The limited link between accommodation space, sediment thickness, and inner platform facies distribution (Holocene–Pleistocene, Bahamas)
The limited link between accommodation space, sediment thickness, and inner platform facies distribution (Holocene–Pleistocene, Bahamas)
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可容纳空间、沉积物厚度和内部台地相分布之间的有限联系（全新世-更新世，巴哈马）
DOI：
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
P. Swart
中科院分区：
文献类型：
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作者：
R. Weij;J. Reijmer;G. Eberli;P. Swart
浅水碳酸盐台地的旋回相变化往往表现出重复的相模式，这往往被解释为反映与轨道变化有关的气候变化--米兰科维奇频率--海平面变化的沉积响应。这些浅海碳酸盐岩是否代表了完整的居住空间，或者是潮下旋回，已经在许多论文中进行了讨论。单一沉积旋回的厚度在多大程度上是相对海平面变化幅度的直接量度，目前还没有完全了解。来自大巴哈马银行的新的浅层地震数据显示，在全新世海平面上升期间创造的可容纳空间并没有以可预测的方式填满。确定了三个地震层：海床、更新世顶部和更新世内的地震层。全新世和更新世地层的深度、表面和厚度图与326个现场水深测量相结合，以评估目前可容纳空间的上限。分析表明，可容纳空间与全新世沉积厚度、水深不相关。此外，实际水深和台地内部相分布没有直接的联系。浅水平台上的能量分布似乎控制着相类型，而不是水深。泥质为主的沉积物主要分布在受地形屏障保护的浅部低能区，而无泥质的粗粒沉积物主要赋存于具有强烈潮流、海水入侵和风的水动力能的深层地区。因此，能量分布的不均匀不仅导致平台上碳酸盐旋回厚度的不可预测的差异，而且还导致了平台内部与水深无关的相分布模式。因此，从古台地的内部相分布和沉积厚度模式推断海平面信号时应特别注意。
Cyclic facies variations in shallow‐water carbonate platforms often show repetitive facies patterns that are frequently interpreted to reflect the sedimentary response to variations in sea‐level related to changes in climate linked to orbital variations, the Milankovitch frequencies. Whether these shallow‐marine carbonates represent a complete infill of accommodation space, or are subtidal cycles, has been discussed in numerous papers. The extent to which the thickness of a single depositional cycle is a direct measure of the amplitude of relative sea‐level change is not fully understood. New shallow seismic data from Great Bahama Bank reveal that accommodation space created during the Holocene sea‐level rise is not filled in a predictable way. Three seismic horizons were identified: the seabed, the Pleistocene top, and a horizon within the Pleistocene. Depth surface and thickness maps of the Holocene and Pleistocene layers were combined with 326 in situ water‐depth measurements to assess the upper limit of the present accommodation space. The analysis showed that accommodation space and Holocene sediment thickness, and water depth are not correlated. In addition, the actual water depth and inner platform facies distribution showed no straightforward link. The energy distribution across the shallow‐water platform appears to control the facies type rather than water depth. Mud‐dominated sediments prevail in shallow low‐energy areas protected by a topographic barrier, whereas mud‐free coarse‐grained sediments mainly occur in deeper areas with hydrodynamic energy induced by strong tidal currents, ocean water influx, and winds. Hence, the uneven energy distribution not only results in unpredictable differences in the carbonate‐cycle thickness on the platform but also to a water depth independent facies distribution pattern within the inner platform. Therefore, care should be taken when deducing sea‐level signals from inner platform facies distribution and sediment thickness patterns on ancient platforms.
影响因子：
2.8
作者：
Isaack, Anja;Gischler, Eberhard;Camoin, Gilbert F.
通讯作者：
Camoin, Gilbert F.
影响因子：
3.5
作者：
Gischler, Eberhard;Hudson, J. Harold;Camoin, Gilbert F.
通讯作者：
Camoin, Gilbert F.