A K and REE Rich and Authigenic Moazite-bearing Phengite Mudstone

SONG Tian-rui; ZHANG Qiao-da; WAN Yu-sheng

A paper entitled discovery of authigenic monazite in Precambrian sedimentary roc k of Dalian area and its significance has been issued in the《Acta Sedimentologi ca Sinica》 (1999). After that we have got financial support for continuing stud y by the Chinese National Natural Scientific Foundation (No.40172044).This pape r introduces the new achievements of the mudstone study as follows: (1) characte ristic chemical composition: K₂O 11.94%, Al₂O₃ 16.47%, SiO ₂ 61.91%; REE 330.69,μg/g, LREE 266.15μg/g, Ce 130.80μg/g; La(N)/Yb(N) 12.44,δEu 0.75,δCe 1.17;(2)the main rock-frming mineral composition is phengite,which is determin ed by electron probe analysis of enery spectrum and wave spectrum methods and co mpared with X-ray diffraction curve. The phengite was altered from illite by in fluence of deep diagenesis and Mesozoic thrust tectonic movement; (3) the authig enic monazite was also suffered by the diagenetic and tectonic influences showin g in the crystal form types such as scattered mini-grains, single needle-like crystal, aggregate of crystals and connected crystals, etc. The size of authigen ic monazite crystals is from 1 to 60 μm, which are quiet different from the sh ort monoclinic prism taken from metamorphic, magmatic rocks or clastic placers. According to above, this paper concludes that the mudstone is a K and REE rich one, which created favorable inner-outside environment for authigenic monazite formation. Meanwhile this paper emphasized on that the wide spread Proterozoic strata in North China might contain many REE-rich beds with authigenic monazite to be used for U, Th-Pb isotopic timing study. It is proposed that the REE-ri ch beds might be the mineral source of the huge rare earth mineral deposits of t he Baiyun Obo along the margin of North China platform.

A K and REE Rich and Authigenic Moazite-bearing Phengite Mudstone

lnstitute of Geology, Chinese Academy of Geological Sciences, Be ijing 100037

Received Date: 2002-09-11

Publish Date: 2003-09-10

Key words:

Abstract: A paper entitled discovery of authigenic monazite in Precambrian sedimentary roc k of Dalian area and its significance has been issued in the《Acta Sedimentologi ca Sinica》 (1999). After that we have got financial support for continuing stud y by the Chinese National Natural Scientific Foundation (No.40172044).This pape r introduces the new achievements of the mudstone study as follows: (1) characte ristic chemical composition: K₂O 11.94%, Al₂O₃ 16.47%, SiO ₂ 61.91%; REE 330.69,μg/g, LREE 266.15μg/g, Ce 130.80μg/g; La(N)/Yb(N) 12.44,δEu 0.75,δCe 1.17;(2)the main rock-frming mineral composition is phengite,which is determin ed by electron probe analysis of enery spectrum and wave spectrum methods and co mpared with X-ray diffraction curve. The phengite was altered from illite by in fluence of deep diagenesis and Mesozoic thrust tectonic movement; (3) the authig enic monazite was also suffered by the diagenetic and tectonic influences showin g in the crystal form types such as scattered mini-grains, single needle-like crystal, aggregate of crystals and connected crystals, etc. The size of authigen ic monazite crystals is from 1 to 60 μm, which are quiet different from the sh ort monoclinic prism taken from metamorphic, magmatic rocks or clastic placers. According to above, this paper concludes that the mudstone is a K and REE rich one, which created favorable inner-outside environment for authigenic monazite formation. Meanwhile this paper emphasized on that the wide spread Proterozoic strata in North China might contain many REE-rich beds with authigenic monazite to be used for U, Th-Pb isotopic timing study. It is proposed that the REE-ri ch beds might be the mineral source of the huge rare earth mineral deposits of t he Baiyun Obo along the margin of North China platform.

HTML

Reference (13)

[1]	宋天锐.大连地区前寒武纪沉积岩中发现自生独居石及其意义[J].沉积学报,1999,17:663～667[Song Tianrui. Discovery of authigenic rare warth mineral-Monazite in Precambrian sedimentary rock of Dalian area and its significance[J]. Acta Sedimentologica Sinica, 1999,17(Supp):663～6671]
[2]	Maksimovic Z T, Panto G Y.Authigenic rare earth minerals in karst-bauxite and karst nickel deposits[A].In: Jense A P, Wall F, Williams C T, eds. Rare earth minerals, chemistry, origin and ore deposits[C].Chapman and Hall, 1996. 257～279
[3]	乔秀夫,宋天锐,李海兵等.辽宁半岛南部震旦系下寒武统成因地层-附大连金石滩海岸国家风景区旅游导游[M].北京:科学出版社,1996. 1～174[Qiao Xiufu,Song Tianrui,Li Haibning et al. Genetic stratigraphy of the Sinian and Lower Cambrian Strata in Shouth Liaoning Povince-Guide Book of National Scenic Area of Jinshitan Beach[M]. Beijing:Scince Press,1996.108～127]
[4]	许志琴,崔军文.大陆山链变形构造动力学[M].北京:冶金工业出版社,1996. 123～126[Xu Zhiqing and Chui Junwen. Tectonic dynamics of continental mountain-chains deformation[M]. Beijing:Metallurical Industrial Press,1996.108～127]
[5]	中国地质科学院地质矿产所.透明矿物显微镜鉴定表[M].北京:地质出版社,1977. 660,700,726,754[Instiute of Geology and Mineral Deposits,CAGS. Microsopic determination tables of transparent minerals[M]. Beijing: Geological Publishing House,1977,660,700,726,754]
[6]	李任伟,孙枢,李忠等.高压-超高压岩石对合肥盆地侏罗系沉积的贡献[J].岩石学报,2002,18(4):526～530[Li R W, Sun S, Li Z, et al. Contribution of High-pressure and ultrahigh-pressure rocks to the Jurassic sedimentation in Hefeibasin[J]. Acta Petrologica Sinica, 18(4): 526～530]
[7]	任磊夫.粘土矿物与粘土岩[M].北京:地质出版社,1992. 230～238[Ren Leifu. Clay minerals and mudstones[M]. Beijing:Geological Publishing House,1992.230～238]
[8]	Taylor S R, Melennan S M. The continental crust: its composition and evolution[M]. London: Blackwell, Scientific Publication, 1985. 9～140
[9]	和政军.辽宁中元古代-中生代泥质岩稀土元素地球化学[J].地球化学,1988,(2):129～135[He Zhengjun. REE geochemistry of middle Proterozoic-Mesozic Pelites in Liaoning Province[J]. Geochemistry,1998,(2):129～135]
[10]	宋天锐,赵震,王长尧等.华北元古宙沉积岩[M].北京:科学技术出版社,1991. 45～50,111～116,181～182[Song Tianriu,Zhao Zhen, Wang Changyao,et al. Proterozoic sedimentary rocks in North China[M].Beijing:Scentific Technological Publishing House,1991.166～184]
[11]	张连昌,卢登蓉,王淑荣等.山西大同钾镁煌斑岩地质地球化学特征[J].矿物岩石,1988,(4): 31～37[Chang Liancheng, Lou Dengreng, Wang Shourong, et al. Geology and geochemistry of Lamproite in Datong area, Shanxi Province[J]. Journal of Mineralogy and Petrology,1998,18(4):31～37]
[12]	白鸽,袁忠信.白云鄂博矿床地质特征和成因论证[M].北京:地质出版社,1996.36～38[Bai G and Yun Z X. Investigation on geological features and origin of Baiyun Obo mineral deposits[m].Beijing:Geological Publishing House,19996. 36～38]
[13]	Drew L J Qingrum M, Weijuns S.Baiyun Obo iron-rare-earth-niobium deposits, lnner Mangolia, China [J].Lithos,1990,16: 43～65

A K and REE Rich and Authigenic Moazite-bearing Phengite Mudstone

Abstract

References

Proportional views

通讯作者: 陈斌, bchen63@163.com

Article Metrics

Proportional views

Related