Field Trips

Descriptions for the following field trips are online; trip registration opens in January 2014. For additional information, please contact the Field Trip Chair, Andrew de Wet.

1. Sources and Sinks of Anthropogenic Sediments in the Mid-Atlantic Region.
Robert C. Walter, Franklin & Marshall College, robert.walteratfandm.edu;
Allen C. Gellis, USGS, agellisatusgs.gov;
William B. Hilgartner, Johns Hopkins Univ. and Friends School, Baltimore, hilgartneratjhu.edu;
Dorothy J. Merritts, Franklin & Marshall College, dorothy.merrittsatfandm.edu.
Description: This one-day field trip to locations within a 60-mile radius of Lancaster will examine potential sources and sinks of Holocene and Anthropocene sediments. These sources include upland farm slopes and eroding stream banks; sinks include sedimentation in valley bottoms, natural and anthropogenic traps (dams) in the Susquehanna River, and in Chesapeake Bay. Evidence from field sampling and modeling that bears on relative magnitudes of these inputs and outputs to the sediment budget, today and as they have changed over the past 10,000 years, will be the focus of discussion.
2. Tectonics of Southeastern Pennsylvania, West Grove Metamorphic Suite.
Howell Bosbyshell, West Chester Univ. of Pennsylvania, hbosbyshellatwcupa.edu;
Gale Blackmer, Pennsylvania Geologic & Topographic Survey, gblackmeratpa.gov;
Sandy Schenk, Delaware Geological Survey, rockmanatudel.edu; LeeAnn Srogi,
West Chester Univ. of Pennsylvania, esrogiatwcupa.edu.
Description: This field trip will focus on metasedimentary rocks that have been informally referred to as the “Glenarm Wissahickon,” to set them apart from the typical “Philadelphia Wissahickon.” New mapping, monazite geochronology, amphibolite geochemistry, and detrital zircon data support the designation of these rocks as the West Grove Metamorphic Suite. Study of outcrops of the Laurels Schist, Doe Run Schist, Embreeville Thrust, Mt. Cuba Gneiss and the Wissahickon Schist in Media, Pennsylvania, will illuminate the Neoproterozoic and Paleozoic tectonic history of this region.
3. Geology of the Baltimore Mafic Complex Adjacent to the PA/MD State Line.
Stephen Shank, Pennsylvania Geologic & Topographic Survey, stshankatpa.gov;
Lynn Marquez, Millersville Univ. of Pennsylvania, lynn.marquezatmillersville.edu.
Description: This field trip will focus on the stratigraphy of the Baltimore Mafic Complex, its contact relations with adjacent metasediments, the mining history of this region, and the distinctive vegetation of the “serpentine barrens.” Stops are expected to include gabbro and serpentinite along Octorara Creek, the Penn-Maryland Quarry with serpentinite and “vermiculite” pipe bearing zircons, contact between the serpentinite and the Peters Creek Formation, a diamictite (Sykesville?) in contact with serpentinite, and the classic Wood chromite mine.
4. Stratigraphy and Structure of the Chilhowee Group in Lancaster and York Counties.
Charles Scharnberger, Millersville Univ. of Pennsylvania, charles.scharnbergeratmillersville.edu;
Joseph P. Smoot, USGS, jpsmootatusgs.gov;
Edward L. Simpson, Kutztown Univ. of Pennsylvania, simpsonatkutztown.edu;
Jeri L. Jones, Jones Geological Services, jonesgeoatcomcast.net.
Description: Re-examination of the latest Proterozoic and Early Cambrian clastics of Lancaster and York Counties is prompted in part by the recent Nature paper by Peters and Gaines (2012). These authors have revived Walcott’s classic concept of the “Great Unconformity.” linking change in the chemistry of the oceans and the Cambrian explosion of marine animal life to this event. In our region, the significant break occurs at the base of the Weaverton and at the base of the Chickies Formation. The latest Proterozoic sedimentary sequence in Virginia and farther south, recently documented by Smoot and Southworth (2012) is largely absent in Pennsylvania. However, it is unclear whether the Hellam Conglomerate should be regarded as a basal facies of the Chickies, as has generally been assumed, or as a prior unit of a different character, like the enigmatic Ausable Formation that occurs below the Potsdam Formation, along the SE margin of the Adirondacks. These and other issues, including examination of Skolithos where it was almost certainly first recognized and study of the structural deformation of these rocks will be undertaken at localities on either side of the Susquehanna River.
5. Late Devonian Vertebrate Fossils from the Catskill Formation at Red Hill, Clinton County, Pennsylvania.
Edward B. Daeschler, Academy of Natural Sciences of Drexel Univ., daeschleratansp.org;
Walter L. Cressler, Westchester Univ. of Pennsylvania, wcressleratwcupa.edu.
Description: This trip will involve study and fossil collecting at the Red Hill site in Hyner, Pennsylvania. This site has yielded much the greater part of evidence of the Famennian fauna and flora that occupied fluvial, over-bank and lacustrine environments in this region. This is the locality from which the famous fin of a fish with eight “fingers” was collected. Discussion will focus on Late Devonian paleontology, notably transitional adaptations of vertebrates at the interface between aquatic and terrestrial modes of life, paleoecology and fluvial sedimentology.

 

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