ABSTRACT Large bolide impacts seem to have strongly affected biological evolution, causing detrimental effects on the biosphere. The best-known case is the Chicxulub impact (Yucatan Peninsula, Mexico), the most probable trigger of the Cretaceous/Paleogene boundary (KPB) mass extinction. Nevertheless, after four decades of intensive research, a consensus on the causal relationship between the impact and the mass extinction has not yet been reached. Most of the scientific community has established multiple, strong arguments for the Chicxulub impact as the most likely and principal cause of the KPB mass extinction. However, a variety of hypotheses link the mass extinction mainly to the volcanism of the Deccan Traps and one or more bolide impact events within a relatively short time through the KPB: one impact in the late Maastrichtian (66.3 Ma), corresponding to the Chicxulub impact, a larger one at the KPB (66 Ma), and a final one in the early Danian (65.9 Ma). Here, we report on the controversies relating to the correlation of the Chicxulub impact event with the mass extinction, with a focus on the stratigraphy and biostratigraphy of sections in Mexico, Cuba, and Haiti, which include ejecta-rich clastic deposits linked to the Chicxulub impact. High-resolution biostratigraphy and quantitative data with planktic foraminifera reveal that these deposits are synchronous with the ejecta-rich airfall layer and the KPB mass extinction horizon of the El Kef, Tunisia, stratotype. Our results provide no support for a multiple impact scenario but confirm that the Chicxulub impact event is indeed the KPB impact event. Furthermore, we have not found any biostratigraphic evidence to support an additional Danian impact event near the Gulf of Mexico region.

ABSTRACT Benjamin Waterhouse Hawkins (1807–1894) was a British scientific illustrator and sculptor who illustrated many British exploration reports in the 1830s and 1840s. In the early 1850s, Hawkins was commissioned to create life-size, concrete sculptures of Iguanodon , ichthyosaurs, and other extinct animals for a permanent exhibition in south London. They were the first large sculptures of extinct vertebrates ever made, and they are still on view today. Inspired by his success in England, Hawkins launched a lecture tour and working trip to North America in 1868. Soon after his arrival, he was commissioned to “undertake the resuscitation of a group of animals of the former periods of the American continent” for public display in New York City. Had it been built, this would have been the first paleontological museum in the world. As part of this ambitious project, with the assistance of the American paleontologist Joseph Leidy, Hawkins cast the bones of a recently discovered Hadrosaurus specimen and used them to construct the first articulated dinosaur skeleton ever put on display in a museum. It was unveiled at the Academy of Natural Sciences of Philadelphia in November 1868. Hawkins worked tirelessly on New York’s proposed “Paleozoic Museum” for two years, until his funding was cut by William “Boss” Tweed, the corrupt leader of the Tammany Hall political machine, who grew hostile to the project and abolished the Central Park Commission that had made it possible. When Hawkins defiantly continued to work, without funding, Tweed dispatched a gang of thugs to break into his studio and smash all of the sculptures and molds. Although Hawkins would create several copies of his articulated Hadrosaurus skeleton for other institutions, the prospect of building a grand museum of paleontology in America was forever destroyed by Tweed’s actions.

The 2021 GSA Northeastern, Southeastern, joint North-Central/South-Central, and Cordilleran Section Meet-ings were held virtually in spring 2021 during continued restrictions on travel and large gatherings due to COVID-19. Eleven groups put together field guides, taking participants on treks to states from Connecticut to Nevada in the United States, to Mexico, and to Italy, and covering topics as varied as bedrock geologic map-ping, geochemistry, paleodrainage, barrier islands, karst, spring systems, a southern Appalachian transect, Ordo-vician and Mississippian stratigraphy, high-energy events, Cretaceous arc granites and dextral shear zones, and Mesoproterozoic igneous rocks. This volume serves as a valuable resource for those wishing to discover, learn more about, and travel through these geologically fascinating areas.

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.