Temporal and Spatial Geochemical Variations in Patagonian Plateau Basalts: Implications for the Evolution of the Continental Lithosphere

大陆弧后和板内玄武质火山岩 省提供了一个了解地幔演化的视角， 大陆下地壳和物质的质量通量 它们被俯冲但不是被弧火山作用提取出来的。 之一 最大的大陆玄武岩区是 南美南部巴塔哥尼亚玄武岩区， 不连续1800公里。在安第斯山脉以东 几乎到达大西洋海岸。 玄武质火山作用区 时代从古新世晚期一直延续到近代，并有活动 在不同的时间集中在不同的地方。 的 玄武岩的地理分布、年龄谱 其多变的基底使巴塔哥尼亚高原成为 这是一个很好的地方来检查的原因和影响， 构造条件对玄武岩演化的影响 间接地，地壳和地幔。 了解来源 弧和弧后岩石的区域取决于 了解哪些成分因构造变化而变化 条件和长期地幔的结果， 地壳非均匀性 这个项目是为了检查时间 地球化学变化（使用主元素和微量元素化学; Nd、Sr和Pb同位素;以及一些矿物化学） 高原地区。 它补充了详细的研究 在安第斯弧正在进行的研究和对 上新世晚期到高原的现代演化。 ***//

Continental back-arcs and within-plate basaltic volcanic provinces provide a view into the evolution of the mantle and lower crust beneath continents and the mass flux of materials that are subducted, but not extracted by arc volcanism. One of the largest of these continental basaltic provinces is the Patagonian basalt field in southern South America which extends discontinuously for 1800 km. east of the Andes and in places almost reaches the Atlantic coast. Basaltic volcanism ranges continuously in age from late Paleocene to Recent with activity concentrated in different places at different times. The geographical distribution of the basalts, their spectrum of ages, and their variable basement make the Patagonian plateau an excellent place to examine the cause and effect of varying tectonic conditions on the evolution of the basalts and more indirectly, the crust and mantle. An understanding of the source region of both arc and back-arc rocks is dependant on understanding which components change due to variable tectonic conditions and which are the result of long term mantle and crustal heterogeneities. This project is to examine temporal geochemical variation (using major and trace element chemistry; Nd, Sr and Pb isotopes; and some mineral chemistry) in two regions of the plateau. It complements the detailed studies being done in the Andean arc and the more limited studies of the late-Pliocene to Recent evolution of the plateau. ***//