Myr

The Million Year is a time unit often used in astronomy and geology of one million years. It is also abbreviated as J. million or in the literature based on the SI units by Ma ( "Mega - years "). Accordingly, there are also Ga for billions of years, an indication of ka for a thousand years but not used in practice.

Since the human imagination fails in such long periods, the year a million is often made clear by comparison. One million years include:

  • ( Was reckoned from the 3000 BC) 200 times longer than the period of our history
  • About a thousand times longer than the longest-lived civilization
  • About 35,000 generations
  • Few percent of the duration of orogeny.

Geologically, interested persons can refer to the following consideration: all seemingly so solid rocks such as granite or slate behave plastically over very slow bending. Only when these accounts for more than about 1 mm per year, they break.

  • In the high mountains large folds are sometimes seen in the rocks of a steep mountain slope. If these 1,000 m high, took their origin ie about 1 million years.
  • The Alps stand for millions of years still - currently about 1 to 2 mm per year. This is about 10 times slower than a tree trunk in thickness increases.
  • In Figure 1 million years to "grow" the Alps, then, assuming a constant growth rate to 1,000 to 2,000 m.
  • At the same time they are removed at a similar rate of wind, water and ice - by crash of each summit, for example, for 1000 years, a one to two meters thick " layer " of rocks at depth.
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