Secondary cratering on Earth: The Wyoming impact crater field

A large number of small impact structures have been discovered in Wyoming, USA, and we raise the question of how this accumulation occurred. We document 31 crater structures of 10–70 m diameter with corresponding shock features but missing meteorite relics. All craters occur along the outcrops of the uppermost Permo-Pennsylvanian Casper Sandstone Formation and are ~280 m.y. old. Their spatial arrangement shows clusters and ray-like alignments. Several craters have elliptical crater morphologies that allow the reconstruction of impact trajectories. The radial arrangement of the trajectories indicates that the craters are secondary craters formed by ejecta from a primary crater whose likely position and size are reconstructed. Modeling ballistic trajectories and secondary crater formation indicates that impacts occurred at around 700–1000 m/s and caused small shock volumes with respect to crater volumes. This is the first field of secondary craters found on Earth, and we disentangle its formation conditions

The replication crisis and its relevance to Earth Science studies: Case studies and recommendations

Numerous scientific fields are facing a replication crisis, where the results of a study often cannot be replicated when a new study uses independent data. This issue has been particularly emphasized in psychology, health, and medicine, as incorrect results in these fields could have serious consequences, where lives might be at stake. While other fields have also highlighted significant replication problems, the Earth Sciences seem to be an exception. The paucity of Earth Science research aimed at understanding the replication crisis prompted this study. Specifically, this work aims to fill that gap by seeking to replicate geological results involving various types of time-series. We identify and discuss 11 key variables for replicating U-Pb age distributions: independent data, global sampling, proxy data, data quality, disproportionate non-random sampling, stratigraphic bias, potential filtering bias, accuracy and precision, correlating time-series segments, testing assumptions and divergent analytical methods, and analytical transparency. Even while this work primarily focuses on U-Pb age distributions, most of these factors (or variations of them) also apply to other geoscience disciplines. Thus, some of the discussions involve time-series consisting of εHf, δ18O-zircon, 14C, 10Be, marine δ13C, and marine δ18O. We then provide specific recommendations for minimizing adverse effects related to these factors, and in the process enhancing prospects for replicating geological results