From April 2016, a team of Scientists, Drillers and Staff from the European Consortium for Ocean Research Drilling Science Operator (ECORD-ESO) will take part in International Ocean Drilling Programme (IODP) /International Continental Scientific Drilling Programme Expedition (ICDP) 364, to drill the topographic peak ring associated with the large asteroid impact frequently associated with the demise of dinosaurs around 66 millions years ago. This 60 day project will drill into the earths crust, near to the craters core; collecting rock material, taking samples for ephemeral properties, and obtaining petrophysical and downhole logging data. After the offshore phase, cored material will be taken to the IODP Bremen Core Repository (for an onshore sampling phase) and split to reveal it’s secrets.
Peak rings are a common feature of large craters on rocky bodies, but there is no consensus on their formation. Expedition 364 will drill into the peak ring to understand how hypervelocity impacts temporarily change rock behaviour in a way that allows them to flow large distances and form features such as peak rings. The hypothesis that impacts may be beneficial to some life will also be investigated, with the idea that
they could have sustained biospheres in the early Earth. Also of interest is how ocean life recovered after this impact, and what changes occurred across the Paleocene-Eocene Thermal Maximum (PETM).
The following themes will be investigated:
• Peak-ring formation: What is the nature of the rocks that form a peak ring? Are they from the upper, mid or lower crust? Why do they have such a low density and seismic velocity? What are the kinematics and dynamics of peak-ring formation? What rock-weakening mechanism controls large crater formation?
• Habitability: Was there intense hydrothermal activity in the rocks that form the peak ring and how long did it last? What microbiological life colonised the peak ring, was it diverse and/or exotic, and was it shaped by the post-impact hydrothermal system?
• Recovery of life: After the impact, how long did it take for the ocean to return to normal
conditions? Did diversity gradually recover, or did the whole assemblage return simultaneously once the environment stabilised? What is the relationship between the survivors of the K-Pg event and newly evolved taxa, and the mass survival at the PETM 10
million years after?
During the Expedition we’ll use this page to communicate about the Expedition, with input from the diverse range of people involved. Expect anything from how to drill a hole to analogues with other planets……..
For more information: www.eso.ecord.org/expeditions/364/364.php