Autostratigraphy: A Framework Norm for Genetic Stratigraphy
Autostratigraphy: A Framework Norm for Genetic Stratigraphy
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DOI：
10.2110/jsr.2007.005
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发表时间：
2007
影响因子：
2
通讯作者：
T. Muto;R. Steel;J. Swenson
中科院分区：
文献类型：
--
作者：
T. Muto;R. Steel;J. Swenson
摘要自生地层学是由大规模自生作用形成的地层学，由于目前层序地层学中对他生控制的过分依赖，因此需要引起重视。自动地层学的主要原理，来自自动后退理论和对冲积层坡度的新认识，来自非平衡地层响应，即，沉积体系平衡构型的普遍缺乏。河流三角洲在稳定动力作用时间（T）期间的非平衡行为导致地层响应的变化，这是沉积体系特有的长度（D）和时间（τ）标度的必然结果，而不一定反映任何外来作用力速率的突然或不稳定变化。地层记录中的某些突变并不一定与异源条件的变化有关，而可能是系统的纯粹自生过程造成的。当T与τ相当或大于τ时，（1）沉积体系表现为非平衡的大规模自生响应;（2）自生和他生强迫分量的叠加表现为显著的非线性，因此（3）建立在平衡响应假设基础上的层序地层学模型是不正确的。自动地层分析通过量化D的大小随时间的变化，可以检测和识别地层记录中复杂的自生响应和不稳定的异源事件。因此，自动地层学是成因地层学的一种“规范”。
Abstract Autostratigraphy is the stratigraphy generated by large-scale autogenic processes, and needs to be heeded because of a current overreliance on allogenic controls in sequence stratigraphy. Key principles of autostratigraphy, emerging from the theory of autoretreat and a new understanding of alluvial grade, derive from the non-equilibrium stratigraphic response, i.e., the general lack of equilibrium configuration of depositional systems. The non-equilibrium behavior of fluvial deltas during times (T) of steady dynamic forcing leads to variable stratigraphic response that is the inevitable result of length (D) and time (τ) scaling particular to the depositional system, rather than necessarily reflecting any sudden or unsteady change in the rate of allogenic forcing. Some abrupt breaks in the stratigraphic record are not necessarily associated with changes in allogenic conditions but can result from purely autogenic processes of the system. When T is comparable to or longer than τ, (1) the depositional system takes the non-equilibrium, large-scale autogenic response, (2) the superposition of autogenic and allogenic components of the forcing is prominently nonlinear, and thus (3) sequence stratigraphic models that have been built on the assumption of equilibrium response are incorrect. Autostratigraphic analysis makes it possible to detect and identify complex autogenic responses and unsteady allogenic events in the stratigraphic record by quantifying a temporal change in the magnitude of D. Autostratigraphy thus functions as a "norm" for genetic stratigraphy.