Zircon in Iceland: Elucidating Generation and Evolution of Silicic Magma and Juvenile Crust

2010年埃亚菲亚德拉火山爆发，导致国际空中交通瘫痪，引起了人们对冰岛的关注？的地质独特性和潜在的全球影响。 它的许多活火山的爆炸行为和丰富的地热能源资源，为这个清洁的岛国提供动力，都与产生丰富的火山熔岩、火山灰和花岗岩的不寻常的海洋岩浆系统有关。该项目强调矿物锆石作为示踪剂，探索冰岛现在和过去产生岩浆的过程，在大西洋中部建造一个大陆状岛屿，并为其动态火山和地热系统提供动力。冰岛？它的大小和地壳的厚度，以及丰富的岩浆活动，使它在地球上独一无二。海洋岛屿。 这些特征使以前的研究人员提出，该岛提供了永久性低密度大陆地壳形成早期阶段的现代例子，可能模仿了40亿年前第一批大陆的形成。 值得注意的是，在冰岛地质学的广泛研究中缺乏对锆石的调查，而锆石在其他地方为我们对岩浆过程和地球起源与演化的理解提供了基础。的外壳。 锆石是一种通常与大陆和岛弧的火山岩有关的矿物，是高温过程放射性测年的最耐用和可靠的材料，同时提供有关其生长环境的信息。 虽然冰岛的大多数？由于该岛地壳硅含量低（玄武岩），因此锆石含量也很低，岛上硅含量较高的岩石（花岗岩和流纹岩）携带了足够的锆石来阐明它的历史。 这项调查建立在调查人员利用放射性测年和锆石的元素和同位素组成进行的试点研究的基础上，以澄清冰岛火山岩浆在喷发前产生和储存和修改的过程。 这项研究将加深对冰岛岩浆和相关地热系统如何工作的理解。 在这样做的过程中，它还将解决气候演变的问题（从温带到冰川条件的变化是否影响了岩浆过程？）和冰岛的构造构造（裂谷和地幔柱过程在岩浆的产生中起什么作用？冰岛的下面是从大西洋开口处遗留下来的古代大陆地壳碎片吗？

The 2010 eruption of Eyjafjallajökoll, which paralyzed international air traffic, called attention to Iceland?s geological uniqueness and potential global impact. Both the explosive behavior of its many active volcanoes and the plentiful geothermal energy resources that power the clean island nation are linked to unusual oceanic magma systems that yield abundant silicic lava, ash, and granitic rocks. This project emphasizes the mineral zircon as a tracer to explore the processes operating in Iceland at present and in the past to generate silicic magmas, build a continent-like island in the mid-Atlantic, and power its dynamic volcanic and geothermal systems. Iceland?s size and the thickness of its crust, as well as its copious silicic magmatism, make it unique among Earth?s oceanic islands. These characteristics have led previous researchers to propose that the island provides a modern example of the early stages of formation of permanent, low-density continental crust, perhaps mimicking the initiation of the first continents over four billion years ago. Notably lacking in the extensive studies of Icelandic geology are investigations of zircon, which have elsewhere provided the underpinnings for much of our understanding of magmatic processes and the origin and evolution of the Earth?s crust. Zircon, a mineral typically associated with the silicic rocks of continents and island arcs, is the most durable and reliable material for radiometric dating of high-temperature processes and at the same time provides information about the environments in which it grows. Although a majority of Iceland?s crust is low in silica (basalt) and therefore poor in zircon, the island's higher-silica rocks (granite and rhyolite) carry sufficient zircon to elucidate its history. This investigation builds on pilot studies by the investigators using radiometric dating and elemental and isotopic compositions of zircon to clarify the processes by which silicic magmas are generated in Iceland and stored and modified prior to eruption. The research will refine understanding of how magmatic and related geothermal systems work in Iceland. In so doing, it will also address issues of evolving climate (did the change from temperate to glacial conditions affect magmatic processes?) and tectonic construction of Iceland (what roles do rifting and plume processes play in production of silicic magma?; is Iceland underlain by fragments of ancient continental crust that remain from the opening of the Atlantic?).