Triassic Ripple Mark First Found in Chongqing

Recently, paleontology amateurs found a huge stripe-patterned stone cliff in Beibei District. Professionals said ocean waves made its ripple marks and estimated that Chongqing was a boundless sea 250 million years ago. It is the first time for a Triassic ripple mark to be found in Chongqing.

This stone cliff is situated in an abandoned mine in Wuji Village, Shuitu Sub-district, Beibei District. It features clear strips in a well-proportioned arrangement. According to Wu Dingjin, paleontology amateur, and Chongqing citizen, while climbing the mountain, they stumbled across this eye-catching stone cliff, which stood out from the surrounding environment with its wave-like pattern.

It is the first time to discover a Triassic ripple mark in Chongqing.

Although relic sites with ripple marks are common, those formed by seawater waves are rare. Doctor Zhang Feng, Senior Engineer, and Paleontologist from No. 208 Geological Team, Chongqing Bureau of Geology and Minerals Exploration, said that it is direct evidence that Chongqing had experienced the last ocean period on the planet. Judging by the formation of the surrounding rocks, this cliff had been formed in the early Triassic period, about 250 million years ago.

Hundreds of millions of years ago, sea waves had left marks on some deposit sediment, giving birth to these considerable ripple mark after a long period. It demonstrates that Chongqing subversed in a vast expanse of water in the early Triassic period when the turbulent seawater could not provide marine organisms, small in number then, with a favorable living environment.

The exposed ripple mark is around 30 meters high and 50 meters wide. Doctor Zhang Feng estimated that another mark, expanding to a thousand square meters, should be hidden in the rock stratum. This ripple mark is of important scientific significance to the paleoclimatology, structural geology, and sedimentary geology, for it records the sedimentary environment and hydrodynamic conditions of that time.

Source: CQCB