Objective The climate signals of the Danxia strata, a representative of Cretaceous continental red beds, offers key insights into red-bed sedimentation and Cretaceous geological events. Methods This study examined fine-grained clastic rocks in the Upper Cretaceous Danxia Basin, specifically the Second member and Fourth member of the Changba Formation and the Jinshiyan member of the Danxia Formation. Sedimentology, elemental and isotopic geochemistry were used to investigate the sedimentary environment and paleoclimate significance during key Upper Cretaceous stages (Cenomanian, Turonian, Campanian). Results It was found that the fine-grained clastic rocks of these formations were deposited during a warm and humid climate phase, with suboxic to oxic water conditions. The water bodies were predominantly brackish, while localized high-salinity brackish and low-oxygen environments (e.g., the Fourth member of the Changba Formation) were associated with lake shrinkage and climatic aridification. Water depth variations exhibit trends of initial contraction followed by expansion, gradual contraction, then initial expansion followed by contraction, which align with the changes in sedimentary facies and environment. Conclusions The Upper Cretaceous terrestrial sedimentary records of the Danxia Basin illustrate the climatic evolution of intermontane basins, shaped by global climate patterns of the Upper Cretaceous, as well as by significant influences from local topographic and geomorphic features.
| 科 Family | 属数 Number of genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) | 属 Genus | 种数 Number of species | 占总种数比例 Percentage of total species (%) |
|---|---|---|---|---|---|---|
| 鹅膏菌科Amanitaceae | 2 | 11 | 5.26 | 鹅膏菌属 Amanita | 10 | 4.78 |
| 小菇科 Mycenaceae | 2 | 12 | 5.74 | 丝盖伞属 Inocybe | 5 | 2.39 |
| 多孔菌科 Polyporaceae | 8 | 14 | 6.70 | 蜡蘑属 Laccaria | 5 | 2.39 |
| 红菇科 Russulaceae | 3 | 23 | 11.00 | 小皮伞属 Marasmius | 6 | 2.87 |
| 小菇属 Mycena | 11 | 5.26 | ||||
| 光柄菇属 Pluteus | 5 | 2.39 | ||||
| 红菇属 Russula | 17 | 8.13 | ||||
| 栓菌属 Trametes | 5 | 2.39 |