Chemical Recycling in Subduction Zones: Implications from B-Be-Li and Be Isotope Studies of Forearc Rocks

为了了解俯冲相关流体在弧前会聚边缘的再循环行为，更好地了解弧前独特火山岩类型的成因，将对墨西哥、Woodlark盆地和巴拿马的弧前火山岩套进行B、Li和10/9Be系统研究。以及在马里亚纳和伊豆前地层中斜位的蛇纹岩。B、Be和Li的分析将由佛罗里达国际大学的IC等离子体光谱法进行，而10Be的测量将在地磁系进行。B和10Be的测量是俯冲起源的明确指标，将有助于确定伊豆和马里亚纳蛇纹岩流体的来源以及这些流体通过弧前的通量的大小。正如在岛弧火山岩中一样，对弧前火山岩中轻元素的测量将使我们能够确定和量化俯冲成分的影响，并确定微量元素从板块进入熔岩的方法。将前弧的轻元素数据与现有的弧火山岩数据库进行比较和结合，建立俯冲带流体化学循环的详细模型。

In order to understand the recycling behavior of subduction-related fluids through forearc regions at convergent margins, and to better understand the origins of volcanic rock types unique to forearc regions, a study of B, Li, and 10/9Be systematics will be undertaken on suites of forearc lavas from Mexico, the Woodlark Basin and from Panama, and on serpentinites emplaced diapirically in the Marianas and Izu forearcs. Analyses for B, Be, and Li will be conducted by IC plasma spectrometry at Florida International University, while 10Be measurements will be made at the Department of Terrestrial Magnetism. Measurements of B and 10Be, unquivocal indicators of a subducted origin, will aid in identifying the sources of serpentinizing fluids in the Izu and Marianas and the magnitude of these fluid fluxes through the forearc. As in island arc volcanic rocks, measurements of light elements in forearc volcanics will allow us to identify and quantify the effects of subducted components, as well as to define the method by which trace elements are transported from the slab into lavas. Light element data from forearcs will be compared and combined with the existent database on arc volcanic rock in order to create a detailed model for the chemical cycle of fluids in subduction zones.