For the first time, an off-shore attempt is being made to drill into the Chicxulub Crater and extract samples from the “Peak Ring,” the layer of rock where earth rebounded after the apocalyptic asteroid hit the earth, apparently causing the dinosaurs and 70% of other life forms to become extinct during the Cretaceous period, 66 million years ago. The estimated 18 km wide asteroid crashed into Earth, creating a 100 km across and 30 km deep crater. Geological surveys reveal an arching chain of mountains on the ocean bed where the rim is located.
Geophysicist Sean Gulick from the University of Texas, Austin and co-chief of the $10 million project says,
Chicxulub is the only preserved structure with an intact Peak Ring that we can get to. All the other ones are either on another planet or they’ve been eroded … We’re 30km off-shore, which allows us to re-supply easily. We’ve also timed the project so that we’re pre the hurricane season. Hence, starting now and trying to finish before June.
An international coalition of researchers are on a lift boat scientific research platform drilling 30 kilometers off shore from the port of Progreso on the Yucatan Peninsula. The lift boat, dubbed Myrtle, is a 137-foot mission-specific drilling platform held steady by three 6-foot wide pylons. For sixty days, the team will be drilling 24 hours a day. Layers of sediment and rock will be extracted unearthing prehistoric biology and planetary geology from the center of the crater.
Using a tungsten–carbide roller cutter, researchers will begin by drilling to 500m meters, cutting through the sediment to the limestone. At 500 meters, the hole will be cased in steel and drillers will switch to a diamond-tipped bit that can be used to retrieve 3-meter long cores. The core samples will be quickly frozen at -80-degrees Celsius to preserve them for research purposes. Though Myrtle has labs for initial investigation, the main study will be conducted after the core samples have been sent to the IODP’s repository in Bremen, Germany.
At 550 m, there is the possibility of finding algae and black shale from 55 million years ago. Upon reaching 550-600m, there is hope of finding evidence of life forms that survived or formed after impact and documenting the size and number of species. The impact layers should be found at 650-800 m. Chunks of rock, impact melt, sediment and some ash crystals of shocked quartz may appear.
Finally, at 800-1,500, the target depth and prime Peak Ring should appear with its volcanic granites and light minerals with fracturing of the rock filled with mineral veins, part of the hydrothermal system. And, the most important part of the process, the search for microbial DNA of chemosynthetic microbes that live in the crack may be extracted.
In that section, the big excitement is, “How did life come back at Ground Zero?” Was it the specialists or the generalists? Is there any clue to what organisms repopulated first, as opposed to what the environmental consequences were for the ocean?
Professor Joanna Morgan, co-lead investigator from Imperial College of London says,
We want to know where the rocks that make up the Peak Ring come from. Are they from the lower, mid or upper crust? Knowing that will help us understand how long craters are formed, and that’s important for us to be able to say what was the total impact energy, and what was the total volume of rock that was excavated and put into the Earth’s stratosphere to cause the environmental damage.
The team’s drilling strategy allows multiple chances to get to the 1,500-meter goal, even if a bit gets stuck or they have to abandon a hole and drill a new one.
Gulick sums up,
Most things just didn’t worry about the high CO2 time, and kind of made it through. However, if you look today, at our current increasing CO2 values, already it’s looking like we have a pretty big extinction event in the making. Is that something to do with vulnerability? Is that something to do with the specific kill mechanisms? We should understand this better, given that we’re kind of in the middle of an experiment ourselves.
That’s something to ponder if we don’t want history repeating itself.