X-ray fluorescence scanning of discrete samples on the Schwalbenberg II loess-paleosol sequence, raw data, magnetic susceptibility, organic carbon and U-ratio as grainsize index

The Schwalbenberg II loess-paleosol sequence (LPS) denotes a key site for Marine Isotope Stage (MIS 3) in Western Europe owing to eight succeeding cambisols, which primarily constitute the Ahrgau Subformation. Therefore, this LPS qualifies as a test candidate for the potential of temporal high-resolution geochemical data obtained X-ray fluorescence (XRF) scanning of discrete samplesproviding a fast and non-destructive tool for determining the element composition. The geochemical data is first contextualized to existing proxy data such as magnetic susceptibility (MS) and organic carbon (Corg) and then aggregated to element log ratios characteristic for weathering intensity [LOG (Ca/Sr), LOG (Rb/Sr), LOG (Ba/Sr), LOG (Rb/K)] and dust provenance [LOG (Ti/Zr), LOG (Ti/Al), LOG (Si/Al)]. Generally, an interpretation of rock magnetic particles is challenged in western Europe, where not only magnetic enhancement but also depletion plays a role. Our data indicates leaching and top-soil erosion induced MS depletion at the Schwalbenberg II LPS. Besides weathering, LOG (Ca/Sr) is susceptible for secondary calcification. Thus, also LOG (Rb/Sr) and LOG (Ba/Sr) are shown to be influenced by calcification dynamics. Consequently, LOG (Rb/K) seems to be the most suitable weathering index identifying the Sinzig Soils S1 and S2 as the most pronounced paleosols for this site. Sinzig Soil S3 is enclosed by gelic gleysols and in contrast to S1 and S2 only initially weathered pointing to colder climate conditions. Also the Remagen Soils are characterized by subtle to moderate positive excursions in the weathering indices. Comparing the Schwalbenberg II LPS with the nearby Eifel Lake Sediment Archive (ELSA) and other more distant German, Austrian and Czech LPS while discussing time and climate as limiting factors for pedogenesis, we suggest that the lithologically determined paleosols are in-situ soil formations. The provenance indices document a Zr-enrichment at the transition from the Ahrgau to the Hesbaye Subformation. This is explained by a conceptual model incorporating multiple sediment recycling and sorting effects in eolian and fluvial domains.施瓦本贝格II号黄土-古土壤序列（loess-paleosol sequence, LPS）因发育有8套连续的雏形土（Cambisols）而成为西欧地区海洋同位素第3阶段（Marine Isotope Stage 3, MIS 3）研究的关键点位，其沉积物主要隶属于阿尔高亚地层（Ahrgau Subformation）。因此，该LPS可作为高时间分辨率地球化学数据研究的候选测试对象：通过对离散样品开展X射线荧光光谱（X-ray fluorescence, XRF）扫描，可实现元素组成的快速无损测定。 本研究首先将获取的地球化学数据与已有的磁化率（magnetic susceptibility, MS）、有机碳（organic carbon, Corg）等代用数据进行关联分析，随后将其整合为两类特征性元素对数比值：一类用于表征风化强度[LOG(Ca/Sr)、LOG(Rb/Sr)、LOG(Ba/Sr)、LOG(Rb/K)]，另一类用于示踪粉尘物源[LOG(Ti/Zr)、LOG(Ti/Al)、LOG(Si/Al)]。 西欧地区的岩石磁性颗粒解译通常面临挑战，因为该区域不仅存在磁性增强过程，还伴随磁性损耗作用。本研究数据显示，施瓦本贝格II号LPS位点存在淋溶作用与表土侵蚀，进而引发了磁化率损耗。 除风化作用外，LOG(Ca/Sr)还易受次生钙化作用影响。研究表明，LOG(Rb/Sr)与LOG(Ba/Sr)同样会受到钙化动力学过程的调控。因此，LOG(Rb/K)被认为是最适宜的风化强度指标，其识别出辛齐格古土壤（Sinzig Soils）S1与S2为本位点最为显著的古土壤层。辛齐格古土壤S3被冰冻潜育土（Gelic Gleysols）所包裹，与S1、S2不同，其仅处于初始风化阶段，表明当时气候较为寒冷。雷马根古土壤（Remagen Soils）同样表现出风化指数呈现微弱至中等的正向偏移特征。 通过将施瓦本贝格II号LPS与邻近的埃菲尔湖沉积档案（Eifel Lake Sediment Archive, ELSA）以及其他分布范围更远的德国、奥地利、捷克境内的LPS进行对比，并探讨时间与气候作为成土作用（pedogenesis）的限制因素，本研究认为岩性界定的古土壤均为原位成土产物。物源指数显示，在阿尔高亚地层向赫斯拜亚地层（Hesbaye Subformation）过渡的层位存在Zr富集现象。这一现象可通过整合风成域与河流域多期沉积物再循环与分选效应的概念模型予以解释。