The excavation of tomb M1 in Quangou cemetery, Wulan County, Qinghai

Tomb M1 at Quangou cemetery in Wulan, Qinghai, is the only Tubo-period tomb with mural paintings discovered thus far on the Qinghai-Xizang Plateau. The tomb includes a tomb entry ramp leading to a rectangular multi-chambered structure built from bricks and timber. The walls of the antechamber and burial chamber are all painted with various images heavily influenced by typical Tang painting techniques, displaying Tang-period stylistic influence, although painted subjects present characteristic scenes of nomadic life on the Qinghai-Xizang Plateau. The color-painted lacquered coffins in the tomb are the first of their kind found in the region, indicating that the tomb occupant must have been of high social status. There is a secret compartment behind the tomb’s burial chamber, where a wooden chest was found containing a luxuriously decorated gilt silver crown and a turquoise-inlaid gold cup. The findings suggest that the tomb occupant was probably closely related to the local royal family under Tubo’s sovereignty.

Application of Hydrochemical and Isotopic Data to Determine The Origin and Circulation Conditions of Karst Groundwater in An Alpine and Gorge Region in The Qinghai–Xizang Plateau: A Case Study Of Genie Mountain

Understanding of the recharge origin, runoff channels, and discharge characteristics of karst groundwater is very important for construction of underground projects and identification of water supply targets. Complex structural systems, lithological differences, and extreme heterogeneity of aquifers combine to create a complex karst aquifer structure in alpine and gorge areas; however, because of the topography, direct investigation of aquifer structure is difficult. In this study, field survey, hydrochemical, and isotopic data are analyzed to reveal the development of karst groundwater and to describe the karst water cycle in Genie Mountain, Qinghai–Xizang Plateau. The results show that atmospheric precipitation and melting ice and snow are the groundwater recharge sources, and groundwater circulation is shallow, with groundwater ages generally no more than 60 yr. The groundwater cycle can be divided into three levels: epikarst water circulation; mid to deep karst water circulation; and deep geothermal water circulation. The karst springs located in the outlet of the Huolong gully contain markedly higher levels of Na + and SO 4 2 − than other karst springs because of the leaching effect of groundwater on mirabilite. The presence of evaporites also indicates that the groundwater of Huolong gully is influenced by evaporation. The runoff of thermal springs undergoes deep circulation and is controlled by faults. This water mainly dissolves carbonate rock, with little influence of evaporation. This study shows that hydrochemical and isotopic methods can be used to discriminate different water types, and can be applied to study the characteristics of complex groundwater runoff in alpine and gorge areas.