X-ray diffraction data of rock samples from Upper Ediacaran Dengying Formation, Northeast Sichuan Basin, SW China

The Dengying Formation, located in the Sichuan Basin of China, represents one of the most significant carbonate sequences of the late Ediacaran in the world. It was deposited on a shallow marine carbonate platform, and its age is constrained between 551 Ma and 541 Ma based on available radiometric dates and stratigraphic correlations.
The Dengying Formation is divided into four lithological members, namely, Dengying 1, 2, 3, and 4 Members, from bottom to top (Figure 1). The Deng 1 Member is composed of crystalline dolomite and microbial dolomite. The Deng 2 Member develops large quantities of microbialites, mainly including stromatolite dolomite, thrombolite dolomite, and crystalline dolomite. It is in unconformable contact with the overlying Deng 3 Member. The Deng 3 Member is mainly composed of argillaceous siltstone and silt-bearing dolomite in the form of dark thin layers, and displays a conformable contact with the overlying Deng 4 Member. The Deng 4 Member is composed of crystalline dolomite, microbialite and silicified dolomite.
This study focuses on three stratigraphic sections in the northern Sichuan Basin: the Hujiaba section (32°57'22.8"N, 106°27'37.1"E) , the Yangba section (32°27'43"N, 106°47'26"E), and the Wuxi section (31°40'22"N, 109°10'16"E, near the Hanfengya Tunnel) . These sites are located at the intersection of northern Sichuan and northern Chongqing, along the northern margin of the Upper Yangtze region .
Fresh rock samples were crushed into smaller fragments and subsequently ground into fine powders using a mortar and pestle for a minimum of 20 minutes to ensure uniformity. Powder X-ray diffraction (XRD) analyses were performed using a Malvern PANalytical X’Pert Pro High-Resolution X-Ray Diffraction System with a CuKα radiation source (λ=1.5406 A). Data were collected over a 2θ range of 5° to 80° with a step size of 0.013°.