The Taltson Magmatic Zone (TMZ) is a north-trending belt of Archean to Paleoproterozoic granitic basement gneiss, amphibolite supracrustal gneissic rock and Paleoproterozoic magmatic rocks in the Canadian Shield, extending from Northern Alberta to the southwestern Northwest Territories. [1] The TMZ basement is 3.2–3.0 Ga and the Rutledge River supracrustal gneisses 2.13–2.09 Ga years old and were intruded by magmatic rocks around 1.99–1.92 Ga. [2]
The 300 km (190 mi) long exposed part of the TMZ in Northern Alberta and the Northwest Territories is bounded by the Great Slave Lake shear zone to the north and by the subsurface Snowbird Tectonic Zone to the south. TMZ is an Andean-type continental magmatic arc and an orogenic belt between the subsurface Buffalo Head Terrane on the west and the Archean Churchill Province on the east. It is also the southern continuation of the Thelon Magmatic Zone, an orogenic belt between the Slave and Churchill cratons. [3] The northern TMZ is divided by major faults and can be subdivided into two main terranes: an eastern gneiss framework and the TMZ batholiths in the west. [4]
The exposed basement in northern Alberta is composed of banded gneissic rocks, predominantly 2.4–2.1 Ga metaplutonic gneissic rock, but it also contains amphibolitic gneiss and paragneiss. This basement also contains slices of Archean gneissic rock up to 3.73 Ga-old; an age similar to those of the Hearne and Rae cratons (also known as the Western Churchill Province), which can indicate that TMZ represents the recycling of parts of this province. [1]
The U–Pb ages and the isotopic composition of TMZ and the Buffalo Head Terrane (west of TMZ), including the Buffalo Head Hills kimberlite field, are identical. It is possible that these two domains represent a single Paleoproterozoic block. This block is composed mostly of contribution from depleted mantle sources but with contribution from the Churchill Province. TMZ basement rock together with the Buffalo Head terrane can represent the earliest Paleoproterzoic magmatism, pre-dating the break-up of the Churchill Province and the Taltson–Thelon orogeny. [1]
The Ungava Peninsula of Nunavik, Quebec, Canada, is bounded by Hudson Bay to the west, Hudson Strait to the north, and Ungava Bay to the east. This peninsula is part of the Labrador Peninsula, and covers about 252,000 square kilometres (97,000 sq mi). Its northernmost point is Cape Wolstenholme, which is also the northernmost point of Quebec. The peninsula is also part of the Canadian Shield, and consists entirely of treeless tundra dissected by large numbers of rivers and glacial lakes, flowing generally east–west in a parallel fashion. The peninsula was not deglaciated until 6,500 years ago and is believed to have been the prehistoric centre from which the vast Laurentide Ice Sheet spread over most of North America during the last glacial epoch.
The Slave Craton is an Archaean craton in the north-western Canadian Shield, in Northwest Territories and Nunavut. The Slave Craton includes the 4.03 Ga-old Acasta Gneiss which is one of the oldest dated rocks on Earth. Covering about 300,000 km2 (120,000 sq mi), it is a relatively small but well-exposed craton dominated by ~2.73–2.63 Ga greenstones and turbidite sequences and ~2.72–2.58 Ga plutonic rocks, with large parts of the craton underlain by older gneiss and granitoid units. The Slave Craton is one of the blocks that compose the Precambrian core of North America, also known as the palaeocontinent Laurentia.
The Kaapvaal Craton, along with the Pilbara Craton of Western Australia, are the only remaining areas of pristine 3.6–2.5 Ga crust on Earth. Similarities of rock records from both these cratons, especially of the overlying late Archean sequences, suggest that they were once part of the Vaalbara supercontinent.
The Churchill Craton is the northwest section of the Canadian Shield and stretches from southern Saskatchewan and Alberta to northern Nunavut. It has a very complex geological history punctuated by at least seven distinct regional tectonometamorphic intervals, including many discrete accretionary magmatic events. The Western Churchill province is the part of the Churchill Craton that is exposed north and west of the Hudson Bay. The Archean Western Churchill province contributes to the complicated and protracted tectonic history of the craton and marks a major change in the behaviour of the Churchill Craton with many remnants of Archean supracrustal and granitoid rocks.
The Rae Craton is an Archean craton located in northern Canada north of the Superior Craton.
The Limpopo Belt is located in South Africa and Zimbabwe, runs E-NE, and joins the Kaapvaal Craton to the south with the Zimbabwe Craton to the north. The belt is of high-grade metamorphic rocks that have undergone a long cycle of metamorphism and deformation that ended 2.0 billion years ago, after the stabilisation of the adjacent massifs. The belt comprises 3 components: the Central Zone, the North Marginal Zone and the South Marginal Zone.
The Wyoming Craton is a craton in the west-central United States and western Canada – more specifically, in Montana, Wyoming, southern Alberta, southern Saskatchewan, and parts of northern Utah. Also called the Wyoming Province, it is the initial core of the continental crust of North America.
The Great Bear Magmatic Zone (GBMZ) is a Paleoproterozoic (1.875–1.86 Ga) multi-collisional orogenic belt of which 100 km × 400 km is exposed in the northwestern Canadian Shield east of Great Bear Lake, Northwest Territories.
The Lewisian complex or Lewisian gneiss is a suite of Precambrian metamorphic rocks that outcrop in the northwestern part of Scotland, forming part of the Hebridean Terrane and the North Atlantic Craton. These rocks are of Archaean and Paleoproterozoic age, ranging from 3.0–1.7 billion years (Ga). They form the basement on which the Torridonian and Moine Supergroup sediments were deposited. The Lewisian consists mainly of granitic gneisses with a minor amount of supracrustal rocks. Rocks of the Lewisian complex were caught up in the Caledonian orogeny, appearing in the hanging walls of many of the thrust faults formed during the late stages of this tectonic event.
The Wopmay orogen is a Paleoproterozoic orogenic belt in northern Canada which formed during the collision between the Hottah terrane, a continental magmatic arc, and the Archean Slave Craton at about 1.88 Ga. The collision lead to the short-lived Calderian orogeny. The formation was named for Wilfrid Reid "Wop" May, OBE, DFC, a Canadian flying ace in the First World War and a leading post-war aviator.
The Grouse Creek block is a Precambrian basement province of 2.45 to 2.70 billion year old orthogneisses. The Grouse Creek block is one of several Proterozoic and Archean accreted terranes that lie to the north and west of the Wyoming craton, including the Farmington Canyon Complex, the Selway terrane, the Medicine Hat block and the Priest River complex. Together, these terranes comprise part of the basement rock of the North American continent and have been critical to studies of crustal accretion in the Precambrian. Ongoing study of the Grouse Creek block will contribute to understanding the paleogeography of the Wyoming craton prior to its incorporation into the supercontinent Laurentia approximately 1.86 billion years ago. The name was proposed by David Foster and others.
The Buffalo Head Terrane (BHT) is a terrane in the western Canadian Shield in northern Alberta. It is covered by 1,600 m (5,200 ft) of Devonian and Cretaceous sediments and its centre is intruded by the 88–86 Ma kimberlites of the diamondiferous Buffalo Head Hills kimberlite province.
The Hottah terrane is a Paleoproterozoic terrane in the northwestern end of the Canadian Shield which is exposed near Hottah Lake, Northwest Territories. It is a belt of multi-deformed metasedimentary and metavolcanic rocks intruded by a series of diorite to granite plutons. Forming the western part of the Wopmay orogenic system, the 1.9 Ga Hottah terrane is separated from the Archean rocks of the orogen by the north-trending Wopmay fault zone and overprinted by the 1.875-1.85 Ga Great Bear magmatism.
The Aravalli Mountain Range is a northeast-southwest trending orogenic belt in the northwest part of India and is part of the Indian Shield that was formed from a series of cratonic collisions. The Aravalli Mountains consist of the Aravalli and Delhi fold belts, and are collectively known as the Aravalli-Delhi orogenic belt. The whole mountain range is about 700 km long. Unlike the much younger Himalayan section nearby, the Aravalli Mountains are much older that can be traced back to the Proterozoic Eon. The collision between the Bundelkhand craton and the Marwar craton is believed to be the primary mechanism for the development of the mountain range.
Eoarchean geology is the study of the oldest preserved crustal fragments of Earth during the Eoarchean era from 4 to 3.6 billion years ago. Major well-preserved rock units dated Eoarchean are known from three localities, the Isua Greenstone Belt in Southwest Greenland, the Acasta Gneiss in the Slave Craton in Canada, and the Nuvvuagittuq Greenstone Belt in the eastern coast of Hudson Bay in Quebec. From the dating of rocks in these three regions scientists suggest that plate tectonics could go back as early as Eoarchean.
The Mars Hill Terrane (MHT) is a belt of rocks exposed in the southern Appalachian Mountains, between Roan Mountain, North Carolina and Mars Hill, North Carolina. The terrane is located at the junction between the Western Blue Ridge and the Eastern Blue Ridge Mountains.
The geology of Alberta encompasses parts of the Canadian Rockies and thick sedimentary sequences, bearing coal, oil and natural gas, atop complex Precambrian crystalline basement rock.
The Grenville Province is a tectonically complex region, in Eastern Canada, that contains many different aged accreted terranes from various origins. It exists southeast of the Grenville Front and extends from Labrador southwestern to Lake Huron. It is bounded by the St. Lawrence River/Seaway to the southeast.
The Eastern Block of the North China Craton is one of the Earth's oldest pieces of continent. It is separated from the Western Block by the Trans-North China Orogen. It is situated in northeastern China and North Korea. The Block contains rock exposures older than 2.5 billion years. It serves as an ideal place to study how the crust was formed in the past and the related tectonic settings.
The Western Block of the North China Craton is an ancient micro-continental block mainly composed of Neoarchean and Paleoproterozoic rock basement, with some parts overlain by Cambrian to Cenozoic volcanic and sedimentary rocks. It is one of two sub-blocks within the North China Craton, located in east-central China. The boundaries of the Western Block are slightly different among distinct models, but the shapes and areas are similar. There is a broad consensus that the Western Block covers a large part of the east-central China.