论文部分内容阅读
对层序地层学模式进行了理论探索,重点是系统地讨论由于相对海平面变化和进入体系域的沉积物供给量变化而产生的沉积旋回的中断现象;通过讨论和概要展示替代已有方案的新方案,对层序地层学模式提出了质疑。“滨线轨迹”被定义为滨线沿沉积倾向的横剖面移动路线,它是描述沉积旋回及其所含体系域内部构型的一个有用的基本概念。滨线轨迹可划分为加积与非加积强制海退、正常海退和加积与非加积强制海进等不同类型。因响应相对海平面连续上升和下降而形成的沉积旋回应分为四个体系域,而并非像文献中通常所说的三个。一个完整的旋回包含三个基本面:最大海退面、最大海进面和形成于相对海平面下降时期的陆上不整合面。与陆上不整合面相关的整合面对应于最低相对海平面时期。低水位楔体系域和高水位体系域的变化可一并考虑,因为二者均发生在相对海平面上升时期,此时沉积物供给量超过所生成的可容空间。因此而产生的进积可能因海进事件而中断,也可能并不中断。可以设想,海进体系域的三端员是非加积海进、加积海进和海进与正常海退结合的逐步后退(backstepping)。引起强制海退体系域变化的重要制约因素是滨线轨迹的坡度和前方沉积基底的坡度。盆底块体重力沉积在所有四个体系域中均可出现,而如果接纳盆地已延伸到了深水区并有过量沉积物供给,最终在缓坡(ramp)环境和陆架—陆坡—盆地环境都会发生。
A theoretical exploration of sequence stratigraphic models focuses on systematically discussing the disruption of sedimentary cycles resulting from changes in relative sea level and sediment supply into the system tract. By discussing and summarizing the alternatives to existing schemes The new scheme has challenged the sequence stratigraphic model. “Coastline Trajectory ” is defined as the cross-sectional movement along the dip line along the shoreline, which is a useful basic concept for describing the sedimentary cycle and the internal configuration of the system tract it contains. The coastal trajectory can be divided into different types, such as accretion and non-accretion, sea regress, normal sea retreat and accretion and non-accretion. Sedimentary cycles formed in response to the continuous ascent and descent of the relative sea level should be divided into four phylogenetic domains rather than the three as generally described in the literature. A complete cycle consists of three fundamentals: the maximum sea surface, the maximum sea surface and the land unconformity formed during the period of relative sea level descent. The integrative surface associated with the onshore unconformity corresponds to the lowest relative sea level period. Changes in the low-water wedge system tract and the high-water system tract can be considered together, as both occur during relative sea-level rise, at which point the sediment supply exceeds the space that is created. The resultant build-up may or may not be interrupted by the sea incident. It is conceivable that the three terminal members of the marine system tract are backstepping of non-accretionary seafloor, cumulated seafloor and seaflood in combination with normal seafloor depression. The main constraints that cause the change of the forced regression system tract are the slope of the foreland track and the slope of the base of the sedimentary front. Gravity deposition in the pelvic floor may occur in all four system fields, and eventually occurs in both the ramp environment and the shelf-slope-basin environment if the receiving basin has been extended to deep water with excess sediment supply.