Determination of Volcanic Flux Rates and Application to Understanding Regional Geochemical Trends and Element Mass Balances in Central America

粤公网安备4403020020000000号 迈克尔·J·卡尔 关于俯冲过程的性质的几个重要问题需要从现有的定性俯冲信号，如Ba/La和10 Be/9 Be，到定量通量，如Ba通量，以克/单位弧长/年为单位。这是通过采用40 Ar/39 Ar测年技术来测量中美洲几个大型火山中心的较老单元的年龄来实现的。这些新的数据，沿着与以前确定的体积测量，使确定平均火山流量率为不同的弧段。将火山通量率与区域地球化学数据相结合，可以对元素通量进行估计。从这些综合数据几个主要的问题正在解决，包括在中美洲俯冲信号沿走向变化的物理原因，通过中美洲弧循环的元素的质量平衡，以及通过俯冲传递到地幔深部的不相容元素的数量。

EAR-0203388 Michael J. Carr Several important questions about the nature of the subduction process require a transition from existing qualitative subduction signals, such as Ba/La and 10Be/9Be, to quantitative fluxes such as Ba flux in gm/unit arc length/yr. This is accomplished by employing 40Ar/39Ar dating techniques to measure the ages of the older units in several large Central American volcanic centers. These new data, along with previously determined volume measurements, enable the determination of average volcanic flux rates for different segments of the arc. Integrating volcanic flux rates with regional geochemical data allows an estimate of element fluxes to be made. From these integrated data several major problems are being addressed, including the physical cause of along-strike variations in subduction signal in Central America, the mass balance of elements cycling through the Central American arc, and the quantity of incompatible elements that are delivered to the deep mantle through subduction.