^1,2Neha Panwar, ¹Neeraj Srivastava, ³Ankita Yadav, ¹Megha Bhatt, ⁴Christian Wöhler, ¹Anil Bhardwaj
Icarus (in Press) Link to Article [https://doi.org/10.1016/j.icarus.2025.116641]
¹Planetary Remote Sensing Section, Planetary Sciences Division, Physical Research Laboratory, Ahmedabad 380009, India
²Discipline of Earth Sciences, Indian Institute of Technology, Gandhinagar, India
³Banasthali Vidyapith, Rajasthan, India
⁴Image Analysis Group, TU Dortmund University, Dortmund, Germany
Copyright Elsevier

The Crisium Basin (17.0°N, 59.1°E) is a Nectarian multi-ring basin hosting extensive volcanism inside the basin center and along its four rings. The Crisium Basin is an essential proxy for understanding basin-related magmatic activity on the Moon. A detailed stratigraphy and chronology have been established for the Mare Crisium in several earlier studies. However, there has been no comprehensive study regarding the composition and emplacement timescales of the basalts along the rings of the Crisium Basin. The basalts along the rings of the Crisium Basin have been emplaced within Mare Undarum, Mare Spumans, Mare Anguis, Cleomedes Crater, and Lacus Bonitatis. Our recent study identified Marginis West as an episode of volcanism along the outermost ring of the Crisium Basin. This study, for the first time, examines the compositional diversity and ages of the basalts emplaced along the rings of the Crisium Basin to better understand its geological evolution. We report the youngest volcanic unit emplaced inside the Crisium Basin at ~2.0 Ga inside Mare Anguis. Based on the spectral signatures, we report that the contemporaneously formed mare units within the Crisium Basin are compositionally different, displaying a westward increase in Ca, and large pre-existing crustal structures would have deeply influenced the volcanism within the basin in the region.

^1,2,3Steven J. Jaret,⁴William R. Hyde,⁵Leah Shteynman
Meteoritics & Planetary Science (in Press) Link to Article [https://doi.org/10.1111/maps.14354]
¹Department Physical Sciences, Kingsborough College CUNY, Brooklyn, New York, USA
²Department Earth and Environmental Sciences, CUNY Graduate Center, New York, New York, USA
³Department Earth and Planetary Sciences, American Museum of Natural History, New York, New York, USA
⁴Department of Geology, Lund University, Lund, Sweden
⁵School of Earth and Space Exploration, Arizona State University, Tempe, Arizona, USA
Published by arrangement with John Wiley & Sons

New mapping and laboratory studies of the impactites at the Gardnos impact structure (Norway) show a variety of impact-deformed rocks. Our mapping and petrographic analyses have subdivided these breccias into three distinct categories: (a) melt-bearing sueivitic breccias, melt-bearing polymict breccias; (b) melt-free, polymict lithic impact breccias; and (c) monomict lithic impact breccias. This illustrates the dynamic nature of crater floor processes where mixing occurs in multiple ways. Feldspar grains exhibit evidence of intense shear, micro-faults, and alternate twin deformation in feldspar. We also observe the development of additional, amphibole-like planar elements (or cleavage) in biotite. Melt-bearing breccias contain carbon concentrations up to an order of magnitude higher than the target rocks. Unusual textures of carbon petrographically associated with shock and post-shock features in feldspars suggest significant postimpact hydrothermal mobilization of carbon within these rocks. Gardnos, therefore, represents an important terrestrial analog for understanding a suite of impact- and postimpact geologic processes.