Boron is an essential,widely used,micronutrient element and is abundant in salt lakes on the Qinghai-Tibet Plateau.The origin and distribution of boron brine deposits on the Qinghai-Tibet Plateau is an important found...Boron is an essential,widely used,micronutrient element and is abundant in salt lakes on the Qinghai-Tibet Plateau.The origin and distribution of boron brine deposits on the Qinghai-Tibet Plateau is an important foundation for B resource formation,evolution,and enrichment,which have long been the subject of debate.The boron isotope system is a sensitive geochemical tracer,making it useful for eff ectively and precisely tracking a wide range of geological processes and sources.This study investigates the major cations,[B],andδB values of samples(lake brine,river waters,and cold spring water)from the Bangor Co Lake which is a typical salt lake rich in boron in Tibet,China.There are magnitude-scale diff erences in[B]among diff erent sample types:river samples<cold spring water<<brine lakes.[B]values vary from 0.73 to~1113 mg/L.Similar to[B],theδB values of the samples exhibit magnitude-scale variations as[B],ranging from-7.35‰to+7.66‰.There are also magnitude-scale diff erences inδB among diff erent sample types.TheδB values of cold spring water are relatively low,and the values range from-1.26‰to-7.75‰.However,the river water samples and saline lakes have higher values,from 0.38‰to 4.62‰,and theδB values of river water samples are basically in the distribution range of those of Bangor Co Lake.This indicates that the sources of boron in Bangor Co Lake are mainly the recharge water with higherδB values and spring water with lowerδB values,and the boron sources and the uneven mixing of lake water are two reasons that account for the large change in theδB value of Bangor Co Lake.展开更多
This research quantifies lake level variations in the Siling Co, Co'e and Bangor Co salt lakes in Central Tibet from 1976 to 2010, and most notably for the 2000-2010 periods. In particular, the effects of differen...This research quantifies lake level variations in the Siling Co, Co'e and Bangor Co salt lakes in Central Tibet from 1976 to 2010, and most notably for the 2000-2010 periods. In particular, the effects of different water replenishment modes on the lakes have been analyzed. Here we have provided new evidences for climate warming and accelerated glacial ablation on the Central Tibetan Plateau from 2000 to 2010. Based on fieldwork involving Differential Global Positioning System (DGPS) surveying and Remote Sensing (RS) interpretations of the lake area, we have drawn the following conclusions. (1) From 1976 to 2010, the process of lake level variation in Siling Co can be divided into two stages. From 1976 to 2000, the lake level rose 4.3 m in a steady fashion (from 4530 to 4534.3 m); the rise rate was 0.18 m/a. From 2000 to 2010, the lake level rapidly rose 8.2 m (from 4534.3 to 4542.5 m), with a dramatically higher rise rate of 0.82 m/a. Compared with the rapidly increasing lake level of Siling Co from 2000 to 2010, the fluctuations observed at Co'e and Bangor Co were smooth and inconspicuous. (2) From 1976 to 2009, the lake area of Siling Co experienced a steady-rapid-steady expansion pattern. The lake area of Siling Co increased 656.64 km2 in the 34 years to 2010, a proportional growth of 39.4%. This was particularly significant in the 2000-2010 period, when the lake area of Siling Co increased by 549.77 km2, a proportional growth of 30.6%. (3) According to correlation analysis, the rise in regional temperatures, which has led to the ablation of glaciers, is the main reason for the rapid rise in Siling Co lake levels in the 10 years to 2010. During this period, Siling Co rose approximately 8 m as the direct result of glacial melting. An increase in precipitation in the Siling Co catchment area is the secondary factor. This contrasts with Bangor Co, where the dominant factor in lake level change is the long-term increase in precipitation; here, the increasing temperature is the secondary factor.展开更多
基金the Shaanxi Provincial Natural Science Foundation for Distinguished Young Scholars(No.2022JC)the 2nd Tibetan Plateau Scientific Expedition and Research(Nos.2019QZKK0805 and 2019QZKK0707)+1 种基金the Innovation Academy for Green Manufacture,Joint Fund Projects(No.IAGM2020C09)Basic Research Program of Qinghai Province(No.2020-ZJ-734)。
文摘Boron is an essential,widely used,micronutrient element and is abundant in salt lakes on the Qinghai-Tibet Plateau.The origin and distribution of boron brine deposits on the Qinghai-Tibet Plateau is an important foundation for B resource formation,evolution,and enrichment,which have long been the subject of debate.The boron isotope system is a sensitive geochemical tracer,making it useful for eff ectively and precisely tracking a wide range of geological processes and sources.This study investigates the major cations,[B],andδB values of samples(lake brine,river waters,and cold spring water)from the Bangor Co Lake which is a typical salt lake rich in boron in Tibet,China.There are magnitude-scale diff erences in[B]among diff erent sample types:river samples<cold spring water<<brine lakes.[B]values vary from 0.73 to~1113 mg/L.Similar to[B],theδB values of the samples exhibit magnitude-scale variations as[B],ranging from-7.35‰to+7.66‰.There are also magnitude-scale diff erences inδB among diff erent sample types.TheδB values of cold spring water are relatively low,and the values range from-1.26‰to-7.75‰.However,the river water samples and saline lakes have higher values,from 0.38‰to 4.62‰,and theδB values of river water samples are basically in the distribution range of those of Bangor Co Lake.This indicates that the sources of boron in Bangor Co Lake are mainly the recharge water with higherδB values and spring water with lowerδB values,and the boron sources and the uneven mixing of lake water are two reasons that account for the large change in theδB value of Bangor Co Lake.
基金supported by the Knowledge Innovating Program of Chinese Academy of Sciences (KZCX2-YW-12)the National Basic Research Program of China (2011CB403106)the National Natural Science Foundation of China (40940018)
文摘This research quantifies lake level variations in the Siling Co, Co'e and Bangor Co salt lakes in Central Tibet from 1976 to 2010, and most notably for the 2000-2010 periods. In particular, the effects of different water replenishment modes on the lakes have been analyzed. Here we have provided new evidences for climate warming and accelerated glacial ablation on the Central Tibetan Plateau from 2000 to 2010. Based on fieldwork involving Differential Global Positioning System (DGPS) surveying and Remote Sensing (RS) interpretations of the lake area, we have drawn the following conclusions. (1) From 1976 to 2010, the process of lake level variation in Siling Co can be divided into two stages. From 1976 to 2000, the lake level rose 4.3 m in a steady fashion (from 4530 to 4534.3 m); the rise rate was 0.18 m/a. From 2000 to 2010, the lake level rapidly rose 8.2 m (from 4534.3 to 4542.5 m), with a dramatically higher rise rate of 0.82 m/a. Compared with the rapidly increasing lake level of Siling Co from 2000 to 2010, the fluctuations observed at Co'e and Bangor Co were smooth and inconspicuous. (2) From 1976 to 2009, the lake area of Siling Co experienced a steady-rapid-steady expansion pattern. The lake area of Siling Co increased 656.64 km2 in the 34 years to 2010, a proportional growth of 39.4%. This was particularly significant in the 2000-2010 period, when the lake area of Siling Co increased by 549.77 km2, a proportional growth of 30.6%. (3) According to correlation analysis, the rise in regional temperatures, which has led to the ablation of glaciers, is the main reason for the rapid rise in Siling Co lake levels in the 10 years to 2010. During this period, Siling Co rose approximately 8 m as the direct result of glacial melting. An increase in precipitation in the Siling Co catchment area is the secondary factor. This contrasts with Bangor Co, where the dominant factor in lake level change is the long-term increase in precipitation; here, the increasing temperature is the secondary factor.
