Noble gas thermometry on fluid inclusions in speleothems: Optimization and application of a new method for paleoclimate reconstruction

地下水中溶解的稀有气体是古地温的良好指示物。所谓的惰性气体温度计的优势在于它能够提供可靠的绝对温度。它的弱点是局限于地下水档案，在绝对测年和时间分辨率方面有局限性。碳酸盐烧结物是可以精确测定年代和高分辨率的档案。然而，根据碳酸盐岩的~（18）O值重建古地温存在问题。最近，通过直接分析储存在微观包裹体中的滴水上的稳定同位素，取得了进展。这种流体包裹体代表了一种气候档案，也可能通过惰性气体温度计获得。如果能测量碳酸盐流体包裹体中的惰性气体浓度并将其转换成温度，这将成为重建古气候的一种非常有效的方法。它将联合收割机结合惰性气体温度计和洞穴沉积物档案的优点。惰性气体将产生绝对温度重建，这将显着促进稳定同位素数据的解释。目前的项目将惰性气体分析和解释方面的经验与研究小组对洞穴沉积物的广泛知识相结合。该项目计划采用最近开发的从流体包裹体中提取水的方法进行惰性气体分析，并评估惰性气体古温度计在该档案中的潜力。

Dissolved noble gases in groundwater are established as excellent indicators of paleotemperatures. The strength of the so-called noble gas thermometer is its ability to provide reliable absolute temperatures. Its weakness is the confinement to the groundwater archive, which has limitations with regard to absolute dating and temporal resolution. Carbonate sinters are archives that can be dated precisely and with high resolution. However, the reconstruction of paleotemperatures based on (18O-values from carbonates is problematic. An improvement has been achieved recently by analysing the stable isotopes directly on the drip water that is stored in microscopic inclusions. Such fluid inclusions represent a climate archive that potentially can be accessed also by the noble gas thermometer. If noble gas concentrations in fluid inclusions of carbonates could be measured and converted into temperatures, this would constitute a very powerful method of paleoclimate reconstruction. It would combine the advantages of the noble gas thermometer and the speleothem archive. The noble gases would yield absolute temperature reconstructions, which would significantly facilitate the interpretation of stable isotope data. The current project combines experience in noble gas analytics and interpretation with the broad knowledge on speleothems present in the researcher group. The project plans to adapt recently developed methods of water extraction from fluid inclusions for noble gas analysis and to assess the potential of the noble gas paleothermometer in this archive.