Lect2-Sequencestrat-Concept探析.pptVIP

Let’s begin!!;层序地层与盆地沉积动力学;Contents;层序地层基本概念和原理;I: 导论;挤压（前陆）盆地（Compressional or Foreland Basin) 由岩石圈加载于冲断带之上形成 特征的向冲断带前沿加厚的楔壮充填物-前陆盆地大层序 走滑盆地（Strike-slip Basin） 没有特征的沉降样式;1.2 盆地边缘 盆地边缘沉积几何形态 顶积层（Topsets)-盆缘近端沉积体（0.10) 滨线（Shoreline）,上超（ onlap） 同向斜坡/进积体(Clinoforms)-盆缘剖面陡倾部分(10) 底积层（Bottomsets) 退超坡折(Offlap break) vs. 沉积滨线坡折（Depositional shelf break);Clinoforms;;;onlap;Types of Basin-margin Shelf-break margins: typical of PCM, with well developed depo-clinoforms, submarine fan deposits due to mass failure. Ramp margins: Shallow WD, STM CRT extensive, dip10, LST turbidites rare. Rift margins: active crustal extension; Accommodation controlled largely by tectonics. Footwall crest-less Subsidence-uplift or erosion; Hangingwall-greater SBSD. Transfer Zone-sediment entry points. Foreland-basin margins: Growth-fault margins: Differentiation across the fault, with thick, deeper deposits on the down-throw side.;SL;II. Relative sea-level, tectonics and eustasy;;Accommodation: Space available for deposition=?eustasy+ ?subsidence+ ?compaction, controlled by base-level. Orders of cyclicity: 1st-order (50 Ma), 2nd-order (3-50 Ma), 3rd-order (0.5-3 Ma), 4th-order (0.01-0.1 Ma), 5th-order (0.01 Ma) ;;;;;;III. Sediment Supply;;IV. Terminology and Concept of Sequence Stratigraphy;Type I;Erosional surface;Type I sequence boundary and sequence;IV.2 Systems tract definition;;Type II sequence boundary and the shelf-margin systems tract Type II SB: downward shift in coastal onlap landward of the offlap break. No shelf bypass, fan deposition or fluvial incision of the HST topsets. Shelf-margin systems tract (SMST): initially slightly prograding pass to aggradational topsets/clinoforms, healed by retrogradational TST.;;Lowstand systems tracts on a ramp margin-two parts: the lower and the upper The lower parts: characterized by stream incision and sediment bypass of the coastal plain-shoreline steps rapidly basinward until SL stablizes during SL fall. The upper part: infilling of the incised