Quebec lake meteorite impact yields rare rocks and evidence of extreme heat

For greater than a decade, Western College planetary geologist Gordon “Oz” Osinski has led expeditions to Kamestastin Lake in Labrador. The atmosphere is an ideal coaching floor as a result of the properties and rock formations—created by the violent affect (and excessive warmth) of an asteroid 36 million years in the past—uniquely mimic the floor on the moon.

Osinski, Neeraja Chinchalkar, the analysis technician at Western’s Earth and Planetary Supplies Evaluation (EPMA) Laboratory, and their collaborators have now found new proof that one other meteorite affect as soon as precipitated equally excessive (and respectively uncommon) excessive temperatures, exceeding 2,370°C (4,172°F), at one other distant affect construction in northern Quebec.

For the study, printed by the journal Earth and Planetary Science Letters, Chinchalkar analyzed glass from rock samples initially collected by Osinski in 2014 on the West Clearwater Lake affect construction in Quebec utilizing an electron microprobe and scanning electron microscope. The evaluation discovered proof of pure cubic zirconia, a mineral which requires a temperature of at the least 2,370°C to type. To place this into perspective, lava flows from volcanoes on Earth vary from about 800°C to a most of round 1,200°C.

“We seemed on the buildings current inside zircon grains to reconstruct a meteorite affect occasion from tens of millions of years in the past. We discovered proof that the goal rocks reached extraordinarily excessive temperatures, which, mixed with excessive strain situations, melted and reworked these Earth rocks. It left behind distinctive space-modified samples that may be studied for years to return and can solely additional our understanding of the cosmos,” mentioned Chinchalkar.

Whereas earlier analysis has recommended that materials melted by meteor collisions can attain such excessive temperatures, direct proof on Earth has been scarce. Actually, till this new research, such proof was solely discovered from one meteorite crater: the Kamestastin Lake affect construction.

“Kamestastin Lake comprises among the best-preserved affect soften rocks on Earth, that are among the highest precedence samples that future astronauts to the moon wish to discover and pattern,” mentioned Osinski, an Earth sciences professor. “Now that we have now discovered proof of those unimaginable affect soften rocks at West Clearwater Lake, we have now a brand new vacation spot on Earth to deliver astronauts, college students and geologists, like me, to coach and research.”

The West Clearwater Lake rock pattern investigation additionally revealed proof of reidite, a mineral that kinds beneath extreme pressure exceeding 20 gigapascals, a measurement of the bodily pressure exerted on an object.

“This discovery underscores the variable and dynamic situations that happen throughout the means of soften technology brought on by meteorite impacts on Earth and past,” mentioned Chinchalkar.

Reidite has beforehand solely ever been discovered at 10 meteorite impact buildings on Earth, together with Haughton, Nunavut and Steen River, Alberta.