East Greenland Orogen
Encyclopedia
The East Greenland mountain range or East Greenland orogen is the linear mountain range
along the eastern Greenland
coast, from 70 to 82 degrees north latitude.
Geologically
, the mountain chain consists of late Cryogenian
to late Devonian
(650 to 350 millions years ago) fold and thrust belts. Little is known about the exact timing and setting of the earlier phases
as this area was later heavily deformed during the Caledonian Orogeny
(450 to 350 million years ago). The rocks of the East Greenland orogen are mostly Silurian
granites with Devonian
sedimentary rocks overlying Ediacarian marine deposits, all on a basement
of gneiss
es.
The current mountain range formed as a result of uplift
during the opening of the Atlantic Ocean
in the Cretaceous
and early Tertiary
(starting 100 million years ago). The related East Greenland Rift Basin oil deposits are estimated to be one of the largest in the world.
Mountain range
A mountain range is a single, large mass consisting of a succession of mountains or narrowly spaced mountain ridges, with or without peaks, closely related in position, direction, formation, and age; a component part of a mountain system or of a mountain chain...
along the eastern 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...
coast, from 70 to 82 degrees north latitude.
Geologically
Geology
Geology is the science comprising the study of solid Earth, the rocks of which it is composed, and the processes by which it evolves. Geology gives insight into the history of the Earth, as it provides the primary evidence for plate tectonics, the evolutionary history of life, and past climates...
, the mountain chain consists of late Cryogenian
Cryogenian
The Cryogenian is a geologic period that lasted from . It forms the second geologic period of the Neoproterozoic Era, preceded by the Tonian Period and followed by the Ediacaran...
to late Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
(650 to 350 millions years ago) fold and thrust belts. Little is known about the exact timing and setting of the earlier phases
Tectonic phase
A tectonic phase or deformation phase is in structural geology and petrology a phase in which tectonic movement or metamorphism took place. Tectonic phases can be extensional or compressional in nature....
as this area was later heavily deformed during the Caledonian Orogeny
Caledonian orogeny
The Caledonian orogeny is a mountain building era recorded in the northern parts of the British Isles, the Scandinavian Mountains, Svalbard, eastern Greenland and parts of north-central Europe. The Caledonian orogeny encompasses events that occurred from the Ordovician to Early Devonian, roughly...
(450 to 350 million years ago). The rocks of the East Greenland orogen are mostly Silurian
Silurian
The Silurian is a geologic period and system that extends from the end of the Ordovician Period, about 443.7 ± 1.5 Mya , to the beginning of the Devonian Period, about 416.0 ± 2.8 Mya . As with other geologic periods, the rock beds that define the period's start and end are well identified, but the...
granites with Devonian
Devonian
The Devonian is a geologic period and system of the Paleozoic Era spanning from the end of the Silurian Period, about 416.0 ± 2.8 Mya , to the beginning of the Carboniferous Period, about 359.2 ± 2.5 Mya...
sedimentary rocks overlying Ediacarian marine deposits, all on a basement
Basement (geology)
In geology, the terms basement and crystalline basement are used to define the rocks below a sedimentary platform or cover, or more generally any rock below sedimentary rocks or sedimentary basins that are metamorphic or igneous in origin...
of gneiss
Gneiss
Gneiss is a common and widely distributed type of rock formed by high-grade regional metamorphic processes from pre-existing formations that were originally either igneous or sedimentary rocks.-Etymology:...
es.
The current mountain range formed as a result of uplift
Tectonic uplift
Tectonic uplift is a geological process most often caused by plate tectonics which increases elevation. The opposite of uplift is subsidence, which results in a decrease in elevation. Uplift may be orogenic or isostatic.-Orogenic uplift:...
during the opening of the Atlantic Ocean
Atlantic Ocean
The Atlantic Ocean is the second-largest of the world's oceanic divisions. With a total area of about , it covers approximately 20% of the Earth's surface and about 26% of its water surface area...
in the Cretaceous
Cretaceous
The Cretaceous , derived from the Latin "creta" , usually abbreviated K for its German translation Kreide , is a geologic period and system from circa to million years ago. In the geologic timescale, the Cretaceous follows the Jurassic period and is followed by the Paleogene period of the...
and early Tertiary
Tertiary
The Tertiary is a deprecated term for a geologic period 65 million to 2.6 million years ago. The Tertiary covered the time span between the superseded Secondary period and the Quaternary...
(starting 100 million years ago). The related East Greenland Rift Basin oil deposits are estimated to be one of the largest in the world.