Accommodation and sediment-supply controls on clastic parasequences: A meta-analysis
Accommodation and sediment-supply controls on clastic parasequences: A meta-analysis
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碎屑准层序的住宿和沉积物供应控制：荟萃分析
DOI：
10.1111/sed.12728
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发表时间：
2020
期刊：
影响因子：
3.5
通讯作者：
Colombera L
中科院分区：
文献类型：
--
作者：
Colombera L
本研究结合了许多已发表案例研究的数据，对碎屑准层序进行定量表征，旨在确定可容纳空间、沉积物供应和自生沉积物储存动态如何记录在其沉积结构和堆叠模式中。本研究的结果被用来批判性地评估范式和模型的有效性，通常用于解释和预测准层序的解剖和排列的趋势。在关系数据库中对来自62个碎屑、浅水层序案例研究的957个准层序数据进行编码，该数据库包括古代和第四纪实例的露头和地下数据集。这些单元涵盖了河流主导的三角洲和波浪主导的海岸的保存记录，代表了时间尺度上的海岸线过境，可能是当地和区域范围。现存的可容纳空间、可容纳空间的形成速率和沉积物供给速率在确定准层序结构中的作用通过分析以下变量之间的关系来评估：（i）这些变量在不同尺度上的替代物（加积和剥蚀速率、相带海岸线轨迹、体系域类型、准层序组堆积模式、准层序剥蚀角和地层上升、补给河流的大小）;和（ii）描述准层序几何形状和叠加样式以及相关浅水砂体的参数。对数据库输出的统计分析表明，哪些可容纳空间、沉积物供应和可容纳空间/沉积物供应比的代理作为准层序结构的预测因子是重要的，并允许解释同种异体和自生因素的重要性。研究结果表明：（1）准层序厚度随水深、可容纳空间生成和侵蚀削截而变化，这种变化也反映在不同类型的体系域和准层序组中;（ii）准层序砂体的倾向长度表明，可容纳空间/沉积物供给比的尺度在多个尺度上是成比例的，部分与沉积物供给对剥蚀率的可能影响有关;（iii）在体系域中，由于自生机制或相对海平面波动的加速或减速，准层序堆叠的地层趋势没有定量揭示;（iv）三角洲或河流为主的准层序的丰度与横向叠加之间存在某种关联;（v）河流系统大小的测量值与浅海准层序砂体的倾角长度之间存在正相关但适度的相关性。由此产生的见解可以应用于指导岩石记录的层序地层学解释和地下层序的次地震地层结构的表征。
This study combines data from many published case studies to undertake a quantitative characterization of clastic parasequences, with the aim to determine how accommodation, sediment supply and autogenic sediment‐storage dynamics are recorded in their sedimentary architecture and stacking patterns. Results of this study are used to critically evaluate the validity of paradigms and models that are routinely used to explain and predict trends in the anatomy and arrangement of parasequences. Data on 957 parasequences from 62 case studies of clastic, shallow‐water successions were coded in a relational database, which includes outcrop and subsurface datasets of ancient and Quaternary examples. These units cover the preserved records of both river‐dominated deltas and wave‐dominated coasts, representing shoreline transits over a breadth of timescales, likely of both local and regional extent. The role of extant accommodation, rates of creation of accommodation and rates of sediment supply in determining parasequence architecture is assessed through analysis of relationships between: (i) proxies of these variables at different scales (rates of aggradation and progradation, facies‐belt shoreline trajectories, systems‐tract type, parasequence‐set stacking patterns, parasequence progradation angle and stratigraphic rise, size of feeder rivers); and (ii) parameters that describe the geometry and stacking style of parasequences, and associated shallow‐water sand bodies. Statistical analyses of database outputs indicate which proxies of accommodation, sediment supply and accommodation/sediment‐supply ratio are significant as predictors of parasequence architecture, and allow for interpretations of the importance of allogenic and autogenic factors. The principal results of this study reveal the following: (i) parasequence thickness varies as a function of water depth, accommodation generation and erosional truncation, and these variations are also reflected across types of systems tracts and parasequence sets; (ii) the dip length of parasequence sand bodies demonstrates scaling with measures of accommodation/sediment‐supply ratio at multiple scales, partly in relation to the possible effect of sediment supply on progradation rates; (iii) in systems tracts, stratigraphic trends in parasequence stacking due to autogenic mechanisms or to acceleration or deceleration in relative sea‐level fluctuations are not revealed quantitatively; (iv) some association is seen between the abundance of deltaic or river‐dominated parasequences and progradational stacking; (v) positive but modest correlation is observed between measures of river‐system size and the dip length of shallow‐marine parasequence sand bodies. The resulting insights can be applied to guide sequence stratigraphic interpretations of the rock record and the characterization of sub‐seismic stratigraphic architectures of subsurface successions.