The role of evaporites in the formation of magnetite–apatite deposits along the Middle and Lower Yangtze River, China: Evidence from LA-ICP-MS analysis of fluid inclusions

Published on Jun 1, 2015in Ore Geology Reviews3.387
· DOI :10.1016/j.oregeorev.2014.12.003
Wanting Li3
Estimated H-index: 3
(University of Bayreuth),
Andreas Audétat33
Estimated H-index: 33
(University of Bayreuth),
Jun Zhang3
Estimated H-index: 3
(China University of Geosciences)
Abstract Numerous magnetite–apatite deposits occur in the Ningwu and Luzong sedimentary basins along the Middle and Lower Yangtze River, China. These deposits are located in the contact zone of (gabbro)-dioritic porphyries with surrounding volcanic or sedimentary rocks and are characterized by massive, vein and disseminated magnetite–apatite ± anhydrite mineralization associated with voluminous sodic–calcic alteration. Petrologic and microthermometric studies on multiphase inclusions in pre- to syn-mineralization pyroxene and garnet from the deposits at Meishan (Ningwu basin), Luohe and Nihe (both in Luzong basin) demonstrate that they represent extremely saline brines (~ 90 wt.% NaCl equiv ) that were trapped at temperatures of about 780 °C. Laser ablation ICP-MS analyses and Raman spectroscopic studies on the natural fluid inclusions and synthetic fluid inclusions manufactured at similar P–T conditions reveal that the brines are composed mainly of Na (13–24 wt.%), K (7–11 wt.%), Ca (~ 7 wt.%), Fe (~ 2 wt.%), Cl (19–47 wt.%) and variable amounts of SO 4 (3–39 wt.%). Their Cl/Br, Na/K and Na/B ratios are markedly different from those of seawater evaporation brines and lie between those of magmatic fluids and sedimentary halite, suggesting a significant contribution from halite-bearing evaporites. High S/B and Ca/Na ratios in the fluid inclusions and heavy sulfur isotopic signatures of syn- to post-mineralization anhydrite (δ 34 S Anh  = + 15.2 to + 16.9‰) and pyrite (δ 34 S Py  = + 4.6‰ to + 12.1‰) further suggest a significant contribution from sedimentary anhydrite. These interpretations are in line with the presence of evaporite sequences in the lower parts of the sedimentary basins. The combined evidence thus suggests that the magnetite–apatite deposits along the Middle and Lower Yangtze River formed by fluids that exsolved from magmas that assimilated substantial amounts of Triassic evaporites during their ascent. Due to their Fe-oxide dominated mineralogy, their association with large-scale sodic–calcic alteration and their spatial and temporal associations with subvolcanic intrusions we interpret them as a special type of IOCG deposits that is characterized by unusually high contents of Na, Ca, Cl and SO 4 in the ore-forming fluids. Evaporite assimilation apparently led to the production of large amounts of high-salinity brine and thus to an enhanced capacity to extract iron from the (gabbro)-dioritic intrusions and to concentrate it in the form of ore bodies. Hence, we believe that evaporite-bearing sedimentary basins are more prospective for magnetite–apatite deposits than evaporite-free basins.
  • References (82)
  • Citations (16)
📖 Papers frequently viewed together
169 Citations
273 Citations
356 Citations
78% of Scinapse members use related papers. After signing in, all features are FREE.
#1Peter Koděra (Comenius University in Bratislava)H-Index: 6
#2Christoph A. Heinrich (ETH Zurich)H-Index: 61
Last. Jaroslav Lexa (SAV: Slovak Academy of Sciences)H-Index: 15
view all 4 authors...
The recently discovered Biely Vrch deposit in the Western Carpathian magmatic arc is the most extreme example of a porphyry gold deposit, being practically free of copper, molybdenum or any other sulfide minerals. Microanalytical data on fluid inclusions in quartz veinlets, including a characteristic type of banded veinlets, show that this deposit formed from nearly anhydrous Fe-K-Na-Cl salt melts containing ∼10 ppm Au, coexisting with hydrous vapor of very low density. This exceptional fluid ev...
19 CitationsSource
#1Mark A. Kendrick (ANU: Australian National University)H-Index: 27
#2Matthew G. Jackson (UCSB: University of California, Santa Barbara)H-Index: 34
Last. Jon D. Woodhead (University of Melbourne)H-Index: 50
view all 6 authors...
Abstract In order to improve characterisation of volatiles in the EM1 and EM2 mantle sources, which are interpreted to contain subducted sedimentary or lithospheric components, we report electron microprobe, FTIR and SIMS CO2, H2O, S, F and Cl concentrations of variably enriched glasses from Pitcairn and Society seamounts in Polynesia. The analyses complement previously published Cl, Br and I data for some of the same glasses and all the techniques show reasonable agreement of better than 5–9% f...
51 CitationsSource
#1Wenhao Liu (China University of Geosciences)H-Index: 2
#2Jun Zhang (China University of Geosciences)H-Index: 1
Last. Jian Wang (China University of Geosciences)H-Index: 8
view all 4 authors...
Abstract The Cretaceous Luzong and Ningwu volcanic basins in eastern China contain numerous magnetite–apatite deposits with similar geological characteristics and mineralization ages (~ 130 Ma). These deposits, however, occur at distinctly different burial depths. To explain this difference, LA-ICP-MS apatite U–Pb and fission track double dating of five samples were carried out to establish the thermal histories from crystallization to the exhumation of four representative deposits: the deeply b...
9 CitationsSource
#1Steven D. ScottH-Index: 34
6 Citations
#1W.C. Pat Shanks (USGS: United States Geological Survey)H-Index: 6
In this chapter, the intent is to summarize the results of traditional stable isotope studies (mainly H, B, O, C, and S) that have greatly contributed to the understanding of ore-forming processes over the last 60 years and to provide an up-to-date assessment of the application of new nontraditional isotope systems (Fe, Cu, Zn, Se, Mo, Hg, and Tl).
11 CitationsSource
The Middle-Lower Yangtze Polymetallic Ore Belt is one of the most important metallogenic belts in East China,comprising more than 200 polymetallic( Cu-Fe-Au,Mo,Zn,Pb,Ag) deposits. Ningwu and Luzong ore distrcts are the most important component of this belt. In these districts,volcanic-subvolcanic rocks,intrusions and subvolcanic rocks-related iron deposits which are well known as porphyrite iron deposits in China are widespread,during the Late Mesozoic. Based on the geological characteristics,sp...
9 Citations
#1Mark D. Barton (UA: University of Arizona)H-Index: 29
The Fe oxide(–Cu–Au–REE–P–U) family of Cu, Fe, and/or Au deposits (or IOCG) represents a geochemically coherent but geologically diverse group that formed globally from the Archean to the Holocene. IOCG systems exhibit intense, voluminous Na–Ca–K–Fe(–H) hydrothermal alteration related to flow of moderately to highly saline metal-rich, sulfur-poor brines. These fluids account for the characteristic sulfide-poor, oxide-rich mineralogy and the alkali-rich character of the alteration and for the var...
57 CitationsSource
#1Yu FanH-Index: 13
#2Yn LiuH-Index: 1
Last. Wc WangH-Index: 1
view all 6 authors...
The Lu-Zong basin is one of the important parts of the Middle-Lower Yangtze River Valley metallogenic belt, where there are widespread iron deposits. The volcanic and intrusive plutons occur widely in Lu-Zong basin, including four formations of volcanic rocks, such as Longmenyuan Formation, Zhuanqiao Formation, Shuangmiao Formation and Fushan Formation and 34 intrusive plutons. Nihe deposit located in the northwest part of Lu-Zong basin, which is a new found large iron deposit. However, the prec...
6 Citations
#1Mark A. Kendrick (University of Melbourne)H-Index: 27
#2Richard J. Arculus (ANU: Australian National University)H-Index: 56
Last. Masahiko Honda (ANU: Australian National University)H-Index: 29
view all 4 authors...
Abstract Volatiles are critically important in controlling the chemical and physical properties of the mantle. However, determining mantle volatile abundances via the preferred proxy of submarine volcanic glass can be hampered by seawater assimilation. This study shows how combined Cl, Br, I, K and H 2 O abundances can be used to unambiguously constrain the dominant mechanism by which melts assimilate seawater-derived components, and provide an improved method for determining mantle H 2 O and Cl...
62 CitationsSource
#1Huayong Chen (CAS: Chinese Academy of Sciences)H-Index: 21
Abstract Although the sources of the ore metals remain problematic in most Iron-oxide Cu and Au (IOCG) deposits, external sulphur, either from surficial basinal brines and seawater (e.g., Central Andean and Carajas deposits) or from formation water and metamorphic fluids (e.g., the Cloncurry deposits), or introduced by magmatic assimilation of metasedimentary units (e.g., Phalaborwa), has been documented in many major Cu-rich IOCG centres. However, only the evaporite-sourced fluids yield diagnos...
37 CitationsSource
Cited By16
#1Stefan T. M. Peters (GAU: University of Göttingen)H-Index: 6
#2Narges Alibabaie (UT: University of Tehran)
Last. Bernd LehmannH-Index: 34
view all 9 authors...
#1Chao Duan (Ontario Ministry of Natural Resources)H-Index: 1
#2Yanhe Li (Ontario Ministry of Natural Resources)H-Index: 3
Last. Wei Li (China University of Geosciences)
view all 8 authors...
Abstract Iron oxide–apatite (IOA) deposits are an important type of iron deposit that may host large reserves of iron and other elements. The Washan deposit in the Ningwu Ore District is a classic giant IOA deposit hosted by porphyritic diorite. At Washan, four Fe mineralization stages have been identified with clear crosscutting relationships, forming four types of ores: disseminated ores, breccia ores, and magnetite–actinolite and magnetite–apatite–actinolite veins. Trace element concentration...
#1Li-Ping Zeng (China University of Geosciences)H-Index: 1
#1Li-Ping Zeng (China University of Geosciences)
Last. Carl Spandler (JCU: James Cook University)H-Index: 28
view all 5 authors...
Scapolite occurs as the major halogen-bearing phase at all paragenetic stages of skarn formation and mineralization in the Jinshandian iron skarn deposit, Eastern China. Here we integrate geochemical characteristics of scapolite with in situ B and Sr isotopes of associated tourmaline and fluorapatite, respectively, to trace the sources and evolution of the fluids responsible for mineralization in this deposit. Pre-ore stage I scapolite has molar Cl/Br ratios ranging from ~ 920 to 2200, which, to...
#1Zhi-Kun Su (China University of Geosciences)H-Index: 1
#2Xin-Fu Zhao (China University of Geosciences)H-Index: 21
Last. Albert H. Hofstra (USGS: United States Geological Survey)H-Index: 17
view all 5 authors...
Abstract Tourmaline is a common boron-bearing mineral in hydrothermal system and has been widely used as a mineral probe to reconstruct geological processes because of its broad range in composition and resistance to metasomatic alteration. The origin of Kiruna-type iron oxide-apatite (IOA) deposits, commonly linked to andesitic subvolcanic or volcanic rocks, is highly controversial. Constraints on the evolution of these mineralizing systems are needed to advance understanding of the ore-forming...
1 CitationsSource
#1Andreas Audétat (University of Bayreuth)H-Index: 33
#2Daohan Zhang (China University of Geosciences)H-Index: 5
Abstract This study reports concentration data for Li, B, Na, Mg, Al, S, Cl, K, Ca, Mn, Fe, Cu, Zn, Ga, Ge, As, Br, Se, Rb, Sr, Nb, Mo, Ag, Cd, In, Sn, Sb, Te, Cs, Ba, Ce, Ta, W, Tl, Pb, Bi, Th and U in 124 high-temperature (350–700 °C) magmatic-hydrothermal fluids investigated from five barren, six sub-economically Mo- or Cu-mineralized, and five economically Sn-, W-, Cu, Mo- or REE-mineralized granodioritic to granitic intrusions, based on Laser-ablation ICP-MS analysis of 304 individual fluid...
1 CitationsSource
#1Wei Li (China University of Geosciences)
#2Guiqing Xie (Ontario Ministry of Natural Resources)H-Index: 1
Last. Jiahao Zheng (SU: Southern University and A&M College)
view all 5 authors...
#1Xi Zhang (USTC: University of Science and Technology of China)H-Index: 1
#2Xiaoyong Yang (USTC: University of Science and Technology of China)H-Index: 25
Last. Franco Pirajno (UWA: University of Western Australia)H-Index: 49
view all 3 authors...
ABSTRACTIn this study, Early Cretaceous skarn deposits and genesis of their host diorite/monzodiorite porphyry in the Xuzhou-Huaibei (Xu-Huai) region, northern Anhui-Jiangsu have been discussed by detailed geochemical work. In-situ zircon U–Pb dating of the diorites related to Fe–Cu–Au deposits shows that they were formed between 131.4 ± 1.5 Ma and 130.8 ± 1.8 Ma. Geochemical data indicate a depletion of high field strength elements (HFSE) in the diorite porphyry with similarity to that of arc-r...
7 CitationsSource
#1Yinan Liu (Hefei University of Technology)H-Index: 2
#2Yu Fan (Hefei University of Technology)H-Index: 13
Last. Lejun Zhang (UTAS: University of Tasmania)H-Index: 10
view all 7 authors...
The iron-copper-gold belt in the Middle and Lower Yangtze River region is among the most important metallogenic provinces in eastern China. The Luzong (Lujiang—Zongyang) ore district hosts many significant iron deposits in the Luzong Basin and is an important part of this belt. The Yangshan deposit is hosted in the Cretaceous volcanic rocks of the middle Luzong Basin. The Makou deposit in the southern-central Luzong Basin has orebodies at the contact between gabbro-diorite and volcanic rocks of ...
#1Daohan Zhang (University of Bayreuth)H-Index: 5
#2Andreas Audétat (University of Bayreuth)H-Index: 33
4 CitationsSource
#1Wenhao Liu (China University of Geosciences)H-Index: 3
#2Man-Rong Jiang (China University of Geosciences)H-Index: 3
Last. Huan Li (China University of Geosciences)H-Index: 13
view all 6 authors...
Abstract The Meishan iron deposit contains 338 Mt of iron-ore reserves at 39% Fe and represents the largest magnetite–apatite deposit in the Ningwu Basin of eastern China. Controversy has long existed about whether this deposit had a hydrothermal or iron-oxide melt origin. Iron mineralization is genetically related to plutons that are composed of gabbro-diorite, which were emplaced at 130 ± 1 Ma. These rocks have SiO2 contents of 51.72–54.60 wt%, Na2O contents of 3.47–4.04 wt%, K2O contents of 2...
3 CitationsSource