Acasta Gneiss - Wikipedia
The Acasta Gneiss Complex, also called the Acasta Gneiss, is a body of felsic to ultramafic Archean basement rocks, gneisses, that form the northwestern edge of the Slave Craton in the Northwest Territories, Canada, about 300 km (190 mi) north of Yellowknife, Canada.
Acasta Gneiss - Smithsonian National Museum of Natural History
At 3.96 billion years old, this gneiss is one of the oldest known Earth rocks. The Earth is 500 million years older still, but little record of that early time has survived our planet's geologic activity.
Earth’s Oldest Rocks – Historical Geology
The Acasta Gneiss Complex located in the Slave Craton of Northwest Canada (see map of Archean Cratons, above) preserve the oldest unquestioned isotopically dated rock thus found anywhere on Earth. This complex includes a variety of highly deformed and metamorphosed tonalite-trondhjemite-granodiorite (TTG) rock.
126. Acasta Gneiss (1983) - Minister for Science
The Canadian Shield, the largest expanse of Precambrian rocks on Earth, is host to Earth’s oldest known rock – the Acasta Gneiss of the Slave Province of the Shield, located about 300 kilometres north of Yellowknife, Northwest Territories.
Acasta Gneiss with Annie Bauer - TravelingGeologist
The Acasta Gneiss is one of our earliest terrestrial repositories of chemical, age, and isotopic information and therefore has significant potential to contribute to our understanding of tectonic processes on the early Earth.
Acasta gneiss | rock | Britannica
…uranium-lead technique revealed that the Acasta gneisses, which occur southeast of Great Bear Lake in the northwestern corner of the shield, were at least 3.8 billion (and possibly up to 3.96 billion) years old. In the northeastern part of the shield, rocks as old as 3.8 billion years are found… Read More
Searching for Earth's Oldest Rocks: Follow a Smithsonian …
2024年9月12日 · The Acasta Gneiss is a vast geologic formation that covers over 5,000 square miles. This makes locating a tiny outcrop of ancient minerals daunting.
Where do you find old iconic rock stars? In Canada, of course!
The iconic Acasta gneiss, found in the Canadian Shield along the shores of the Acasta River in the Northwest Territories, is over four billion years old — making it the oldest known rock on Earth and the planet’s original rock star.
Acasta Gneiss - SpringerLink
2021年5月25日 · The Acasta Gneisses are the oldest dated rocks on Earth. They are exposed in northwestern Canada (65° 10′ N and 115° 30′ W) along the western margin of the Archean Slave craton (>2.5 Ga), in the core of a north-trending fold in the foreland of the Wopmay orogen, a 2.02–1.84 Ga-old orogenic belt.
An impact melt origin for Earth’s oldest known evolved rocks
2018年8月13日 · Earth’s oldest evolved (felsic) rocks, the 4.02-billion-year-old Idiwhaa gneisses of the Acasta Gneiss Complex, northwest Canada, have compositions that are distinct from the felsic rocks that...