The Meguma terrane, also known as Megumia, is a

terrane In geology, a terrane (; in full, a tectonostratigraphic terrane) is a crust fragment formed on a tectonic plate (or broken off from it) and accreted or " sutured" to crust lying on another plate. The crustal block or fragment preserves its own ...

exposed in southern

Nova Scotia Nova Scotia ( ; ; ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. Nova Scotia is Latin for "New Scotland". Most of the population are native Eng ...

, that became joined to the present

North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...

n landmass as part of the

Appalachian orogeny The Alleghanian orogeny or Appalachian orogeny is one of the geological mountain-forming events that formed the Appalachian Mountains and Allegheny Mountains. The term and spelling Alleghany orogeny was originally proposed by H.P. Woodward in 195 ...

. The exposed part of the Meguma terrane, the Meguma Group, is largely composed of thick

Cambrian The Cambrian Period ( ; sometimes symbolized C with bar, Ꞓ) was the first geological period of the Paleozoic Era, and of the Phanerozoic Eon. The Cambrian lasted 53.4 million years from the end of the preceding Ediacaran Period 538.8 million ...

Ordovician The Ordovician ( ) is a geologic period and System (geology), system, the second of six periods of the Paleozoic Era (geology), Era. The Ordovician spans 41.6 million years from the end of the Cambrian Period million years ago (Mya) to the start ...

turbidite A turbidite is the geologic deposit of a turbidity current, which is a type of amalgamation of fluidal and sediment gravity flow responsible for distributing vast amounts of clastic sediment into the deep ocean. Sequencing Turbidites were ...

s that have been interpreted as submarine fan deposits. The Meguma terrane is joined to the Avalon terrane along the

Minas Fault Zone Minas or MINAS may refer to: People with the given name Minas * Menas of Ethiopia (died 1563) * Saint Menas (Minas, 285–309) * Minias of Florence (Minas, Miniato, died 250) * Minas Alozidis (born 1984), Greek hurdler * Minas Avetisyan (1928 ...

, which runs east–west from

Chedabucto Bay Chedabucto Bay is a large bay on the eastern coast of mainland Nova Scotia between the Atlantic Ocean and the Strait of Canso next to Guysborough County. At the entrance to Chedabucto Bay is the community of Canso at the head is the community ...

Cobequid Bay Cobequid Bay is an inlet of the Bay of Fundy and the easternmost part of the Minas Basin, located in the Canadian province of Nova Scotia. The bay was carved by rivers flowing into the eastern end of the Bay of Fundy. The eastern end of the b ...

and the

Minas Basin , image = Lookout On Way to Cape Split - 25006718579.jpg , alt = , caption = Looking east across the Southern Bight of Minas Basin from The Lookoff , image_bathymetry = , alt_bathymetry = , ca ...

. The Meguma Group is intruded by numerous

Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...

and

Carboniferous The Carboniferous ( ) is a geologic period and system of the Paleozoic that spans 60 million years from the end of the Devonian Period million years ago ( Mya), to the beginning of the Permian Period, million years ago. The name ''Carbonifero ...

pluton In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

s. The extent of the formation is unclear; some geologists believe that a magnetic anomaly along the coast of

Cape Cod Cape Cod is a peninsula extending into the Atlantic Ocean from the southeastern corner of mainland Massachusetts, in the northeastern United States. Its historic, maritime character and ample beaches attract heavy tourism during the summer mont ...

may represent a suture between the Meguma and Avalon terranes in that region. Unlike the Avalon terrane, the Meguma terrane has not been definitely associated with a territory on the other side of the Atlantic. It may be represented in either the Galicia-Tras-Os-Montes Zone in Spain and Portugal; the

West African Craton The West African Craton (WAC) is one of the five cratons of the Precambrian basement rock of Africa that make up the African Plate, the others being the Kalahari craton, Congo craton, Saharan Metacraton and Tanzania Craton.Jessell M.W., Liégeo ...

in Morocco; or the

Amazonian Craton The Amazonian Craton is a geologic province located in South America. It occupies a large portion of the central, north and eastern part of the continent and represents one of Earth's largest cratonic regions. The Guiana Shield and Central Brazi ...

. Meguma was, nevertheless, part of

Gondwana Gondwana () was a large landmass, often referred to as a supercontinent, that formed during the late Neoproterozoic (about 550 million years ago) and began to break up during the Jurassic period (about 180 million years ago). The final stages ...

during the Cambrian, and possibly formed a single peri-Gondwanan fragment together with Avalon. Meguma then became shortened during the Acadian orogeny but Avalon somehow escaped those Acadian deformations. Geologically this area is of interest not only to students of geological history, but because metamorphism produced

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile met ...

deposits which were mined extensively (up to ) in the latter half of the 19th century, and which remain potentially exploitable today during periods of higher gold prices.

References

; Notes ; Sources * * * * * Geography of Nova Scotia Natural history of North America Plate tectonics Terranes {{Canada-geology-stub

See also

References