Tracing paleofluid sources using clumped isotope thermometry of diagenetic cements along the Moab Fault, Utah
Tracing paleofluid sources using clumped isotope thermometry of diagenetic cements along the Moab Fault, Utah
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使用犹他州摩押断层沿线成岩胶结物的团簇同位素测温法追踪古流体来源
DOI：
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发表时间：
2013
影响因子：
2.9
通讯作者：
J. Crider
中科院分区：
文献类型：
--
作者：
S. Bergman;K. Huntington;J. Crider
流体、变形结构和沉积物化学变化之间的相互作用影响浅层地壳的变形，影响其所含经济资源的保存和开采。这些相互作用已经在犹他州悖论盆地的摩押断层沿线进行了研究，这里的成岩胶结物、节理、碎裂变形带和断层作用期间形成的滑移面被认为控制断层渗透性。先前的流体包裹体显微测温和沿莫阿布断层收集的方解石胶结物的稳定同位素数据表明，胶结物是从热盆流体中沉淀出来的，这些流体沿着断层迁移并与较浅的大气地下水源相互作用。在这项研究中，我们利用摩押断层沿线方解石胶结物的聚集同位素测温技术研究了这些流体与变形结构的相互作用。在变形结构和方解石胶结物的先前高分辨率绘图的指导下，我们测量了在距断层段和断层交叉点不同距离处收集的方解石胶结物的生长温度。各个段的水泥温度差异很大；沿着相对简单的断层段的胶结物表明温度范围为 67 至 128 °C，类似于先前公布的在同一地点收集的胶结物样本的流体包裹体均质化温度，而附近的断层交叉点的胶结物温度为 13 至 88 °C。团块同位素测温揭示的水泥温度的空间分布表明，与断层交叉点相关的强烈节理带使得冷地表水能够快速向下断层迁移，而变形带断层及其相关滑移面可能进一步分隔流体流动，将流体源限制在与节理带外的围岩热平衡的温暖水域。我们的数据证实，断层与流体流动之间的关系在短长度范围内可能有很大变化，并表明一些断裂带可以高度传导至 2 公里的深度。
Interactions among fluids, deformation structures, and chemical changes in sediments impact deformation of the shallow crust, influencing the preservation and extraction of the economic resources it contains. These interactions have been studied along the Moab Fault, in the Paradox Basin, Utah, where diagenetic cements, joints, cataclastic deformation bands and slip surfaces developed during faulting are thought to control fault permeability. Previous fluid inclusion micro-thermometry and stable isotopic data from calcite cements collected along segments of the Moab Fault suggest cements precipitated from hot basin fluids that migrated up the fault and interacted with a shallower meteoric groundwater source. In this study, we investigate the interactions of these fluids with deformation structures using clumped isotope thermometry of calcite cements along the Moab Fault. Guided by prior high-resolution mapping of deformation structures and calcite cements, we measured the growth temperature of calcite cements collected at varying distance from fault segments and fault intersections. Cement temperatures from individual segments vary greatly; cements along a relatively simple fault segment indicate temperatures ranging from 67 to 128 °C, similar to previously published fluid inclusion homogenization temperatures from a cement sample collected in the same locality, while a nearby fault intersection hosts cements with temperatures of 13 to 88 °C. The spatial pattern of cement temperatures revealed by clumped isotope thermometry suggests that intensely jointed zones associated with fault intersections enable rapid down-fault migration of cool surface waters and that deformation-band faults with their associated slip surfaces may further compartmentalize fluid flow, restricting fluid sources to warm waters thermally equilibrated with the country rock outside the jointed zone. Our data confirm that the relationship between faults and fluid flow can vary greatly over short length scales, and suggest that some fracture zones can be highly conductive to depths as great as 2 km.
影响因子：
2.3
作者：
Huntington, K. W.;Eiler, J. M.;Came, R.
通讯作者：
Came, R.