Philly Landforms Web Site Overview

· Project information

To find specific landforms of interest use the category list on the side. 

This Philly Landforms website is creating in a blog format a catalog of Philadelphia, Pennsylvania area erosional landforms. Landforms of interest can be located by using the side bar category list where all landforms of a specific type or contained in a specific drainage basin can be located. Use the identified drainage divide names to locate landforms along those drainage divides. Drainage divides in this catalog are always named so the first drainage basin name listed is alphabetically before the second named drainage basin.

Erosional landform types being catalogued here include drainage basins, drainage divides, wind gaps and through valleys crossing important drainage divides, aligned drainage routes, valley orientations, notable valley orientation changes (elbows of capture), barbed tributaries, water gaps and gorges, and notable hills and upland surfaces. While not as spectacular as similar erosional landforms elsewhere in Pennsylvania the Philadelphia area contains a wide variety of erosional landforms and is located at the southern end of the Schuylkill River-Delaware River drainage divide. For this reason understanding Philadelphia area erosional landforms is scientifically important as they contain information required to understand Schuylkill River and Delaware River drainage basin erosional history.

Each catalogued erosional landform is illustrated using a detailed United State Geological Survey topographic map digitally presented by use of National Geographic TOPO software and then described and explained. Contour intervals on the maps shown here are in feet and for that reason distances and elevations are described in miles and feet. All distances and elevations presented here are approximations and are not precise. While being written in a blog format the catalogued erosional landforms are classified by categories including type of landform and drainage basin in which the landform is found. The process of building the catalog began in early January of 2015 and will continue as time permits until most significant Philadelphia area erosional landforms have been catalogued. Readers are encouraged to provide comments, especially when they are able to assist in naming landforms not named (or not properly named) on the topographic maps.

The project author is Eric Clausen who received a BA in Geology from Columbia University and PhD in Geology from the University of Wyoming. At both institutions he studied how to use topographic map interpretation methods to decipher regional geomorphology history. Following completion of his graduate work he taught Earth Science and Geology at Minot State University (in North Dakota) and also administered science education, faculty development, geography education, and various other grant programs. He is now retired and holds the position of Professor Emeritus. He is a member of the Geological Society of America, Sigma Xi, the American Association of Geographers, and several regional professional organizations. His Missouri River drainage basin landforms origin research project includes 550 essays illustrating, describing, and explaining all major drainage divides within and surrounding the Missouri River drainage basin. He recently moved from Minot, North Dakota to Jenkintown, Pennsylvania and is developing this catalog of Philadelphia area erosional landforms as a project to become familiar with Philadelphia area landscape features. He welcomes questions and comments either on this website or privately via email at


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