Footprints of ice: Ice loading and its effects on sedimentary basins and the carbon cycle

了解沉积盆地的冰负荷效应是理解古温度对油藏和可能在一定深度的烃源岩的影响，以及古孔隙超压和古孔隙度导致含碳流体爆炸性泄漏并迅速逃逸到大气或海洋水柱的关键。要了解和量化沉积盆地内有机碳的储存、迁移和泄漏循环，就必须了解这些性质在冰加载和卸载下的表现。尚未解决的问题仍然是，通过冰的加载和卸载，温度变化对储层、密封层和烃源岩的影响，可能导致石油泄漏，以及岩石物理性质（孔隙度、渗透率、压力）的表现，这些似乎与冰的波动直接相关。盆地历史模拟表明，在大多数沉积盆地中，大部分生成的流体向上迁移到海洋的水柱中，并进入大陆的大气。因此，数值模拟已成为研究大尺度、大时间跨度沉积体系的重要分析工具，同时考虑到岩石物性（如渗透率、孔隙度和气体吸附能力）以及受沉积有机质成因和类型控制的地球化学性质。然而，很少有盆地历史模拟考虑了冰期和间冰期。本研究将重点研究第四纪冰负荷对德国（德国北部和鲁尔地区）、荷兰和挪威北极沉积盆地内碳循环的影响。这些地区非常适合，因为一方面它们含有富含有机碳的沉积岩。另一方面，在过去100万年的大冰期中，这些地区多次被冰盖覆盖。建议的研究将集中在(1)与冰川期间碳循环相关的地球化学和地球物理参数的规定；(2)冰荷载厚度和持续时间对不同类型沉积物的影响；(3)与冰川过程相关的潜在碳迁移和泄漏途径；(4)冰荷载消退后的可逆性程度（岩石物理/地球化学参数；渗透率、压力、孔隙度）。这项研究的结果有望为沉积盆地内冰负荷对碳循环的影响及其与地表和大气碳的相互作用提供新的和更详细的见解。基于这种方法，可以量化释放到地表和大气的含碳流体的通量，并且可以更好地了解冰负荷和退缩对碳循环的影响。在预期的全球变暖和相关的冰盖融化的背景下，了解这一点很重要。

Knowing the ice loading effects on sedimentary basins is a key to understand the paleo- temperatures as affecting petroleum reservoirs and possibly source rocks in certain depths as well as paleo- pore overpressures and paleo- porosity leading to explosive leakage of carbon bearing fluids and thus rapid escape to the atmosphere or the water column of the oceans. To understand and quantify the organic carbon cycle in terms of storage, migration and leakage within sedimentary basins, it is thus indispensable to know the performance of these properties under ice load and unload. Unsolved questions remain the impact of temperature variabilities through ice load and unload on reservoir, seal and source rocks, potentially leading to petroleum leakage, as well as the performance of petrophysical properties (porosity, permeability, pressure) which directly seem to be coupled to ice fluctuation.Basin history simulations suggest that in most sedimentary basins the bulk of the generated fluids are lost migrating upwards into the water column of the oceans and into the atmosphere on continents. Thus, numerical modeling has become an important analytical tool to study sedimentary systems on large scales and over large time spans taking into account petrophysical properties (such as permeability, porosity and gas adsorption capacity) as well as geochemical properties that are controlled by the origin and type of the sedimentary organic matter. However, few basin history simulations took into account the glaciational and interglaciational phases. This proposed study will focus on the impact of Quaternary ice loads on the carbon cycle inside sedimentary basins in Germany (north Germany and Ruhr area), the Netherlands and Arctic Norway. These areas are very well suited, because on the one hand they contain sedimentary rocks rich in organic carbon. On the other hand, these areas were covered by ice shields several times during major glaciations in the past million years. The proposed investigations will focus on (1) the specification of geochemical and geophysical parameters relevant for the carbon cycle during glaciations, (2) the impact of thickness and duration of ice loads on different types of sediments, (3) potential carbon migration and leakage pathways related to glaciation processes, and (4) degree of reversibility (of petrophysical/geochemical parameters; permeability, pressure, porosity) after retreat of the ice loads. The results of this study are expected to provide new and more detailed insights on the effects of ice loads on the carbon cycle within sedimentary basins and its interaction with surface and atmospheric carbon. Based on this approach, the flux of carbon-bearing fluids released to the surface and the atmosphere can be quantified and the impact of ice load and retreat on the carbon cycle will be much better understood. This is important to know in the context of the expected global warming and related ice shield melting.