clouds Triassic sequence stratigraphy of

Title: clouds Triassic sequence stratigraphy ofAuthor: Zhang GodDegree-granting unit: Kunming University of ScienceKeywords: clouds areas;; Triassic;; sedimentary facies;; deposition system;; sequence stratigraphy;; basin evolutionSummary:

Anticline in the Sichuan-Yunnan region clouds Taiwan, Lijiang platform margin with folds, Lanping - Simao depression of three two structural units binding site, because of its tectonic evolution of complexity and specificity, the deposition of Triassic rare earth magnets strata environment and sequence stratigraphy is quite rough and obscure. In this paper, a lot of access to data and regional geological study area based on the results of previous studies, over a long period of field mapping, surveying and interior stratotype section main sections, detailed study of geochemical data to sedimentology, stratigraphy, sequence stratigraphy science, tectonics, paleontology to basin analysis of history and rationale of theory, combined with regional geological setting and geochemical characteristics of sedimentary rocks, clouds and areas of Triassic sedimentary geochemistry, depositional environment, depositional systems, sequence stratigraphy, etc. research, and thus evolution of sedimentary basins has been studied.

1, through paleontology, lithology, sedimentary structures such as the Triassic strata of the study area was divided into sedimentary facies and depositional environments.

2, Triassic strata of the study area was constant, trace, rare earth element geochemistry of sediments. At the same time by a constant, trace, REE geochemistry of ancient climate and paleo-salinity, redox, the ancient water depth, the distribution of the source region of the five aspects of work area Triassic paleoenvironment.

3, according to the stratotype section of rock composition, sedimentary sequences, sedimentary structures, sedimentary rock mineral composition and composition of biological and geochemical characteristics of four groups of Triassic strata in the area is divided into seven sedimentary system: ① bathyal system (Luo mountain group of the second paragraph); ② shelf system; ③ carbonate platform; ④ the coastal system; ⑤ Delta system; ⑥ lake system; ⑦ river system. And a detailed analysis of the characteristics of each depositional system.

4, in the depositional environment and depositional systems analysis, based on the use of the principles of sequence stratigraphy, the study area of ​​the Upper Triassic sequence of the three characteristics of the interface, the interface of genetic types in-depth study. Third-type interface work area types Ⅰ and Ⅱ, divided into: deposition discontinuities (SB11), weathering surface (SB12, SB23, SB14), at the end of gravel erosion surface (SB, 5). The work area of ​​the Upper Triassic is divided into five third-order sequence, that is, Carnian two (TSQ1, TSQ2), Norian stage two (TSQ3, TSQ4), Rhaetian 1 (TSQ5).

5, analysis of the internal structure of all three sequences: the type and characteristics of the domain system. TSQl and TSQ2 missing low system tracts (LST), TSQ3, TSQ4, TSQ5 three systems within the domain (LST, TST, HST) development complete. http://www.chinamagnets.biz/ There were five times transgression, in which third-order sequence TSQl and TSQ3 transgression within the speed and magnitude are significant. Detailed analysis of the structure, sea-level change, climatic factors, sediment supply four factors of the study area development control action sequence.

6, the Late Triassic period, the clouds in the Lijiang region Kangdian ancient land plots and the separation between the rift and thrusting under the influence of extrusion, forming a composite basin; for the separation of pre-rift rift developed under basin and post-extrusion under thrusting of foreland basin development. Basement through a rift - stable - rift - squeezing thrust (return) four stages. Basin-fill sequence evolution experienced marine (molasse, flysch construction, carbonate build) - paralic (construction of coal-bearing sandstone and mudstone) - continental (fluvial coal-bearing clay, sandy rock construction ) the conversion process.Degree Year: 2010