Introduction: In 2016, the IODP-ICDP Expedition 364 drilled into the peak-ring structure of the Chicxulub impact crater, Yucatán, recovering the near continuous core M0077A, which includes ±130 m of suevite and impact melt rocks, and ±610 m of granitoid basement material [e.g., 1]. The basement material is intruded by both impact melt rocks and pre-impact magmatic dikes, with the latter ranging from voluminous dolerites to rare dacites and felsites. The pre-impact lithologies have been subjected to pre-impact tectonic deformation and hydrothermal alteration and syn-impact shock-metamorphism . Moreover, the entire core has been subjected to post-impact tectonic deformation and hydrothermal alteration [1,2]. This study concerns the major and trace element composition of 101 samples from core M0077A to better constrain the geochemical variation (or lack thereof) of the suevite and of the two impact melt rock units, while also characterizing the basement lithologies. This approach aims to better understand impact melt formation through the direct study of both the product (impact melt rocks and suevites) and its initial components (the pre-impact lithologies).
2 okt 2019
Large Meteorite Impacts and Planetary Evolution VI: LMIVI 2019