Description

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Context

Scientists have discovered a submerged microcontinent off west coast of Greenland named Davis Strait Proto-Microcontinent formed between 49–58 million years ago due to tectonic evolution of strait between Greenland & Canada.

Key Highlights

It is a newly discovered submerged microcontinent located in Davis Strait a large marine stretch between Canada Baffin Island & Greenland.

Named due to its formation being linked to tectonic evolution of Davis Strait.

The microcontinent is composed of thinned continental crust 19–24 km thick & is surrounded by two bands of thinner crust (15–17 km) that isolate it from Greenland & Baffin Island.

The discovery highlights a fragment of thick continental lithosphere now classified as a primitive proto-microcontinent.

Geological Context & Formation

The Davis Strait lies along boundary between North American & Greenland Plates.

The region experienced initial rifting ~118 Ma (Lower Cretaceous).

Seafloor spreading began around 61 Ma in Labrador Sea & Baffin Bay.

The microcontinent main formation occurred between ~49–58 Ma due to a shift in seafloor spreading direction along Pre-Ungava Transform Margin isolating crust.

Later Greenland collision with Ellesmere Island made it part of North American Plate.

Research & Definition

Defined by researchers (Longley, Phethean, Schiffer) as a proto-microcontinent i.e. a thick continental lithosphere segment isolated by thinner continental zones.

Research published in Gondwana Research.

Used plate tectonic reconstructions, gravity maps & seismic reflection data spanning ~30 million years to model its formation.

Key Facts about Davis Strait (Geographical Context)

The Davis Strait is a bay in northern Atlantic Ocean between southeastern Baffin Island (Canada) & southwestern Greenland.

It acts as a link between Baffin Bay (north) & Labrador Sea (south).

Forms part of Northwest Passage which connects Atlantic & Arctic Oceans through Canadian Arctic Archipelago.

Approximately 400 miles (650 km) long & 200 to 400 miles wide making it one of broadest straits in world.

The strait features complex underwater basins & ridges formed due to strike-slip faulting along Ungava Fault Zone (~45–62 Ma).

These tectonic activities triggered seafloor spreading in adjacent seas & contributed to emergence of Davis Strait proto-microcontinent.

Microcontinent Theory

Aspect	Description
Definition	A microcontinent is a fragment of continental crust that is relatively small but not fully part of a major landmass.
Formation	Microcontinents form through tectonic processes such as rifting & plate movements that separate portions of continent.
Tectonic Origin	Typically formed at plate boundaries, either through rifting, subduction or collision which isolates fragments of continental crust.
Size	Smaller than regular continents but still large enough to be considered distinct from oceanic crust.
Examples	Davis Strait Proto-Microcontinent (offshore of West Greenland) Laccadive Plateau (Indian Ocean)
Age	Microcontinents can range from tens of millions to several hundred million years old depending on tectonic history of region.
Crust Characteristics	Often features thick continental crust surrounded by thinner oceanic crust.
Significance in Plate Tectonics	They provide evidence for past tectonic events such as continental break-up, rifting & oceanic crust formation.
Potential for Mineral Resources	Microcontinents often contain valuable mineral deposits particularly in areas of past volcanic activity.
Impact on Seafloor Spreading	Microcontinents may play a role in alteration of seafloor spreading patterns affecting ocean circulation & global tectonics.
Key Studies	Studies focus on movement & separation of these small landmasses & how they influence larger plate movements.

Major Tectonic Events of Paleogene Period

Aspect	Details
Geological Timeframe	~66 to 23 million years ago (Ma)
Major Tectonic Plates	North American, Eurasian, African, Indian, Pacific, Antarctic, South American, Australian
Key Events	Continued break-up of Gondwana Opening of North Atlantic Seafloor spreading in Labrador Sea & Baffin Bay Alpine orogeny
North Atlantic Opening	Seafloor spreading intensified between Greenland & North America; development of Davis Strait microcontinent
Indian Plate Movement	Indian Plate moved rapidly northwards (~15–20 cm/year), collided with Eurasian Plate (~55 Ma), initiating Himalayan orogeny
Alpine Orogeny	Formation of Alps, Carpathians, Zagros & related mountain systems due to Africa-Eurasia collision
Pacific Plate Changes	Subduction zones active along eastern Asia & western Americas Volcanic arcs & mountain belts formed
South Atlantic Expansion	Further rifting between South America & Africa; expansion of South Atlantic Ocean
Transform Faulting	Major transform faults such as San Andreas Fault began developing towards late Paleogene
Greenland–Canada Rifting	Formation of Davis Strait proto-microcontinent due to altered spreading direction along Pre-Ungava Transform (~49–58 Ma)
Oceanic Changes	Formation of deep ocean basins, rearrangement of global ocean currents, affecting global climate
Volcanic Activity	Intense volcanism in North Atlantic Igneous Province (NAIP); creation of flood basalts, dykes & sills
Climate & Tectonics Link	Tectonic reconfigurations changed ocean currents, triggering Paleocene-Eocene Thermal Maximum (PETM) ~56 Ma
Significance	Plate tectonics reshaped continents & ocean basins Gave rise to modern mountain ranges & microcontinents

Paleogene Tectonics by Continent

Continent / Region	Tectonic Events during Paleogene (66–23 Ma)
North America	Opening of Labrador Sea & Baffin Bay Rifting along Greenland-Canada margin Formation of Davis Strait microcontinent
South America	Continued westward drift Andes Mountain building due to Nazca Plate subduction Expansion of South Atlantic Ocean
Europe	Alpine Orogeny due to collision with African Plate Closure of Tethys Sea Uplift of Carpathians & Apennines
Africa	Northward movement Initiation of collision with Europe Volcanism in East African Rift System (earliest stages)
Asia	Collision of Indian Plate with Eurasia (~55 Ma) Onset of Himalayan Orogeny Tibetan Plateau began rising
India	Rapid northward drift (~15–20 cm/year) Major impact with Eurasian Plate at ~55 Ma
Australia	Broke away from Antarctica Drifted northwards Initiated formation of Coral Sea & Tasman Sea
Antarctica	Separation from Australia & South America Formation of Southern Ocean Cooling & glaciation began
Greenland	Partially rifted from North America Formation of Davis Strait & associated proto-microcontinent
Pacific Region	Subduction along Ring of Fire intensified Formation of island arcs & deep ocean trenches

Cretaceous vs Paleogene Tectonics

Aspect	Cretaceous (145–66 Ma)	Paleogene (66–23 Ma)
Major Plate Movements	- Breakup of Gondwana - Opening of South Atlantic & Indian Oceans	- Continued drift of continents - Opening of North Atlantic - Collision of India with Eurasia
Mountain Building	Limited Some uplift in Andes & Rockies	Major orogenies: Himalayas, Alps, Carpathians, Zagros
Seafloor Spreading	Active in Atlantic, Indian Ocean	Continued in North Atlantic, Labrador Sea, Baffin Bay
Greenland–Canada Rift	Early stages of separation	Formation of Davis Strait proto-microcontinent due to change in seafloor spreading orientation (~49–58 Ma)
Climate Influence	Greenhouse conditions dominated	Initiation of cooling trend PETM (~56 Ma) linked to tectonic reconfigurations
Volcanism	Large igneous provinces like Deccan Traps (late Cretaceous)	North Atlantic Igneous Province (NAIP) activity Regional volcanism in East Africa & western North America
Ocean Currents	Simple equatorial circulation	More complex deep ocean currents began due to continental reorganization
Significant Microcontinents	Formation of some continental fragments (e.g., Greater Adria)	Davis Strait proto-microcontinent formed between Greenland & Baffin Island