Precipitation and Lake Water Evaporation Recorded by Terrestrial and Aquatic n‐Alkane δ²H Isotopes in Lake Khar Nuur, Mongolia

Abstract

The compound-specific hydrogen isotopic composition (δ 2 H) of n-alkanes has been widely used for paleohydrological reconstructions in lacustrine sediments (e.g., Aichner et al., 2019;Thomas et al., 2016;Wirth & Sessions, 2016). Lacustrine sediments comprise terrestrial and aquatic n-alkanes, whose primary hydrogen source is the environmental water used for biosynthesis (Sachse et al., 2004;Xia et al., 2008). Terrestrial n-alkanes (e.g., C 31 ) mainly derive from the leaf waxes of higher terrestrial plants and primarily incorporate the local precipitation of the growing season as their source water for photosynthesis (

North Atlantic Oscillation polarity during the past 3 ka derived from lacustrine sediments of large lowland lake Schweriner See, NE-Germany

“…The compound-specific isotopic hydrogen signatures (δ 2 H) of the n-alkanes C23 to C31 show a comparable pattern (Supplement S2), further indicating a predominantly aquatic origin of the n-alkanes (e.g. Strobel et al, 2022b;Sachse et al, 2004). Ca, Sr, TIC, and Sr/Ca indicate carbonate precipitation (Haberzettl et al, 2005;Haberzettl et al, 2019;Haberzettl et al, 2009).…”

“…Moreover, the individual and summed (C21-C35) n-alkane concentrations correlate with the in-lake productivity of Schweriner See (r > 0.8, Supplement S2), indicating a predominance of in-situ aquatically-derived n-alkanes (e.g. Strobel et al, 2022b;Sachse et al, 2004). The compound-specific isotopic hydrogen signatures (δ 2 H) of the n-alkanes C23 to C31 show a comparable pattern (Supplement S2), further indicating a predominantly aquatic origin of the n-alkanes (e.g.…”

“…Sachse et al, 2012;Strobel et al, 2020;Strobel et al, 2022a). However, the δ 2 H signal of precipitation mainly depends on the atmospheric moisture source of the precipitation in the mid-latitudes (Strobel et al, 2020;Strobel et al, 2022b;Bliedtner et al, 2020;Wirth and Sessions, 2016) and also additional fractionation processes can occur at the plant-soil interface, with evaporation of soil water and transpiration of leaf water being prominent factors (Feakins and Sessions, 2010;Kahmen et al, 2013;Zech et al, 2015). In contrast, shortchain n-alkanes are produced by aquatic macrophytes and algae (e.g., C21-C25) and incorporate the δ 2 H signal of the lake's water, which integrates the δ 2 H precipitation signal throughout the year.…”

Assessing Lock-in Depth and Establishing a Late Holocene Paleomagnetic Secular Variation Record From the Mongolian Altai

“…in the Mongolian Altai (48°37'22.9"N, 88°56'42.5"E; Figure 1). The lake was previously described in detail by Strobel et al (2021Strobel et al ( , 2022. The endorheic Khar Nuur basin was formed during the Last Glacial Maximum by glacial advances from the Tsengel Khairkhan Massif, leaving prominent moraine lobes in the main valley (Walther et al 2017).…”

In the Weeds: Aquatic Plant Biomarker Sources to Arctic Lake Sediments

“…While the isotope effect of evaporation from leaves and lakes sometimes cancel each other out (Aichner et al., 2010), differences in δ 2 H records of paired biomarkers within a single sediment core are common, supporting the potential of the dual‐biomarker method. Variations of this approach have been used to reconstruct humidity in Greenland (Balascio et al., 2013; Thomas et al., 2018; Zhao et al., 2022) and the Svalbard Archipelago (Balascio et al., 2018; Kjellman et al., 2020), as well as in several mid‐ and low‐latitude sites (Jacob et al., 2007; Mügler et al., 2008; Rach et al., 2014; Seki et al., 2011; Strobel et al., 2022; Toney et al., 2020). This dual‐biomarker method and its assumption are described in detail by Rach et al.…”