Which Virginia region has long parallel ridges and valleys formed by folded and faulted rocks during the collision of Africa and North America in the Paleozoic Era?

Which Virginia region has long parallel ridges and valleys formed by folded and faulted rocks during the collision of Africa and North America in the Paleozoic Era?

• A. Piedmont
• B. Appalachian Plateau
• C. Valley and Ridge
• D. Blue Ridge

Answer: (C)

Virginia’s Valley and Ridge region shows how a major collision deformed rocks to create long, parallel ridges separated by valleys. In the Paleozoic, the collision of Africa with North America along the Appalachian margin caused intense compression that folded and faulted sedimentary rocks. Anticlines rose into ridge crests, while synclines formed the valleys, producing the characteristic long, straight or gently curving parallel features that run across the landscape. The ridges stay prominent because they’re made of more resistant rock, while the valleys occupy weaker rock that erodes more easily. This pattern is the hallmark of the Valley and Ridge topography. Other Virginia regions have different histories: the Piedmont lies on ancient metamorphic rocks with rolling hills; the Blue Ridge is an older, rugged system of high mountains; the Appalachian Plateau is a broad, relatively flat-lying plateau—none show the distinct parallel ridge-and-valley arrangement produced by this Paleozoic collision.

Virginia’s Valley and Ridge region shows how a major collision deformed rocks to create long, parallel ridges separated by valleys. In the Paleozoic, the collision of Africa with North America along the Appalachian margin caused intense compression that folded and faulted sedimentary rocks. Anticlines rose into ridge crests, while synclines formed the valleys, producing the characteristic long, straight or gently curving parallel features that run across the landscape. The ridges stay prominent because they’re made of more resistant rock, while the valleys occupy weaker rock that erodes more easily. This pattern is the hallmark of the Valley and Ridge topography. Other Virginia regions have different histories: the Piedmont lies on ancient metamorphic rocks with rolling hills; the Blue Ridge is an older, rugged system of high mountains; the Appalachian Plateau is a broad, relatively flat-lying plateau—none show the distinct parallel ridge-and-valley arrangement produced by this Paleozoic collision.