The conference dealt mainly with the bedrock and glacial geology of Susquehanna County. Highlights of the field trip were stops at several active “bluestone,” crushed-stone, and sand-and-gravel quarries, as well as visits to two of Pennsylvania’s most impressive and historic railroad bridges, the great Starrucca (1848) and Tunkhannock (1915) Viaducts. Tying all these various aspects of the trip together is the “Summit sluiceway,” a remarkable valley that cuts across the east-west stream divide in the central part of Susquehanna County. Formed by overflow from the various generations (pre-Illinoian to late Wisconsinan) of Glacial Lake Great Bend, the sluiceway was utilized by the Delaware, Lackawanna & Western Railroad as its major northward route from Scranton to the Great Lakes—culminating early in the 20th century with the completion of the “Summit cut-off” and the Tunkhannock Viaduct.

Much of the conference took place in the Delaware Water Gap National Recreation Area (DEWA) (New Jersey and Pennsylvania). Emphases was on stratigraphy, structural geology, glacial geology, geomorphology, paleontology, and geoarcheology—but guidebook articles, field-trip stops, and pre-conference trips also dealt with mineral resources, historical geography, and ecology, among other topics. Day 1 of the conference field trip was mostly in New Jersey and highlighted stops at Delaware Water Gap, the Yards Creek Pump Storage Project, and High Point State Park. Day 2 was entirely in Pennsylvania and featured stops in the Schoharie Formation/Onondaga Limestone, an ice-contact delta, and a Mahantango shale-chip rubble deposit. The trip concluded with a grand synthesis of stratigraphy, glacial history, geomorphology, and geoarcheology at Raymondskill Creek and Falls.

Day one included a brief overview of the Pittsburgh area from atop Mt. Washington for orientation. After a stop to examine the impact of an old coal mine on the construction of the Mon-Fayette expressway, we boarded the US Army Corps of Engineers’ “pleasure barge” for an excursion down the Monongahela and Ohio Rivers from Braddock to Emsworth. Field slowdowns along the way gave conferees the opportunity to view the making of a new dam, the redevelopment of old brownfields, and a variety of geotechnical problems associated with attempting to build and maintain roads on Pittsburgh’s steep hillsides. Day two featured a visit to the Bruce Mansfield Power Plant in Beaver County where conferees had the opportunity to view the process of recycling scrubber sludge to make wallboard. We traveled to northern Allegheny County to examine what purportedly is the oldest documented major landslide in the world (Pennsylvanian age), and the structurally most complex area in Allegheny County. We also visited Fall Run Park, a small slice of native western Pennsylvania which has been severely impacted by surrounding sprawl.

The Field Conference examined two of the active mainstay mineral industries of the Allentown-Bethlehem area – cement and aggregate – as well as a site of the now dormant jasper industry possibly used by Indians for as long as 10,000 years. The conference also examined the Heleva superfund site and a smaller, unheralded environmental site that poses numerous issues. In addition, attendees saw some of the oldest glacial deposits in Pennsylvania and the Ringing Rocks Boulder Field. The trip concluded with the view from the top of South Mountain and a discussion of the controls of the landscape.

Whereas past interpretation of the Erie area included little of tectonic features, this field trip demonstrated the influence of movements along the bounding cross-strike structural discontinuities throughout the Phanerozoic on depositional environments and their resulting sedimentary rocks. The compressional features seen in northwestern Pennsylvania are a result of reactivation of pre-existing major fault zones. These zones are reactivated due to lineation with the current lithospheric horizontal stress field.

Focus of the conference was the Carboniferous stratigraphy and Pleistocene geomorphology of the Wilkes-Barre/Scranton area of the Northern Anthracite field. Stops of the two-day conference field trip concentrated on the radical changes in thickness and lithology which occur in the Mississippian units (particularly the Spechty Kopf and Mauch Chunk Formations) northeastward around the fringes of the Lackawanna basin, the lithologic and depositional characteristics of Loyalhanna Member-equivalent rocks in the Mauch Chunk Formation, the nature and extent of disconformities beneath the “Loyalhanna Member” and the Pottsville Formation in northeastern Pennsylvania, and the origin and geologic significance of scenic Pleistocene and post-Pleistocene “potholes” and bedrock gorges. Other topics considered at various stops included the complex-and often spectacular-tectonic structures at and near the Pottsville-Mauch Chunk contact, coalbed stratigraphy of the lower Llewellyn Formation, calcretes in the upper Llewellyn, the “infamous” Wal-Mart rockslide at Dickson City, and environmental geology of the Keystone Landfill northeast of Scranton. Two pre-conference field trips were held, one to Nay Aug Park supplementing the stratigraphic and geomorphologic emphases of the main conference and the other featuring a descent into the Lackawanna Coal Mine.

Structures of the Ridge and Valley Province, commonly ascribed to the Alleghany Orogeny, did not form simultaneously, but rather, were created in a sequence of stages including: (1) horizontal layer-parallel shortening (LPS) and transport to the northwest along major bedding detachments, (2) imbricate thrusting and major folding, (3) vertical extension on steep fold limbs, (4) steep, out-of-sequence reverse faulting, only found on the southwest limb of the Pennsylvania Salient. During this sequence, the principle shortening direction progressively rotated clockwise on the northeast limb of the Pennsylvania Salient and counter-clockwise on its southwest limb.

This trip focused upon the role that earth sciences play in solving some of society’s problems, including treatment of natural hazards, halting environmental degradation, and safe extraction of natural resources.

The trip examined carbonates, siliciclastic rocks, metabasalts, and pre-Taconian to Late Alleghanian structures. Attendees also observed the results of Piedmont landscape evolution, and the evolution of Late Cenozoic terraces along the lower Susquehanna River.

Several excellent outcrops demonstrated sedimentological interpretations of rocks of Devonian, Mississippian, and Pennsylvanian age. Newly discovered Devonian fish bone horizons and “fish wallows” highlight one stop. Multiple point-bar and crevasse splay deposits were exposed in an active strip mine. In the Allegheny Mountain section of the Appalachian Plateaus province, the diverse and spectacular erosional topography reflects rock structure differently than in adjacent physiographic sections and provinces. The highest point in Pennsylvania, Mount Davis, was visited.