Clearwater East

Clearwater East is one of two impact craters that form the Clearwater Lakes, a significant geological feature located on the Canadian Shield in Quebec, Canada, near Hudson Bay.

Impact Structure

This impact structure is a complex crater with an estimated diameter of 26 kilometers (16 miles). Its central peak, a common feature in complex craters, is submerged beneath the lake's waters and sediments. Despite this cover, bathymetric surveys and core drilling have confirmed its presence. The crater is significantly eroded, obscuring its original surface features.

Age and Formation

Repeated dating of impact melt rocks from Clearwater East suggests an age of approximately 460–470 million years. This places its formation during the Middle Ordovician period. While previously believed to be the same age as the nearby Clearwater West crater, recent evidence indicates different formation times and potentially different impactors, as suggested by distinct geophysical and geochemical signatures.

Discovery and Naming

Explorer and geologist Albert Peter Low, associated with the Geological Survey of Canada, provided an early account of the Clearwater Lakes in 1896, noting the extraordinary clarity of their waters. The lakes' Cree name, Wiyâšâkamî, translates to "clear water," which was later calqued into French as Lac à l'Eau Claire and then officially named Lac Wiyâšâkimî. The English name, Clearwater Lakes, is a direct translation.

Significance

Clearwater East, along with Clearwater West, represents a valuable site for studying impact cratering processes. The presence of submerged central peaks and the distinct geological and geochemical signatures offer insights into the mechanics of large impacts and the nature of the impacting bodies. The area surrounding the lakes is now part of Tursujuq National Park, Quebec's largest national park.