Geochemical characteristics and genesis of volcanic and sub-volcanic rocks from porphyrite-type iron deposits in Ningwu metallogenic province, eastern China: Constraints from elements

Abstract

Ningwu porphyrite-type iron deposits are located in Ningwu Mesozoic volcanic basin, which belongs to the middle and lower reaches of the Yangtze River metallogenic province. The volcanic rocks can be divided into Longwangshan, Dawangshan, Gushan and Niangniangshan Formations from early to late. All these volcanic rocks are rich in alkali, and show the similar patterns in rare earth element (REE) distribution. However, some differences can be found in the trace elements and REE patterns. The study of petrology and REE geochemical characteristics shows that these rocks are derived from the underplating of the lithospheric mantle and are contaminated by crustal materials, undergo AFC process during the magmatic evolution.

Keywords

rare earth elements / porphyrite-type iron deposit / Ningwu volcanic basin / mantle-derived magma / assimilation fractional crystallization

References

[1] ChenJ-f, ZhouT-x, XingF-m, XuX, XuL-hua. The characteristics of Pb, Sr and Nd isotopes of copper-bearing rocks from middle-low area of yantze river magmatic zone [J]. Acta Geoscientica Sinica, 1994111-116

[2] JiangY-hong. Metallogenic regularity and prospecting of Fe-Cu deposits in Lujiang-Zongyang are a of Anhui [J]. Global Geology, 2010372-382

[3] ChangY-f, LiuX-p, WuY-changCopper and iron metallogenic belt in middle and lower reaches of Yangzi river [M], 1991, Beijing, Geological Publishing House: 733-749

[4] MaoJ-w, YuJ-j, YuanS-d, ChengY-b, XieG-q, HouK-j, XiangJ-f, YangZ-xi. Iron oxide-copper-gold deposits (IOCG): Characteristics, present research situation and ore prospecting [J]. Mineral Deposits, 2008267-278

[5] DongS-w, ZhangY-q, LongC-x, YangZ-y, JiQ, WangT, HuJ-m, ChenX-hua. Jurassic tectonic revolution in China and new interpretation of the Yanshan Tectonic movement [J]. Acta Geologica Sinica, 20071449-1461

[6] ZhengJ-p, LuF-x, GriffinW L, YuC-m, ZhangR-s, YuanX-p, WuX-ling. Lithospheric thinning accompanying mantle lateral spreading, erosion and replacement beneath the eastern part of North China: Evidence from peridotites [J]. Earth Science Frontiers, 200676-85

[7] Ningwu Project Working Group.Ningwu porphyrite-type iron deposits [M], 1978, Beijing, Geological Publishing House: 4-33

[8] JiangB, XuJ-hui. Formation and evolution of theNingwu basin as a Mesozoic pull-apart-basin [J]. Chinese Journal of Geology, 1989314-322

[9] WuF-y, SunD-you. The Mesozoic magmatism and lithospheric thinning in eastern China [J]. Journal of Changchun University of Science and Technology, 1999313-318

[10] ZhangQ, JianP, LiuD-y, WhangY-l, QianQ, WangY, XueH-min. Shrimp U-Pb geochronology of volcanic rocks in Ningwu basin and its significance [J]. Science Sinica Terrae D, 2003309-314

[11] PearceJ A, CannJ R. Tectonic setting of basic volcanic rocks determined using trace element analyses [J]. Earth and Planetary Science Letters, 1973, 19(2): 290-300

[12] PearceJ A, HarrisN B W, TindleA G. Trace element discrimination diagrams for the tectonic interpretation of granitic rock [J]. Petrol, 1984, 25: 956-983

[13] IrvineT N, BaragarW A. A guide to the chemical classification of the common volcanic rocks [J]. Canadian Journal of Earth Sciences, 1971, 8(5): 523-548

[14] MckenzieD. The extraction of magma from the crust and mantle [J]. Earth and Planetary Science Letters, 1985, 74(1): 81-91

[15] ChenJ-h, ZengJ-n, WangS-y, LiJ-w, QiuJ-l, ZhangYan. Characteristic of deposit geochemistry and discussion with metallogenic dynamics background of porphyrite iron in Ningwu and Luzong volcanic basins [J]. Geological Science and Technology Information, 2012, 31(1): 86-94

[16] DiS-w, FanY, ZhangL-j, MaL, QianBing. Geological and geochemical characteristics and genesis of Baixiangshan iron deposit in Ningwu basin [J]. Journal of Hefei University of Techonlogy, 2011, 34(1): 123-127