Stratigraphy and Paleoenvironments of the Red Hill Site near Hyner, Pennsylvania

Open Access
Author:
Peterson, Daniel Adam
Graduate Program:
Geosciences
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
August 04, 2009
Committee Members:
  • Mark E Patzkowsky, Thesis Advisor
  • MARK E PATZKOWSKY, Thesis Advisor
Keywords:
  • fluvial
  • Devonian
  • tetrapod
  • avulsion
  • Acadian orogeny
  • Pennsylvania
  • Red Hill
  • stratigraphy
  • floodplain
  • paleosol
  • sandstone
Abstract:
The Red Hill outcrop on Route 120 near Hyner, Pennsylvania, consists of repeating cycles of mostly fining-upward facies ranging from siltstones and lower fine massive sandstones at the base of the cycles to mudstones near the top of each cycle. In the readily accessible portions of the outcrop, a wide variety of vertebrate and plant material can be found. Vertebrates recognized from Red Hill include various fishes (placoderms, chondrychthyans, acanthodians, actinopterygians, and sarcopterygians) as well as two early tetrapods first identified at this site (Hynerpeton bassetti and Designathus rowei). Strata at Red Hill appear cyclical and are interpreted to represent two stages of fluvial deposition. Stage I avulsive deposits include crevasse-splay sandstone bodies and sandy siltstone channel fills, overlain by the fossiliferous siltstones and interbedded erosional-based sandstones. These beds are overlain by simple paleosol packages that indicate Stage II avulsive deposition. High sedimentation rates on the Catskill Delta combined with regularly avulsing fluvial systems likely led not only to an excellent taphonomic setting for preserving early tetrapods, large freshwater fish, and a variety of other fossil material, but also created a highly dynamic environment in which these organisms were interacting and evolving.