Evidence of Carboniferous arc magmatism preserved in the Chicxulub impact structure

Abstract Determining the nature and age of 200-km-wide Chicxulub impact target rock is an essential step in advancing our understanding Maya Block basement. Few constraints exist for northern crust, specifically basement underlying 66 Ma, 200 km-wide structure. The International Ocean Discovery Program-International Continental Scientific Drilling Program Expedition 364 core recovered a continuous section rocks from rocks, which provides unique opportunity to illuminate pre-impact tectonic evolution terrane key development Gulf Mexico. Sparse published ages point Mesoproterozoic, Ediacaran, Ordovician Devonian crust are consistent with plate reconstruction models. In contrast, granitic peak ring during yielded new zircon U-Pb laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) concordant dates clustering around 334 ± 2.3 Ma. Zircon rare earth element (REE) chemistry granitoids having formed continental arc setting. Inherited grains fall into three groups: 400–435 500–635 940–1400 incorporation Peri-Gondwanan, Pan-African, Grenvillian respectively. Carboniferous ages, trace compositions, inherited indicate pre-collisional volcanic located along Block's margin before NW Gondwana collided Laurentia. existence suggests southward-directed subduction Rheic oceanic beneath similar evidence that documented Suwannee terrane, Florida, USA, Coahuila NE México.