Seismic attribute analysis of Chicxulub impact crater

Acta Geophysica

article

Salguero-Hernández, E.¹  Pérez-Cruz, L.²  Urrutia-Fucugauchi, J.² 

[1] Universidad Autónoma del Carmen;Programa Universitario de Perforaciones en Océanos y Continentes, Instituto de Geofísica, Universidad Nacional Autónoma de México;Instituto de Investigación Científica y Estudios Avanzados Chicxulub

关键词: Seismic attributes;    Chicxulub crater;    Pre-impact target structures;    Impact deformation;    Crater structure and stratigraphy;   

DOI  :  10.1007/s11600-020-00442-z

学科分类：地球科学(综合)

来源: Polska Akademia Nauk * Instytut Geofizyki

【 摘 要 】

Chicxulub crater formed ~ 66 Ma ago by an asteroid impact on the Yucatan platform in the southern Gulf of Mexico. The crater has a ~ 200 km rim diameter and has been covered by carbonate sediments up to ~ 1.1 km thick in the central zone. Previous studies have identified the structure and major crater units through geophysical models from seismic reflection and potential field data, classified as the central uplift, terrace zone, outer and inner ring fault zones and impactite deposits. Impact produced a deep excavation cavity, with fragmentation and ejection of large volumes of crustal target rocks. Understanding the pre-existing structures, impact-induced deformation and post-impact processes requires high-resolution images of the crater and target zone. For this study, we use complex trace attributes of instantaneous phase, frequency, envelope amplitude and similarity, in an E-W seismic reflection profile crossing the crater in the marine sector. Geophysical logs and borehole lithological columns from the on-land drilling projects are used to constrain the petrophysical analysis. Seismic attributes aid to characterize the radial fault zones and physical property contrasts, revealing asymmetries in the crater structure. The reflector packages in the post-impact sediments and target Cretaceous sequence are identified in the frequency and phase attributes. The bottom crater reflectors, with the basal sediments filling the crater floor topography, are enhanced with the envelope amplitude attribute. A set of high-amplitude reflectors is shown in the similarity attribute, in which the reflector geometry is delineated on the target carbonate sequence. The offsets in the high-amplitude reflectors between the eastern and western sectors are possibly associated to target pre-impact asymmetries, impact deformation and effects of central crater collapse.

【 授权许可】

Unknown