The surface of our planet is surprisingly diverse due to the work of wind, flowing waters, glaciers, etc. One of the interesting and unusual landforms is the “ram's forehead”. How does it look and how is it formed?
Earth Relief: Glacial Forms
Large massifs of ice, referred to in science as glaciers, are doing tremendous geological work. First of all, this work consists in moving rock fragments, sometimes over very considerable distances.
The glacier, as you know, is formed from snow, which eventually turns into dense ice. Under the influence of gravity, this huge ice mass begins to move, “slide” on the earth's surface. Moreover, it exerts substantial mechanical pressure on the underlying surface. Figuratively speaking, the glacier, as it were, plows rocks located beneath it, transfers its fragments and deposits in the form of the so-called moraine. The composition of such a moraine can be very diverse. It depends on the geological structure of the area, as well as on the size of the glacier itself.
There are many different forms of glacial relief. Some of them are formed by mountain glaciers (cars, circuses, trogs and others). The formation of others is associated with the deposition of moraine material (zander, oz, kama and others).
In the geological history of the Earth there were at least four periods of glaciation, which scientists are aware of. Our planet experienced the last and most powerful of them relatively recently - in the Quaternary period. At this time, vast territories of North America, Europe and Asia were covered with a continuous shell of ice. Soft rocks glaciers simply "plowed". But if on their way there were solid crystalline rocks, then a unique landform could form - a “ram's forehead”. It will be discussed further.
Definition: “lamb foreheads” is ... The origin of the shape of the relief
What is a “lamb forehead”? In geography, this term refers to rocky ledges, the surface of which is smoothed and polished by a glacier. Moreover, the slope that was facing the movement of the glacier is more smooth and gentle. The opposite is usually steep and uneven.
“Lamb forehead” is a classic glacial landform. This term is usually written in quotation marks. Although many geologists believe that these quotes can be removed, because the concept has long lost its original metaphor.
These landforms are not very large in size. Their length rarely exceeds 100-200 meters, and their height reaches 50 meters. “Lamb foreheads” are found in zones of the last and more ancient periods of glaciation. They are widespread within the Baltic (northern Europe) and Canadian (North America) shields. The complex of several "mutton foreheads" is called curly rocks.
In Russia, “sheep’s foreheads” can be seen on the Kola Peninsula, in Karelia and in the Northern Ladoga. Very often they are located on the shores of northern lakes of glacial origin. We will talk about one of these lakes below.
Semenovskoe Lake - a recreational pearl of Murmansk
In the northern part of Murmansk, in the area of Chelyuskintsev Street, is located the picturesque Semenovskoe Lake. It was named after the local "overgrown and gray-haired" fisherman Semyon, who lived and fished on the shore of the Kola Bay.
The lake is small (the area of the water mirror is about 20 hectares). Its maximum depth is 18 meters. From November to May, the lake is covered with a thick layer of ice. The pond has an irregular shape and is connected to the Kola Bay by a stream.
Semenovskoe Lake is an important recreational and tourist attraction of the northern city. On its shores there is a children's town, a boat station, an aquarium and an amusement park. In the summer, a fountain runs in the middle of the pond. The city was presented to him by one of the enterprises of Kirovsk. The fountain blends wonderfully into the green zone of Murmansk.
In the summer, the water surface of Lake Semenovsky is cut by sailing regattas. In winter, a skier with pleasure goes on lake ice and lovers dive into the ice hole.
Natural monument: "ram's forehead" at Lake Semenovskoye
Murmansk is one of the northern cities of Russia. This is the largest settlement on the planet, located beyond the Arctic Circle. The city is located on the Kola Peninsula, on the east coast of the bay of the same name. It is here, as mentioned above, that unique forms of a glacial relief - “ram's foreheads” —are widespread. And one of them can be seen right in the city. This is the "ram's forehead" at Lake Semenovskoye.
Murmansk is located in the zone of the last (Quaternary) glaciation. Therefore, it is not surprising that the ancient glaciers left many traces on this earth.
The "ram's forehead" by Lake Semenovskoye is a natural geological monument, which has great scientific and educational significance. It is located in the area of Askoldovtsev Street, approximately in the middle between the shore of Lake Semenovsky and the coast of the Kola Bay. This natural site became a monument in 1980. Its total area is only half a hectare.
Description of the monument and its value
The object has the appearance of a small rocky ledge of ancient granites of Archean age. This rock was carefully polished at one time and generously covered with a furrow by a glacier. Its slope is directed to the south side - it was from there that a powerful glacier once moved.
Vegetation near this outcrop is also interesting. The local flora is represented by shrubby tundra and birch twig. Within the natural monument, several rare species of moss are found.
Such objects are not very rare for this region. However, this "ram's forehead" is unique and valuable in that it is located within the boundaries of a large city. Thanks to this, tourists, students and pupils of schools very often visit it.
Finally
“Lamb forehead” is a landform whose origin is associated with glacial abrasion. Its surface is smooth, polished with ice and covered with shallow “scratches” (cracks and grooves). The "ram's forehead" by Lake Semenovskoye is a vivid example of such a landform. This unique natural monument is located within the Kola Peninsula, in the northern part of the city of Murmansk.