Springerville Volcanic Field, East-Central Arizona: A Case Study of Crust/Mantle Evolution and Petrogenetic Processes in a Tectonophysical Transition Zone

不同构造物理区域喷发岩浆的化学和同位素特征为岩浆的产生与演化、壳幔演化和构造发育之间的关系提供了新的认识。美国西南部，特别是科罗拉多高原-盆地和山脉地区，提供了研究这些关系的机会。对亚利桑那州中东部Springerville火山场的基性熔岩的初步研究表明，该火山场标志着科罗拉多高原-盆地和山脉过渡带的一部分，并被独特的地幔和地壳储层所覆盖。已经确定了两个地幔源，但这些源之间或衍生熔体之间相互作用的性质的阐明，以及额外的地壳或地幔储层输入的表征，有待于进一步详细的微量元素和多同位素研究。该项目将建立在最近发表和获得的野外、岩石学、年代学和化学数据的基础上，通过更详细的化学和多同位素（Sr,Nd, Pb， O）研究整个Springerville的熔岩成分谱。最终目标是确定过渡带斯普林维尔部分下的次大陆地幔的特征，并确定在该区域内发生的成岩作用的范围。这将使我们更全面地了解岩石圈的构造状态对地幔储层发育和相互作用性质的影响，以及引起大陆火山套化学和同位素多样性的成岩过程。

The chemical and isotopic characteristics of erupted magmas from regions bounding distinct tetonophysical provinces provide insights into relationships between magma generation and evolution, crust/mantle evolution, and tectonic development. the southwestern United Stated, particularly the Colorado Plateau - Basin and Range region, yields opportunities to investigate these relationships. Preliminary investigations of mafic lavas from the Springerville volcanic field, east-central Arizona, suggest that this field marks a portion of the Colorado Plateau - Basin and Range transition zone and is underlain by distinct mantle and crustal reservoirs. Two mantle sources have been identified, but elucidation of the nature of interactions between these sources, or between derivative melts, and the characterization of additional crustal or mantle reservoir input awaits further detailed trace element and multi-isotope investigations. This project will build on recently published and acquired field, petrographic, chronologic, and chemical data through more detailed chemical and multi-isotope (Sr,Nd, Pb, O) studies of lavas from the entire Springerville compositional spectrum. The ultimate goal is to define the character of the subcontinental mantle beneath the Springerville portion of the transition zone and to define the range of petrogenetic processes acting within this region. This will lead to a more complete understanding of the effects that the tectonic state of the lithosphere have on the nature of mantle reservoir development and interaction, and the petrogenetic processes giving rise to chemical and isotopic diversity in continental volcanic suites.