Geochemistry of last glacial lacustrine sediments in core region of the North American Monsoon, northwest Mexico: Source of biomass, hydrological balance and chemical weathering
Geochemistry of last glacial lacustrine sediments in core region of the North American Monsoon, northwest Mexico: Source of biomass, hydrological balance and chemical weathering
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墨西哥西北部北美季风核心区末次冰期湖沉积物的地球化学：生物量来源、水文平衡和化学风化
DOI：
10.1002/gj.3827
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发表时间：
2020
影响因子：
1.8
通讯作者：
P. Roy
中科院分区：
文献类型：
--
作者：
J. D. Quiroz‐Jiménez;P. Roy
生物量中的碳同位素 (δ13Corg)、自生方解石中的碳 (δ13Ccarb) 和氧 (δ18Ocarb) 同位素以及对位于墨西哥西北部北美季风核心区域的短暂 Babicora 盆地的湖泊沉积物中硅质碎屑矿物的化学风化作用（化学蚀变指数 [CIA] 和斜长石蚀变指数 [PIA]）的估计，有助于评估末次冰期三个不同海洋同位素阶段（晚 MIS 4：≥65.4–59.5 cal ka BP、MIS 3：~59.5–28 cal ka BP 和 MIS 2：~28–15cal ka BP）的生物量来源、水文平衡变化和沉积物-水相互作用。 δ13Corg 与之前发表的 C/N、硅藻丰度和化石花粉记录的比较表明，MIS 4 晚期的生物量来源于 C3 水生和陆地植物。在MIS 3期间，C3植物继续贡献生物量，但湖相藻类的影响在其后期有所增加。与其他两个 MIS 阶段相比，水柱经历了更多的蒸发，沉积物与水的相互作用在最小到中等之间变化（CIA：49-68）。在较湿润的时期，沉积物被输送更远的距离，而在较干燥的时期，沉积物被附近的岩性侵蚀。在 MIS 2 期间，沉积物和流入水之间的相互作用 (CIA: 59-65) 保持均匀。然而，生物量的来源是可变的。湖泊藻类和 C3 陆地植物在 MIS 2 早期（~28–19cal cal ka BP）期间贡献了生物量，而 C4 和 CAM 植被的贡献在冰消期（~19–15cal cal ka BP）略有增加。
Carbon isotopes (δ13Corg) in biomass, carbon (δ13Ccarb) and oxygen (δ18Ocarb) isotopes in authigenic calcite and estimations of chemical weathering of siliciclastic minerals (chemical index of alteration [CIA] and plagioclase index of alteration [PIA]) in lacustrine sediments of the ephemeral Babicora Basin, located within the core region of the North American Monsoon at northwest Mexico, helped to evaluate the source of biomass, variations in hydrological balance and sediment–water interactions during three different marine isotope stages (late MIS 4: ≥65.4–59.5 cal ka BP, MIS 3: ~59.5–28 cal ka BP and MIS 2: ~28–15 cal ka BP) of the last glacial. Comparisons of δ13Corg with previously published records of C/N, diatom abundance and fossil pollen indicate that biomass of the late MIS 4 was sourced from C3 aquatic and land plants. During the MIS 3, the C3 plants continued to contribute biomass and the influence of lacustrine algae, however, increased during its later part. The water column experienced more evaporation compared to two other MIS stages and sediment–water interactions varied between minimal to moderate (CIA: 49–68). Sediments were transported for longer distances during the wetter intervals and eroded from nearby lithologies during the drier intervals. Interactions between sediments and inflowing water (CIA: 59–65) remained homogeneous during the MIS 2. Source of the biomass, however, was variable. Lacustrine algae and C3 land plants contributed biomass during the early MIS 2 (~28–19 cal ka BP) and contributions from the C4 and CAM vegetation slightly increased towards the deglaciation (~19–15 cal ka BP).
影响因子：
64.8
作者：
Cerling, TE;Harris, JM;Ehleringer, JR
通讯作者：
Ehleringer, JR