Stable Vanadium Isotopes in the Igneous Rocks of the Shatsky Rise: IODP Expedition 324

我们生活在一个不断变化的世界。我们地球的表面永远在运动，坚硬的外表面“板块”以每年厘米的速度移动。正是这些板块的运动导致了地球上大部分的地震和火山活动。在这个动态的表面上，海洋覆盖的面积比陆地大得多。在一些地方，大量的火山岩形成了孤立的海底高原。我们称这些为“大火成岩省”或“唇”。他们为什么在那里？有些人认为，它们可能是在板块破裂时形成的，地球内部较热的部分融化，形成熔岩，冷却形成唇部。另一些人认为lip与来自地球更深更热的东西有关。夏威夷就是一个例子，那里没有板块边界，但有很多很多的岩石。这些地方有时被称为“热点”。我们如何测试lip的深热点起源与浅板块起源？在太平洋中有一个被称为沙斯基隆起的LIP，它有近1.5亿年的历史，占地面积与日本相当。然而，这个LIP的特别之处在于它位于一个不再活跃的旧板块边界上。像夏威夷这样的“热点”岩石与在大洋中脊形成的岩石不同的一个原因是它们的化学成分。因此，“综合海洋钻探计划”（IODP）正在对沙茨基火山岩进行钻探探险。我们带回的样本可以进行分析，以帮助我们确定这些岩石是来自深处的热“羽流”，还是更像是板块分裂时形成的洋中脊岩石。这是一次激动人心的探险。我们首先要钻到3000多米深的水下才能到达下面的岩石。这是将近300个足球场的长度。我们带回来的岩石会让我们发现一亿多年前沙斯基LIP形成的原因。无论沙斯基是由深层热羽形成的，还是仅仅是表面板块运动的结果，都将告诉我们很多关于地球内部如何演变和管理其热量预算的信息。

We live in a constantly changing world. The surface of our Earth is in perpetual motion, with hard outer surface 'plates' moving about at rates of centimeters every year. It is the movement of these plates as they pull apart and collide with one another that causes most of the Earth's earthquakes and volcanic activity. On this dynamic surface, there is a much larger area covered by sea than by land. In some places, massive amounts of volcanic rocks make isolated undersea plateaus. We call these 'Large Igneous Provinces' or 'LIPs'. Why are they there? Some people think that they might have formed when plates broke apart and let the hotter interior of the Earth melt, making lava, and cooling to form the LIPs. Other people think that LIPs are related to something coming from much deeper and hotter in the Earth. An example of this is Hawaii, where there are no plate boundaries, but lots and lots of rock. These places are sometimes called 'hotspots'. How do we test a deep hotspot origin versus shallow plate origin for LIPs? There is a LIP in the Pacific Ocean called the Shatsky Rise that is almost 150 million years old and covers an area about the size of Japan. What makes this LIP special, however, is that it sits on an old plate boundary that is no longer active. One thing that makes 'hotspot' rocks like Hawaii different from rocks formed at mid-ocean ridges where plates break apart is their chemical compositions. Therefore the Integrated Ocean Drilling Program (IODP) is going on an expedition to drill into the Shatsky volcanic rocks. The samples that we bring back can then be analyzed to help us decide whether these rocks come from deep, hot 'plumes', or if they look more like mid-ocean ridge rocks that form where plates break apart. This is an exciting expedition. We first have to drill down through over 3000 meters of water to get to the rocks below. That is the length of almost 300 football pitches lined up together. The rocks that we bring back will let us discover what was happening to cause the formation of the Shatsky LIP over 100 million years ago. Whether Shatsky resulted from a deep hot plume, or was just the result of surface plate processes will tell us a great deal about how the interior of the Earth evolves and manages its heat budget.