PDF
Full
Outline
Objective The Late Triassic was a crucial period for the Mesozoic Qiangtang Basin evolution. However， the previous research concentrating on the sedimentology of the Upper Triassic strata is rare in the Qiangtang Basin， making it not conducive for elaborately analyzing the characterization of Late Triassic sedimentary evolution and predicting the distribution of source and reservoir rocks. Methods Based on the measured section， we synthesized the thin section， grain size of detrital particle， and typical primary sedimentary structure to identify the sedimentary facies of the Jiapila Formation， Bolila Formation， and Bagong Formation in the Jiang’ai Darina section and then establish the Late Triassic sedimentary evolution model in the central Qiangtang Basin. In addition， the whole-rock and clay minerals， physical properties， and total organic carbon （TOC） contents of sandstone and mudstone samples were analyzed to evaluate the characteristics of source and reservoir rocks. Results （1） In the Jiang’ai Darina section， the sedimentary facies of the Upper Triassic strata have experienced the evolution of the fan-delta facies → barrier-free coastal facies → carbonate ramp facies → neritic shelf facies → delta facies upward， and ten subfacies and eight microfacies were identified. （2） The Upper Triassic strata in the study area constitute an upward deepening transgressive succession and then a shallower regressive succession. The transgressive succession is mainly composed of the Jiapila Formation and Bolila Formation， whereas the regressive succession is primarily composed of the Bagong Formation. （3） The sandstone samples from the Jiapila Formation and Bagong Formation are ultra-low porosity and permeability reservoirs with secondary pores primarily. The mudstone samples of the Bagong Formation from the Jiang’ai Darina section are poor source rocks and non-source rocks， whereas they improve to the north （Woruoshan section）. We inferred that the depression between Jiang’ai Darina and Woruoshan may develop well source rocks and have a good exploration prospect based on the latest tectono-lithofacies paleogeographic data， but confirmation is required. Conclusions These results would provide a valuable reference for the researches of Late Triassic sedimentary-tectonic evolution and oil and gas resource evaluation in Qiangtang Basin.
PDF
2
1
| 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 |
关闭全屏
No. 86 Xueyuan South Road, Haidian District, Beijing
010-62199257
qkjq@cast.org.cn
Copyright © 2025 China Association for Science and Technology. All rights reserved. For all open access content, the relevant licensing terms apply.
Sponsored by the Office of the Leading Group for Cybersecurity and Informatization of CAST, and supported by Science and Technology Review Publishing House
