An asteroid that created the 180 kilometre-wide Chicxulub Impact Crater at Yucatán in Mexico is infamous for causing 75 per cent of life on Earth to go extinct after impact, which occurred 66 million years ago.
In April and May earlier this year, a joint expedition, organised by the International Ocean Discovery Program (IODP) and International Continental Scientific Drilling Program (ICDP), recovered rock cores from the Chicxulub Crater, from 506-1335 metres below the modern-day sea floor.
Core samples from the crater have now been returned to Australia and will be studied in detail.
Curtin University WA-Organic and Isotope Geochemistry researchers from the Department of Chemistry and The Institute for Geoscience Research (TIGeR) are part of the international team that will analyse samples from the crater, from a time when dinosaurs and marine reptiles dominated the world.
Researchers are hoping to provide an understanding of how microbial and marine life recovered and evolved following the catastrophic asteroid impact event.
Associate Professor Marco Coolen, a geomicrobiologist and expert on ancient DNA, was the only representative from Australia to visit the drilling location earlier this year. He is currently at the IODP Core Repository at the MARUM – Center for Marine Environmental Sciences, University of Bremen (Germany), where the cores are being split in halves, described and samples taken.
The 31-person science party and the European Consortium for Ocean Drilling (ECORD) Science Operator support team are undertaking a suite of IODP measurements on these cores. Researchers take samples for further measurements on half of each core, with the other half preserved for future study.
“During the drilling mission we were able to extract cores from the Crater, which contain 120 metres of limestone sediments deposited between 66 million years ago to around 50 million years ago,” Associate Professor Coolen said.
“We were also able to sample broken and melted rocks that buried a ring of mountains which surround the centre of the Crater.
“Initial analyses show evidence of fluids flowing in the broken and melted rocks indicating that a hydrothermal system existed in the aftermath of the impact,” he said.
John Curtin Distinguished Professor Kliti Grice, a world leader in applying molecular fossil and stable isotope expertise to mass extinctions, will analyse sedimentary organic molecules in the samples. From this, she will reconstruct environmental changes and reveal details of the ancient organic matter in the deep subsurface environment of the time.
“Initial results suggest that microbial life established itself in the Crater, likely by taking advantage of the chemistry and porous nature of the broken and melted rocks,” Professor Grice said.
“By analysing the sediments that buried the Crater, we will also be able to investigate how marine life recovered from the period after the impact in which the ocean conditions may have been toxic.”
The scientific ocean drilling carried out by the IODP is the world’s largest scientific geoscience program, involving 25 countries and an annual operational budget of $US180 million.
Its aim is to discover how the Earth has worked in the past and how it works now, and to help predict how it may work in the future.
Curtin University gains access to IODP as a member of the Australian and New Zealand IODP Consortium, involving 16 universities and four government research agencies.
Notes to Editor:
- International Ocean Drilling Program (IODP) is the world’s largest scientific geoscience program. See www.iodp.org for more information.
- See www.iodp.org.au for information on the Australian and New Zealand IODP Consortium.