Isua greenstone belt
Encyclopedia
The Isua Greenstone Belt is an Archean
greenstone belt
in southwestern Greenland
. The belt is aged between 3.7 and 3.8 Ga, making it among the oldest rock in the world. The belt contains variably metamorphosed mafic volcanic and sedimentary rocks. The occurrence of Boninitic geochemical signatures offers evidence that plate tectonic processes may be responsible for the creation of the belt. Pillowed basalts indicate that liquid water existed on the surface at this time.
Archean
The Archean , also spelled Archeozoic or Archæozoic) is a geologic eon before the Paleoproterozoic Era of the Proterozoic Eon, before 2.5 Ga ago. Instead of being based on stratigraphy, this date is defined chronometrically...
greenstone belt
Greenstone belt
Greenstone belts are zones of variably metamorphosed mafic to ultramafic volcanic sequences with associated sedimentary rocks that occur within Archaean and Proterozoic cratons between granite and gneiss bodies....
in southwestern Greenland
Greenland
Greenland is an autonomous country within the Kingdom of Denmark, located between the Arctic and Atlantic Oceans, east of the Canadian Arctic Archipelago. Though physiographically a part of the continent of North America, Greenland has been politically and culturally associated with Europe for...
. The belt is aged between 3.7 and 3.8 Ga, making it among the oldest rock in the world. The belt contains variably metamorphosed mafic volcanic and sedimentary rocks. The occurrence of Boninitic geochemical signatures offers evidence that plate tectonic processes may be responsible for the creation of the belt. Pillowed basalts indicate that liquid water existed on the surface at this time.