Trace fossils (also called ichnofossils or lebenspuren) are the evidence of animal's activity. Unlike molds and casts which are evidence or replicas of skeletal remains or body impressions, trace fossils are sedimentologic or lithologic disturbance from an animal's (or plant's) activity such as resting, locomotion, or feeding.
The utility in trace fossils comes not from their biostratigraphic value, but instead their use in the interpretation of paleoenvironments. All too often, the organism that produced the trace is unknown. Given that trace fossils reflect activity, many different organisms doing the same thing can produce similar traces. Likewise, an organism engaged in different activity can leave more than one trace.
Trace fossil classifications:
Scoyenia - Resting and Hiding Traces
Trypanites - Dwelling Traces Skolithos - Locomotive Traces
Cruziana, Zoophycos, and Nereites - Feeding Traces
Locomotive Traces (Repichnia) are usually straight or slightly curved trails in addition to tracks and trackways. Long, narrow tubes filled with sediment are the infilled dwelling burrows of marine worms, are known as Skolithos. These Skolithos commonly occur in clusters oriented perpendicular to the bedding surfaces. They may be found in many quartzite outcrops and loose blocks found throughout the South Mountain area, and right here at Kings Gap!
The posted coordinates will bring you to the beautiful flagstone patio at the rear of the Kings Gap Mansion. Built in the early 1900's as a summer home by the prominent local Cameron family, the 2700-acre Kings Gap area was purchased by the Pennsylvania DER in 1973. Now one of our beautiful state parks, it boasts one of the best views from this very patio.
Requirements:
1) Posted coordinates take you to an information sign on the patio overlooking the beautiful Cumberland Valley. After taking in the view, look just to the left of the sign on the top of the wall. Facing upward you'll find two very obvious examples of Skolithos. In an email or message, please describe the size of the particular rocks with the trace fossils, as well as the length, texture, color, and other features of these specimens.
2) To show that you learned from your reading, do you feel these are from resting and hiding, dwelling, locomotion, or feeding.
3) Pictures from this spot are optional but always encouraged, but please, no spoilers!
References:
1) Your Guide to the Geology of the Kings Gap Area, by John H. Way, PA Geological Survey, 1986
2) Cortland University "Trace Fossils" - http://paleo.cortland.edu/tutorial/Trace%20Fossils/tracefossils.htm