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VIRGINIA PHYSIOGRAPHY. MATHEMATICS & SCIENCE CENTER. Go to website http://arcims.mathsciencecenter.info Then click on Virginia Physiography. 1998 Geology Summer Field School – Radford University. Courtesy of Virginia Division of Mineral Resources. Courtesy of USGS. THE COASTAL PLAIN.
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VIRGINIA PHYSIOGRAPHY MATHEMATICS & SCIENCE CENTER
Go to website http://arcims.mathsciencecenter.info Then click on Virginia Physiography
THE COASTAL PLAIN • A region of sedimentary strata consisting of sands, muds, and gravels • Tidal waters occupy not only the Chesapeake Bay, but also lower portions of the James, York, Rappahannock and Potomac rivers • Extends inland for more than 100 miles and is monotonously flat
THE PIEDMONT • Largest province extending from the Fall Line westward to the Blue Ridge Mountains • Comprised of a complex of metamorphic and igneous rocks, overlain in a few places by Triassic-age sedimentary beds • Important rocks and minerals include pegmatites, slate, kyanite, gold and pyrite
The Blue Ridge Mountain • A long narrow, northeast-southwest trending mountain chain • Consists of old Precambrian-age sedimentary and volcanic rocks • Old Rag Granite is the oldest rock unit dated in Virginia at 1.2 billion years • The two highest mountains in the state, Mt Rogers (elevation 5,719 ft.) and White Top (elevation 5,520 ft.) are both in the southern Blue Ridge
The Valley and Ridge • Composed of folded and faulted 550 to 300 million-year-old sedimentary rocks • Most ridges are held up by resistant sandstone, and most valleys are underlain by less resistant shale, limestone, and dolostone • Karst features, such as caves and sinkholes are common throughout this province
The Appalachian Plateau • Contains deep narrow valleys and steep, rugged mountain sides caused by downcutting by streams • Consists of 320 to 280 million-year-old sandstone and shale with coalbeds • Most of the rock layers are relatively flat-lying • Coal is Virginia’s most important mineral resource