Surface expression of the Chicxulub crater

Abstract

Analyses of geomorphic, soil, and topographic data from the northern Yucatan Peninsula, Mexico, confirm that the buried Chicxulub impact crater has a distinct surface expression and that carbonate sedimentation throughout the Cenozoic has been influenced by the crater. Late Tertiary sedimentation was mostly restricted to the region within the buried crater, and a semicircular moat existed until at least Pliocene time. The topographic expression of the crater is a series of features concentric with the crater. The most prominent is an approximately 83-km-radius trough or moat containing sinkholes (the Cenote ring). Early Tertiary surfaces rise abruptly outside the moat and form a stepped topography with an outer trough and ridge crest at radii of approximately 103 and approximately 129 km, respectively. Two discontinuous troughs lie within the moat at radii of approximately 41 and approximately 62 km. The low ridge between the inner troughs corresponds to the buried peak ring. The moat corresponds to the outer edge of the crater floor demarcated by a major ring fault. The outer trough and the approximately 62-km-radius inner trough also mark buried ring faults. The ridge crest corresponds to the topographic rim of the crater as modified by postimpact processes. These interpretations support previous findings that the principal impact basin has a diameter of approximately 180 km, but concentric, low-relief slumping extends well beyond this diameter and the eroded crater rim may extend to a diameter of approximately 260 km.

Magnetostratigraphy of the impact breccias and post‐impact carbonates from borehole Yaxcopoil‐1, Chicxulub impact crater, Yucatán, Mexico

“…Before the drilling of the ICDP Yaxcopoil-1 (Yax-1) borehole, several geophysical surveys were conducted in the area, such as seismic reflection (Bell et al 2004;Snyder and Hobbs 1999;Brittan et al 1999;Morgan and Warner 1999;Christeson et al 1999), aeromagnetism (Pilkington et al 2000;Ortíz-Alemán 1999), gravimetry (Sharpton et al 1992;Hildebrand et al 1991), and several other surveys (CamposEnriquez 1997; Pope et al 1996). With these data available, during a workshop sponsored by ICDP in the city of Mérida in 1998, a group of 14 scientists discussed drilling a deep scientific borehole within the crater limits (UrrutiaFucugauchi et al 2001).…”

Magnetostratigraphy of the Cretaceous/Tertiary boundary and early Paleocene sedimentary sequence from the Chicxulub Impact Crater

“…In UNAM-6 borehole the upper breccias are not present, indicating a major hiatus. Considering a diameter of the crater between 180 and 200 km (Hildebrand et al, 1991;Pope et al, 1996;Urrutia-Fucugauchi et al, 2004a) and the location of the boreholes from the center of the crater (UNAM-5, 110 km; UNAM-6, 152 km and UNAM-7, 127), we interpret the low apparent sedimentation rates as a consequence of a hiatus between the top of the impact breccias and the base of the Tertiary carbonates. Studies based on microfossils, stable isotopes and magnetostratigraphy from borehole Yaxcopoil-1 drilled within the crater reported a hiatus between the top of the impact breccias and the base of the Tertiary carbonate sequence (Keller et al, 2004;Rebolledo-Vieyra and UrrutiaFucugauchi, 2004).…”

“…4). Urrutia-Fucugauchi et al (1996, 2004b reported results on the behavior of the magnetic susceptibility in boreholes UNAM-6 and UNAM-7 and Yaxcopoil-1; we extended the study on these boreholes and in addition included UNAM-5. Our aim has been to obtain high-resolution magnetic susceptibility logs to characterize the impact lithologies.…”

High-Density LiDAR Mapping of the Ancient City of Mayapán

“…There is rapid drainage of seasonal rainfall into the karst limestone underground. Mayapán's location was probably determined in part by the density of water bearing cenotes in the area [1,2] as it is near a "ring of cenotes" around the brim of the Chicxulub crater [4], a zone that has a large number of archaeological sites [5]. …”