Fresh Horizons in Science Education: Geology of Maryland • National Geoscience Teachers' Conference

This Saturday I will be attending the National Geoscience Teachers' Eastern Division Conference and taking a field trip to Maryland's Blue Ridge Province.

Physiographic Provinces of Maryland

As you can see in the map above Maryland has 6 physiographic provinces. Quite a rich geologic character for such a small state.

In the east the barrier islands of Asseteague and Ocean City/ Fenwick comprise the Atlantic Continental Shelf province. The inlet in ocean city has caused longshore drift which starves Asseteague of sand and as a consequence the island is migrating landward.

Moving west we have the coastal plain with the Delmarva Penninsula separated from the western upland area by the Chesapeake Bay. The eastern shore is characterized by slow moving, blackwater rivers and unconsolidated sediment. The western upland region contains the Calvert and St Mary's formations replete with Miocene fossils, particularly coral and sharks teeth.

Under the light of the full moon Cove Point beach in the western coastal plain is a spawning ground for Limulus polyphemus or Atlantic horseshoe crabs.

The fall line separates the tortured metamorphic piedmont from the coastal plain. Important formations in the Piedmont include the Baltimore Gneiss which fronts the central police station in the city, the Ellivott City Granite, the Loch Raven Schist and the Cockeysville Marble, whose stone makes up the Washington monument and the iconic stoops in Baltimore city.

The Cockysville Marble in the Washington monument.

The westernmost provinces, the Blue Ridge, The ridge and Valley and the Appalachian plateau were created by three separate orogenies and are largely sedimentary with a few Jurassic igneous dikes. The Blue Ridge and the Ridge and Valley were created when two microcontinents collided with the coast of what is now North America. The Appalachian province consists of the eroded roots of an ancient mountain range and has large dissected plateaus that are rich in Carboniferous coal formations. In this province we find the Youngiheny river, the only river in Maryland that is not part of the Chesapeake Bay Watershed. It instead drains to the Missouri and eventually the Mississippi.