Multiscale simulation of fluvio-deltaic stratigraphy was used to quantify the elements of the geometry and architectural arrangement of sub-seismic-scale fluvial-to-shelf sedimentary segments. We conducted numerical experiments of fluvio-deltaic system evolution by simulating the accommodation-to-sediment-supply (A/S) cycles of varying wavelength and amplitude with the objective to produce synthetic 3-D stratigraphic records. Post-processing routines were developed in order to investigate delta lobe architecture in relation to channel-network evolution throughout A/S cycles, estimate net sediment accumulation rates in 3-D space, and extract chronostratigraphically constrained lithosomes (or chronosomes) to quantify large-scale connectivity, that is, the spatial distribution of high net-to-gross lithologies. Chronosomes formed under the conditions of channel-belt aggradation are separated by laterally continuous abandonment surfaces associated with major avulsions and delta-lobe switches. Chronosomes corresponding to periods in which sea level drops below the inherited shelf break, that is, the youngest portions of the late falling stage systems tract (FSST), form in the virtual absence of major avulsions, owing to the incision in their upstream parts, and thus display purely degradational architecture. Detailed investigation of chronosomes within the late FSST showed that their spatial continuity may be disrupted by higher-frequency A/S cycles to produce “stranded” sand-rich bodies encased in shales. Chronosomes formed during early and late falling stage (FSST) demonstrate the highest large-scale connectivity in their proximal and distal areas, respectively. Lower-amplitude base level changes, representative of greenhouse periods during which the shelf break is not exposed, increase the magnitude of delta-lobe switching and favour the development of system-wide abandonment surfaces, whose expression in real-world stratigraphy is likely to reflect the intertwined effects of high-frequency allogenic forcing and differential subsidence.

中文翻译：

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河流-三角洲地层的大规模连通性：模拟适应-供应周期的推论和时间体的自动提取

河流三角洲地层学的多尺度模拟被用于量化亚地震尺度河流到陆架沉积段的几何结构和结构排列的元素。我们通过模拟不同波长和振幅的适应-沉积物供应 (A/S) 循环进行了河流-三角洲系统演化的数值实验，目的是产生合成 3-D 地层记录。开发后处理程序是为了研究与整个 A/S 循环中的河道网络演化相关的三角叶结构，估计 3-D 空间中的净沉积物积累率，并提取年代地层学上受限的岩石体（或计时体）以量化大-尺度连通性，即高净毛岩性的空间分布。在通道带聚集条件下形成的染色体被与主要撕脱和三角叶转换相关的横向连续废弃表面隔开。对应于海平面下降到继承的大陆架断裂以下时期的染色体，即后期下降阶段系统域 (FSST) 的最年轻部分，由于其上游部分的切口，在几乎没有大撕裂的情况下形成，从而显示纯粹的退化架构。对晚期 FSST 中的 chronosomes 的详细调查表明，它们的空间连续性可能会被更高频率的 A/S 循环破坏，从而产生包裹在页岩中的“搁浅”富含砂体。在早期和晚期下降阶段 (FSST) 形成的染色体在其近端和远端区域表现出最高的大规模连通性，分别。较低幅度的基准水平变化，代表没有暴露架子断裂的温室时期，增加了三角叶转换的幅度，并有利于系统范围内废弃表面的发展，其在现实世界地层中的表达可能反映高频同种异体强迫和差异沉降的相互影响。