COLLABORATIVE RESEARCH: Experimental Study of Basin Stratigraphy

合作研究：盆地地层学实验研究

• 批准号: 9725989
• 负责人: Christopher Paola
• 金额: $ 16.81万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1998
• 资助国家: 美国
• 起止时间: 1998-05-01 至 2000-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9725989&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; Experimental; Study; Basin

9725989 Paola We propose a three-year program of experimental studies o the formation of physical stratigraphy, using a large new experimental basin with a subsiding floor at the St. Anthony Falls Laboratory (SAFL). This facility allows study of scaled basin processes with complete control of base level, sediment supply and, especially, subsidence pattern and rate. The basin is 13m by 6.5m and allows up to 1.3m of accommodation space for deposition. The subsiding floor comprises 432 independently controllable subsidence cells arranged in a honeycomb pattern. This design allows the creation of a nearly unlimited range of spatial and temporal subsidence patterns. Sediment and water can be fed from anywhere along the basin margin and base level (i.e. water level) is independently controllable. Our first experiments will be aimed at testing some of the first-order predictions of models that have been proposed for formation of physical stratigraphy at basin scales, such as: (1) the relationship of shoreline migration and associated stratigraphy to the interplay between subsidence rate and eustatic sea level; (2) the control of subsidence rate and geometry, and sediment supply, on alluvial coarse-facies distribution (i.e. the origin of syntectonic gravel's); and (3) the influence of subsidence rate and sediment supply on the development of alluvial architecture. Initial results suggest that the experiments can also provide insight on processes such as growth faulting that have not been widely incorporated into existing models. These experiments will use relatively simple subsidence and sediment-feed geometries and will focus on demonstrating "unit" stratigraphic response to changes in one or at most two variables simultaneously. The second set of experiments will focus on 3-D effects in both subsidence and sediment supply, including: 1) 3-D effects of base-level change; 2) propagating active folding in the proximal basin associated with blind thrusts and development of progressive un conformities; 3) sedimentation in an asymmetric half graben combining both transverse and axial drainage. The principal products of the experiments will include: time records of the imposed variables (water and sediment supply, base level, and basement topography); measurements of bed-surface topography through time; video records of flow pattern, shoreline position and other surface features; 3-D block diagrams of the resulting deposits, presented both as directly digitized (photographic) and synthetic seismic images; and synthetic geophysical logs of selected profiles. The synthetic seismics are a crucial link with field observations, since the only way that researchers can obtain views of the rock record comparable to those generated by the experimental basin is through the filter of seismic reflection profiling. The synthetic seismics and well logs, when contrasted against the actual experimental stratigraphy, will also advance our understanding of what is and is not retained from the rock record when it is imaged via these widely used techniques. The experimental results would represent the first test under fully controlled conditions of a wide variety of theoretical predictions of stratigraphic response that have been developed since Pitman's (1978) model of shoreline response to changing sea level. They would also provide a template that could be compared with field observations and interpretations based on seismic and outcrop data. Although laboratory scale models can never capture all of the complex processes that occur in real basins, they serve as a bridge between untested theoretical models and difficult-to-constrain natural examples.

9725989 Paola我们提出了一个为期三年的实验研究计划。物理地层的形成，使用一个大型的新实验盆地，并在圣安东尼瀑布实验室（SAFL）的地板上放下地板。 该设施允许研究缩放盆地过程，并完全控制基础水平，沉积物供应，尤其是沉降模式和速率。 盆地为13m x 65m，最多可容纳13m的住宿空间。 地板的底层包含432个以蜂窝状模式排列的独立控制的沉降细胞。 这种设计允许创建几乎无限的空间和时间沉降模式。 沿盆地边缘和基础水平（即水位）可以从任何地方提供沉积物和水是独立控制的。 我们的第一个实验将旨在测试已提出的一些模型的一阶预测，这些预测是为了形成盆地尺度上物理地层的一阶预测，例如：（1）海岸线迁移与相关地层与沉降速率与优质海平面之间的相互作用的关系； （2）对冲积粗调子分布的沉降速率和几何形状以及沉积物供应的控制（即语法砾石的起源）； （3）沉降率和沉积物供应对冲积结构发展的影响。 最初的结果表明，实验还可以提供有关未广泛纳入现有模型等过程的过程的见解。 这些实验将使用相对简单的沉降和沉积物喂养的几何形状，并专注于同时表现出对一个或最多两个变量变化的“单位”地层响应。 第二组实验将重点放在沉降和沉积物供应中的3-D效应上，包括：1）基础水平变化的3-D效应； 2）在与盲推的近端盆地中传播活跃的折叠以及进行性联合国的发展； 3）在不对称的半抓地力中进行沉降，结合了横向和轴向排水。 实验的主要产品将包括：施加变量的时间记录（水和沉积物供应，基础水平和地下室地形）；随着时间的推移测量床表面的地形；流动模式，海岸线位置和其他表面特征的视频记录；所得沉积物的3-D框图，既显示为直接数字化（照相）和合成地震图像；和选定轮廓的合成地球物理日志。 合成的地震学是与现场观测的关键联系，因为研究人员可以通过地震反射分析的过滤器获得与实验盆地产生的岩石记录观点相比可比的岩石记录的唯一途径。 当与实际的实验地层形成对比时，合成的地震学和井原木也将提高我们对通过这些广泛使用的技术成像时对岩石记录的理解，也不会从岩石记录中保留。 实验结果将代表自Pitman（1978）的海岸线响应对变化海平面的海岸线响应模型以来已经开发出的各种理论预测的完全控制条件下的首次测试。 他们还将提供一个模板，可以将其与基于地震和露头数据的现场观察和解释进行比较。 尽管实验室规模模型永远无法捕获实际盆地中发生的所有复杂过程，但它们是未经测试的理论模型和难以构成的自然实例之间的桥梁。