Location Rocks of Ordovician through Mississippian age are exposedalong roads and railroads paralleling the Lehigh River between Palmerton and Jim Thorpe in Carbon County, Pennsylvania (Fig. 1). Rocks of the Ordovician Martinsburg Formation and the Silurian Shawangunk Formation are well exposed on the eastside of Lehigh Gap along an abandoned railroad bed (Fig. 2). Anunmaintained access road along the railroad bed is reached from Pennsylvania 248 just east of the former railroad overpass or byclimbing the slope near the east end of the bridge across the Lehigh River (Fig. 2). Part of the Silurian Bloomsburg Formationis exposed along a small side road paralleling Pennsylvania 248 (Fig. 2). This road is accessed from Delaware Avenue in Palmertonor Pennsylvania 248 just south of Aquashicola Creek. Several Lower, Middle, and Upper Devonian rock units arebeautifully exposed at Bowmanstown (Fig. 2). These exposuresare reached by exiting from Pennsylvania 248 to Bowmanstown. The Devonian Ridgeley (Oriskany), Schoharie-Esopus, Palmerton, Buttermilk Falls, and Marcellus Formations (Fig. 3) areexposed in a deep roadcut along the Northeast Extension Pennsylvania Turnpike at West Bowmans. Proceed west on Pennsylvania 895 from Pennsylvania 248 and park in a pull-off areaon the north side of the road at the east end of the bridge over theturnpike. It is possible to go over the southeast side of the bridge

Abstract The Martinsburg Formation at Lehigh Gap, Pennsylvania, undergoes a transition from shales to slates, reflecting local progressive deformation on an outcrop scale. The anisotropy of magnetic susceptibility (AMS) was measured in low and high fields. The high-field measurements show that the magnetic susceptibility is controlled by the paramagnetic minerals. X-ray goniometry was used to define the mineral fabrics of chlorite and mica. The phyllosilicates are initially oriented preferentially in the bedding plane and are gradually reoriented into the cleavage plane through rotation, microfolding and recrystallization. The AMS fabric mirrors this change in mineral fabric. The magnetic fabric is originally oblate in the least deformed site, with the plane of flattening parallel to bedding, and becomes prolate with increasing deformation, reflecting the development of pencil structure in the shales. In the most deformed site, shortening results in a tectonic cleavage fabric, which controls the magnetic fabric. A similar pattern of fabric development can be observed on a regional scale at other sites across the central Appalachian fold and thrust belt. The AMS and mineral fabric from the Martinsburg Formation has undergone bedding compaction in the foreland near the Allegheny Front. The AMS and textural analysis both show that, as the deformation increases towards the hinterland, prolate fabrics develop and in the most deformed sites slaty cleavage controls both the mineral and magnetic fabrics.

Abstract Many of the parks within the National Park System owe their uniqueness to their geologic framework. Their scenery is the result of diverse natural processes acting upon a variety of rocks that were deposited in varied environments in the geologic past. The Delaware Water Gap National Recreation Area (DEWA) contains a rich geologic and cultural history within its 68,714 acre boundary. Following the border between New Jersey and Pennsylvania, the Delaware River has cut a magnificent gorge through Kit-tantinny Mountain, the Delaware Water Gap, to which all other gaps in the Appalachian Mountains have been compared. Proximity to many institutions of learning in this densely populated area of the northeastern United States (Fig. 1 ) makes DEWA an ideal locality to study the geology of this part of the Appalachian Mountains. This one-day field trip comprises two stops within the gap itself and will include discussion on stratigraphy, structure, geomorphology, and glacial geology. The first stop will be at the bottom of the gap in Pennsylvania to look at the magnificent exposures in the cleft on the New Jersey side. This will be followed by a traverse to the top of Mount Tammany along a popular trail, where we will compare the geology across the river in Pennsylvania. Much of the information presented in this guidebook is summarized from Epstein (2001a , 2001b , 2001c ) and Epstein and Lyttle (2001) .

Abstract The Delaware Water Gap National Recreation Area (DEWA) contains a rich geologic and cultural history within its 68,714 acre boundary. Following the border between New Jersey and Pennsylvania, the Delaware River has cut a magnificent gorge through Kittatinny Mountain, the Delaware Water Gap, to which all other gaps in the Appalachian Mountains have been compared. Proximity to many institutions of learning in this densely populated area of the northeastern United States (Fig. 1 ) makes DEWA an ideal locality to study the geology of this part of the Appalachian Mountains. This one-day field trip comprises an overview discussion of structure, stratigraphy, geomorphology, and glacial geology within the gap. It will be highlighted by hiking a choice of several trails with geologic guides, ranging from gentle to difficult. It is hoped that the “professional” discussions at the stops, loaded with typical geologic jargon, can be translated into simple language that can be understood and assimilated by earth science students along the trails. This trip is mainly targeted for earth science educators and for Pennsylvania geologists needing to meet state-mandated education requirements for licensing professional geologists. The National Park Service, the U.S. Geological Survey, the New Jersey Geological Survey, and local schoolteachers had prepared “The Many Faces of Delaware Water Gap: A Curriculum Guide for Grades 3–6” ( Ferrence et al., 2003 ). Copies of this guide will be given to trip participants and can be downloaded from the GSA Data Repository 1 . The trip will also be useful for instruction at the graduate level. Much of the information presented in this guidebook is modified from Epstein (2006) .