Highly resolved δ13C and trace element ratios of precisely dated stalagmite from northwestern China: Hydroclimate reconstruction during the last two millennia

Multi‐Timescale Variations of δ18O‐δ13C in Stalagmites: Insights Into Isotopic Disequilibrium and Human Activities

“…Positive covariations between stalagmite δ 18 O and δ 13 C profiles have been widely observed, and they are commonly attributed to climate changes and partially to the kinetic isotope effects (Bar‐Matthews et al., 2003; Denniston et al., 2001; Dorale et al., 1998; Duan et al., 2014; Genty et al., 2003; Jia et al., 2022; Li et al., 2000; Liang et al., 2022; Mickler et al., 2006; Spotl & Mangini, 2002; Tan et al., 2013; Zhang et al., 2021; Zhao et al., 2020). A previous study has indicated that the interannual and shorter timescale changes in Chinese stalagmite δ 18 O may not always be indicative of climate changes (Tan, 2009).…”

“…Carbon isotope compositions of speleothems mainly reflect that of soil CO 2 overlying the cave (Genty & Massault, 1999;Genty et al, 2001;Li et al, 2011;Luo & Wang, 2009), which are influenced by biological processes such as plant root respiration, organic matter decomposition, and vegetation type (C4/C3 plant ratio) (Baker et al, 1997;Denniston et al, 2001;Dreybrodt, 1980;Duan et al, 2014Duan et al, , 2022Genty et al, 2003Genty et al, , 2006Hou et al, 2003;Jia et al, 2022;McDermott, 2004;Tan et al, 2013;Yin et al, 2017;Zhang et al, 2021;Zhao et al, 2020). Before 1588 AD, the δ 13 C of both stalagmites TS9701 and TS950 fluctuates between −11.7‰ and −7.7‰ (Figure 2), indicating that the vegetation overlying Shihua cave was predominantly C3 plants, as expected from speleothem δ 13 C values (−14‰ to −6‰) at such sites (Baker et al, 1997;Dreybrodt, 1980;McDermott, 2004).…”

“…Nevertheless, the variations in these speleothems' δ 13 C and δ 18 O have also been interpreted in relation to past climatic and environmental changes (Mickler et al., 2006). This could be attributed to the fact that such covariations of δ 13 C and δ 18 O can arise from common climatic and environmental factors and/or that the imprints of climatic and environmental changes on speleothems' δ 13 C and δ 18 O are not entirely masked by kinetic isotope effects (Bar‐Matthews et al., 2003; Denniston et al., 2001; Dorale et al., 1998; Duan et al., 2014; Genty et al., 2003; Jia et al., 2022; Li et al., 2000; Liang et al., 2022; Spotl & Mangini, 2002; Tan et al., 2013; Zhang et al., 2021; Zhao et al., 2020). To investigate the causes of the covariations between speleothem δ 13 C and δ 18 O, high‐resolution stalagmite records that can be compared with meteorological data are essential.…”

A Highly Resolved Speleothem δ13C Record from Central China and Its Manifestation on Multiple Time Scales during the Last Glacial

“…Later, the relative fluctuation of the local hydrology was reconstructed based on the ratio of speleothem anhysteretic remanent magnetism (ARM) to saturation isothermal remanent magnetism (SIRM) [7]. Recently, stalagmite δ 13 C has been proposed as a potential way to reconstruct local ecological environments and hydrological climates [8,9].…”

Characteristics and Influencing Factors of Dissolved Organic Matter in Cave Drip Water—A Case Study from Furong Cave, Southwest China

“…Similar to the proxies of oxygen and carbon isotopes and trace elements in stalagmites, understanding the significance of organic matter in stalagmite paleoclimate reconstruction through modern cave monitoring and deciphering the signal transmission and mechanisms of organic matter in karst systems is particularly important. Long-term monitoring studies in caves have primarily focused on stable isotopes (δ 18 O, δ 13 C) [12][13][14][15][16] and trace elements (Mg, Ca Ba Sr) as representatives of inorganic geochemical processes with climatic implications [17][18][19][20]; relatively less attention has been paid to organic geochemical processes [3,[21][22][23][24]. Currently, the modern monitoring of organic matter in caves has been limited in duration, with the majority of studies focused on investigating the mechanisms behind the formation of fluorescent luminescence laminae in stalagmites [10,25,26].…”