Discovery of ∼4.0 Ga detrital zircons in the Changdu Block,North Qiangtang,Tibetan Plateau

Using in situ zircon dating by LA-ICP-MS and MC-ICP-MS, detrital zircon of 3981±9 Ma age was found in metamorphic rocks of the Ningduo Rock Group, Changdu Block of Northern Qiangtang. This is the oldest age record that has been found in the Qiangtang area. This finding also constitutes the third zircon locality in China with an age older than 3.9 Ga. Thus, the discovery provides new information for the study of Hadean crust. In addition, we found 3.51–3.13 Ga, ∼2440 Ma, ∼1532 Ma, ∼982 Ma and ∼618 Ma age peaks from 100 test spots. The younger ages of ∼982 Ma and ∼618 Ma correspond to the formation of the Rodinian super-continent and the Pan-African event, respectively. These findings suggest a close relationship between these zircons and the Gondwanan super-continent. The age of ∼618 Ma defines the lower limit on the deposit time of the protolith for the garnet-mica-quartz schist in the Ningduo Rock Group. Zircons with an age of ∼982 Ma generally display a negative ɛ_Hf(t) and a two-stage Hf model with concentrated ages around 1933–2553 Ma. This pattern indicates that the source area of the Ningduo Rock Group underwent a significant separation of depleted mantle into the crust during the Paleoproterozoic Era. However, zircons with ages of 2854–3505 Ma also show a negative ɛ_Hf(t) and a two-stage Hf model with a concentration of ages around 3784–4316 Ma. These results demonstrate that the source area of the Ningduo Rock Group contains a residual amount of ancient (Hadean) crustal materials. This paper provides new information on the relationship between the basement of the Qiangtang area and the Paleoproterozoic basements of the Gangdese and Himalayan regions, which constrains the northern boundary of Gondwana.     

西藏昌都芒康县新发现吐蕃时期大日如来石刻像

2014年1月,西藏社会科学院宗教研究所所长古格·次仁加布研究员在芒康县做田野调研时,在该县境内发现了吐蕃时期的大日如来石刻像。有关该石刻的记载在现存的藏、汉文献资料中尚未发现,在现代文物普查者和考古学者的研究成果中也未提及。因此,此次发现的吐蕃时期的石刻具有重大的学术价值和历史意义,为研究芒康县历史、宗教、服饰和艺术等提供了重要资料。     

解放战争起讫时间之我见

就狭义军事史范畴而言，解放战争起讫应该以中国共产党领导下的人民革命武装与国民党及其他反动势力武装之间大规模持续性军事冲突的最初爆发和最终结束为标志。由此解放战争应该始于１９４５年９月的上党战役，而终于１９５０年１０月的昌都战役，历时达５年，并非３年或４年。     

近代西藏城市与商业研究——兼论近代昌都城市发展与商业和商人资本结合

19世纪末至20世纪初,随着西藏地方政府对对外开放、内部革新、商人数量的增加和交换的需要,城市重新成为商业的基地,迎来了城市发展的又一个重要时期。昌都城成为西藏地方与内地以及对外贸易的重要商埠,也逐渐转变成近现代具有政治、经济和文化功能的城市。