Reading the sediment archive of the Eastern Campeche Bank (southern Gulf of Mexico): from the aftermath of the Chicxulub impact to Loop Current variability

Abstract

This is the first high-resolution seismic study showing how the Chicxulub impact shaped the eastern slope of the Campeche Bank in the south-eastern Gulf of Mexico. The induced shock wave fractured Cretaceous strata causing the collapse of the upper slope and shelf over a length of ca. 200 km. Failed material was either transported downslope or remained in parts on the accommodation space created by the collapsed. In the Cenozoic, the East Campeche Plastered Drift developed within the created accommodation space, controlled by the inflowing surface current from the Caribbean, which forms the Loop Current. The internal reflection configuration of the drift shows that the closure of the Suwannee Strait in the Late Oligocene and the closure of the CAS in the Mid to Late Miocene controlled the variability of the southern Loop Current in time. Since the Loop Current transports heat and moisture from the western Atlantic warm water pool into the North Atlantic and further to NW Europe by the Gulf Stream, the drift represents an archive for controlling factors that influenced climate of the northern hemisphere. This first high-resolution seismic reflection study from the eastern Campeche Bank expands the understanding of destructive processes that a meteorite impact induces into the earth system. Furthermore, these data document that the East Campeche Plastered Drift bears the potential to understand the link between the climate variability of the northern hemisphere and oceanic processes in the equatorial western Atlantic.

Seismic Stratigraphy of Contourite Drift Deposits Associated With the Loop Current on the Eastern Campeche Bank, Gulf of Mexico

“…Hübscher et al. (2023) map a relatively thick K/Pg boundary deposit on the eastern Campeche Bank, but this is directly contradicted by core material at DSDP Site 95 (Lowery & Bralower, 2022; Worzel et al., 1970). In our view, most of what Hübscher et al.…”

“…The presence of active sediment drifts on the Campeche Bank has been known for years thanks to the pioneering work of Hübscher and colleagues on successive cruises of the R/V Meteor (Hübscher et al., 2010, 2023; Hübscher & Nürnberg, 2023). To reconstruct the history of these drifts we carried out a multichannel seismic survey on the R/V Justo Sierra in July 2022 (Figure 1b).…”

“…Results from a short multichannel seismic survey undertaken by the R/V Meteor on the eastern Campeche Bank in 2013 were recently published (Hübscher et al., 2023) and make an important point of comparison for our work. This survey was undertaken with two 45/105 cubic inch generator‐injector air guns and a 100 m active length 16 channel streamer (Hübscher et al., 2014); the results achieve a similar depth of penetration to our survey (since the sources are equal volume) but exhibit lower vertical resolution (due to shorter streamer and thus lower offset; shot rate was not reported).…”

“…This survey was undertaken with two 45/105 cubic inch generator‐injector air guns and a 100 m active length 16 channel streamer (Hübscher et al., 2014); the results achieve a similar depth of penetration to our survey (since the sources are equal volume) but exhibit lower vertical resolution (due to shorter streamer and thus lower offset; shot rate was not reported). The authors identify nine seismic units, including a basal carbonate platform, pre‐drift flat lying reflectors, the Cretaceous‐Paleogene Boundary Layer, and a series of evolving drift deposits (Hübscher et al., 2023). While their interpretations of these units do not always correspond to ours, the general trends in the evolution of the Loop Current are evident in both surveys.…”

“…There are no cores that penetrate the contourite drifts on the eastern Campeche Bank, so Hübscher et al. (2023) constrain the age of these units by comparing seismic units on the western Florida platform, which have biostratigraphic age control (Gardulski et al., 1991), to seismic units on the Campeche Bank with similar characteristics (e.g., aggradational, progradational) and then assigning the latter the same age as the former. A major problem with this approach is that the seismic architecture in these two areas has been controlled by fundamentally different processes.…”