Meguma terrane
Encyclopedia
The Meguma terrane is a terrane
Terrane
A terrane in geology is short-hand term for a tectonostratigraphic terrane, which is a fragment of crustal material formed on, or broken off from, one tectonic plate and accreted or "sutured" to crust lying on another plate...

 exposed in southern Nova Scotia
Nova Scotia
Nova Scotia is one of Canada's three Maritime provinces and is the most populous province in Atlantic Canada. The name of the province is Latin for "New Scotland," but "Nova Scotia" is the recognized, English-language name of the province. The provincial capital is Halifax. Nova Scotia is the...

, that became joined to the present North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

n landmass as part of the Appalachian orogeny. Composed largely of Cambrian
Cambrian
The Cambrian is the first geological period of the Paleozoic Era, lasting from Mya ; it is succeeded by the Ordovician. Its subdivisions, and indeed its base, are somewhat in flux. The period was established by Adam Sedgwick, who named it after Cambria, the Latin name for Wales, where Britain's...

 to Ordovician
Ordovician
The Ordovician is a geologic period and system, the second of six of the Paleozoic Era, and covers the time between 488.3±1.7 to 443.7±1.5 million years ago . It follows the Cambrian Period and is followed by the Silurian Period...

 sedimentary deposits, it is joined to the Avalon terrane
Avalonia
Avalonia was a microcontinent in the Paleozoic era. Crustal fragments of this former microcontinent underlie south-west Great Britain, and the eastern coast of North America. It is the source of many of the older rocks of Western Europe, Atlantic Canada, and parts of the coastal United States...

 along the Minas Fault Zone
Chedabucto Fault
The Chedabucto Fault is a fault that divides Mainland Nova Scotia from the Minas Basin in the west to Chedabucto Bay in the east into the Avalon zone in the north and the Meguma Zone in the south .The Avalon and Meguma Zones are different because they belonged to different land masses that were...

, which runs east-west from Chedabucto Bay
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...

 to Cobequid Bay
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....

 and the Minas Basin
Minas Basin
The Minas Basin is an inlet of the Bay of Fundy and a sub-basin of the Fundy Basin located in Nova Scotia, Canada. It is known for its extremely high tides.- Geography :- Boundary :...

. Numerous 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...

 and Carboniferous
Carboniferous
The Carboniferous is a geologic period and system that extends from the end of the Devonian Period, about 359.2 ± 2.5 Mya , to the beginning of the Permian Period, about 299.0 ± 0.8 Mya . The name is derived from the Latin word for coal, carbo. Carboniferous means "coal-bearing"...

 pluton
Pluton
A pluton in geology is a body of intrusive igneous rock that crystallized from magma slowly cooling below the surface of the Earth. Plutons include batholiths, dikes, sills, laccoliths, lopoliths, and other igneous bodies...

s are also found. The extent of the formation is unclear; some geologists believe that a magnetic anomaly along the coast of Cape Cod
Cape Cod
Cape Cod, often referred to locally as simply the Cape, is a cape in the easternmost portion of the state of Massachusetts, in the Northeastern United States...

 may represent a suture between the Meguma and Avalon terranes in that region. Unlike the Avalon terrane, the Meguma terrane has not been definitively associated with territory on the other side of the Atlantic. It may be represented in the Galicia-Tras-Os-Montes Zone in Spain and Portugal. It appears to have been separated from Gondwana
Gondwana
In paleogeography, Gondwana , originally Gondwanaland, was the southernmost of two supercontinents that later became parts of the Pangaea supercontinent. It existed from approximately 510 to 180 million years ago . Gondwana is believed to have sutured between ca. 570 and 510 Mya,...

, but there are competing theories as to whether it came from the northern or southern coast.

Geologically this area is of interest not only to students of geological history, but because metamorphism produced gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

deposits which were mined extensively in the latter half of the 19th century, and which remain potentially exploitable today.
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