The geological and geochemical characteristics of nephrites in Maxianshan, Gansu province and their implication for raw material source of the Qijia Culture jadewares
ZHANG Yuyan, QIU Zhili, YANG Jiangnan, et al. The geological and geochemical characteristics of nephrites in Maxianshan, Gansu province and their implication for raw material source of the Qijia Culture jadewares[J]. Acta Scientiarum Naturalium Universitatis SunYatseni, 2018,57(2):1-11.
ZHANG Yuyan, QIU Zhili, YANG Jiangnan, et al. The geological and geochemical characteristics of nephrites in Maxianshan, Gansu province and their implication for raw material source of the Qijia Culture jadewares[J]. Acta Scientiarum Naturalium Universitatis SunYatseni, 2018,57(2):1-11.DOI:
Maxianshan nephrite ore in Gansu Province was found in the Neoproterozoic Maxianshan group
a set of metamorphic strata consisting of migmatite
marble and biotite schist
which was regarded as one of the most important material sources of the nephrite jadewares of the Qijia Culture. In order to find out the probability of the Maxianshan nephrites as the raw materials of the nephrite jadewares of the Qijia Culture
the combined field investigation and instrumental analyses of XRD
SEM
EMPA
ICP-MS and LA-ICP-MS are applied to analyze the mineralogy
petrology and geochemisty of Maxianshan nephrites and their country rocks
including mineral composition
structure feature
and chemical composition of the nephrites such as major & trace elements
rare earth elements
and therefore to explore the mineralization of the Maxianshan nephrite mine. The main findings are summarized as follows: ① Maxianshan nephrites are yellow-white to yellow-green (mostly green) in color
characterized by lamellar amorphous structure and fiber interwoven structure
and composed of more than 98% amount of tremolite mineral and tiny amount of sphene
zoisite and apatite minerals; ② The tremolite minerals in nephrites were formed in three mineralization periods
and the principal nephrite ore is mainly related to the tremolites of middle and late periods. The formation of jade grade nephrites was associated with marbleization caused by metasomatism in connection with late intruded alkali granites; ③ The Maxianshan nephrite is characterized by high Th/U
low Cu and REE element
and seagull REE distribution pattern
being different from other nephrites from Hetian of Xinjiang
Qinghai and Liaoning.
关键词
软玉成矿地球化学产地来源特征甘肃马衔山
Keywords
nephritemineralizationgeochemistryorigin characteristicsMaxianshan of Gansu