The Wutong Formation of Upper Devonian is widely distributed in Southern Jiangsu Province and storm deposits developed in many places in this formation. According to the analysis characteristics

the storm deposits are considered to be proximal facies developed in litteral environment. A new kind of mega-ripple marks were found in the storm de-posits and named"tri-ridge ripple markes"which were resulted by interference of storm vortex flow in water bottom. So the authors point out that the tri-ridge ripple marks are one of discriminative feature for storm deposit especially for proximal storm deposits.