The history of the cold periods in Central Europe and its importance for Lusatia

The history of the earth is characterized by long periods of time in which the climate has changed significantly. Especially in Central Europe, which also includes Lusatia, this climate shift has played a decisive role in the design of the landscape. For several million years, more precisely in the last approximately 2.6 million years, the region has had a number of cold timesexperienced that have significantly influenced the geological and ecological development. These long periods, characterized by extreme cold, alternated with warmer phases and shaped the external conditions for plants, animals and the landscape. The understanding of these climate phases is essential to the current nature and nature of Lusatia and itsto understand the environment. The various ice and warm periods have repeatedly put the region in a state of change that affected the landscape, soil and water. The cold periods, also known as the ice age phases, are particularly interesting because they resulted in the formation of large masses of ice and the geological processes associated with them. but whatExactly are cold times, and how did you shape the landscape in Central Europe? In order to answer these questions, it is necessary to take a closer look at the climatic conditions and the geological processes in the past millennia.

The course of the cold periods and the separation of warm periods

In the last 2.6 million years, around 50 cold periods have alternated in Central Europe with longer periods, in which the climate was significantly milder and so-called warm periods prevailed. A cold time is a long phase that lasts several thousand or even ten thousand years and during which the average temperature is significantly higher annually.below 0 degrees Celsius. These cold periods are characterized by the sharp drop in temperatures, which means that winter temperatures remain below freezing. In contrast, the warm periods are marked by average annual average temperatures of about 8 degrees Celsius or higher and in which the temperatures in theusually increase again. This cyclic pattern of cold and warmth has fundamentally changed the landscape of Europe and created the conditions for the formation of glaciers and ice layers. The cold times are thus a central phase in the history of the earth, which has had a significant impact on the current landscape of Central Europe.

Just a few cold days, real ice ages

Of the fifty cold periods of the last 2.6 million years, only a few were actually associated with large-scale ice ages, during which huge masses of ice spread over large parts of Central Europe. These so-called real ice ages are characterized by the permanent presence of large inland ice masses, which deposited more snow in winter than in summer again.melt away. The result of these long-lasting amounts of snow was the formation of huge ice caps that covered the landscape and had a lasting impact on the region’s climate and geology. During the ice ages, there was a massive cooling that significantly changed the ecosystem and profoundly influenced the flora and fauna. These phases are the most important in theClimate history of Europe, since they have had a lasting impact on the landscape forms, river courses and groundwater. The last three of these ice ages were the only ones in our region where permanent layers of ice actually formed that resulted in the most well-known geological changes.

The Elster cold time and the inland ice advances

During the last great ice ages, especially during the so-called Elster cold season, there were several inland ice advances that significantly changed the landscape in Central Europe. During this cold period, which took place about 340,000 years ago, northern Central Europe was twice completely covered by glacial inland ice. The second advance in which theIce shield stretched along a line that ran from Hamburg via Berlin to Warsaw. This line marked the maximum extent of the ice and stretched for more than 1000 kilometers across what was then Europe. During this time, one of the largest stretches of the ice in Central Europe occurred, which resulted in significant changes in the landscape. The advance of theEises led to huge glacier tongues formed, modeling the landscape and having a lasting influence on soil geology. During this process, impressive glacier tongues developed, which had a lasting impact on the landscape and significantly influenced the geological development of the region.

Muskau Glacier and its peculiarities

During the second Elster cold season, a large glacier tongue, called Muskau glacier tongue, broke out of the inland ice mass and moved much faster south as the large mass of ice advanced overall. This glacier tongue was about 20 by 20 kilometers in size and had a thickness of up to 500 meters. have geotechnical modelsproved that this tongue had an exceptional thickness and differed significantly in its extent from today’s glaciers. Compared to today’s mountain glaciers, the Muskau Glacier was short, but very broad and thick, which is due to its enormous mass and the climatic conditions there. This peculiarity shows how dynamic and complex theGlacial processes during the Ice Age phases and what force the ice was able to exert on the landscape. The movement of this glacier tongue was a crucial component in the design of today’s surface structures in Lusatia and in the adjacent regions.

Origin and behavior of the glacier

It has not yet been fully clarified why the glacier tongue jumped out at this point. It is assumed that there was probably a small valley of a river or stream, which made it easier to run out of the ice and drive the glacier in particular at this point. Interestingly, this waterway has nothing to do with today’s Neisse, since thisriver form was created much later. Under the enormous weight of the ice, the rock layers were folded by so-called plastic deformation, in which the rock was moved by the pressure of the ice. You can imagine that you’re stuck a layer of rock between the jaws of a vise: The earth forms the upper cheek that is upis pressed while the ice is the lower cheek that presses down. Prior to the advance of the ice, the main fracture deformations took place, in which the rock layers broke into tectonic scales. These tectonic scales were straightened and were pressed together to form a high moraine, now known as a crisp moraine. These circumstances show howwere enormously the forces of the ice and how profound the geological processes were during the ice ages.

The formation of moraine and the geological consequences

The Muskau fold arch, which was created by the movement and weight of the ice, was not shifted by thrust, but rather crushed and deformed by the enormous load of the ice. This type of deformation, which is referred to as so-called ice load deformation in technical jargon, led to the rock layers breaking in a kind of ground break or shifting.This process is comparable to the so-called ground break in construction, where the pollution from heavy buildings deforms the soil. Due to this deformation, the Muskau fold arch is also referred to as a groundbreaking moraine. After the ice melted, the deformed rock layers remained and formed a basin in the hinterland, which is now known as the Bahren basinis. This basin was filled with sediments transported through the meltwater over the millennia. These deposits, the so-called ribbon tones, consist of sediments deposited in lakes and today provide important information about the glacial processes. The folding and breaking processes in the rocks as well as the deposits in the Bahren basin are themost important geological remains of the Ice Age phase in Lusatia. The area around the Muskau Flecknow and its filled back country today represent the most important contiguous forest area in Lusatia, which was characterized by its complex geological history. It is a unique testimony to the power and extent of the glacial processes that the landscape in theformed in recent millennia.