Fossils suggest that today's Loess Plateau used to be a great lake 60 million years ago, and the mountains on the plateau were islands.

The Loess Plateau is one of the four major plateaus in China, covering an area of 580 thousand sq km, in six provinces and autonomous regions. It is the largest loess area in the world, and the most typical one as well.

However, fish fossils found in Ningxia revealed its past as a lake. These fossils were found in the shale in Jingyuan County, Ningxia Hui Autonomous Region. They are so well preserved that it is very easy to see their scales, fins and even the tiny structures of their skulls. Fossils of some leaves were found together with the fish, which clearly reflect that the plateau used to be a lake.

Geologists explain that the Loess Plateau was part of the ancient ocean, and the orogenic movement started 460 million years ago finally out an end to its history as an ocean. Though in the Carboniferous Period, it was still under water, The Himalayan orogenic movement 240 thousand years ago finally drained off the waters and brought a plateau out. Long-time weathering since then at last created the Loess Plateau we see today.
 
(Chinanews.cn August 23, 2006)