Sedimentary Rocks

Sedimentary rocks were once called ‘aquatic rocks’ in Chinese. They form on or near the Earth’s surface from the consolidation of loose sediments. They often appear in layered formations and are one of the three major rock types (igneous, sedimentary and metamorphic rocks) that constitute the Earth’s crust. Sedimentary rocks are widely distributed, and they cover 75% of the surface of the Earth. Based on their formation, composition and structure, they can be divided into clastic rocks, clay rocks and biochemical rocks. The most common sedimentary rocks are shale, sandstone, conglomerate and limestone, which account for approximately 95% of all sedimentary rocks. Based on the source of the rock materials, they can be divided into volcaniclastic rocks, terrestrial sedimentary rocks and endogenous sedimentary rocks. Sedimentary rock is an important landscape rock type. Many famous scenic areas in China are composed of sedimentary rocks, such as Zhangjiajie, Danxia Mountain and Wuyi...