Mainland islands (examples will be given below) are part of the land that was previously part of the continent, and later separated from it. This occurs as a result of various hydrological or geological processes. As a rule, the mainland and the island have a fairly similar relief. They are separated by water areas, such as shelf seas and straits. The observation of scientists shows that the distance between the main landmass and the island can vary. This is due to the mobility of the earth's crust.
Islands of mainland origin are divided into several types. All of them are connected with their continents at the genetic level. However, despite this, the flora and fauna of such islands can differ significantly. So, let's look at the types of islands depending on the origin.
Platform mainland islands
Platform islands, in fact, are a continuation of the continent. They lie on the continental shelf and are separated from the mainland area by various water areas, such as straits and seas. The islands of the Canadian archipelago, Severnaya Zemlya, Svalbard and British have such an origin. These land areas practically do not differ from the mainland in flora and fauna. And this is due to the fact that they were formed relatively recently.
Islands of the mainland slope
The second type is the islands of the continental slope. They are not much different from the first, but their break with the continent took place a little earlier. Unlike platform ones, their separation from the main land occurred due to deep tectonic splits, and not troughs, as in the first case. A mainland island of this type is separated from the continent by an oceanic strait. Prominent examples are Fr. Greenland and about. Madagascar.
Orogenic Islands
The third type is orogenic islands. These land areas are formed from the continuation of the mountain folds of the mainland. These include New Zealand, Tasmania, Fr. Nova Zemlya, which, in fact, is a continuation of the Ural Mountains. They are all orogenic continental islands. Examples can go on and on. Sakhalin, which is a continuation of the Far Eastern mountain range.
Island arcs
And finally, the most active type of mainland islands - island arcs. They are found in large numbers on the coast of East Asia, Central America and between South America and Antarctica. These include the Japanese island arc, the Aleutian, the Philippine and others. It is worth noting that it is these areas of land inare currently in an area of high crustal activity.
Features
Due to its remoteness from the main continent and complete isolation from other lands, the mainland island has a high level of endemic flora and fauna. The earlier it separated from the mainland, the more peculiar its flora and fauna. Islands such as Hawaii, Novaya Zemlya are located at a considerable distance from their continents. This led to the formation of more than 70% of endemics in the flora and fauna of these lands. Also, representatives of the animal world live on the islands, which have some deviations from the usual norms. For example, gigantism in reptiles and, conversely, island mammals are usually smaller than on the mainland. The first group includes Komodo monitor lizards and Galapagos tortoises - they are unusually large in size. The second includes various types of ungulates.
Tasmania
The mainland island of Tasmania is separated from the mainland by Bass Strait. Its geological structure and topography allow us to say that this is a continuation of the East Australian mountains. The island has a unique fauna. Animals from Antarctica are found here, as well as a number of some representatives that have long been destroyed on the mainland.
New Earth
The archipelago of Novaya Zemlya is also classified by scientists as a continental type. The main islands are separated from each other by the narrow strait Matochkin Shar. The archipelago is also washed by the Kara Strait, which separates it from Vaygach Island.
Sakhalin Island
Sakhalin Island –mainland island. Located off the east coast of Asia. It is separated by the Strait of La Perouse from about. Hakkaido, whose minimum width is 40 km, as well as Tatar (from the mainland) and Nevel. The latter freezes in winter and has a width of no more than 8 km.
Islands of New Zealand
The islands of New Zealand have a mainland origin. The arc on which they are located is located from New Guinea for the entire length of Australia. There are many faults in New Zealand, accompanied by volcanic eruptions and earthquakes.
After reading the information in the article, everyone will be able to correctly answer which islands are mainland.
