Seeking new paleotemperature proxies: Noble gases in evaporites

古气候记录为预测复杂气候变异性的模型提供了必要的约束。然而，在地球上温暖、干旱的地区，古温度的替代物很少。在环境温度下与大气平衡的地表水可能以流体包裹体的形式被捕获在矿物中，在这种条件下形成蒸发矿物。由于惰性气体在水中的溶解度与温度有关，本项目将研究蒸发岩用于惰性气体古测温的可能性。活跃的盐场和现代盐岩提供了相对可控的露天环境，在这种环境中发生了岩盐沉淀。这些现代环境使我们能够研究短期温度波动如何反映在岩盐中流体包裹体的惰性气体温度中，从而校准替代记录。在这个项目中，集合的研究时间将分析在已知地点和已知时间段(即已知平均温度)形成的盐岩中流体包裹体中的惰性气体浓度，以调查惰性气体温度与当地温度记录的关系。一个积极的结果将导致进一步研究建立这一新的古温度指标，并可能通过提供较长时间段干旱地区的温度记录而对气候模拟产生广泛的影响。更广泛的意义和重要性。能够预测我们星球上的气候变化对地球上的人类来说可以说是至关重要的，因为气候可以直接影响农业等重要活动。为了了解我们现代世界的气候，了解地球古代的气候是很有帮助的？S。通常我们通过地质记录了解过去的气候。然而，保存古代温度记录的地质材料在地球上温暖、干燥的地区很少，这使得我们很难确定这些地区的气候记录。这一奖项为探索一种潜在的非常有用的方法提供了支持，通过检查天然盐样本来检查这些地区的气候。当这些盐晶体形成时，液体和气体的微小气泡被困在里面。这些被困住的气泡被称为包裹体。已经确定，水和盐水中化学惰性(惰性)气体的浓度取决于温度。因此，有可能通过测量包裹体中的气体含量来确定古代地球温度。为了确定这种方法是否真的有用，研究人员计划测量在已知条件下形成的盐晶体包裹体中的气体浓度(主要是盐场)。他们将观察这些现代盐晶包裹体中气体浓度得出的温度是否与当地的温度记录相匹配或对应。如果该方法被证明是一种成功的测温方法，将导致对该方法能否应用于从古代样品中获得古温度估计的进一步研究。因此，这样的工作可以为现代世界提供更好的气候预测。

Paleoclimate records provide essential constraints for models to predict complex climate variability. However, paleotemperature proxies are scarce in warm, arid regions of the Earth. Surface water equilibrated with the atmosphere at ambient temperatures may be trapped as fluid inclusions in minerals forming evaporite minerals under such conditions. As noble gas solubility in water is temperature-dependent, this project will examine the potential of evaporites for noble gas-based paleothermometry. Active salt farms and modern halite provide relatively well-controlled open-air environments in which halite precipitation occurs. These modern environments allow us to examine how short-term temperature fluctuations are reflected in the noble gas temperatures of fluid inclusions in halite, and thus to calibrate the proxy record. In this project, the assembled research time will analyze noble gas concentrations of fluid inclusions in halite that formed at known locations and during known periods of time (i.e. known average temperature) in order to investigate how the noble gas temperature relates to the local temperature record. A positive result will lead to further studies for establishing this new paleotemperature proxy and may have broad implications on climate modeling by providing temperature records for dry regions over extended time periods. Broader Significance and Importance.Being able to predict climate change on our planet is arguably of critical for humans on this planet, as climate can directly affect important activities such as agriculture. In order to understand climate in our modern world, it is very helpful to know about Earth?s climate throughout the ancient past. Usually we learn about past climates via geological records. However, geological materials that preserve records of ancient temperature are scarce in warm, dry regions of the Earth, which makes it difficult for us to determine the climate record for such areas.This award provides support to explore a potentially very useful method for examining climates of these regions by examining natural salt samples. When these salt crystals form, tiny bubbles of liquid and gas are trapped inside. These trapped bubbles are known as inclusions. It has been established that concentrations of chemically inert (noble) gases in water and brine depend upon temperature. Therefore, it is possible that the gas content of the inclusions could be measured to determine ancient Earth temperatures.To establish whether this method could really be useful, the investigators plan to measure the gas concentrations in inclusions of salt crystals formed under known conditions (mainly salt farms). They will see if the temperatures derived from gas concentrations in these modern salt crystal inclusions actually match or correspond to the local temperature records. If the method proves to be successful way to measure temperature, it will lead to further study on whether the method can be applied to obtain paleotemperature estimates from ancient samples. Consequently such work could enable better climate prediction for the modern world.