ABSTRACT Here we present an overview of the geology of the Manhattan Prong and a specific guide for field stops in northern Central Park. This guide is intended to provide a brief introduction to these complex rocks for researchers, undergraduate students, and teachers. Given the easy access to Central Park and numerous schools and institutions nearby, these outcrops provide ideal teaching outcrops for students of all levels. We also present new geochemical and isotopic results for the Manhattan and Hartland Schists. Previous work has focused primarily on field mapping, structural relationships, or infrastructure-related mapping, whereas our new geochemistry data allow for more detailed discussions of provenance and overall tectonic history of these rocks. Our results suggest that all of the rocks in northern Central Park (regardless of mapped unit) are derived from Laurentia.

ABSTRACT Feldspars are the dominant mineral in the crust of most terrestrial planetary bodies, including Earth, Earth’s moon, and Mars, as well as in asteroids, and thus in meteorites. These bodies have experienced large numbers of hypervelocity impact events, and so it is important to have a robust understanding of the effects of shock waves exerted on feldspars. However, due to their optical complexity and susceptibility to weathering, feldspars are underutilized as shock barometers and indicators of hypervelocity impact. Here, we provide an overview of the work done on shocked feldspars so far, in an effort to better frame the current strengths and weaknesses of different techniques, and to highlight some gaps in the literature.

ABSTRACT The Flynn Creek impact structure was originally recognized in 1968 by David Roddy as one of the original six confirmed impact structures on Earth. The Flynn Creek impact structure is also the first recognized marine-target impact structure. Exposure at Flynn Creek varies, as there is no obvious rim and the geological map of the area does not look like a crater. But, there is an impact breccia unit dominated by two classes of breccia—the lower, chaotic, slump breccia and the upper graded resurge breccia. The post-impact unit is Chattanooga Shale, of which one facies is present only in the crater itself. Participants will visit historical outcrops identified by Roddy, including both the breccia units and the central uplift. New results from ongoing reinvestigations of a drill core from Flynn Creek, as well as insight from other marine-target impact structures in the southeast, will add to lively discussions.