An Investigation of Crustal and Upper Mantle Magmatic Sources in the High Plains Province, New Mexico and Colorado, A Unique View into Late Cenozoic Magmatic...

火山作用和伸展构造作用 新生代美国西部的一个地区。 研究 近年来，人们对 构造作用与岩浆作用的关系 美国西部，但有关驾驶的未解决问题 延伸的力量依然存在。 新生代火山岩 高平原提供了一个独特的视角， 问题 这些火山岩的构造 成分和密切同期火山场 在格兰德河裂谷向西南进入亚利桑那州。 然而，高平原火山区位于东部100-200公里处， 格兰德河裂谷的影响范围远远超出了 地壳伸展 的空间和时间变化 我们的初步研究显示， 研究（例如，同位素变化）需要显著的 物源成分及壳幔差异 结构 对这片火山区的详细研究将 允许与扩展区域内的字段进行比较 并为物理模型提供必要的约束 解释岩浆作用与伸展作用的关系 构造作用

Volcanism and extensional tectonism spread across a broad region of the western U.S. during the Cenozoic. Studies in recent years have provided much insight into the relationship between the tectonism and magmatism in the western U.S., but unsolved questions relating to the driving forces for extension remain. The Cenozoic volcanic rocks of the High Plains provide a unique perspective on such problems. These volcanic rocks are broadly similar in composition and closely contemporaneous with volcanic fields in the Rio Grande Rift and southwestward into Arizona. However, the High Plains volcanic fields lie 100-200 km east of the Rio Grande Rift in an area well beyond the effects of crustal extension. Spatial and temporal variations in composition of volcanic rocks shown from our preliminary study (e.g., isotopic changes) require significant differences in source composition and crust and mantle structure. A detailed study of this volcanic field will enable comparison with fields within the region of extension and provide essential constraints for physical models explaining relationship between magmatism and extensional tectonism.