Basaltic Volcanism Associated with Basin and Range Extension, Central Nevada - Geochemical Variation in Space and Time

通过初步研究，岩浆转换的地点（例如， 从高Ba/Nb类Steens熔岩到低Ba/Nb碱性玄武岩） 在内华达州中北部（靠近温内穆卡， 法伦以东，凯恩斯普林斯和月球之间 火山口火山场）。 然而，这些岩浆的成分 也可能受到基底横向变化的影响 （包括岩石圈地幔）年龄和成分。 这 该项目将对镁铁质岩石进行详细的地球化学研究， 熔岩从大致南北和东西的断面， 内华达州中北部，以评估源特性。 年龄 将对选定的样品进行测定，以确定 岩浆源转换年代学 这些数据将提供 新生代地幔卷入的重要制约因素 科迪勒拉地区的延伸。

Through preliminary studies, loci of magmatic transitions (e.g., from high Ba/Nb Steens-like lavas to low Ba/Nb alkalic basalts) have been identified in north central Nevada (near Winnemucca, East of Fallon, and between Kane Springs Wash and the Lunar Crater volcanic field). However, compositions of these magmas could also be influenced by lateral variations in basement (including lithospheric mantle) age and composition. This project will carry out a detailed geochemical study of mafic lavas from roughly north-south and east-west transects across north-central Nevada to evaluate source characteristics. Age determinations will be made for selected samples to establish the chronology of magma source transitions. These data will provide important constraints on mantle involvement during the Cenozoic regional extension of the Cordilleran region.