Pliocene to Recent Basic Magmatism in the East-Central Mexican Volcanic Belt

墨西哥中东部火山带上新世至近期基本岩浆活动

• 批准号: 9104184
• 负责人: Stephen Nelson
• 金额: $ 9.52万
• 依托单位: Tulane University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-06-01 至 1994-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9104184&HistoricalAwards=false
• 关键词: Pliocene; Recent; Basic; Magmatism; East

This project will use field studies to determine the spatial and temporal distribution of Pliocene to Recent basic volcanic rocks in the east-central MVB. Selected samples will be analyzed for major elements, trace elements, Sr, Nd, Pb, and O isotopic ratios, in addition to electron microprobe analyses of minerals. Some of the older rocks will be dated K-Ar methods. This data will be combined with existing data on basic volcanic rocks in the MVB to develop and/or test models for the origin of basic magmas in the MVB by placing constraints on the composition of materials contributing to the source of these basic magmas. The project will determine any correlation that exist between the distribution of the various types of basic volcanic rocks with crustal structure, age of and depth to the subducted lithosphere, and age of the rocks. It will also document the occurrence of various types of basic volcanic rocks that have only recently been recognized to occur in subduction-related volcanic arcs, and will provide a basis upon which the more common, more fractionated, and/or more contaminated calc-alkaline rocks can be understood.

该项目将通过实地研究来确定 MVB 中东部上新世至现代基性火山岩的时空分布。 除了对矿物进行电子显微探针分析外，还将分析选定样品的主量元素、微量元素、Sr、Nd、Pb 和 O 同位素比。 一些较古老的岩石将采用 K-Ar 方法测年。 该数据将与 MVB 中基性火山岩的现有数据相结合，通过对促成这些基性岩浆来源的材料成分进行限制，开发和/或测试 MVB 中基性岩浆起源的模型。 该项目将确定各类基性火山岩的分布与地壳结构、俯冲岩石圈的年龄和深度以及岩石的年龄之间存在的相关性。 它还将记录各种类型的基性火山岩的出现情况，这些火山岩最近才被认为出现在俯冲相关的火山弧中，并将提供一个基础，在此基础上可以理解更常见、更分馏和/或更受污染的钙碱性岩石。