An amateur astronomer planning a camping trip in Quebec’s Côte-Nord region discovered a massive, previously unrecognized 390-million-year-old impact crater near Lake Marsal in 2024. Researchers confirmed the 25-kilometre circular structure during an arduous October 2025 expedition after identifying definitive shatter cones and impact melt rock.
Earth guards its ancient scars carefully. Weather, relentless tectonic shifts, glaciation, and thick vegetation steadily erase the evidence of prehistoric collisions, leaving only about 200 confirmed impact structures worldwide according to planetary geologists. Yet a stunning remnant of deep time hid in plain sight across remote Canadian wilderness until an amateur map-watcher paused to look closer at a peculiar circular depression.
From a Satellite Map to a Scientific Submission
In 2024, Joël Lapointe was preparing for a camping trip in Quebec’s rugged Côte-Nord region when online satellite imagery revealed a nearly circular pattern of ridges hugging Lake Marsal. Wondering if the depression might represent an ancient impact structure, Lapointe reached out to specialists in North America and Europe as reported in academic releases.
Most public tips sent to researchers turn out to be ordinary geological formations, but Lapointe submitted his observation through Space Daily, a public reporting channel and database maintained by Western University planetary geologist Gordon Osinski. French researchers took the tip seriously enough to present the Lake Marsal area as a potential impact structure at a 2024 meeting of the Meteoritical Society.
Initially skeptical, Osinski organized an expedition to the isolated site in October 2025.
Navigating Difficult Terrain to Find Shatter Cones
Reaching the remote Quebec structure tested a seasoned field team that included Osinski and French geophysicist Pierre Rochette. Transported by floatplane, the aircraft could not reach the shoreline, forcing researchers to wade through 165 feet of water while carrying their heavy equipment.
Once ashore, the expedition confronted swamps, insects, and brutal undergrowth. Osinski, who has conducted fieldwork across six continents, described the journey as one of the most arduous expeditions he had ever undertaken, navigating terrain filled with deep, twisty, gnarly vegetation.
Earlier geological surveys of the region had mistakenly categorized local breccia rocks as a diatreme—a funnel-shaped volcanic pipe formed by explosive magma eruptions. However, by the second day of fieldwork, the team discovered definitive proof of a collision: shatter cones etched into rock outcrops.
It’s the only unequivocal evidence of an impact event that you can see in the field with the naked eye.
Gordon Osinski, planetary geologist at Western University
Alongside these branching fracture patterns, researchers documented cliffs of impact melt rock located roughly four kilometres from the center of the structure according to specialized expedition coverage. Melt rock forms when thermal energy and intense shock pressures completely liquefy target rock, creating a texture that rules out standard volcanic activity or glacial scouring.
Dating the Uhackatik Impact and What Comes Next
Laboratory analysis of collected rock samples places the collision in the Devonian Period, roughly 390 million years ago. That places the event approximately 100 million years before a later spike in Earth’s impact rate that scientists connect to asteroid belt collisions.
The impact created a complex crater measuring about 25 kilometres (16 miles) across, complete with a raised central uplift and high cliffs displaying columnar jointing. Osinski noted that a modern impact of this scale in the same region would cause regional devastation on a scale that would wipe out major cities and have global climate impacts.
Following consultations with the Innu Council of Ekuanitshit, whose traditional territory encompasses the region, the research team adopted the name Uhackatik for the crater. The discovery represents the largest impact structure found since the 31-kilometer Hiawatha structure was identified beneath Greenland ice in 2018.