Samarium–Neodymium Isotope Systematics of Hydrothermal Calcites from the Xikuangshan Antimony Deposit (Hunan, China): the Potential of Calcite As a Geochronometer

中国科技论文在线 http://www.paper.edu.cn

Chemical Geology 200 (2003) 129–136 www.elsevier.com/locate/chemgeo

Samarium–neodymium isotope systematics of hydrothermal calcites from the Xikuangshan antimony deposit (Hunan, China): the potential of calcite as a geochronometer

J.-T. Penga,*, R.-Z. Hua, P.G. Burnardb

a Institute of Geochemistry, Chinese Academy of Sciences, 73, Guanshui Road, Guiyang City 550002, China b Department of Earth and Space Sciences, University of California, Los Angeles, CA 90095, USA Received 29 May 2002; accepted 25 April 2003

Abstract

The Xikuangshan antimony mine located at Central Hunan, China, is the largest antimony deposit in the world. Hydrothermal calcites from the Xikuangshan Mine display relatively large variations in REE abundance and Sm/Nd ratios and are characterized by MREE- and HREE-enriched and LREE-depleted patterns. Sm–Nd isotopic compositions of syn-sulfide calcites fall on well-defined lines in the isochron plot. Calcites from early- and late-stage mineralization form two distinct isochrons corresponding to 155.5 F 1.1 and 124.1 F 3.7 Ma, respectively. The isochron ages suggest that Sb mineralization took place during the Late Jurassic–Early Cretaceous Period in the Xikuangshan district, consistent with previous geological observations and with independent isotope data. Samarium–neodymium dating of calcites shows potential for determining ages of hydrothermal mineralization. D 2003 Elsevier Science B.V. All rights reserved.

Keywords: Sm–Nd isotope systematics; Hydrothermal calcite; Dating; Antimony mineralization

1. Introduction to discern tectonic and/or geological events respon- sible for metal deposition—limits development of ge- The ability to accurately determine the timing of netic models for ore deposition (Chesley et al., 1994). mineralization is crucial for understanding the genesis Sm and Nd are similar in chemical properties, so the of ore deposits. However, the ages of hydrothermal daughter 143Nd decayed by a-decay from the parent mineralization in South China are poorly constrained, 147Sm is easy to be preserved in mineral lattice, i.e. the mainly due to the lack of minerals suitable for conven- Sm–Nd isotope systematics is liable to be kept closed tional radiometric measurements. This inability to ac- and capable of resisting weathering and/or alteration to curately constrain the timing of ore formation—in order some degree. Thus, the Sm–Nd dating technique is a powerful potential geochronometer for dating hydrothermal events, even for relatively young mineraliza- * Corresponding author. Fax: +86-851-5895574. tion (Chesley et al., 1991) provided there is a E-mail address: [email protected] (J.-T. Peng). significant range in Sm/Nd ratio. Direct Sm–Nd dating

130 J.-T. Peng et al. / Chemical Geology 200 (2003) 129–136 of an unconformity-type uranium deposit (Fryer and a target mineral for direct Sm–Nd isotopic dating (Nie Taylor, 1984) showed the potential of this method for et al., 1999). However, not all calcites are depleted in determining the time of ore deposition of hydrothermal HREE (e.g. Subı´as and Ferna´ndez-Nieto, 1995; Hecht deposits. In recent years, some hydrothermal Ca-bear- et al., 1999). In the present study, we report data from ing minerals have been used for dating as these miner- some hydrothermal calcites from the Xikuangshan als generally contain significant concentrations of antimony deposit. These calcites are relatively REEs; minerals such as scheelite (Bell et al., 1989; MREE- and HREE-enriched and therefore are a Kent et al., 1995; Anglin et al., 1996; Darbyshire et al., suitable target for Sm–Nd isotopic dating. 1996; Eichhorn et al., 1997; Kempe et al., 2001), fluorite (Li et al., 1987; Halliday et al., 1990; Chesley et al., 1991, 1994) and tourmaline (Anglin et al., 1996; 2. Geological setting Jiang et al., 2000) have been successfully dated using the Sm–Nd geochronometer. The Xikuangshan antimony deposit located in Calcite usually has low REE contents compared to Central Hunan Province, South China, with total Sb the above minerals and is often characterized by the metal reserves of about 2110000 ton (Laznicka, LREE-enriched pattern; the Sm/Nd ratios in calcites 1999), is the largest Sb deposit so far reported in the are less than chondritic value. As a result, few at- world. The deposit is restricted to an area of about 18 tempts have been made to use hydrothermal calcite as km2, including the south mine (Wuhua, Feishuiyan)

Fig. 1. Geological map of the Xikuangshan antimony deposit, Central Hunan. 中国科技论文在线 http://www.paper.edu.cn

J.-T. Peng et al. / Chemical Geology 200 (2003) 129–136 131 and the north mine (Laokuangshan, Tongjiayuan) (see contents in the range of 16.5 to 68.0 ppm, mostly Fig. 1). more than 30 ppm (Peng et al., in press). Nearly all Only Middle-Upper Devonian and Lower Carbon- syn-sulfide calcites have Sm/Nd ratios that are greater iferous strata are present in the mining district. The than chondritic. The chondrite-normalized REE pat- exposed strata are predominantly carbonates, locally terns for the syn-sulfide calcites are presented in Fig. interbedded with siltstone, argillite and shale. Struc- 2, which are characterized by MREE- and HREE- turally, the deposit is located in the Xikuangshan enriched, LREE-depleted patterns. However, there are complex anticline, consisting of four en echelon some differences between the early and late syn- anticlines. These sub-anticlines control the occurrence sulfide calcites: LREE concentrations for early cal- of Laokuangshan, Tongjiayuan, Feishuiyan and cites are lower, and HREE contents are usually higher Wuhua ore bodies (see Fig. 1). The NW limb of the relative to the late calcites. complex anticline is cut by a regional fault (F75), and Interestingly, the C, O and Sr isotopic composi- the SE part is cut by a reverse fault F1 (see Fig. 1). tions of the early and the late syn-sulfide calcites are With the exception of a lamprophyre dyke in the obviously different (Peng et al., 2001, 2002).As eastern part of the deposit, there are no igneous rocks shown in Fig. 3, for the early syn-sulfide calcites, within or around the mining district. This calc-alka- their C and O isotope composition varied from line dyke (Liu et al., 1985) has biotite K–Ar ages of À 8.2xto À 4.3xand 16.1xto 18.6x,res- 119 Ma (Liu and Jian, 1983) and 127.8 Ma (Wu and pectively. However, for the late syn-sulfide calcites, Hu, 2000). Despite the uncertainty of the age of the their C isotope values ranged from À 0.2xto dyke, the dyke was believed to have formed before Sb 2.1x(mostly more than 0), and the corresponding mineralization (Liu and Jian, 1983; Liu et al., 1985). values of O isotope varied between 11.0xand The ore bodies, which occur predominantly in the 17.1x. As shown in Table 1, the Sr concentrations Devonian Shetianqiao Formation (D3s) and subordi- and its isotope compositions for hydrothermal cal- nately in the Qiziqiao Formation (D2q), are usually stratiform or stratoid and tend to be locally irregular in shape. The ores are simple in composition, with stibnite as the ore mineral. The gangue minerals include quartz and calcite, with minor amounts of fluorite, barite and secondary gypsum. The alteration of the host limestone is dominated by silicification, subordinately by carbonatization and, to a lesser extent, baritization and fluoritization. Calcite is a common gangue mineral in the deposit. Based on field and microscopic observations, the calcites can be classified into syn-sulfide and post- sulfide calcites. Syn-sulfide calcites are usually veined. Early syn-sulfide calcites are intergrown with coarse-grained tabular stibnite and are generally milky-white, locally yellowish-pink, whereas late syn-sulfide calcites are intergrown with fine-grained acicular stibnite and are generally white to colorless. Fig. 2. The chondrite-normalized REE patterns for the syn-sulfide Post-sulfide calcites are usually colorless and clear, calcites from the Xikuangshan Mine (data from Peng et al., in coarse-grained and usually appear in druses. The press). REE abundances were analyzed on a Finnigan MAT homogenization temperatures for the early syn-sulfide ELEMENT inductively coupled plasma spectrometer at the calcites are about 180–250 jC, and 100–150 jC for Institution of Geochemistry, Chinese Academy of Sciences (CAS). The samples were analyzed using the methods described the late syn-sulfide calcites. by Qi and Gre´goire (2000). The analytical accuracy is better than The syn-sulfide calcites contain considerable con- 10%. All data are normalized for REE plot using the chondrite REE centrations of rare earth elements, with the SREE + Y values of Herrmann (1970). 中国科技论文在线 http://www.paper.edu.cn

132 J.-T. Peng et al. / Chemical Geology 200 (2003) 129–136

episodes, but were also deposited from isotopically distinct hydrothermal solutions. So, the data process- ing for the early and late syn-sulfide calcites is independently made.

3. Sampling and analytical method

Based on field textural features and microscopic observation, 13 calcites that formed coevally with stibnite were selected for analysis. These samples consisted of five ‘‘early’’ syn-sulfide calcites from Tongjiayuan mine and eight ‘‘late’’ syn-sulfide calcites from Feishuiyan mine. Calcite chips were cut from hand specimens and lightly crushed to 0.3 to 0.5 mm in size, and then pure calcite separates were Fig. 3. Plot of C and O isotope composition for the syn-sulfide calcites from the Xikuangshan Mine (data from Peng and Hu, handpicked under a binocular microscope, and finally 2001). crushed to 200 mesh in an agate mortar. All the specimens analyzed in this study were collected from underground exposures. cites of different ore stage are markedly different. The Calcite samples were analyzed for their Sm and Nd 87Sr/86Sr ratios for the early syn-sulfide calcites content and isotopic composition. The samples were ranged from 0.7121 to 0.7128, averaging 0.7125, dissolved with HF and HClO4. Two separate sample and the 87Sr/86Sr ratios for the late syn-sulfide aliquots were dissolved, one for Sm and Nd concen- calcites varied between 0.7097 and 0.7124, with an tration measurement and the other for 143Nd/144Nd average of 0.7107. Therefore, the two generations of analysis. Sm and Nd were separated by a reversed syn-sulfide calcites not only formed during different phase extraction technique with HDEHP coated on

Table 1 Sr contents and its isotope composition for syn-sulfide calcites from the Xikuangshan Mine Stage No. sample Color Occurrence Sr (ppm) 87Sr/86Sr (2r) Early syn-sulfide XN3-9 yellowish pink cc 787 0.712684 F 8 XN3-10 milky white cc + stb. 777 0.712823 F 7 XN3-11 815 0.712193 F 6 XN3-13 642 0.712790 F 5 XN3-15 654 0.712115 F 7 Late syn-sulfide XS11-2 white cc + stb. 158 0.709739 F 5 XS11-5 white-colorless 187 0.712410 F 8 XS11-36 white 153 0.710198 F 8 XS19W-1 white-colorless 175 0.710317 F 7 XS19E-2 white 147 0.710317 F 7 XS19W-3 199 0.710375 F 6 XS19W-7 209 0.711409 F 8 XS19W-13 cc + Q + stb. 111 0.710610 F 7 Abbreviations: cc = calcite, stb = stibnite, Q = quartz.

The samples were dissolved with HF and HClO4; Sr was separated using a standard ion-exchange chromatography procedure. The isotopic ratios were measured on a MAT 261 mass spectrometer at Tianjin Institute of Geology and Mineral Resources, Chinese of Academy of Geological Sciences (CAGS). The reproducibility of duplicate samples was always better than 0.000010(2r). The measured blanks for Sr throughout the procedure were about 0.5 ng. Five replicate analyses of the NBS 987 standard gave an average value of 0.710259 F 0.000009 (2r). The Sr concentrations were determined by the isotope dilution method at Tianjin Institute of Geology and Mineral Resources, CAGS. 中国科技论文在线 http://www.paper.edu.cn

J.-T. Peng et al. / Chemical Geology 200 (2003) 129–136 133

Teflon powder. Abundances of Sm and Nd were od of York (1969) as implemented in the Program determined by isotope dilution using 149Sm- and ISOPLOT 2.71 (Ludwig, 1994). 145Nd-enriched spikes. Present-day 143Nd/144Nd ratios were determined from unspiked dissolutions of the preconcentrated sample spilt. 4. Results and discussion Isotope ratio measurements were made on a MAT- 261 mass spectrometer at Tianjin Institute of Geology Abundances of Sm and Nd for the early and late and Mineral Resources, CAGS. Nd ratios were nor- syn-sulfide calcites and its Nd isotope compositions malized to 146Nd/144Nd = 0.7219, using a power law are listed in Table 2. As shown in Table 2, the two fractionation correction. The reproducibility of the groups of syn-sulfide calcites display remarkable isotopic ratios is better than 0.005% at the two-sigma differences in Nd concentrations, 147Sm/144Nd and level; the precision for Sm and Nd concentrations is 143Nd/144Nd ratios. For the early syn-sulfide calcites, less than 0.5% of the quoted values (2 sigma). Six the Nd abundances are obviously less than those for replicate analyses of the BCR-1 during this study the late syn-sulfide calcites, and the 147Sm/144Nd and gave the average values of 6.57 ppm for Sm, 28.75 143Nd/144Nd ratios of the late syn-sulfide calcites are ppm for Nd and 0.512644 F 0.000011(2r)for remarkably less than those of the early calcites. It is 143Nd/144Nd. This compares well to the literature worthwhile to note that the 147Sm/144Nd ratios for the values of 6.58–6.7 ppm for Sm and 28.4–29.3 early syn-sulfide calcites are remarkably higher than ppm for Nd (Bell et al., 1989; Gupta and Bertrand, those for common geological samples so far reported. 1995; Panteeva et al., 2003). Five replicate analyses On the 147Sm/144Nd– 143Nd/144Nd diagrams, the of JMC Nd standard (the Johnson and MatteyR Nd calcite samples from the early and late-stage mineral- standard) gave an average 143Nd/144Nd value of ization, respectively, display a good linear relationship 0.511132 F 0.000012(2r), which coincides well with (Fig. 4), which represents an isochron or a mixed line the published JMC values of 0.511114 F 0.000026 with two end-members of different 147Sm/144Nd and (Galindo et al., 1994) and 0.5111125 F 0.000008 143Nd/144Nd ratios. Because no linear relationships (Nie et al., 1999). Blanks during this study were 30 exist on the 1/Nd– 143Nd/144Nd diagrams for the early pg for Sm and 54 pg for Nd. syn-sulfide calcites or the late syn-sulfide calcites, we The decay constant used in the age calculation is can rule out the possibility of a mixed line. Early syn- k147Sm = 6.54 Â 10À 12 yearÀ 1. The Sm–Nd isochron sulfide calcites have an isochron slope corresponding ages were calculated by using the least-squares meth- to an age of 155.5 F 1.1 Ma and an intercept of

Table 2 Sm and Nd isotope composition for syn-sulfide calcites from the Xikuangshan Mine Stage No. Sm Nd 147Sm/144Nd 143Nd/144Nd (2r) sample (ppm) (ppm) Early syn-sulfide XN3-9 0.6699 0.2505 1.6167 0.513287 F 24 XN3-10 0.8539 0.1986 2.5994 0.514287 F 26 XN3-11 4.4302 0.3181 8.4197 0.520207 F 25 XN3-13 0.6331 0.4067 0.9411 0.512598 F 22 XN3-15 0.7250 0.2407 1.8210 0.513495 F 24 Late syn-sulfide XS11-2 0.3733 0.8538 0.2643 0.511923 F 26 XS11-5 0.7013 0.7046 0.6017 0.512198 F 09 XS11-36 0.7906 1.5580 0.3068 0.511958 F 24 XS19W-1 0.5334 3.6229 0.0890 0.511782 F 08 XS19E-2 0.4020 0.7706 0.3154 0.511966 F 11 XS19W-3 0.9139 1.5280 0.3616 0.512005 F 10 XS19W-7 1.3211 1.9509 0.4094 0.512044 F 18 XS19W-13 0.5709 0.9952 0.3468 0.511988 F 22 The colors and occurrences of syn-sulfide calcites are referred to Table 1. 中国科技论文在线 http://www.paper.edu.cn

134 J.-T. Peng et al. / Chemical Geology 200 (2003) 129–136

occurred after the Sb mineralization; therefore, the influence of thermal disturbance on the hydrothermal calcites from the Xikuangshan Mine is probably negligible. Thus, Sm–Nd isotopic systematics in the syn-sulfide calcites from the Xikuangshan Mine should have been closed and preserves initial mineralization information, i.e. the isochron ages of the calcites should represent the timing of the coeval antimony mineralization. These data show that multistage mineralization took place during Late Jurassic to Early Cretaceous times. C, O and Sr isotopic data indicate that early and late syn-sulfide calcites from the Xikuangshan Mine were likely precipitated from different hydrothermal solutions, and that there were at least two large-scale fluid–rock interactions related to antimony mineralization in Central Hunan (Peng et al., 2001; Peng and Hu, 2001). Field relationships and petrographic observations are also consistent with two stages of silicification closely associated with the antimony mineralization in Central Hunan (Jin and Jin, 1998). Based on the field observations, previous research- ers concluded that ore precipitation in the Xikuangshan Mine took place in late Yenshanian Period (about 140 to 65 Ma) (Chen et al., 1983; Tu et al., 1984). Our results generally support this opinion; however, it is more reasonable that the early mineralization in the Xikuangshan Mine is considered to happen during early Yenshanian Period (about 213 to 140 Ma). In the vicinity of the Xikuangshan, there are some addi- Fig. 4. Sm–Nd isochrons for the (A) early syn-sulfide calcites and tional Sb deposits, hosted in Precambrian strata, which (B) late syn-sulfide calcites from the Xikuangshan Mine. also probably formed during the Yenshanian Period. Rb–Sr isochron ages of fluid inclusions in quartz from 0.511642 F 19 (initial eNd = À 15.5); the mean square the Longshan Au–Sb mine, Central Hunan and the of weighted deviates (MSWD) is 0.01 (Fig. 4A). The Woxi Au–Sb–W mine, Western Hunan are 175 F 27 late syn-sulfide calcites define a slope corresponding Ma and 144.8 F 11.7 Ma, respectively (Shi et al., to an age of 124.1 F 3.7 Ma and an intercept of 1993). The reported ages of both deposits overlap with 0.511709 F 9 (initial eNd = À 15.0); the MSWD is the early mineralization at Xikuangshan within errors 0.04 (Fig. 4B). Noticeably, the MSWD values re- (155.5 F 1.1 Ma). Therefore, a Yenshanian age of Sb ported here are anomalously low, which may be mineralization may be widespread throughout the related to the overestimated analytical errors. Hunan Province. The Yenshanian Orogeny is a very Rare earth elements (REEs) are incorporated in important tectonic event in China, with widespread calcite by substitution at Ca2+ structural sites. REE tectonism and magmatism that led to large-scale metal diffusion in calcite is very slow (Cherniak, 1998). mineralization including W, Sn, Pb, Zn, Nb–Ta, Au, Even during diffusive alteration, REE isotope and Sb and Hg in South China (Chen, 1960, 1992). The chemical information in calcite is quite possibly hitherto defined ages, including that of the Xikuang- preserved (Cherniak, 1998). In the Xiangzhong (Cen- shan deposit, mostly fall in the range of 160–120 Ma tral Hunan) district, no tectonic–magmatic activity (Mao and Wang, 2000). Thus, antimony mineralization 中国科技论文在线 http://www.paper.edu.cn

J.-T. Peng et al. / Chemical Geology 200 (2003) 129–136 135 in this area is closely associated with the Yenshanian G1999043200) and National Climbing Program (No. Orogeny. However, the exact mechanism that deposit- Grant 95-Yu-25) from the Chinese National Ministry ed Sb mineralization at Xikuangshan is not yet clear. of Science and Technology. We wish to thank the It is noticeable that the initial eNd values for the two geological workers from the Xikuangshan Mine for regression lines are similar ( À 15.5 and À 15.0, their great help during our field investigation. Mr. Lin respectively). These relatively low initial 143Nd/144Nd Yuanxian is greatly appreciated for his help with values are less than the eNd(t) values of the host analyses and technical assistance. Special thanks to Devonian strata at the time of mineralization, but are Prof. Qiu Yuzhuo, Prof. Chen Jiangfeng and Prof. close to those of the underlying Proterozoic Banxi Zhang Qian for fruitful discussions on isotope dating. Group (Zhu, 1997). This indicates that the Nd in the Finally, we would like to express our indebtedness to ore-forming solutions probably originated from the the editor (Prof. Steven L. Goldstein) and two underlying Proterozoic basement, and that the miner- reviewers, whose invaluable revision suggestions alizing fluid was derived from, or flowed through, the helped us elaborate and improve our argument. [SG] basement underlying the Devonian carbonate cover. This is consistent with our previous Sr isotope results (Peng et al., 2001) indicating that the hydrothermal References solutions acquired radiogenic 87Sr by interaction with Proterozoic clastic rocks underlying the carbonate Anglin, C.D., Jonasson, I.R., Franklin, J.M., 1996. Sm–Nd dating rocks of the Xiangzhong Basin. of scheelite and tourmaline: implications for the genesis of Archean gold deposits, Val d’Or, Canada. Econ. Geol. 91, 1372–1382. Bell, K., Anglin, C.D., Franklin, J.M., 1989. Sm–Nd and Rb–Sr 5. Conclusions isotope systematics of scheelites: possible implications for the age and genesis of vein-hosted gold deposits. Geology 17, Syn-sulfide calcites from the Xikuangshan antimo- 500–504. ny deposit contain considerable concentrations of rare Chen, G.D., 1960. Theory of Activation of Platforms and its Significance in Ore Searching. Geological Press, Beijing, earth elements and variable Sm/Nd ratios. Their pp. 1–408. In Chinese with English abstract. chondrite-normalized REE patterns are characterized Chen, G.D., 1992. New Development of the Diwa Theory. Science by MREE- and HREE-enriched, LREE-depleted pat- Press, Beijing, pp. 1–314. In Chinese with English abstract. tern, which makes it possible to use these calcites to Chen, X.L., Jiang, Y.H., Li, S.Y., Liao, H.Z., 1983. A preliminary date directly the hydrothermal mineralization. Early study on the origin of the Xikuangshan antimony deposit in Hunan. Geol. Rev. 29, 486–492 (in Chinese with English syn-sulfide calcites define a Sm–Nd isochron age of abstract). F 155.5 1.1 Ma (eNd = À 15.5; MSWD: 0.01), while Cherniak, D.J., 1998. REE diffusion in calcite. Earth Planet. Sci. late syn-sulfide calcites define a Sm–Nd isochron age Lett. 160, 273–287. Chesley, J.T., Halliday, A.N., Scrivener, R.C., 1991. Samarium– of 124.1 F 3.7 Ma (eNd = À 15.0; MSWD: 0.04). These Sm–Nd isochron ages agree well with previous neodymium direct dating of fluorite mineralization. Science 252, 949–951. geological deduction. Chesley, J.T., Halliday, A.N., Kyser, T.K., Spry, P.G., 1969. Direct Considering calcite is common in many hydrother- dating of MVT mineralization: use of Sm–Nd in fluorite. Econ. mal deposits, Sm–Nd direct dating of calcites has Geol. 89, 1192–1199. great potential for determination of the ages of hy- Darbyshire, D.P.F., Pitfield, P.E.J., Campbell, S.D.G., 1997. Late drothermal deposits. Therefore, Sm–Nd isotope sys- Archean and Early Proterozoic gold–tungsten mineralization in the Zimbabwe Archean craton: Rb – Sr and Sm – Nd isotope tematics of hydrothermal calcites is a potential constraints. Geology 24, 19–22. geochronometer. Eichhorn, R., Ho¨ll, R., Jagoutz, E., Scha¨rer, S., 1997. Dating scheelite stages: a strontium, neodymium, lead approach from the Felbertal tungsten deposit, Central Alps, Austria. Geochim. Cos- Acknowledgements mochim. Acta 61, 5005–5022. Fryer, B.J., Taylor, R.P., 1984. Sm–Nd direct dating of the Collins Bay hydrothermal uranium deposit, Saskatchewan. Geology 12, This research was financially supported by Na- 479–482. tional Key Basic Development Program (No. Grant Galindo, C., Tornos, F., Darbyshire, D.P.F., Casquet, C., 1994. The 中国科技论文在线 http://www.paper.edu.cn

136 J.-T. Peng et al. / Chemical Geology 200 (2003) 129–136

age and origin of the barite–fluorite (Pb–Zn) veins of the Sierra and geodynamic setting of large-scale metallogeny in East Chi- del Guadarrama (Spanish Central System, Spain): a radiogenic na. Miner. Depos. 19 (4), 289–296 (in Chinese with English (Nd, Sr) and stable isotope study. Chem. Geol. 112, 351–364. abstract). Gupta, J.G.Sen, Bertrand, N.B., 1995. Direct ICP-MS determina- Nie, F.J., BjØrlykke, A.B., Nilsen, K.S., 1999. The origin of the tion of trace and ultratrace elements in geological materials after Proterozoic Bidjovagge gold–copper deposit, Finnmark, North- decomposition in a microwave oven I. Quantitation of Y, Th, U ern Norway, as deduced from rare earth element and Nd isotope and the lanthanides. Talanta 42, 1595–1607. evidences on calcites. Resour. Geol. 49 (1), 13–25. Halliday, A.N., Shepherd, J.T., Dicken, A.P., Chesley, J.T., 1990. Panteeva, S.V., Gladkochoub, D.P., Donskaya, T.V., Markova, V.V., Sm–Nd evidence for the age and origin of a MVT ore deposit. Sandimirova, G.P., 2003. Determination of 24 trace elements in Nature 344, 54–56. felsic rocks by inductively coupled plasma mass spectrometry Hecht, L., Freiberger, R., Gilg, H.A., Grundmann, G., Kostitsyn, after lithium metaborate fusion. Spectrochim. Acta, Part B: Y.A., 1999. Rare earth element and isotope(C, O, Sr) charac- Atom. Spectrosc. 58, 341–350. teristics of hydrothermal carbonates: genetic implications for Peng, J.T., Hu, R.Z., 2001. C, O isotope systematics in the Xi- dolomite-hosted talc mineralization at Go¨pfersgru¨n (Fichtelge- kuangshan superlarge antimony deposit, Central Hunan. Geol. brirge, Germany). Chem. Geol. 155, 115–130. Rev. 47, 34–41 (in Chinese with English abstract). Herrmann, A.G., 1970. Yttrium and Lanthanides. In: Wedepohl, Peng, J.T., Hu, R.Z., Deng, H.L., Su, W.C., 2001. Strontium isotope K.H. (Ed.), Handbook of Geochemistry, vol. II/2. Springer-Ver- geochemistry of the Xikuangshan antimony deposit, Central lag, Berlin, Heidelberg, New York, pp. 57–71. Section 39. Hunan. Geochimica 30, 248–256 (in Chinese with English Jiang, S.Y., Slack, J.F., Palmer, M.R., 2000. Sm–Nd dating of the abstract). giant Sullivan Pb–Zn–Ag deposit, British Columbia. Geology Peng, J.T., Hu, R.Z., Zou, L.Q., Liu, J.X., 2002. Isotope tracing of 28, 751–754. ore-forming materials for the Xikuangshan antimony deposit, Jin, X.X., Jin, B.H., 1998. Study on the silicified rocks in Central Central Hunan. Acta Miner. Sin. 22 (2), 156–159 (in Chinese Hunan. Hunan Geol. 14 (2), 91–98 (in Chinese with English with English abstract). abstract). Peng, J.T., Hu, R.Z., Qi, L., Zhao, J.H., 2003. The REE distribution Kempe, U., Belyatsky, B.V., Krymsky, R.S., Ivanov, P.A., 2001. pattern for the hydrothermal calcites from Xikuangshan anti- Sm – Nd and Sr isotope systematics of scheelite from the mony deposit and its controlling factors. Geol. Rev. (in press). giant Au (–W) deposit Muruntau (Uzbekistan): implications Qi, L., Gre´goire, D.C., 2000. Determination of trace elements in for the age and sources of Au mineralization. Miner. Depos. twenty-six Chinese geochemistry reference materials by induc- 36, 379–392. tively coupled plasma-mass spectrometry. Geostand. Newsl. 24, Kent, A.J.R., Campbell, I.H., McCulloch, M.T., 1995. Sm–Nd 51–63. systematics of hydrothermal scheelite from the Mount Char- Shi, M.K., Fu, B.Q., Jin, X.X., Zhou, X.C., 1993. Antimony Metal- lotte Mine, Kalgoorlie, Western Australia: an isotopic link be- logeny in the Central Part of Hunan Province. Hunan Press of tween gold mineralization and komatiites. Econ. Geol. 90, Science and Technology, Changsha, pp. 53–65. In Chinese 2329–2335. with English abstract. Laznicka, P., 1999. Quantitative relationships among giant deposits Subı´as, I., Ferna´ndez-Nieto, C., 1995. Hydrothermal events in the of metals. Econ. Geol. 94, 455–474. Valle de Tena (Spain Western Pyrenees) as evidenced by fluid Li, Z.C., Wan, J.H., Du, G.M., 1987. Sm–Nd isochron of fluorites. inclusions and trace-element distribution from fluorite deposits. Geol. Geochem. 15 (9), 67–68 (in Chinese with English Chem. Geol. 124, 267–282. abstract). Tu, G.C., et al., 1984. Geochemistry of Strata-bound Ore Deposits Liu, G.M., Jian, H.M., 1983. Geological characteristics of the in China, vol. I. Science Press, Beijing, pp. 129–188. In Xikuangshan antimony ore field. Miner. Depos. 2 (3), 43–49 Chinese. (in Chinese with English abstract). Wu, L.S., Hu, X.W., 2000. Xikuangshan mica-plagioclase lamp- Liu, H.P., Zhang, Y.L., Hu, W.Q., 1985. A study on the origin of rophyre and its granite inclusions, Hunan Province. Geol. Geo- the Xikuangshan Sb deposit, Hunan. Hunan Geol. 4 (1), 28–39 chem. 28 (2), 51–55 (in Chinese with English abstract). (in Chinese with English abstract). York, D., 1969. Least-squares fitting of a straight line with corre- Ludwig, K., 1994. ISOPLOT, version 2.71, rev. Of USGS Open lated errors. Earth Planet. Sci. Lett. 5, 320–324. File Report, 91-445. Zhu, B.Q., 1997. Theory and Application of Isotope Systematics in Mao, J.W., Wang, Z.L., 2000. A preliminary study on time limits Geological Sciences. Science Press, Beijing, pp. 178–179.