Date of Graduation
2004
Document Type
Thesis
Degree Type
MS
Committee Chair
J. Steven Kite
Abstract
The Gettysburg Formation preserves the sedimentological record of the Late Triassic – Early Jurassic filling of the Newark-Narrow Neck-Gettysburg rift basin and subsequent intrusion by diabase. In the study area, bedrock is exposed only on the floor of the Susquehanna River. Exploratory borings drilled across the river, as part of a geotechnical investigation to obtain data for design of a foundation system for a replacement of the existing bridge carrying the Pennsylvania Turnpike (S.R. 0076) over the Susquehanna River, provided an opportunity to document the general stratigraphy of the surficial materials and the Gettysburg Formation in areas inaccessible to previous researchers. Drilling revealed two broad bedrock straths lying beneath east shore alluvium and a previously undocumented strath lying beneath diabase colluvium on the west shore, and that the bedrock on the west side of the study lies within the thermal aureole of a diabase intrusion. Laboratory testing revealed significant differences in unconfined compressive strength (Uc) values of bedrock across the study area. Cross-sections indicate that channel has been shaped by multiple episodes of glaciation, deglaciation, and non-glaciation, which has resulted in channel adjustments to changing discharges, sediment loads, and differential resistance of the Gettysburg Formation to erosion.
Recommended Citation
Hawk, Joan L., "The role of geology and engineering properties of the Gettysburg Formation in the geomorphic form of the Susquehanna River at Highspire, Pennsylvania." (2004). Graduate Theses, Dissertations, and Problem Reports (ETD). 10799.
https://researchrepository.wvu.edu/etd/10799