow showing the direction of younging of the strata
oops, forgot to put this map at the beginning of this thread — note how the Pine Mountain Thrust forms this conspicuous ridge amongst the topographically dissected flat-lying strata
those photos are from the lower part of this epic road cut, in what's known as the Grainger Formation (doesn't matter what it's called, don't get bogged down in nomenclature) — it's Mississippian (lower Carboniferous) in age, here's a strat column summary w/ this unit in context
what's cool about this outcrop is the contact with the unit overlying this interbedded siltstone/sandstone — above is the Newman Limestone and it's mapped as an unconformity/disconformity
