Spatial patterns of oxygen isotope exchange during one‐dimensional fluid infiltration
Spatial patterns of oxygen isotope exchange during one‐dimensional fluid infiltration
复制标题
一维流体渗透过程中氧同位素交换的空间模式
DOI：
10.1029/91gl01079
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发表时间：
1991
影响因子：
5.2
通讯作者：
S. Willett
中科院分区：
文献类型：
--
作者：
J. R. Bowman;S. Willett
一维运移方程的解表明，岩石与渗流流体之间氧同位素交换的时空演化取决于流体的渗流速率、岩石基质的分散性、同位素交换速率和质量氧比。在岩石层序中形成的同位素交换锋的几何形状取决于前三个参数之间的相互作用。岩石中同位素比率的变化取决于岩石在流体通道中的位置和与流体的同位素交换速率以及累积流体通量。因此，常规的水/岩（W/R）比也将取决于流动路径中的位置。在岩石序列中缺乏显着的18 O亏损并不需要低的W/R比，但可能只意味着岩石是在一个岩石为主的部分的流道或流体渗透的特点是非平衡交换。
Solutions of one-dimensional transport equations indicate that the time-space evolution of oxygen isotope exchange between rock and infiltrating fluid is dependent on 1)the rate of fluid infiltration, 2)the dispersive properties of the rock matrix, 3)the rate of isotopic exchange, and 4)the mass oxygen ratio. The geometry of isotopic exchange fronts developed in a rock sequence depends on the interplay between these first three parameters. The change in isotopic ratio in a rock depends on its position in the flowpath and the rate of isotopic exchange with the fluid in addition to the cumulative fluid flux. Thus conventional water/rock (W/R) ratios will also depend on position in flow paths. Absence of significant 18O depletions in rock sequences does not require low W/R ratios, but may only mean that the rock is in a rock-dominated segment of a flowpath or alternatively that fluid infiltration was characterized by nonequilibrium exchange.