The Monteregian Hills () is a linear chain of isolated mountains in
Montreal
Montreal is the List of towns in Quebec, largest city in the Provinces and territories of Canada, province of Quebec, the List of the largest municipalities in Canada by population, second-largest in Canada, and the List of North American cit ...
and
Montérégie
Montérégie () is an administrative region in the southwest part of Quebec. It includes the cities of Boucherville, Brossard, Châteauguay, Longueuil, Saint-Hyacinthe, Saint-Jean-sur-Richelieu, Salaberry-de-Valleyfield and Vaudreuil-Dorion.
...
, between the
Laurentian Mountains
The Laurentian Mountains, also known as the Laurentians or Laurentides, are a mountain range in Canada. The range is long and ranges in height from with peaks over . The Laurentian Mountains extend across Labrador and Quebec within the Laurent ...
and the
Appalachians
The Appalachian Mountains, often called the Appalachians, are a mountain range in eastern to northeastern North America. The term "Appalachian" refers to several different regions associated with the mountain range, and its surrounding terrain ...
.
Etymology
The first definition of the Monteregian Hills came about in 1903 when Montreal geologist Frank Dawson Adams began referring to
Mount Royal
Mount Royal (, ) is a mountain in the city of Montreal, immediately west of Downtown Montreal, Quebec, Canada. The city's name is derived from the mountain's name.
The mountain is part of the Monteregian Hills situated between the Laurentian M ...
(
Latin
Latin ( or ) is a classical language belonging to the Italic languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...
, ''Mons Regius'') and mountains of similar geology in the Saint Lawrence Lowlands as the "Royal Mountains" (). Other mountains in the chain included Mont Saint-Bruno,
Mont Saint-Hilaire
Mont Saint-Hilaire (; English: Mount Saint-Hilaire; ;, ; see for other names) is a mountain, high, in the Montérégie region of southern Quebec. It is about thirty kilometres east of Montreal, and immediately east of the Richelieu River. It ...
Each mountain in the chain consists of an erosional remnant of
Cretaceous
The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...
igneous
Igneous rock ( ), or magmatic rock, is one of the three main rock types, the others being sedimentary and metamorphic. Igneous rocks are formed through the cooling and solidification of magma or lava.
The magma can be derived from partial ...
rock
Rock most often refers to:
* Rock (geology), a naturally occurring solid aggregate of minerals or mineraloids
* Rock music, a genre of popular music
Rock or Rocks may also refer to:
Places United Kingdom
* Rock, Caerphilly, a location in Wale ...
and associated
hornfels
Hornfels is the group name for a set of Metamorphism#Contact .28thermal.29, contact metamorphic rocks that have been baked and hardened by the heat of Intrusive rock, intrusive igneous masses and have been rendered massive, hard, splintery, and in ...
, which are more resistant to
weathering
Weathering is the deterioration of rocks, soils and minerals (as well as wood and artificial materials) through contact with water, atmospheric gases, sunlight, and biological organisms. It occurs '' in situ'' (on-site, with little or no move ...
than the surrounding
sedimentary
Sedimentary rocks are types of rock formed by the cementation of sediments—i.e. particles made of minerals (geological detritus) or organic matter (biological detritus)—that have been accumulated or deposited at Earth's surface. Sedime ...
rock. All of the mountains have dark-coloured
mafic
A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include ...
rock such as
gabbro
Gabbro ( ) is a phaneritic (coarse-grained and magnesium- and iron-rich), mafic intrusive igneous rock formed from the slow cooling magma into a holocrystalline mass deep beneath the Earth's surface. Slow-cooling, coarse-grained gabbro is ch ...
syenite
Syenite is a coarse-grained intrusive igneous rock with a general composition similar to that of granite, but deficient in quartz, which, if present at all, occurs in relatively small concentrations (< 5%). It is considered a Great Meteor hotspot track, formed as a result of the North American Plate sliding westward over the long-lived New England hotspot, and are the
eroded
Erosion is the action of surface processes (such as water flow or wind) that removes soil, rock, or dissolved material from one location on the Earth's crust and then transports it to another location where it is deposited. Erosion is disti ...
remnants of intrusive
stocks
Stocks are feet and hand restraining devices that were used as a form of corporal punishment and public humiliation. The use of stocks is seen as early as Ancient Greece, where they are described as being in use in Solon's law code. The law de ...
. These intrusive stocks have been variously interpreted as the feeder intrusions of long
extinct volcano
A volcano is commonly defined as a vent or fissure in the Crust (geology), crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and volcanic gas, gases to escape from a magma chamber below the surface.
On Earth ...
es, which would have been active about 125 million years ago,A Hundred-Million Year History of the Corner Rise and New England Seamounts http://www.oceanexplorer.noaa.gov/explorations/05stepstones/background/geologic_history/geologic_history.html Retrieved on 2007-08-01 or as intrusives that never breached the surface in volcanic activity. The lack of an obvious track west of the Monteregian Hills may be due either to failure of the plume to penetrate the
Canadian Shield
The Canadian Shield ( ), also called the Laurentian Shield or the Laurentian Plateau, is a geologic shield, a large area of exposed Precambrian igneous and high-grade metamorphic rocks. It forms the North American Craton (or Laurentia), th ...
, to the lack of recognizable intrusions, or to strengthening of the plume when it approached the Monteregian Hills region. However, there is evidence the hotspot track extends northwestwards, including epeirogenic uplift, mantle velocity anomalies and kimberlitic volcanic features (e.g. the Attawapiskat,
Kirkland Lake
Kirkland Lake is a town and municipality in Timiskaming District, Ontario, Timiskaming District of Northeastern Ontario. The 2021 population, according to Statistics Canada, was 7,750.
The community name was based on a nearby lake which in turn ...
and
Lake Timiskaming
Lake Timiskaming or Lake Temiskaming (, ) is a large freshwater lake on the Provinces and territories of Canada, provincial boundary between Ontario and Quebec, Canada. The lake, which forms part of the Ottawa River, is in length and covers ...
kimberlite fields) that become older away from the Monteregian Hills.
The shallow, rocky sandy loam soils of the summits are mostly covered in
forest
A forest is an ecosystem characterized by a dense ecological community, community of trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, ...
. Where the underlying rock is rich in
olivine
The mineral olivine () is a magnesium iron Silicate minerals, silicate with the chemical formula . It is a type of Nesosilicates, nesosilicate or orthosilicate. The primary component of the Earth's upper mantle (Earth), upper mantle, it is a com ...
, as over large areas of Mont Saint-Bruno and Mont Rougemont, these soils are classed as dystric brunisol. Podzol tends to develop over rock which lacks olivine, although many of these podzols lack an eluvial (Ae) horizon. Lower slopes are covered with aprons of gravel or sand. The sandy soils are usually podzols with classic Ae development; they often have subsoil hardpan and are undesirable for agriculture. The free-draining gravels are preferred for
apple
An apple is a round, edible fruit produced by an apple tree (''Malus'' spp.). Fruit trees of the orchard or domestic apple (''Malus domestica''), the most widely grown in the genus, are agriculture, cultivated worldwide. The tree originated ...
orchards, which grow in thermal belts where cold air can drain to the valley floor.https://sis.agr.gc.ca/cansis/publications/surveys/pq/pq62/pq62_report.pdf Orchard Soils of the Province of Quebec
Gallery
Monteregian Hills in the Fall.jpg, Four of the Monteregian Hills in the late fall
Mont Saint-Hilaire south.jpg,
Mont Saint-Hilaire
Mont Saint-Hilaire (; English: Mount Saint-Hilaire; ;, ; see for other names) is a mountain, high, in the Montérégie region of southern Quebec. It is about thirty kilometres east of Montreal, and immediately east of the Richelieu River. It ...
Volcanism of Canada
Volcanic activity is a major part of the geology of Canada and is characterized by many types of volcanic landform, including lava flows, volcanic plateaus, lava domes, cinder cones, stratovolcanoes, shield volcanoes, submarine volcanoes, calder ...