Sneaking a peek at the ring of a 180km crater

Researchers from the universities of Leicester and Montpellier will be heading to the Yucatán Peninsula of Mexico to participate in a drilling expedition that addresses the science behind the Chicxulub impact structure.

There are few scientific topics that truly captivate the general audience; a meteorite impact that is associated with an extinction that wiped out most forms of life 66 million years ago, including the dinosaurs, is one of them.  The scar of this collision, a 180 km diameter crater, is preserved beneath the Yucatán Peninsula of Mexico. In April and May 2016, Expedition 364 of the International Ocean Discovery Program (IODP) will attempt to drill a 1.5 km deep hole and recover samples from the Chicxulub crater. Data collected will improve our understanding of the physical, environmental and biological processes involved during and immediately after this dramatic event.

“Chicxulub K-Pg Impact Crater” expedition will look at the peak ring of the impact crater, a structure observed on other rocky bodies and planets (Moon, Venus) but Chicxulub is the only one on Earth with an intact ring. Scientists are seeking to test their models of peak ring formation, an event so violent that Earth’s rocks behaved like a fluid during the impact. Other objectives include investigating whether microbiological life colonised the peak ring and how it interacted with hydrothermal systems resulting from the impact. Did life return gradually or abruptly post-impact? Co-chiefs Professor Sean Gulick and Professor Joanna Morgan will lead an international team of scientists to address these challenging scientific issues.

From the first week of April until late May, the Lift Boat (L/B) Myrtle will stand up in 17 m of water, 30 km northwest of Progreso, Mexico, and drill to reach the peak ring. This is a mission specific platform expedition conducted for IODP by the European Consortium for Ocean Research Drilling (ECORD). The operations will be undertaken by the ECORD Science Operator, comprising the British Geological Survey, the University of Bremen and the European Petrophysics Consortium (universities of Leicester (lead), Montpellier, Aachen). Johanna Lofi (Montpellier) and Erwan Le Ber (Department of Geology, University of Leicester) will be working offshore on the downhole logging data from the borehole and measuring physical properties on the core recovered. Laurence Phillpot (Leicester) will also be part of the offshore team. Following the drilling, the core material recovered will be shipped to the IODP Core Repository in Bremen, Germany for further analyses.  Staff from the European Petrophysics Consortium will also be heavily involved in this part of the project.

Leicester and Bremen universities containerised labs. ©Sally Morgan, Leicester

EPC Technical Manager Sally Morgan from our Department of Geology, who has just returned from pre-mobilisation of L/B Myrtle in Louisiana said: “It is really exciting for the group to be involved in this unusual project which is already capturing the imagination of the wider public.  The pre-mobilisation of the vessel in Louisiana has allowed me to see our efforts and planning over the last months (and years) become a reality. Next stop Mexico!”

“This is the seventh Mission Specific Platform that has involved Leicester, in its role as lead of the European Petrophysics Consortium. Each expedition is unique and continues the great contribution by IODP and its precursors (DSDP, ODP, IODP1) in advancing our knowledge of Earth history through drilling, sampling, logging and monitoring boreholes in the Earth’s oceans.” Commented PI Professor Sarah Davies, also from the Department of Geology.

• You can read media coverage of the project on the CNN and Daily Mail websites. A BBC team is also planning to follow expedition scientists offshore and onshore to produce a documentary of the process and findings of the project.

• You can keep up-to-date with project developments through the expedition webpage and by following @EPC_Research.