Paleogeography
Continents continued to drift toward their present positions. Of the modern geologic features, only the land bridge between South America and North America was absent, although South America was approaching the western subduction zone in the Pacific Ocean, causing both the rise of the Andes and a southward extension of the Meso-American peninsula.
Mountain building took place in western North America, Europe, and east Asia. Both continental and marine Miocene deposits are common worldwide with marine outcrops common near modern shorelines. Well studied continental exposures occur in the North American Great Plains and in Argentina.
India continued to collide with Asia, creating dramatic new mountain ranges. The Tethys Seaway continued to shrink and then disappeared as Africa collided with Eurasia in the Turkish-Arabian region between 19 and 12 Ma. The subsequent uplift of mountains in the western Mediterranean region and a global fall in sea levels combined to cause a temporary drying up of the Mediterranean Sea (known as the Messinian salinity crisis) near the end of the Miocene.
The global trend was towards increasing aridity caused primarily by global cooling reducing the ability of the atmosphere to absorb moisture. Uplift of East Africa in the Late Miocene was partly responsible for the shrinking of tropical rain forests in that region, and Australia got drier as it entered a zone of low rainfall in the Late Miocene.
Read more about this topic: Miocene