(Table T1) Fluid inclusions in siltstone and sandstone grains from ODP Hole 210-1276A

Twenty samples of siltstones and sandstones were taken from Ocean Drilling Program Site 1276 during Leg 210 for fluid inclusion studies. With the exception of one sample of vein calcite, all inclusions were in quartz grains. The results of fluid-inclusion petrology and microthermometry indicate the presence of three fluid inclusion types (Types 1, 2, and 3). Type 1 fluid inclusions are two-phase (liquid + vapor) aqueous inclusions, and Type 2 inclusions are monophase fluid inclusions (liquid or vapor). These are common in all samples and are formed either as primary isolated inclusions or as secondary inclusions as trails along annealed fractures in the grain. Type 3 fluid inclusions are three-phase (liquid + vapor + solid) inclusions. Type 3 inclusions are rare and are observed as isolated inclusions or in a cluster with other types (i.e., Types 1 and 2). The predominant population throughout the different units sampled is two-phase (liquid + vapor) aqueous fluid inclusions (i.e., Type 1). The temperature of homogenization (TH) bivariate plots for Type 1 inclusions shows dominance throughout the hole of low- to medium-salinity fluids with minimum trapping temperatures between 150° and 400°C.本研究从大洋钻探计划（Ocean Drilling Program, ODP）210航次1276站位采集了20件粉砂岩与砂岩样品，用于流体包裹体（fluid inclusion）相关研究。除一件脉状方解石样品外，所有流体包裹体均赋存于石英颗粒内部。流体包裹体岩相学与显微测温结果显示，样品中共存在三类流体包裹体（1型、2型与3型）。1型流体包裹体为两相（液相+气相）水溶液包裹体，2型包裹体为单相流体包裹体（液相或气相），两类包裹体在所有样品中均广泛分布，既可形成原生孤立包裹体，也可沿颗粒内退火裂隙呈线状分布形成次生包裹体。3型流体包裹体为三相（液相+气相+固相）包裹体，较为稀少，可呈孤立状产出，或与1型、2型包裹体伴生形成集合体。在所采集的不同地层单元中，优势包裹体类型均为两相（液相+气相）水溶液包裹体（即1型包裹体）。针对1型包裹体的均一温度（TH）双变量图显示，本钻孔整体以低盐度至中盐度流体为主，流体最低捕获温度介于150℃至400℃之间。