Clinoforms, as fundamental components in sedimentary basin fills, represent the preserved stratal expression of slope systems that link shallow-water and deep-water environments in carbonate depositional systems. Although large-scale carbonate clinoforms developed extensively in the Tarim Basin during the early Cambrian, their geometry, sedimentary evolution, and controlling factors have not yet been systematically studied. This research integrates 3-D seismic, drilling and well-logging data to perform a quantitative and systematic analysis of the seismic facies, geometrical characteristics, and depositional evolution of the Cambrian (Stage 3) Xiaoerbulake Formation clinoforms. A high-resolution sequence stratigraphic framework is constructed using the Integrated Prediction Error Filter Analysis (INPEFA) method. Seven distinctive seismic facies (SF1-SF7) are identified in the study area; these correspond to seven facies belts distributed in three depositional environments: mixed tidal flats, inner ramp and middle ramp. The analysis recognizes five higher-order composite clinothems (CC1–CC5) and seventeen subordinate clinoforms (C1–C17). Collectively, these record an overall progradation from southwest to northeast. Clinoform-edge trajectory patterns initially exhibit an aggradational trend that progressively transitions to a predominantly progradational trend. Two 3rd-order sequences (SQ1 and SQ2) are distinguished within Stage 3, each containing multiple 4th- and 5th-order sequences. SQ1 comprises CC1–CC3 (C1–C10), whereas SQ2 comprises CC4–CC5 (C11–C17). The early depositional system is characterized by a gently inclined carbonate ramp system, whereas the later stage evolves into a distally-steepening ramp. The development of these clinoforms was controlled by the interplay of several factors. Relative sea-level fluctuations directly controlled available accommodation and the resultant geometry of developed clinoforms. The spatial variability of paleogeomorphological features, such as a central depression surrounded by elevated margins, governed accommodation and controlled clinoform trajectory, progradation distance, and aggradation thickness. Moreover, paleoclimate and paleoceanographic conditions indirectly influenced clinoform development by modulating carbonate production and hydrodynamic energy. This study addresses the knowledge gap concerning the sequence-stratigraphic evolution of carbonate clinoforms on a ramp and clarifies the main controlling factors on clinoform growth. These findings provide valuable insights into the evolution of ancient carbonate ramps and contribute to a more comprehensive understanding of global carbonate clinoform systems.
CORE (COnnecting REpositories)
CORE (COnnecting REpositories)