An overview of the history of the earth

history of earth

Most of biological evolution occurred during this time period. Simple cells are believed formed in such a wet environment.

Of the modern geologic features, only the land bridge between South America and North America was absent, the subduction zone along the Pacific Ocean margin of South America caused the rise of the Andes and the southward extension of the Meso-American peninsula.

Fortunately, Saturn soon started pulling Jupiter back, toward where it is today, even as the Solar wind stripped away all of the residual gas in the solar system into interstellar space.

history of earth timeline

It was as big as Africa and existed somewhere near the equator for a hundred million years before breaking up. This was primitive photosynthesis.

The carbon dioxide would have been produced by volcanoes and the methane by early microbes.

Origin of earth

Valleys in the western part of the continent were filled with great thicknesses of sediments from the mountain ranges. Sea level changes exposed the land-bridge between Alaska and Asia. North America was essentially a lowland that was periodically flooded by the ocean, forming extensive deposits of sandstone, limestone, and barrier reefs. Rain created the oceans. Photosynthesis enabled organisms to create their own food for the first time. Humans have a massive effect on biodiversity and the natural environment and are partially responsible for the '6th mass extinction'. Life forms continued to become more complex. Banded iron formations — layers of rock from the ocean showing pulses of iron oxide deposits due to reaction with oxygen — dating back to 3. Mass extinctions are massive losses in life, and there have been five mass extinction events in history. Under the influence of its own gravity, the ejected material became a more spherical body: the Moon. It is commonly assumed and accepted that one of the main causes of the creation of life is the presence of large oceans. Geological timescales are divided into eons, eras and periods. Common sedimentary deposits are red sandstones and mudstones. These major extinction events are called the Big Five.

In western North America, mountain building started in the Eocene, and huge lakes formed in the high flat basins among uplifts. So, in representations such as the table above, they are usually collectively called the Precambrian.

The fossil record has preserved layered algal mounds called stromatolites, an abundance of microscopic species, and trails and burrows from wormlike organisms. Holocene marine deposits along low-latitude coastlines are rare because the rise in sea levels during the period exceeds any likely upthrusting of non-glacial origin.

How earth was born

The second type is a complex of felsic magmatic rocks. The most solid evidence of photosynthesis, however, dates back to 2. Gondwana started to drift toward the South Pole. More recent potassium isotopic studies suggest that the Moon was formed by a smaller, high-energy, high-angular-momentum giant impact cleaving off a significant portion of the Earth. Surviving species included turtles, snakes, crocodiles, and various lizards. Source: Author provided Apart from nitrogen, methane, and ammonia, volcanoes also released a lot of carbon into the atmosphere. Since cyanobacteria were aquatic they saturated the oceans with oxygen too. As the southern supercontinent Gondwana drifted over the South Pole, ice caps formed on it. Geologically, the Paleozoic starts shortly after the breakup of a supercontinent called Pannotia and at the end of a global ice age.
Rated 8/10 based on 28 review
Download
An Overview of the Geological History of Earth