Back in the mid-17th century, the Italian geologist Giovanni Arduino proposed the first stratigraphic divisions. The only division that is still in use from that old system is the "Quarto ordine" (The Fourth Order, or Quaternary). This period is divided into the Pleistocene and the Holocene (in which we're currently living).

Paleogeography

At the start of the Quaternary, the distribution of the continents was nearly identical to the present. However, the continents continue to move, which we can monitor using modern technologies. The Americas are migrating westwards away from Europe and Africa at a rate of 2.5 centimetres per year, expanding the Atlantic. The Indian Peninsula continues to push northwards at a speed of about 5 cm per year, continuously raising the Himalayas and Mount Everest. Australia is the fastest-moving of the continents, moving northwards at 7 cm per year.

Climate

The Quaternary is characterised by a relatively cool climate with cyclical cooling and warming periods. The Pleistocene saw an increase in rainfall in the intertropical zone. Poles have been covered with ice since the beginning of the Quaternary, with polar ice sheets growing significantly during Pleistocene glacial periods.

Glaciations in Poland

The Pleistocene experienced periods of cooling (glaciations), separated by warmer periods known as interglacials.

The ice sheet covered Poland for the first time 1.2 million years ago and returned to the area many times, partially or fully covering the region. The last Polish glacial episode ended 11 thousand years ago, marking the end of the Pleistocene and the beginning of the Holocene, which is considered an interglacial episode in the ongoing Ice Age.

Life on Earth

Flora

Steppes and glacial tundras, dominated by grasses and dwarf trees, were common in the cold climate zone. During interglacials, the tundra moved northwards and was replaced with multi-species mixed forests, swamps, and meadows with many extant plants.

The megafauna of the Pleistocene

Vast, empty steppes were the roaming grounds for huge animals such as mammoths (Eurasia) and mastodons (North America), woolly rhinos, wild cattle (aurochs), large cats, and marsupials (in Australia). Most of these large mammals died out by the end of the Pleistocene, replaced by the species we know today.

First modern people

With the gradual drying and steppe formation in Africa in the Pleistocene, the evolution of modern humans began. Different lines of hominids appeared and often lived beside each other. One of these lineages, Homo erectus, lived around 300-200 thousand years ago and eventually led to the evolution of our species.

Do you know...

The Baltic Sea began with the disappearance of the Scandinavian ice sheet. The in-and-out glaciations meant that the Baltic changed several times from lake to sea before gaining its present form.

A woolly rhino could reach heights of two metres and be five metres long, weighing about 3.5 tons