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The shallow-water braided deltas are hot topic in global sedimentology. In China, this depositional environment forms an important reservoir and exploration target within the basins. Therefore, geological and sedimentologic settings of the Jurassic shallow-water braided deltas in the Junggar basin of western China have attracted much attention in recent years based on the comprehensive analysis of geological and geophysical data acquired. These braided deltas deposited in the shallow Junggar lacustrine basins with gentle slope gradients and prograded towards to the central basin from northeast to southwest (more than 10 km). This kind of Jurassic delta was characterized by coarse grain-size (sand to pebble), large cross-beddings, discontinuous fining-upward successions vertically, high percentage of sandstone ratios (up to 70%), very unique distributary channels with few distributary mouth bars, and seismic facies of shingled with a progradational reflections. Based on the detailed research on basin evolution and sedimentary characteristics of deltaic sub-facies, this paper presents the relationship between the shallow-water braided deltaic deposition and lithologic traps predicted to be the favorable and explorable lithological traps in the Junggar Basin. [ABSTRACT FROM AUTHOR]

This paper presents the current body of knowledge regarding the evolution of a braided–meandering system in the southern Junggar Basin, north‐west China, based on the preserved architecture evidences. The response to climate change was also discussed. Herein, 10 types of lithofacies are summarized, including information of their primary sedimentary structures, characteristic lithology, and geometry. This study focuses on recognizing the architectural elements within the channels (migrating channel: CHm, switching channel: CHs, transiting channel: CHt, and filling channel: CHf), the bar units (downstream accretion: DA, lateral accretion: LA, unit bar: UB, and compound bar: CB), and fine‐grained clastic deposits (floodplain fines: FF and overbank fines: OF). Three representative sections of outcrops were selected, and detailed observation and analysis of these sections revealed 3 stages can be divided: the braided stage, in which the deposits show an evidence of CHm, DA elements which are the mainly architectural elements, multichannel with aggradational filling; The transformation between braided–meandering stage, during which the fluvial system consists of CHt and CHm elements with lateral accretion; and meandering stage which is characterized by dominance of CHm, LA elements, and the channels become isolated and meandering. Finally, this paper concludes with an interpretation of climate events as manifested by the fluvial archives of the colours of sedimentary rocks, special mineral, palaeontology, geochemistry spanning the Middle–Upper Jurassic (between 166.1 and 152.1 Ma). [ABSTRACT FROM AUTHOR]