The geology of Quebec involves several different geologic provinces, made up of ancient Precambrian crystalline igneous and metamorphic rock, overlain by younger sedimentary rocks and soils. Most of southern Quebec is dominated by the Grenville Province, while the vast north is divided between the large Superior Province and the Churchill Province to the east, near Labrador. [1]
The Grenville Province, which dominates southern Quebec, particularly the northern shore of the St. Lawrence formed beginning in the Archean, more than 2.5 billion years ago. Geologists subdivide the Grenville Province into the Allochthon along the river itself and the more northern Parautochthon. [2]
The Parautochthon is a band running parallel to the Grenville Front, which varies in width from Labrador to northeastern Georgian Bay on Lake Huron. Parautochthonous rocks are made up composed of ancient Archean and Proterozoic rocks that are highly deformed plutonic and metamorphosed supracrustal (metasedimentary and metavolcanic) rocks that reached greenschist to granulite facies on the sequence of metamorphic facies during the Grenville orogeny. These rocks correlate with the least deformed rocks north of the Grenville Front in the Superior Province and show signs of east-west lateral extension. [2]
The Allochthon includes all the lands of the Grenville Province south of the Parautochtone. The Allochthon juxtaposed on the Parautochthon during the Grenville orogeny cycle from 1.09 billion to 985 million years ago. The Allochthon is composed of Paleoproterozoic to Mesoproterozoic rocks. In the western part, it is mainly marble, quartzite, and pelite platform levels and Mesoproterozoic amphibolite-grade rocks. There are also charnockite and anorthosite intrusions that intersect metasediments and orthogneiss. In the center, migmatite, quartzo-feldspathic orthogneisses and mangerites predominate. In its eastern part, it consists mainly of gneissic rocks of varied composition and origin, metasedimentary rocks, granitoid intrusions, gabbro, gabbronorite and anorthosite. There are also several anorthositic intrusions scattered throughout the Allochthon belt. [2]
The Canadian Shield spans much of northern Quebec, which is primarily underlain by the Superior Craton, a 160-mile thick section of stable continental crust formed beginning 4.03 billion years ago. In the northwest and at the northern tip of the Ungava Peninsula is the large Churchill Craton, which extends into Labrador and Nunavut as the eastern extent of the Canadian Shield. Quebec's northern bedrock is also regionally composed of the Hudson Platform along the shore of James Bay and a small section of the Nain Province, near the northern tip of Labrador.
The St. Lawrence Platform occupies the lowlands where much of Quebec's urban population lives, while the Gaspé Peninsula, Anticosti Island and the Magdalene Islands are part of the Appalachian Province. [3]
During the Taconic orogeny that began the formation of the Appalachian Mountains, amphibolite, mica schist and other metamorphic rocks formed a belt running down the Gaspe Peninsula to Sherbrooke. Muscovite bearing granites and metamorphic rocks around Asbestos formed over a broad span from 468 to 379 million years ago. While slate and plutonic tonalite formed in the vicinity of Becancour and Quebec City respectively. [1]
Around 292 million years ago, volcanism deposited tuff in the Magdalene Islands. [1]
Sedimentary deposition and some volcanic activity took place during the Mesozoic, particularly in the lowlands of the St. Lawrence Platform. Central Montreal is underlain by 119 to 117 million year old plutonic basanite, lamprophyre and camptonite while to the immediate southeast amphibole gabbro and peralkaline rocks formed from 141 to 123 million years ago.
Cretaceous intrusive rocks formed hills housed in the sedimentary rocks of the St. Lawrence Lowlands Platform, notably Mount St. Bruno.
Quebec experienced intense erosion during the past 2.5 million years of the Quaternary, which often mobilized older rocks, such as Proterozoic granite boulders found offshore in the moraines which formed parts of the Magdalene Islands.
The Grenville orogeny was a long-lived Mesoproterozoic mountain-building event associated with the assembly of the supercontinent Rodinia. Its record is a prominent orogenic belt which spans a significant portion of the North American continent, from Labrador to Mexico, as well as to Scotland.
The Gascoyne Complex is a terrane of Proterozoic granite and metamorphic rock in the central-western part of Western Australia. The complex outcrops at the exposed western end of the Capricorn Orogen, a 1,000 km-long arcuate belt of folded, faulted and metamorphosed rocks between two Archean cratons; the Pilbara craton to the north and the Yilgarn craton to the south. The Gascoyne Complex is thought to record the collision of these two different Archean continental fragments during the Capricorn Orogeny at 1830–1780 Ma.
The geology of the Rocky Mountains is that of a discontinuous series of mountain ranges with distinct geological origins. Collectively these make up the Rocky Mountains, a mountain system that stretches from Northern British Columbia through central New Mexico and which is part of the great mountain system known as the North American Cordillera.
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 Labrador Trough or the New Quebec Orogen is a 1,600 km (994 mi) long and 160 km (99 mi) wide geologic belt in Canada, extending south-southeast from Ungava Bay through Quebec and Labrador.
The Algoman orogeny, known as the Kenoran orogeny in Canada, was an episode of mountain-building (orogeny) during the Late Archean Eon that involved repeated episodes of continental collisions, compressions and subductions. The Superior province and the Minnesota River Valley terrane collided about 2,700 to 2,500 million years ago. The collision folded the Earth's crust and produced enough heat and pressure to metamorphose the rock. Blocks were added to the Superior province along a 1,200 km (750 mi) boundary that stretches from present-day eastern South Dakota into the Lake Huron area. The Algoman orogeny brought the Archean Eon to a close, about 2,500 million years ago; it lasted less than 100 million years and marks a major change in the development of the Earth's crust.
In Labrador, Canada, the North Atlantic Craton is known as the Nain Province. The Nain geologic province was intruded by the Nain Plutonic Suite, which divides the province into the northern Saglek block and the southern Hopedale block.
The Vishnu Basement Rocks is the name recommended for all Early Proterozoic crystalline rocks exposed in the Grand Canyon region. They form the crystalline basement rocks that underlie the Bass Limestone of the Unkar Group of the Grand Canyon Supergroup and the Tapeats Sandstone of the Tonto Group. These basement rocks have also been called either the Vishnu Complex or Vishnu Metamorphic Complex. These Early Proterozoic crystalline rocks consist of metamorphic rocks that are collectively known as the Granite Gorge Metamorphic Suite; sections of the Vishnu Basement Rocks contain Early Paleoproterozoic granite, granitic pegmatite, aplite, and granodiorite that have intruded these metamorphic rocks, and also, intrusive Early Paleoproterozoic ultramafic rocks.
The geology of Ontario is the study of rock formations in the most populated province in Canada- it is home to some of the oldest rock on Earth. The geology in Ontario consists of ancient Precambrian igneous and metamorphic rock which sits under younger, sedimentary rocks and soils.
The geology of Somalia is built on more than 700 million year old igneous and metamorphic crystalline basement rock, which outcrops at some places in northern Somalia. These ancient units are covered in thick layers of sedimentary rock formed in the last 200 million years and influenced by the rifting apart of the Somali Plate and the Arabian Plate. The geology of Somaliland, the de facto independent country recognized as part of Somalia, is to some degree better studied than that of Somalia as a whole. Instability related to the Somali Civil War and previous political upheaval has limited geologic research in places while heightening the importance of groundwater resources for vulnerable populations.
The geology of the Democratic Republic of the Congo is extremely old, on the order of several billion years for many rocks. The country spans the Congo Craton: a stable section of ancient continental crust, deformed and influenced by several different mountain building orogeny events, sedimentation, volcanism and the geologically recent effects of the East African Rift System in the east. The country's complicated tectonic past have yielded large deposits of gold, diamonds, coltan and other valuable minerals.
The geology of Mauritania is built on more than two billion year old Archean crystalline basement rock in the Reguibat Shield of the West African Craton, a section of ancient and stable continental crust. Mobile belts and the large Taoudeni Basin formed and filled with sediments in the connection with the Pan-African orogeny mountain building event 600 million years ago and a subsequent orogeny created the Mauritanide Belt. In the last 251 million years, Mauritania has accumulated additional sedimentary rocks during periods of marine transgression and sea level retreat. The arid country is 50% covered in sand dunes and has extensive mineral resources, although iron plays the most important role in the economy.
The geology of Niger comprises very ancient igneous and metamorphic crystalline basement rocks in the west, more than 2.2 billion years old formed in the late Archean and Proterozoic eons of the Precambrian. The Volta Basin, Air Massif and the Iullemeden Basin began to form in the Neoproterozoic and Paleozoic, along with numerous ring complexes, as the region experienced events such as glaciation and the Pan-African orogeny. Today, Niger has extensive mineral resources due to complex mineralization and laterite weathering including uranium, molybdenum, iron, coal, silver, nickel, cobalt and other resources.
The geology of Nigeria formed beginning in the Archean and Proterozoic eons of the Precambrian. The country forms the Nigerian Province and more than half of its surface is igneous and metamorphic crystalline basement rock from the Precambrian. Between 2.9 billion and 500 million years ago, Nigeria was affected by three major orogeny mountain-building events and related igneous intrusions. Following the Pan-African orogeny, in the Cambrian at the time that multi-cellular life proliferated, Nigeria began to experience regional sedimentation and witnessed new igneous intrusions. By the Cretaceous period of the late Mesozoic, massive sedimentation was underway in different basins, due to a large marine transgression. By the Eocene, in the Cenozoic, the region returned to terrestrial conditions.
The geology of Bosnia & Herzegovina is the study of rocks, minerals, water, landforms and geologic history in the country. The oldest rocks exposed at or near the surface date to the Paleozoic and the Precambrian geologic history of the region remains poorly understood. Complex assemblages of flysch, ophiolite, mélange and igneous plutons together with thick sedimentary units are a defining characteristic of the Dinaric Alps, also known as the Dinaride Mountains, which dominate much of the country's landscape.
The geology of Sweden is the regional study of rocks, minerals, tectonics, natural resources and groundwater in the country. The oldest rocks in Sweden date to more than 2.5 billion years ago in the Precambrian. Complex orogeny mountain building events and other tectonic occurrences built up extensive metamorphic crystalline basement rock that often contains valuable metal deposits throughout much of the country. Metamorphism continued into the Paleozoic after the Snowball Earth glaciation as the continent Baltica collided with an island arc and then the continent Laurentia. Sedimentary rocks are most common in southern Sweden with thick sequences from the last 250 million years underlying Malmö and older marine sedimentary rocks forming the surface of Gotland.
The geology of North Carolina includes ancient Proterozoic rocks belonging to the Grenville Province in the Blue Ridge. The region experienced igneous activity and the addition of new terranes and orogeny mountain building events throughout the Paleozoic, followed by the rifting of the Atlantic Ocean and the deposition of thick sediments in the Coastal Plain and offshore waters.
Geology of Latvia includes an ancient Archean and Proterozoic crystalline basement overlain with Neoproterozoic volcanic rocks and numerous sedimentary rock sequences from the Paleozoic, some from the Mesozoic and many from the recent Quaternary past. Latvia is a country in the Baltic region of Northern Europe.
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 geology of Newfoundland and Labrador includes basement rocks formed as part of the Grenville Province in the west and Labrador and the Avalonian microcontinent in the east. Extensive tectonic changes, metamorphism and volcanic activity have formed the region throughout Earth history.