Understanding the Origin of Patterned Silica Diagenetic Reaction Fronts

化学反应边界是在初始化学反应物和最终反应产物之间形成的一层。随着反应的进行，边界在化学混合物中扩散。反应边界已被记录在原子（纳米）尺度的实验室到米尺度的沉积岩。它们形成模式和模式反应边界，它们形成的过程被广泛研究，因为它们存在于化学、生物和地质系统中。化学过程在把沉积物变成岩石和把流体从沉积物中赶出来方面是非常重要的。大多数研究都是在厘米尺度上观察化学边界是如何形成的，但我们已经在沉积岩中发现了千米尺度上的反应边界，并希望找出它们是如何形成的。这是以前没有尝试过的。我们已经开始记录迄今为止全球最大的化学反应边界。它们形成的模式由超过几十平方公里的蜂窝或脊型网络组成。这些单元高50-200米，宽2.7公里。反作用锋面的发育与许多其他地质现象有关，反作用锋面似乎是沉积盆地演化的一个基本方面。关于这些模式是如何形成的，我们有三种理论，这一提议将使我们能够精确地确定IODP钻孔的位置，从而找出我们的理论中哪一种是正确的。我们的工作可分为两部分：1.工作内容：我们将分析石油和天然气行业提供的地震反射数据集，并通过与挪威国家石油公司的合作，我们将确定IODP钻孔的位置。这项研究将导致提交预iodp和全iodp钻井建议。2. 这些数据将使我们能够评估遇到浅层天然气或碳氢化合物的风险，以及斜坡不稳定的可能性。我们将对此进行全面评估，因此我们的IODP提案不需要任何额外和昂贵的数据收集。

A chemical reaction boundary is a layer that forms between the initial chemical reactants and final products of a reaction. As the reaction develops the boundary propagates through a chemical mixture. Reaction boundaries have been documented at atomic (nanometer) scale in the laboratory upto metre-scale in sedimentary rocks. They form patterns and patterned reaction boundaries and the processes by which they form are widely studied, since they are found in chemical, biological and geological systems. Chemical processes are very important in changing sediment into rock and for driving fluids out of sediment. Most studies involve looking at how chemical boundaries form at a centimentre scale - but we have identified patterned reaction boundaries at kilometre-scale in sedimentary rocks and want to find out how they form. This has not been attempted before. We have started to document the largest scale chemical reaction boundaries yet to be seen on the globe. They form patterns which consist of cell or ridge-type networks over 10s of square kilometres. The cells are in 50-200 m in height and up to 2.7 km across. The development of the reaction fronts and the patterns are linked to a host of other geological phenomena and the reaction fronts appear to be a fundamental aspect of sedimentary basin evolution. We have three theories as to how the patterns form, this proposal would allow us to refine where exactly IODP borehole should be positioned to find out which - if any - of our theories is correct. Our work can be divided into two parts: 1. We would analyse seismic reflection datasets provided by the oil and gas industry and through a partnership with StatoilHydro we would establish where IODP boreholes should be located. This research would result in the submission of pre- and full-IODP drilling proposals. 2. The data would allow us to evaluate the risk of encoutering shallow gas or hydrocarbons as well as the chances of slope instability. We would compile a comprehensive assessment of this, therefore our IODP proposal would not require any additional and costly data collection.