ROW: Petrogenesis of Late Cenozoic Mafic Lavas From the Southern Rio Grande Rift, New Mexico

里约热内卢大裂谷是美国西南部的一个主要构造和火山特征。本文提出的研究将描述裂谷南部新墨西哥部分晚新生代熔岩的岩石学和地球化学特征。重点将放在大陆裂谷带熔体产生的动力学和次大陆地幔的化学和同位素性质上。在北段进行了大量的地球化学研究；南部地区很少有类似细节的研究。这是一项研究的第一阶段，该研究将试图通过对新墨西哥州南部三个不同领域的详细地层研究来弥补这一缺陷。熔岩、斑晶、异晶和幔源包体的主要元素和微量元素组成将用于模拟源岩性、岩浆生成深度和熔体演化。

The Rio Grande Rift is a major tectonic and volcanic feature of the southwestern United States. The study proposed here will characterize the petrology and geochemistry of late Cenozoic lavas in the southern New Mexico portion of the Rift. Emphasis will be place on the dynamics of melt generation in continental rift zones and the chemical and isotopic nature of the subcontinental mantle. There have been a number of geochemical studies in the northern portion; the southern part has had few studies of comparable detail. This is the first stage of a study which will attempt to remedy the deficiency with detailed stratigraphic study of three different fields in southern New Mexico. Major-and trace-element compositions of the lavas, phenocrysts, xenocrysts, and mantle-derived xenoliths will be used to model source lithology, depth of magma generation, and melt evolution.