TOPOGRAPHIC ODDITIES AND DRAINAGE BATTLES: A SAGA OF WATER AND ICE

Pleistocene glaciations of Northwestern Pennsylvania changed environmental conditions and employed glaciogenic geomorphic processes within the Woodcock, Sugar, and Muddy Creek watersheds. This epoch of glaciation changed the landscape and its subsequent evolution. In order to interpret changes in the landscape, water well lithologic logs, soil survey information, and digital elevation models were integrated to analyze drainage and to draw subsurface cross sections of these creek valleys. Moreover, Late Quaternary geomorphic reconstructions attempt to better understand the preglacial, glacial, and, interglacial landscapes and modern drainage of these watersheds.

By observing unglaciated drainage on the Appalachian Plateau, it can be concluded dendritic stream patterns that followed the northwest-southeast and north-south trending joints were present prior to glacial advance in this area. Multiple advances of the Erie Lobe deposited large packages of sediment and shifted drainages to a southern drainage network. During glacial advance, preglacial drainage patterns were impacted by ice (and perhaps subglacial streams); the landscape was eroded, then a till blanket was deposited thinly on uplands and thickly in valleys, and north-flowing drainages were blocked and ponded in repeated battles. Braided streams draining ice margins carried a large bedload from the ice. These streams followed earlier-formed glacially-widened stream valleys. Thick outwash valley trains, with occasional lake environments, snaked through the till-topped landscape. This was a chaotic time which involved an abundance of water, sediment, and ice wastage.

Following deglaciation and climatic amelioration, streams incised into the glacial residue. However, larger glacial discharges no longer existed and the fluvial systems of Woodcock, Sugar, and Muddy Creek were coping with an excess of sediment without the power to move it. This resulted in topographic oddities such as poorly-drained, low-lying drainage divides.