Pennsylvanian

How To Use Pennsylvanian In A Sentence

• This occurred prior to a major pre-Pennsylvanian erosional interval that removed Silurian sedimentary strata from the region.
• Nodules of Pennsylvanian age are marine, having likely formed in the quiet, brackish, oxygenated waters of lagoons.
• The oldest known amniotes - close to the ancestry of all reptiles, birds, and mammals - appeared in the early Pennsylvanian, about 310 million years ago.
• ‘Take it slow, guys,’ a sergeant of the Pennsylvanians called out as the troops approached the fortifications and breastworks.
• Nodules and crystal groups of iron sulfide of Middle Devonian to Pennsylvanian age are frequently present in beds of black shale and coal or, less commonly, dolostone.
• The term flint is used here to describe high-purity microcrystalline quartz with a conchoidal fracture that is prominent in beds of Pennsylvanian age in the Appalachian region.
• Thick, resistant Pennsylvanian quartzose sandstone caps the ridges and Mississippian limestone, shale, and siltstone are exposed on lower slopes and in valleys. Ecoregions of Kentucky (EPA)
• A Lower Pennsylvanian silicified ostracode fauna occurs just above the conformable Mississippian-Pennsylvanian boundary within the Barnett Formation in Texas.
• In this initiative he reversed the whole purpose of Sweden's great mission to its people stranded along the Delaware littoral, which had been to preserve their national character in the midst of Pennsylvanian chaos.
• In the middle Devonian the first collembolans made their appearance, and by the Pennsylvanian, or late Carboniferous, winged insects were present, including the first mayflies and cockroaches.