滇西金宝山铂钯矿床S-Os同位素特征及其对成矿过程的制约
  岩石学报  2018, Vol. 34 Issue (5): 1258-1270   PDF    
滇西金宝山铂钯矿床S-Os同位素特征及其对成矿过程的制约
卢宜冠 , 和文言     
中国地质大学地质过程与矿产资源国家重点实验室, 北京 100083
摘要:金宝山铂钯矿床位于扬子板块西缘,毗邻哀牢山造山带北段,是三江成矿带唯一的大型岩浆型铂族元素矿床。以往的研究中,金宝山岩体是否经历地壳混染存在较大争议,制约了对硫饱和机制和矿床成因的认识。前人对矿石中硫化物的S同位素的研究发现绝大部分δ34S值位于1‰~2‰,表现为幔源特征,显示少量或无明显地壳混染作用。本文对含非常规硫化物组合(紫硫镍矿-黄铁矿-黄铜矿)的矿石展开了同位素研究,结合最新研究数据,利用质量平衡原理定量建立了R值(硅酸盐岩浆/硫化物)、百分百硫化物PGE含量和δ34S之间的关系。富PGE矿石具有较高的R值(2000~10000)和PGE含量(如Ir百分百硫化物:2429×10-9~10738×10-9),并具有地幔特征的δ34S范围(1‰~2‰),而贫PGE(如Ir百分百硫化物:449×10-9~2017×10-9)的矿石R值较低(500~2000),表现出显著的地壳S同位素的特征(4.4‰~6.7‰)。此外,Re-Os同位素研究表明金宝山铂钯矿床相比一些富硫化物铜镍矿床(如力马河和杨柳坪)具有较低的γOs(21.9~60.5)和较高R值,是大量岩浆与硫化物反应导致的结果,表明其矿石γOs的高低并不能直接反应岩体的地壳混染程度。因此我们在利用S-Os同位素在研究岩浆型铜镍铂族元素矿床时需特别注意,虽然δ34S和γOs的大小通常作为研究地壳混染作用的指示剂,但它们却往往受到矿床类型(铂钯矿床、铜镍矿床)以及矿石类型(富PGE矿石、贫PGE矿石)的影响。特别是对于高R值的铂族元素矿床,矿石呈现出接近幔源特征的δ34S和γOs同位素值并不能排除其在形成的过程中没有地壳物质的加入,而应综合Sr-Nd同位素以及微量元素地球化学特征综合判断是否发生了明显的地壳混染作用。
关键词: 铂钯矿床     地壳混染     R值     S-Os同位素     金宝山    
Characteristics of S-Os isotopes and its constraints on the mineralization for the Jinbaoshan Pt-Pd deposit, western Yunnan, China.
LU YiGuan, HE WenYan     
State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Beijing 100083, China
Abstract: Jinbaoshan Pt-Pd deposit is located in the western margin of Yangtze block, adjacent to the northern part of Ailaoshan orogenic belt. It is the only large magmatic PGE deposit in the Sanjiang region. Previous studies show that whether there is a process of crustal contamination of Jinbaoshan intrusion is still an issue of debate, which constrain the understanding of sulfide saturation and ore genesis. It was suggested that most sulfides from the disseminated ores have δ34S values varying from 1‰ to 2‰ (mantle value), indicating there is no obvious crustal contamination. Combined with published data, this paper reports the S isotopes of the ores with an unusual sulfide assemblage (violarite-pyrite-chalcopyrite), and establishes the relationship among R factor (silicate magma/sulfide ratio), PGE contents and δ34S values by mass balance calculation. Generally, the PGE-rich ores have relatively high R factor (2000~10000) and PGE contents (Ir100:2429×10-9~10738×10-9), together with mantle-like δ34S values (1‰~2‰), in contrast, PGE-poor ores (Ir100:449×10-9~2017×10-9) have low R factors (500~2000) and show crustal S isotopic features (δ34S:4.4‰~6.7‰). Besides, compared with sulfide-rich Ni-Cu deposits, Jinbaoshan Pt-Pd deposit has low γOs (21.9~60.5), which is the result of the sulfide droplet mixed with large amounts of magma, consistent with high R factors. It is suggested that the γOs values of ores cannot reflect crustal contamination degree of the intrusion directly. Thus, it needs to be particularly careful when we apply S-Os isotopes to study magmatic Ni-Cu-PGE deposits. Although the δ34S and γOs values of ores are good indicators to evaluate crustal contamination degree, they are also affected by the deposit type (PGE deposit or Ni-Cu deposit) and ore type (PGE-rich ore or PGE-poor ore). The ores have mantle-like S-Os isotopes cannot exclude that the magma did not experience massive crustal contamination. We also need to consider Sr-Nd isotopes and trace element data to study the degree of crustal contamination comprehensively.
Key words: Pt-Pd deposit     Crustal contamination     R factor     S-Os isotopes     Jinbaoshan    

岩浆型Ni-Cu-PGE矿床蕴含了世界上大约56%的镍金属资源和96%铂族金属资源(Mudd and Jowitt, 2014; Barnes et al., 2017a, b)。它的形成源自于岩浆在达到S饱和状态下,硫化物不混溶珠滴熔离并聚集,在这一过程中金属元素Ni、Cu、PGE等在硫化物珠滴中富集并达到工业品位(Naldrett, 2004, 2010; Lightfoot and Evans-Lamswood, 2015; Barnes et al., 2016a)。岩浆硫化物矿床根据硫化物含量的高低以及Ni、Cu、PGE的相对富集程度可分为两大类:富硫化物型Ni-Cu矿床(硫化物含量大于10%)和贫硫化物型PGE矿床(硫化物含量小于5%)(Naldrett, 2010)。它们形成于相对富Mg的幔源岩浆,在岩浆侵位的过程中经历了分离结晶、地壳混染、岩浆混合等一系列过程,通常伴随着镁铁质-超镁铁质岩石产出(Li and Ripley, 2005; Maier et al., 2015; Ripley and Li, 2017; Lesher, 2017)。PGE矿床中矿石富集PGE源于在动态岩浆房中熔离出来的硫化物与大量岩浆发生混合从而使得PGE富集(Li et al., 2001; Barnes and Lightfoot, 2005)。PGE矿床主要产自于大型侵入岩体中,矿层的厚度从几十厘米至几十米不等,铂族元素通常伴随着硫化物(磁黄铁矿-镍黄铁矿-黄铜矿)和铬铁矿(Barnes et al., 2016b; Barnes and Ripley, 2016)。空间关系上,PGE矿床主要产出在克拉通的内部,例如Kaapvaal克拉通(Bushveld),Zimbabwe克拉通(Great Dyke)以及Hearne克拉通(Stillwater)(Maier and Groves, 2011)。

复合造山指多期次造山以及其它类型壳幔过程(裂谷作用、地幔柱活动、克拉通减薄等)在同一构造带先后发生或者多类型过程同时同位发生的地质事件,它驱动了复合成矿系统的形成,是中国区域成矿典型特色(邓军等, 2016)。而复合造山及复合成矿系统研究理论在也矿床学研究领域被广泛运用(Deng et al., 2009, 2015a, b, 2017a, b, c, 2018; Deng and Wang, 2016; Yang et al., 2014, 2015, 2016a, b, c, d, 2017a, b; Wang et al., 2014, 2015; 杨立强等, 2014)。中国西南三江造山带作为复合造山和复合成矿系统研究的典型解剖区,是我国重要的多金属富集区,Au、Cu、Pb、Zn、Mo、Ag、W、Sn等优势资源潜力巨大(Deng et al., 2010a, 2014a, b; Yang et al., 2017c, d; 邓军等, 2013, 2014, 2016; 杨立强等, 2015)。金沙江-哀牢山成矿带形成于三江特提斯复合造山过程中(杨立强等, 2010, 2011a, b),带内不仅发育大量热液多金属矿床如铜厂沟铜钼矿床(Yang et al., 2017d),红山铜矿床(Yang et al., 2016e),北衙金多金属矿床(Deng et al., 2015c; He et al., 2015, 2016),老王寨金矿床(Deng et al., 2015d)和墨江金镍矿床(熊伊曲等, 2015),也发育岩浆型硫化物矿床(如白马寨、牛栏冲、新安里铜镍矿床等, Wang and Zhou, 2006; 张学书, 2005)。金宝山铂钯矿床位于扬子板块西缘,毗邻哀牢山造山带北段(杨立强等, 2011b),是区域内也是中国唯一的大型岩浆型铂族元素矿床,因此对于金宝山铂钯矿床的研究不仅是对金沙江-哀牢山成矿带内岩浆硫化物矿床成矿理论的重要补充,而且对于我国的铂族资源找矿勘查工作具有指导意义。

前人对其年代学、岩浆起源、硫化物饱和机制以及成因模式展开了较多研究工作并取得了一些重要成果(Tao et al., 2007, 2009; Zhou et al., 2008; Wang et al., 2010; 王生伟等, 2012; 卢宜冠等, 2014)。金宝山富PGE岩浆起源于峨眉山低钛苦橄岩(Zhou et al., 2008; Wang et al., 2018),经过大量的岩浆与硫化物的混合使得岩浆中的PGE富集而形成富PGE的母岩浆(Tao et al., 2007; Song et al., 2008; Wang et al., 2010)。然而关于硫饱和机制,特别是地壳混染作用对于成矿的影响尚存在较大争议。其中Zhou et al. (2008)通过对微量元素及Sr-Nd同位素的研究认为包括金宝山在内的一系列峨眉山大火成岩省内的岩浆硫化物矿床都经历了明显的地壳混染,Wang et al. (2018)对金宝山矿石中的硫化物进行了原位S同位素研究发现δ34S值为4.4‰~6.7‰,也为地壳混染提供了充分的证据。然而在Tao et al. (2007)的研究中绝大多数硫化物的δ34S值位于1‰~2‰之间,而且陶琰等(2010)通过Os同位素计算得出金宝山浸染状矿石下地壳混染程度 < 5%。本文通过对金宝山矿床中含紫硫镍矿-黄铁矿-黄铜矿硫化物组合样品S同位素研究,并结合前人对于Re-Os同位素的研究,定量化地建立起铂族元素、S同位素、Re-Os同位素之间的关系,为以S-Os同位素工作探讨地壳混染作用提供新的思路。

1 区域及矿床地质背景

中国西南峨眉山大火成岩省分布于中国西南部(云南、四川、贵州)以及越南北部,分布面积达2.5×105~3×105km2(Chung and Jahn, 1995; Xu et al., 2001; Xiao et al., 2004; Deng et al., 2010b)。西北界为龙门山-小菁河断裂,西界则为哀牢山-红河断裂,南界在中越边界,甚至到越南境内,东部延伸至贵阳以东的都匀-瓮安一带(李宏博, 2012)。金宝山铂钯矿床位于扬子板块西缘,红河断裂东侧,与之对应的喷出岩是空间紧邻的大理宾川玄武岩(图 1)。锆石SHRIMP定年结果显示侵入体的形成年龄为260±3.5Ma,与峨眉山玄武岩同期(Tao et al., 2009)。金宝山铂钯矿床和朱布铂钯矿床、杨柳坪铜镍铂族元素矿床、力马河铜镍矿床和白马寨铜镍矿床等,代表了峨眉山大火成岩省中岩浆硫化物矿床的不同类型端元(Song et al., 2008; Zhou et al., 2008)。

图 1 峨眉山大火成岩省溢流玄武岩、镁铁-超镁铁质岩体及典型岩浆硫化物矿床地质简图(据王生伟等, 2012) Fig. 1 Distribution of continental flood basalts and contemporaneous mafic-ultramafic intrusions and typical magmatic sulfide deposits, the Emeishan large igneous province, South China (after Wang et al., 2012)

金宝山岩体为一大型层状岩体,长约5km,宽约1.2km,厚度达170m(图 2)。共计11个层状超镁铁质岩体和21个镁铁质岩体侵入泥盆系和下二叠统的地层(Wang et al., 2010)。泥盆系的地层主要由夹层状石灰岩、砂岩和板岩构成,下二叠统地层主要由石灰岩和砂质板岩构成。金宝山岩体被礼舍江分割为南北两端,矿体主要集中在北段。金宝山铂钯矿床约含45t铂钯金属,矿石品位为1~5g/t(Wang et al., 2010)。

图 2 金宝山铂钯矿床矿区地质简图(据Wang et al., 2010) Fig. 2 Geological sketch map of the Jinbaoshan Pt-Pd ore district (after Wang et al., 2010)

金宝山岩体类型较单一,主要为辉石橄榄岩(约占整个岩体的92%),岩体底部和边部可见一些小的橄榄辉石岩、辉石岩和斜长角闪岩。矿体呈似层状、透镜状,主要产于辉石橄榄岩中,其它超基性岩类也都有不同程度的矿化,个别地段近岩体的围岩也见有矿化(Wang et al., 2005; Tao et al., 2007)。超基性岩蛇纹石化和滑石化强烈,在岩体与围岩的接触带发育角岩化、大理岩化、滑石化和绿泥石化。矿体与围岩呈渐变过渡,无明显岩性差异及界线。纵向上岩体共有三个矿层,其中储量最大的矿层位于岩体底部,长2100m,宽400~600m,厚4~16m,规模占整个矿床储量的44%(Wang et al., 2005)。含矿超基性岩具致密块状构造,以半自形-他形粒状结构为主,矿石以稀疏浸染状构造为主,呈自形-半自形粒状结构、半自形-他形粒状结构和交代结构。矿床贫铜、镍,富铂、钯,矿石平均品位为0.5g/t,矿石基性程度越强,蚀变越强,铂钯丰度值越高。矿石品位较贫,但矿化普遍,按勘探工程的厚度统计,岩体总矿化率为27.35%,最高者为角闪石岩及蚀变超基性岩(44.54%及41.43%)。铂钯矿化与金属硫化物关系密切,当金属硫化物含量高,种类复杂时则矿化较好,反之则差。金属硫化物主要为磁黄铁矿、镍黄铁矿和黄铜矿,其它的硫化物还包括黄铁矿、紫硫镍矿和针镍矿(Tao et al., 2007; Wang et al., 2010)。矿床中铂族矿物主要是含Te、Sn、As等半金属元素的铂族矿物,常常和金属硫化物共生在一起(Wang et al., 2008)。

2 样品采集及分析方法 2.1 样品采集和岩相学特征

本次研究的样品取自金宝山矿区坑道PD1339、PD1495和PD1508。辉石橄榄岩为含矿的主要岩相,岩石呈黑绿色,自形-半自形包橄结构。几乎所有橄榄石均蚀变为蛇纹石,难见新鲜橄榄石。蛇纹石呈自形-半自形,颗粒大小0.3~0.8mm,含量约为50%,辉石多为单斜辉石,和角闪石以半自形或他形充填于蛇纹石之间(图 3a, c, d)。其中单斜辉石颗粒大小0.2~0.5mm,含量约为25%,角闪石颗粒大小0.3~0.6mm,含量约为15%。岩体整体蚀变强烈,局部可见辉石蚀变为滑石,填充在蛇纹石之间(图 3b)。透闪石为角闪石的蚀变产物,常常交代角闪石并保留角闪石假晶(图 3c, d)。

图 3 金宝山岩体部分岩矿石显微照片Srp-蛇纹石;Cpx-单斜辉石;Tlc-滑石;Amp-角闪石;Trem-透闪石;Viol-紫硫镍矿;Py-黄铁矿;Ccp-黄铜矿;Mlr-针镍矿;Mag-磁铁矿;Ilm-钛铁矿;Chr-铬铁矿 Fig. 3 Microphotographs of rocks and ores from the Jinbaoshan intrusion

金宝山矿床矿石均为贫硫化物浸染状矿石,矿石中S含量小于5%。金属硫化物包括紫硫镍矿、黄铁矿、黄铜矿、硫镍矿以及针镍矿(图 3e, f)。氧化物主要为磁铁矿、钛铁矿和铬铁矿(图 3g, h)。不同于其他铜镍铂族元素矿物金属硫化物组合为磁黄铁矿-镍黄铁矿-黄铜矿。本次研究中矿石的主要金属矿物组合为紫硫镍矿(硫镍矿)-黄铁矿-黄铜矿,通常与磁铁矿共生,充填于蛇纹石间隙中,展现出晚期岩浆硫化物特点(图 3e, f)。针镍矿通常交代紫硫镍矿,与黄铁矿和磁铁矿共生(图 3f)。钛铁矿为自形-半自形,填充于蛇纹石之间(图 3g)。铬铁矿作为主要副矿物,形态上包括六边形铬铁矿及浑圆状环绕结构铬铁矿,根据其分布形式以及化学成分特点可以将其分为原生铬铁矿和粒间铬铁矿两类(图 3h)(卢宜冠等, 2014)。

2.2 分析方法

将全岩样品粉碎至200目,硫同位素的分析测试在国家地质实验测试中心完成,测定数据采用以国际硫同位素CDT标准标定的国家硫同位素标准(硫化银)GBW-4414(δ34S=-0.07‰)和GBW-4415(δ34S=22.15‰)校正,测量误差小于±0.2‰(详见杨勇等, 2010)。分析数据结果见表 1

表 1 金宝山岩体S同位素数据 Table 1 S isotope data of the Jinbaoshan intrusion

铂族元素及全岩硫含量由中国地质科学院国家地质实验测试中心测试。铂族元素分析使用等离子质谱ICP-MS。方法要点:称取试样,加入溶剂熔融,将熔融体注入铁模,冷却后,取出硫镍扣,粉碎后用HCl溶解;加入碲共沉淀剂沉淀后,过滤,王水溶解转入比色管中定容,ICP-MS检测。方法精密度RSD < 10%。全岩硫含量分析使用高频红外碳硫仪HIR-944。方法要点:称取0.0500g样品,于高频感应炉的氧气流中加热燃烧,生成的二氧化硫(碳)由氧气载至红外线分析器中的测量室,二氧化硫(碳)吸收某特定波长的红外能,用红外吸收仪测定。分析数据结果见表 2

表 2 金宝山岩体矿石样品中S(wt%)、Ni(wt%)、Cu(wt%)、PGE(×10-9)全岩含量及百分百硫化物(PGE100)含量 Table 2 S (wt%), Ni (wt%), Cu (wt%) and PGE (×10-9) contents in the whole rock and 100% sulfide from the ores in the Jinbaoshan intrusion
3 讨论 3.1 R值效应

镁铁质岩浆中不仅富含Ni、Co、Cu等元素,且岩浆中的硫化物可以萃取相当程度的金属元素因为Co(30)、Ni(100~500)、Cu(500~1000)、PGE(105~106)等元素具有相对较高的硫化物/硅酸盐分配系数(DSul/Sil)(Naldrett, 2004; Barnes and Lightfoot, 2005; Mungall and Brenan, 2014)。通过质量平衡计算可以计算出硫化物中某金属元素的含量(Campbell and Naldrett, 1979; Naldrett, 1981; Lesher and Burnham, 2001):

其中Xio为金属元素i在初始硅酸盐岩浆中的含量,Yio为金属元素i在硫化物中的含量,R为硅酸盐岩浆/硫化物质量比值,DiSul/Sil为金属元素i在硫化物和硅酸盐中的分配系数,Yif为金属元素i最终在硫化物熔体中的含量。由于大量的岩浆与硫化物发生反应,硫化物可以不断萃取岩浆中的金属元素,所以通常岩浆硫化物矿床都具有较高的R值(硅酸盐岩浆/硫化物)(比如Kambalda矿床R值100~500, Thompson矿床R值500~2500, Lesher et al., 1993; Franchuk et al., 2016)。而富含铂族元素的矿床其R值更是可以高到105(如Norilsk矿床和金宝山矿床, Barnes and Lightfoot, 2005; 卢宜冠等, 2014)。然而R值不仅仅会影响矿石的Ni、Cu以及PGE含量,还会影响到其同位素比值,在高R值的情况下岩浆硫化物矿石通常具有接近地幔特征的δ34S、γOs和S/Se比值(例如Kambalda矿床, Lesher, 2017)。

3.1.1 R值对硫同位素的影响

岩浆型Ni-Cu-PGE硫化物矿床形成的关键在于岩浆中的S达到饱和,进而硫化物熔体从硅酸盐岩浆中熔离出来,在一定的空间内与足够的硅酸盐岩浆混合使Ni、Cu、PGE等元素品位提高,并保存于合适的空间形成铜镍铂族元素矿床(Naldrett, 1999)。尽管有一系列机制都可以导致硫化物饱和(比如分离结晶、岩浆混合等, Li and Ripley, 2005),然而外界S的加入被认为是促使硫化物饱和的最可能的方式(Ripley and Li, 2013),而且世界上很多已知的岩浆硫化物矿床都显示出明显的地壳硫同位素特征,如Noril’sk(Grinenko, 1985)、Thompson(Bleeker, 1990)和Voisey’s Bay(Ripley et al., 1999)。Lesher (2017)收集并对比了一些岩浆Ni-Cu-PGE矿床矿石样品和其围岩的δ34S范围,对于其中一些矿床,矿石样品和围岩样品有着极为接近的δ34S范围,如Raglan(Lesher et al., 1999)、Thompson(Bleeker, 1990)、Kambalda(Donnelly et al., 1978)和Alexo(Naldrett, 1966)。前人测试了金宝山浸染状矿石黄铁矿的硫同位素发现δ34S范围主要集中在1‰~2‰之间,接近幔源硫范围且远远偏离地层中黄铁矿的δ34S(5.4‰~18.6‰),认为其地壳混染作用不明显(Tao et al., 2007; 马言胜等, 2009),然而这种认识忽略了R值对同位素的影响。

Lesher and Burnham (2001)将岩浆体系分为硅酸盐岩浆、硫化物熔体、硅酸盐捕掳体、残余熔体和橄榄石几部分,并提出了计算不同组分混合后同位素的公式:

其中A、B、C、E、F分别代表硅酸盐岩浆,硫化物熔体,硅酸盐捕掳体,残余熔体和橄榄石的相对含量,R’=A/(B+C+E+F);Xi0、Yi0、Zi0、Qi0和Si0分别代表i元素在上述各组分中的含量;RA0、RB0、RC0、RE0和RF0则代表各组分中的初始同位素比值。

我们假设金宝山岩浆系统主要构成组分为硅酸盐岩浆和硫化物捕掳体,且硫化物捕掳体为岩浆提供了硫源。金宝山岩体原始岩浆为苦橄岩,将混染源(硫化物捕掳体)分别设为白云岩硫化物、白云质底岩硫化物和硬石膏进行模拟发现这种类双峰式的硫同位素分布特征和矿石样品的不同R值有关。结果指示富PGE矿石(高R值~10000)表现出地幔硫同位素特征(δ34S: 1‰~2‰),而贫PGE矿石(低R值~1000)则表现出明显的围岩混染特征(δ34S: 4‰~7‰)(图 4)。

图 4 金宝山岩体R值-δ34S图解 蓝色柱体代表金宝山矿石样品δ34S值频率分布;红色、绿色和蓝色曲线分别代表当混染源分别为硬石膏(16.3‰)、白云岩硫化物包体(18‰, Tao et al., 2007)和白云质底岩矿脉(12‰, Tao et al., 2007)与岩浆混合模拟得到的曲线.假设原始岩浆中的S含量和δ34S分别为0.04%和0 Fig. 4 R factor vs. δ34S diagram of the Jinbaoshan intrusion The blue bars represent the frequency of δ34S in ores distribution; The red, green and blue curves represent the magma mixed with a contaminant of anhydrite (δ34S ~16.3‰), dolomite xenolith (δ34S ~18‰, Tao et al., 2007), and dolomite footwall (δ34S ~12‰, Tao et al., 2007) respectively. The S contents and initial δ34S are assumed to be 0.04% and 0 respectively

为了表示R值和元素中铂族元素的富集程度之间的关系通常需要计算出样品中百分百硫化物含量。Barnes and Lightfoot (2005)介绍了根据矿石全岩样品的S、Cu、Ni含量计算百分百硫化物的公式。然而,不同于传统的富硫化物铜镍矿床硫化物组合主要为镍黄铁矿-磁黄铁矿-黄铜矿,金宝山铂钯矿床为一贫硫化物矿床,且在本次采集的样品当中金属硫化物主要为紫硫镍矿-黄铁矿-黄铜矿,因此不能简单采用Barnes and Lightfoot et al. (2005)所提到的公式。本次研究所采集的样品相比Wang et al. (2010)中靠近底部采集的贫PGE矿石样品更加富集Ni,可能与镍黄铁矿蚀变为更富集镍的紫硫镍矿有关。样品线性关系所展示的截距大致代表了橄榄石中Ni的含量,其中富Ni样品橄榄石的Ni含量约为0.1%(图 5a)。假设样品中的Ni均来自橄榄石和紫硫镍矿,Cu均来自黄铜矿,S均来自紫硫镍矿、黄铜矿及黄铁矿,利用质量平衡原理计算本次研究各样品硫化物含量,并依此计算金属元素的百分百硫化物含量(表 2)。

图 5 金宝山岩体S-Ni (a)和Ir100-Pd100 (b)图解 Fig. 5 Diagrams of S vs. Ni (a) and Ir100 vs. Pd100 (b) of the Jinbaoshan intrusion

金宝山富PGE岩浆起源于峨眉山大火成岩省低钛苦橄岩(Zhou et al., 2008; Wang et al., 2018),假设原始岩浆含Pd 10×10-9(Wang et al., 2007, 2010),Ir 1×10-9(Li et al., 2012),Pd和Ir的硫化物和岩浆中的分配系数为105(Mungall and Brenan, 2014)。通过前文提到R值公式可以模拟出R值与硫化物金属含量之间的关系可以发现具有较低R值的贫PGE样品对应较高的δ34S值(6.7‰~4.4‰),而具有较高R值的富PGE样品对应较低的δ34S值(1.5‰~1.3‰)(图 5b)。通过铂族元素估算出的贫PGE矿石和富PGE矿石R值和通过硫同位素所得到的R值接近,分别对应了两个δ34S范围的峰值(图 4),也反映了计算的可靠性。因此,这也说明了R值不仅能影响矿石中PGE含量,也能造成初始S同位素比值的改变。如果大量的岩浆与硫化物发生反应(高R值),不仅能使得岩浆中的PGE发生富集,还能使得本应反映壳源特征的矿石样品展现出幔源S同位素特征。

3.1.2 R值对Re-Os同位素体系的影响

Re-Os同位素常常用来研究岩浆硫化物矿石的起源和形成过程,因为这些元素强烈富集于硫化物珠滴中(Lesher and Campbell, 1993; Lesher and Stone, 1996)。此外亲铜元素的行为在Re-Os体系中比亲石Rb-Sr、Sm-Nd和U-Th-Pb体系中更为显著(Lambert et al., 1998a, b, 1999, 2000)。相对于地幔,地壳具有非常高的Re值和非常低的Os值,并具有强放射性Os同位素组成(Morgan et al., 1981; Esser and Turekian, 1993)。因此,在矿石形成的过程中,岩浆如果和地壳物质发生反应将会使得Re/Os和γOs升高。然而,和S同位素类似,在岩浆和硫化物反应的过程中,大量岩浆的不断补充会使得硫化物矿石的Re-Os同位素特征接近地幔范围值(Lambert et al., 1998a, b, 1999, 2000; Ripley et al., 1999; Lesher and Burnham, 2001; Lesher et al., 2001)。这是因为新的不含地壳混染成分的岩浆具有较低的γOs值,使得和大量岩浆发生反应的硫化物最终形成具有较低γOs值的矿石,这一过程也在一定程度上掩饰了地壳混染的特征(Yang et al., 2012)。Os同位素混染公式如下(Faure, 1986):

γOsM=(γOsAOsAf+γOsBOsB(1-f))/(OsAf+OsB(1-f))

其中f为组分A在混合成分A+B中的比例;OsA和OsB分别代表组分A和B中的Os含量。而在动态岩浆系统当中,可以通过公式来反映γOs,Os值与R值的关系(详见Lesher and Stone, 1996):

γOsfS=(γOsiMOsM(R/(1+R))+γOsiSOsS(1/(1+R)))/(OsM(R/(1+R))+OsS(1/(1+R)))

其中i和f分别代表初始和最终同位素的比值,M和S分别代表岩浆和硫化物,R代表硅酸盐岩浆和硫化物质量之比。我们假设矿床起源于未遭受混染的玄武质岩浆,成分与起源于亏损地幔的硅质高MgO玄武质岩浆相同,含Os 0.2×10-9,Re/Os比值为1,γOs值为0(Lambert et al., 1998a, b)。相比亏损地幔起源的岩浆,硫化物捕掳体具有较高的γOs和Re/Os,假设峨眉山大火成岩省中的岩浆硫化物矿床最初形成的硫化物捕掳体的γOs值为900,和Kambalda硫化物捕掳体成分类似(Lesher and Burnham, 2001),通过前人研究可知力马河铜镍矿床中致密块状矿石含Re 253×10-9~311×10-9,Os 0.97×10-9~1×10-9,成分与混染源硫化物捕掳体接近(Tao et al., 2010)。假设当硫化物捕掳体含Re 300×10-9,Os 1×10-9时,硫化物捕掳体和不断加入的玄武质岩浆发生反应所模拟出来的Re/Os和γOs关系曲线和各类型岩浆硫化物矿床的矿石样品产生了较好的拟合(图 6)。由图中可以看出贫PGE的富铜镍矿床力马河具有较低的R值(网脉状矿石R值~100),含中等铜镍及PGE的矿床杨柳坪相比铜镍矿床R值更高(R>1000)。而富PGE亏损铜镍的矿床金宝山则具有极高的R值,从几千到几万不等,这也和通过S同位素所模拟出的R值相符合。金宝山矿床中具有更高R值的样品来自于富PGE矿石并表现出更接近于地幔S-Os同位素的特征,而那些相对较低的R值样品则来自于贫PGE矿石,表现出明显地壳S同位素的特征,具有相对较高的Re/Os比值,对应地壳端元Re-Os同位素特征。通过Re-Os同位素特征所模拟得到的各矿床R值范围也和利用PGE含量所计算得到的R值一致(Tao et al., 2008; 卢宜冠等, 2014)。

图 6 峨眉山大火成岩省典型岩浆硫化物矿床Re/Os与γOs图解 曲线为硫化物捕掳体不断与硅质高MgO玄武质岩浆混合模拟得到的曲线;硫化物捕掳体和玄武质岩浆Re-Os数据来源于Lambert et al., 1998a, b; Lesher and Burnham, 2001;金宝山PGE矿床数据引自Tao et al., 2007;杨柳坪Ni-Cu-PGE矿床数据韩梅梅, 2017;力马河Ni-Cu矿床数据引自Tao et al., 2010 Fig. 6 Re/Os vs. γOs diagram for some typical magmatic sulfide deposits in ELIP The curve represents the sulfide mixed with siliceous high MgO magma; data source of Re-Os isotopes of sulfide and magma are from Lambert et al., 1998a, 1998b; Lesher and Burnham, 2001; data of Jinbaoshan PGE deposit from Tao et al., 2007; data of Yangliuping Ni-Cu-PGE deposit from Han, 2017; data of Limahe Ni-Cu deposit from Tao et al., 2010
3.2 S-Os同位素对金宝山富PGE岩体成因的指示与应用

我们在利用同位素判别岩体的混染程度时常常用到样品的εNd、γOs来联合制约其地壳混染程度(Yang et al., 2012; Wang et al., 2013; Wei et al., 2013; Zhang et al., 2016)。然而很多矿床都具有变化范围较小的εNd和变化范围较大的γOs,如力马河(Zhou et al., 2008; Tao et al., 2010)、夏日哈木(Peng et al., 2016; Zhang et al., 2017)和菁布拉克(Yang et al., 2012)。Yang et al. (2012)通过对菁布拉克矿床Nd-Os同位素的综合研究发现分别用两种同位素体系解释地壳混染程度会出现偏差,比如对于Os同位素数据表明需要大于30%的地壳混染作用,而Nd同位素数据证明仅仅发生了5%~10%的地壳混染。他认为造成这种偏差的原因在于岩浆选择性混染了更多的地壳硫化物。除此之外,R值可能也是导致Nd-Os同位素发生偏差的原因之一,特别是对于那些R值较大的PGE矿床和Ni-Cu-PGE矿床(如金宝山和杨柳坪)。R值的大小对于样品εNd的影响非常有限,特别是当考虑到岩浆体系只由硅酸盐岩浆和硫化物捕掳体组成时,R值对初始εNd值几乎不造成任何影响(Lesher and Burnham, 2001)。然而对于S同位素和Os同位素,由于这些元素在硫化物和硅酸盐岩浆之间有着非常大的分配系数,使得它们的同位素比值也会受到R值的显著影响。Sr-Nd同位素显示金宝山岩体遭受了10%~20%的地壳混染作用(Zhou et al., 2008),同样和Os-S同位素显示出的小于5%的地壳混染产生偏差(Tao et al., 2007; 陶琰等, 2010),原因在于在形成金宝山富PGE岩体的过程中,大量的岩浆不断与早先熔离出来的硫化物混合,使得硫化物不断富集PGE。与此同时,岩浆也对具有显著地壳混染特征的硫化物进行不断稀释,使得最终形成的PGE岩体并没有表现出明显壳源的S-Os同位素特征。因此,金宝山富PGE岩体不具备明显的S-Os地壳混染特征,并非是其地壳混染程度低,而是大量岩浆混合硫化物导致的结果,掩盖了其在最初硫化物熔离时所具有的强烈壳源S-Os同位素特征。

金宝山铂钯矿床富PGE岩浆的形成源于大量的岩浆与硫化物反应,硫化物不断萃取岩浆中的金属元素从而形成富PGE的岩浆(Tao et al., 2007; Wang et al., 2010)。金宝山铂钯矿体在纵向上主要分布在顶部、中部和底部三个矿层中。相比中部和顶部矿层,底部矿层储量高,品位低,这是由于岩浆在上侵的过程中,大量的铬铁矿和硫化物受到重力作用的影响,聚集在底部层位(Wang et al., 2010),这使得底部层位的岩体富集硫化物,相对贫PGE,S同位素具有明显地壳混染特征(Wang et al., 2018)。之后后续的岩浆仍在源源不断的注入早先沉淀下来的硫化物层位中,并携带少量硫化物继续上侵到中部以及顶部层位,不断上涌的岩浆的紊流性也使得这些悬浮于中部及顶层的少量硫化物得以充分和岩浆混合(Wang et al., 2010),最终使得在中部和顶部形成富PGE的岩体。在这一过程中那些早期具有明显地壳混染特征的硫化物受到R值效应影响,矿石呈现出高PGE品位和幔源S-Os同位素的特征。

因此我们在利用S-Os同位素判别岩体地壳混染作用的时候需要特别注意,不能简单拿样品数据跟地壳地幔端元的S和Re-Os同位素范围对比得出其混染程度。特别是对于高R值的铂钯矿床或富含PGE的铜镍铂族元素矿床,R值效应可以使得样品往往呈现出地幔特征S-Os同位素范围,从而掩饰了其初始硫化物地壳混染的特征。因此对于高R值矿床,具有幔源δ34S和γOs的样品不能简单归结于没有或者少量地壳混染。

4 结论

(1) 金宝山铂钯矿床S同位素比值受到R值(岩浆/硫化物质量之比)影响,通过质量平衡计算定量建立R值、铂族元素含量和δ34S发现富PGE矿石具有高R值和幔源δ34S值,而低PGE矿石则具有低R值和壳源δ34S值。因此不同类型矿石(贫PGE或富PGE)中S同位素比值会呈现较大差异。

(2) 金宝山铂钯矿床相比富硫化物的力马河铜镍矿床和杨柳坪铜镍铂族元素矿床具有更接近幔源的γOs值,是开放岩浆系统中大量岩浆与硫化物反应(高R值)导致的结果。因此不同类型矿床(铂钯矿床或铜镍矿床)中Os同位素比值也会呈现较大差异。

(3) R值效应也是一些岩浆硫化物矿床中Nd-Os同位素结果发生偏差的原因之一,具有幔源δ34S和γOs的矿石样品不能简单排除没有或者仅有少量地壳混染,还应综合Sr-Nd同位素以及微量元素地壳化学特征综合判断是否发生了明显的地壳混染作用。

致谢 研究工作得到了中国地质大学(北京)杨立强教授和劳伦森大学Lesher教授的指导与帮助;野外工作得到了云南云宝铂钯矿业有限公司工作人员的帮助和支持;S同位素测试分析和PGE测试分析得到国家地质实验测试中心相关工作人员的协助;在此一并致以诚挚的感谢!
参考文献
Barnes SJ and Lightfoot PC. 2005. Formation of magmatic nickel sulfide ore deposits and processes affecting their copper and platinum group element contents. Economic geology 100th Anniversary vVolume, 34: 179-214.
Barnes SJ and Ripley EM. 2016. Highly siderophile and strongly chalcophile elements in magmatic ore deposits. Reviews in Mineralogy and Geochemistry, 81(1): 725-774. DOI:10.2138/rmg.2016.81.12
Barnes SJ, Cruden AR, Arndt N and Saumur BM. 2016a. The mineral system approach applied to magmatic Ni-Cu-PGE sulphide deposits. Ore Geology Reviews, 76: 296-316. DOI:10.1016/j.oregeorev.2015.06.012
Barnes SJ, Pagé P, Prichard HM, Zientek ML and Fisher PC. 2016b. Chalcophile and platinum-group element distribution in the Ultramafic series of the Stillwater Complex, MT, USA:Implications for processes enriching chromite layers in Os, Ir, Ru, and Rh. Mineralium Deposita, 51(1): 25-47. DOI:10.1007/s00126-015-0587-y
Barnes SJ, Holwell DA and Le Vaillant M. 2017a. Magmatic sulfide ore deposits. Elements, 13(2): 89-95. DOI:10.2113/gselements.13.2.89
Barnes SJ, Mungall JE, Le Vaillant M, Godel B, Lesher CM, Holwell D, Lightfoot PC, Krivolutskaya N and Wei B. 2017b. Sulfide-silicate textures in magmatic Ni-Cu-PGE sulfide ore deposits:Disseminated and net-textured ores. American Mineralogist, 102(3): 473-506. DOI:10.2138/am-2017-5754
Bleeker W. 1990. New structural-metamorphic constraints on Early Proterozoic oblique collision along the Thompson nickel belt, Manitoba, Canada. In: Lewry JF and Stauffer MR (eds. ). The Early Proterozoic Trans-Hudson Orogen of North America. Geological Association of Canada, Special Paper, 37: 57-73
Campbell IH and Naldrett AJ. 1979. The influence of silicate:sulfide ratios on the geochemistry of magmatic sulfides. Economic Geology, 74(6): 1503-1506. DOI:10.2113/gsecongeo.74.6.1503
Chung SL and Jahn BM. 1995. Plume-lithosphere interaction in generation of the Emeishan flood basalts at the Permian-Triassic boundary. Geology, 23(10): 889-892. DOI:10.1130/0091-7613(1995)023<0889:PLIIGO>2.3.CO;2
Deng J, Yang LQ, Gao BF, Sun ZS, Guo CY, Wang QF and Wang JP. 2009. Fluid evolution and metallogenic dynamics during tectonic regime transition:Example from the Jiapigou gold belt in Northeast China. Resource Geology, 59(2): 140-152. DOI:10.1111/rge.2009.59.issue-2
Deng J, Wang QF, Yang LQ, Wang YR, Gong QJ and Liu H. 2010a. Delineation and exploration of geochemical anomalies using fractal models in the Heqing area, Yunnan Province, China. Journal of Geochemical Exploration, 105(3): 95-105. DOI:10.1016/j.gexplo.2010.04.005
Deng J, Wang QF, Yang SJ, Liu XF, Zhang QZ, Yang LQ and Yang YH. 2010b. Genetic relationship between the Emeishan plume and the bauxite deposits in western Guangxi, China:Constraints from U-Pb and Lu-Hf isotopes of the detrital zircons in bauxite ores. Journal of Asian Earth Sciences, 37(5): 412-424.
Deng J, Ge LS and Yang LQ. 2013. Tectonic dynamic system and compound orogeny:Additionally discussing the temporal-spatial evolution of Sanjiang orogeny, Southwest China. Acta Petrologica Sinica, 29(4): 1099-1114.
Deng J, Wang QF, Li GJ and Santosh M. 2014a. Cenozoic tectono-magmatic and metallogenic processes in the Sanjiang region, southwestern China. Earth-Science Reviews, 138: 268-299. DOI:10.1016/j.earscirev.2014.05.015
Deng J, Wang QF, Li GJ, Li C and Wang CM. 2014b. Tethys tectonic evolution and its bearing on the distribution of important mineral deposits in the Sanjiang region, SW China. Gondwana Research, 26(2): 419-437. DOI:10.1016/j.gr.2013.08.002
Deng J, Wang CM, Li WC, Yang LQ and Wang QF. 2014. The situation and enlightenment of the research of the tectonic evolution and metallogenesis in the Sanjiang Tethys. Earth Science Frontiers, 2(1): 52-64.
Deng J, Wang CM, Bagas L, Carranza EJM and Lu YJ. 2015a. Cretaceous-Cenozoic tectonic history of the Jiaojia fault and gold mineralization in the Jiaodong Peninsula, China:Constraints from zircon U-Pb, illite K-Ar, and apatite fission track thermochronometry. Mineralium Deposita, 50(8): 987-1006. DOI:10.1007/s00126-015-0584-1
Deng J, Liu XF, Wang QF and Pan RG. 2015b. Origin of the Jiaodong-type Xinli gold deposit, Jiaodong Peninsula, China:Constraints from fluid inclusion and C-D-O-S-Sr isotope compositions. Ore Geology Reviews, 65: 674-686. DOI:10.1016/j.oregeorev.2014.04.018
Deng J, Wang QF, Li GJ, Hou Z, Jiang CZ and Danyushevsky L. 2015c. Geology and genesis of the giant Beiya porphyry-skarn gold deposit, northwestern Yangtze Block, China. Ore Geology Reviews, 70: 457-85. DOI:10.1016/j.oregeorev.2015.02.015
Deng J, Wang QF, Li GJ and Zhao Y. 2015d. Structural control and genesis of the Oligocene Zhenyuan orogenic gold deposit, SW China. Ore Geology Reviews, 65: 42-54. DOI:10.1016/j.oregeorev.2014.08.002
Deng J and Wang QF. 2016. Gold mineralization in China:Metallogenic provinces, deposit types and tectonic framework. Gondwana Research, 36: 219-274. DOI:10.1016/j.gr.2015.10.003
Deng J, Wang QF and Li GJ. 2016. Superimposed orogeny and composite metallogenic system:Case study from the Sanjiang Tethyan belt, SW China. Acta Petrologica Sinica, 32(8): 2225-2247.
Deng J, Liu XF, Wang QF, Yildirim Dilek and Liang YY. 2017a. Isotopic characterization and petrogenetic modeling of Early Cretaceous mafic diking-lithospheric extension in the North China craton, eastern Asia. The Geological Society of America Bulletin, 129: 1379-1407. DOI:10.1130/B31609.1
Deng J, Wang CM, Zi JW, Xia R and Li Q. 2017b. Constraining subduction-collision processes of the Paleo-Tethys along the Changning-Menglian Suture: New zircon U-Pb ages and Sr-Nd-Pb-Hf-O isotopes of the Lincang Batholith. Gondwana Research, doi.org/10.1016/j.gr.2017.10.008
Deng J, Wang QF and Li GJ. 2017c. Tectonic evolution, superimposed orogeny, and composite metallogenic system in China. Gondwana Research, 50: 216-266. DOI:10.1016/j.gr.2017.02.005
Deng J, Yang LQ, Li RH, Groves DI, Santosh M, Wang ZL, Sai SX and Wang SR. 2018. Regional structural control on the distribution of world-class gold deposits: An overview from the Giant Jiaodong Gold Province, China. Geological Journal (in press)
Donnelly TH, Lambert IB, Oehler DZ, Hallberg JA, Hudson DR, Smith JW, Bavinton OA and Golding L. 1978. A reconnaissance study of stable isotopes ratios in Archaean rocks from the Yilgarn Block, Western Australia. Geol. Soc. Australia J., 24: 409-420.
Esser BK and Turekian KK. 1993. The osmium isotopic composition of the continental crust. Geochimica et Cosmochimica Acta, 57(13): 3093-3104. DOI:10.1016/0016-7037(93)90296-9
Faure G. 1986. Principles of Isotope Geology: New York: Wiley & Sons, 1-589
Franchuk A, Lightfoot PC and Kontak DJ. 2016. High tenor Ni-PGE sulfide mineralization in the South Manasan ultramafic intrusion, Paleoproterozoic Thompson Nickel Belt, Manitoba, Canada. Ore Geology Reviews, 72: 434-458. DOI:10.1016/j.oregeorev.2015.07.021
Grinenko LI. 1985. Sources of sulfur of the nickeliferous and barren gabbro-dolerite intrusions of the Northwest Siberian platform. International Geology Review, 27(6): 695-708. DOI:10.1080/00206818509466457
Han MM. Mineralization study of Yangliuping Cu-Ni sulphide deposit in Sichuan Province. 2017. Master Degree Thesis. Beijing: China University of Geosciences, 1-62 (in Chinese with English summary)
He WY, Mo XX, He ZH, White NC, Chen JB, Yang KH, Wang R, Yu XH, Dong GC and Huang XF. 2015. The geology and mineralogy of the Beiya skarn gold deposit in Yunnan, Southwest China. Economic Geology, 110: 1625-1641. DOI:10.2113/econgeo.110.6.1625
He WY, Yang LQ, Brugger J, McCuaig TC, Lu YJ, Bao XS, Gao XQ, Lu YG and Xing YL. 2016. Hydrothermal evolution and ore genesis of the Beiya giant Au polymetallic deposit, western Yunnan, China:Evidence from fluid inclusions and H-O-S-Pb isotopes. Ore Geology Reviews, 90: 847-862.
Lambert DD, Foster JG, Frick LR, Ripley EM and Zientek ML. 1998a. Geodynamics of magmatic Cu-Ni-PGE sulfide deposits; new insights from the Re-Os isotope system. Economic Geology, 93(2): 121-136. DOI:10.2113/gsecongeo.93.2.121
Lambert DD, Foster JG, Frick LR, Hoatson DM and Purvis AC. 1998b. Application of the Re-Os isotopic system to the study of Precambrian magmatic sulfide deposits of Western Australia. Australian Journal of Earth Sciences, 45(2): 265-84. DOI:10.1080/08120099808728386
Lambert DD, Foster JG, Frick LR, Li C and Naldrett AJ. 1999. Re-Os isotopic systematics of the Voisey's Bay Ni-Cu-Co magmatic ore system, Labrador, Canada. Lithos, 47(1): 69-88.
Lambert DD, Frick LR, Foster JG, Li C and Naldrett AJ. 2000. Re-Os isotope systematics of the Voisey's Bay Ni-Cu-Co magmatic sulfide system, Labrador, Canada:Ⅱ. Implications for parental magma chemistry, ore genesis, and metal redistribution. Economic Geology, 95(4): 867-888.
Lesher CM and Campbell IH. 1993. Geochemical and fluid dynamic modeling of compositional variations in Archean komatiite-hosted nickel sulfide ores in Western Australia. Economic Geology, 88(4): 804-816. DOI:10.2113/gsecongeo.88.4.804
Lesher CM and Stone WE. 1996. Exploration geochemistry of komatiites. Geological Association of Canada, Short Course Notes, 12: 153-204.
Lesher CM, Barnes SJ, Gillies SL and Ripley EM. 1999. Ni-Cu-(PGE) sulphides in the Raglan Block. In: Lesher CM (ed. ). Komatiitic Peridotite-Hosted Fe-Ni-Cu-(PGE) Sulphide Deposits in the Raglan Area, Cape Smith Belt, New Québec. Guidebook Series 2, Mineral Exploration Research Centre, Laurentian University, Sudbury: 177-184
Lesher CM and Burnham OM. 2001. Multicomponent elemental and isotopic mixing in Ni-Cu-(PGE) ores at Kambalda, Western Australia. The Canadian Mineralogist, 39(2): 421-446. DOI:10.2113/gscanmin.39.2.421
Lesher CM, Burnham OM, Keays RR, Barnes SJ and Hulbert L. 2001. Trace-element geochemistry and petrogenesis of barren and ore-associated komatiites. The Canadian Mineralogist, 39(2): 673-696. DOI:10.2113/gscanmin.39.2.673
Lesher CM. 2017. Roles of xenomelts, xenoliths, xenocrysts, xenovolatiles, residues, and skarns in the genesis, transport, and localization of magmatic Fe-Ni-Cu-PGE sulfides and chromite. Ore Geology Reviews, 90: 465-484. DOI:10.1016/j.oregeorev.2017.08.008
Li C, Maier WD and de Waal SA. 2001. Magmatic Ni-Cu versus PGE deposits:Contrasting genetic controls and exploration implications. South African Journal of Geology, 104(4): 309-318. DOI:10.2113/gssajg.104.4.309
Li C and Ripley EM. 2005. Empirical equations to predict the sulfur content of mafic magmas at sulfide saturation and applications to magmatic sulfide deposits. Mineralium Deposita, 40(2): 218-230. DOI:10.1007/s00126-005-0478-8
Li C, Tao Y, Qi L and Ripley EM. 2012. Controls on PGE fractionation in the Emeishan picrites and basalts:Constraints from integrated lithophile-siderophile elements and Sr-Nd isotopes. Geochimica et Cosmochimica Acta, 90: 12-32. DOI:10.1016/j.gca.2012.04.046
Li HB. 2012. Mantle plume geodynamics significances of the Emeishan Large Igneous Province: Evidence from mafic dykes, geochemistry and stratigraphic records. Ph. D. Dissertation. Beijing: China University of Geosciences, 1-176 (in Chinese with English summary)
Lightfoot PC and Evans-Lamswood D. 2015. Structural controls on the primary distribution of mafic-ultramafic intrusions containing Ni-Cu-Co-(PGE) sulfide mineralization in the roots of large igneous provinces. Ore Geology Reviews, 64: 354-386. DOI:10.1016/j.oregeorev.2014.07.010
Lu YG, Zhao K, Xiong YQ, Li P, Du DY and Yuan MW. 2014. Elements geochemistry of Jinbaoshan Pt-Pd deposit, western Yunnan, China. Acta Petrologica Sinica, 30(9): 2681-2694.
Ma YS, Tao Y, Zhu FL and Wang XZ. 2009. The Sulfur isotopic characteristics and geological significance of Jinbaoshan Pt-Pd deposit and Limahe nickel deposit. Bulletin of Mineralogy, Petrology and Geochemistry, 28(2): 123-127.
Maier WD and Groves DI. 2011. Temporal and spatial controls on the formation of magmatic PGE and Ni-Cu deposits. Mineralium Deposita, 46(8): 841-857. DOI:10.1007/s00126-011-0339-6
Maier WD, Määttää S, Yang S, Oberthür T, Lahaye Y, Huhma H and Barnes SJ. 2015. Composition of the ultramafic-mafic contact interval of the Great Dyke of Zimbabwe at Ngezi mine:Comparisons to the Bushveld Complex and implications for the origin of the PGE reefs. Lithos, 238: 207-222. DOI:10.1016/j.lithos.2015.09.007
Morgan JW, Wandless GA, Petrie RK and Irving AJ. 1981. Composition of the Earth's upper mantle:I. Siderophile trace elements in ultramafic nodules. Tectonophysics, 75(1): 47-67.
Mudd GM and Jowitt SM. 2014. A detailed assessment of global nickel resource trends and endowments. Economic Geology, 109(7): 1813-1841. DOI:10.2113/econgeo.109.7.1813
Mungall JE and Brenan JM. 2014. Partitioning of platinum-group elements and Au between sulfide liquid and basalt and the origins of mantle-crust fractionation of the chalcophile elements. Geochimica et Cosmochimica Acta, 125: 265-289. DOI:10.1016/j.gca.2013.10.002
Naldrett AJ. 1966. The role of sulphurization in the genesis of iron-nickel sulphide deposits of the Porcupine District, Ontario. Can. Inst. Mining Metal. Trans., 69: 147-155.
Naldrett AJ. 1981. Nickel sulfide deposits:Classification, composition, and genesis. Economic Geology, 75: 628-685.
Naldrett AJ. 1999. World-class Ni-Cu-PGE deposits:Key factors in their genesis. Mineralium deposita, 34(3): 227-240. DOI:10.1007/s001260050200
Naldrett AJ. 2004. Magmatic Sulfide Deposits: Geology, Geochemistry and Exploration. Berlin: Springer
Naldrett AJ. 2005. A history of our understanding of magmatic Ni-Cu sulfide deposits. The Canadian Mineralogist, 43(6): 2069-2098. DOI:10.2113/gscanmin.43.6.2069
Naldrett AJ. 2010. Secular variation of magmatic sulfide deposits and their source magmas. Economic Geology, 105(3): 669-688. DOI:10.2113/gsecongeo.105.3.669
Peng B, Sun FY, Li BL, Wang G, Li SJ, Zhou TF, Li L and Zhi YB. 2016. The geochemistry and geochronology of the Xiarihamu Ⅱ mafic-ultramafic complex, Eastern Kunlun, Qinghai Province, China:Implications for the genesis of magmatic Ni-Cu sulfide deposits. Ore Geology Reviews, 73: 13-28. DOI:10.1016/j.oregeorev.2015.10.014
Ripley EM, Park YR, Li C and Naldrett AJ. 1999. Sulfur and oxygen isotopic evidence of country rock contamination in the Voisey's Bay Ni-Cu-Co deposit, Labrador, Canada. Lithos, 47(1): 53-68.
Ripley EM and Li C. 2013. Sulfide saturation in mafic magmas:Is external sulfur required for magmatic Ni-Cu-(PGE) ore genesis?. Economic Geology, 108(1): 45-58. DOI:10.2113/econgeo.108.1.45
Ripley EM and Li C. 2017. A review of the application of multiple S isotopes to magmatic Ni-Cu-PGE deposits and the significance of spatially variable Δ33S values. Economic Geology, 112(4): 983-991. DOI:10.2113/econgeo.112.4.983
Song XY, Zhou MF, Tao Y and Xiao JF. 2008. Controls on the metal compositions of magmatic sulfide deposits in the Emeishan large igneous province, SW China. Chemical Geology, 253(1): 38-49.
Tao Y, Li C, Hu RZ, Ripley EM, Du AD and Zhong H. 2007. Petrogenesis of the Pt-Pd mineralized Jinbaoshan ultramafic intrusion in the Permian Emeishan large igneous province, SW China. Contributions to Mineralogy and Petrology, 153(3): 321-337. DOI:10.1007/s00410-006-0149-5
Tao Y, Li C, Song XY and Ripley EM. 2008. Mineralogical, petrological, and geochemical studies of the Limahe mafic-ultramatic intrusion and associated Ni-Cu sulfide ores, SW China. Mineralium Deposita, 43(8): 849-872. DOI:10.1007/s00126-008-0207-1
Tao Y, Ma YS, Miao LC and Zhu FL. 2009. SHRIMP U-Pb zircon age of the Jinbaoshan ultramafic intrusion, Yunnan Province, SW China. Chinese Science Bulletin, 54(1): 168-172. DOI:10.1007/s11434-008-0488-x
Tao Y, Li C, Hu RZ, Qi L, Qu WJ and Du AD. 2010. Re-Os isotopic constraints on the genesis of the Limahe Ni-Cu deposit in the Emeishan large igneous province, SW China. Lithos, 119(1-2): 137-46. DOI:10.1016/j.lithos.2010.02.006
Tao Y, Hu RZ, Qi L, Qu WJ, Chu ZY and Gou TZ. 2010. Sr-Nd-Os isotopic constraints on magma origin and evolution of the Jinbaoshan Pt-Pd deposit, Yunnan. J. Mineral. Petrol., 30(2): 60-67.
Wang CY, Zhou MF and Zhao D. 2005. Mineral chemistry of chromite from the Permian Jinbaoshan Pt-Pd-sulphide-bearing ultramafic intrusion in SW China with petrogenetic implications. Lithos, 83(1): 47-66.
Wang CY and Zhou MF. 2006. Genesis of the Permian Baimazhai magmatic Ni-Cu-(PGE) sulfide deposit, Yunnan, SW China. Mineralium Deposita, 41(8): 771-783. DOI:10.1007/s00126-006-0094-2
Wang CY, Zhou MF and Qi L. 2007. Permian flood basalts and mafic intrusions in the Jinping (SW China)-Song Da (northern Vietnam) district:Mantle sources, crustal contamination and sulfide segregation. Chemical Geology, 243(3): 317-343.
Wang CY, Prichard HM, Zhou MF and Fisher PC. 2008. Platinum-group minerals from the Jinbaoshan Pd-Pt deposit, SW China:Evidence for magmatic origin and hydrothermal alteration. Mineralium Deposita, 43: 791-803. DOI:10.1007/s00126-008-0196-0
Wang CY, Zhou MF and Qi L. 2010. Origin of extremely PGE-rich mafic magma system:An example from the Jinbaoshan ultramafic sill, Emeishan large igneous province, SW China. Lithos, 119(1): 147-161.
Wang CY, Wei B, Zhou MF, Minh DH and Qi L. 2018. A synthesis of magmatic Ni-Cu-(PGE) sulfide deposits in the 260Ma Emeishan large igneous province, SW China and northern Vietnam. Journal of Asian Earth Sciences, 154: 162-186. DOI:10.1016/j.jseaes.2017.12.024
Wang MX, Wang CY and Sun YL. 2013. Mantle source, magma differentiation and sulfide saturation of the 637Ma Zhouan mafic-ultramafic intrusion in the northern margin of the Yangtze Block, Central China. Precambrian Research, 228: 206-222. DOI:10.1016/j.precamres.2013.01.015
Wang QF, Deng J, Li C, Li GJ, Yu L and Qiao L. 2014. The boundary between the Simao and Yangtze blocks and their locations in Gondwana and Rodinia:Constraints from detrital and inherted zircons. Gondwana Research, 26(2): 438-448. DOI:10.1016/j.gr.2013.10.002
Wang SW, Sun XM, Liao ZW, Zhou BG, Luo MJ, Guo Y, Jiang XF, Zhu HP, Ma D and Shen ZW. 2012. Platinum group elements geochemistry of Jinbaoshan Pt-Pd deposit in Yunnan Province and its exploration implications. Mineral Deposits, 31(6): 1259-1276.
Wang ZL, Yang LQ, Guo LN, Marsh E, Wang JP, Liu Y, Zhang C, Li RH, Zhang L, Zheng XL and Zhao H. 2015. Fluid immiscibility and gold deposition in the Xincheng deposit, Jiaodong Peninsula, China:A fluid inclusion study. Ore Geology Reviews, 65: 701-717. DOI:10.1016/j.oregeorev.2014.06.006
Wei B, Wang CY, Li C and Sun YL. 2013. Origin of PGE-depleted Ni-Cu sulfide mineralization in the Triassic Hongqiling No.7 orthopyroxenite intrusion, Central Asian orogenic belt, northeastern China. Economic Geology, 108(8): 1813-1831. DOI:10.2113/econgeo.108.8.1813
Xiao L, Xu YG, Mei HJ, Zheng YF, He B and Pirajno F. 2004. Distinct mantle sources of low-Ti and high-Ti basalts from the western Emeishan large igneous province, SW China:Implications for plume-lithosphere interaction. Earth and Planetary Science Letters, 228(3): 525-546.
Xiong YQ, Yang LQ, Shao YJ, Zhao K, Li P, Lu YG and Du DY. 2015. Metallogenic process in Jinchang gold-nickel deposit, Mojiang County, SW Yunnan, China:Constraints from occurrence of gold and nickel. Acta Petrologica Sinica, 31(11): 3309-3330.
Xu YG, Chung SL, Jahn BM and Wu GY. 2001. Petrologic and geochemical constraints on the petrogenesis of Permian-Triassic Emeishan flood basalts in southwestern China. Lithos, 58(3): 145-168.
Yang LQ, Liu JT, Zhang C, Wang QF, Ge LS, Wang ZL, Zhang J and Gong QJ. 2010. Superimposed orogenesis and metallogenesis:An example from the orogenic gold deposits in Ailaoshan gold belt, Southwest China. Acta Petrologica Sinica, 26(6): 1723-1739.
Yang LQ, Deng J, Zhao K, Liu JT, Ge LS, Zhou DQ and Li SH and Cao BB. 2011a. Geological characteristics and genetic type of Daping gold deposit in the Ailaoshan orogenic belt, SW China. Acta Petrologica Sinica, 27(12): 3800-3810.
Yang LQ, Deng J, Zhao K and Liu JT. 2011b. Tectono-thermochronology and gold mineralization events of orogenic gold deposits in Ailaoshan orogenic belt, Southwest China:Geochronological constraints. Acta Petrologica Sinica, 27(9): 2519-2532.
Yang LQ, Deng J, Goldfarb RJ, Zhang J, Gao BF and Wang ZL. 2014. 40Ar/39Ar geochronological constraints on the formation of the Dayingezhuang gold deposit:New implications for timing and duration of hydrothermal activity in the Jiaodong gold province, China. Gonwana Research, 25: 1469-1483. DOI:10.1016/j.gr.2013.07.001
Yang LQ, Deng J, Wang ZL, Zhang L, Guo LN, Song MC and Zheng XL. 2014. Mesozoic gold metallogenic system of the Jiaodong gold province, eastern China. Acta Petrologica Sinica, 30(9): 2447-2467.
Yang LQ, Deng J, Dilek Y, Qiu KF, Ji XZ, Li N, Taylor RD and Yu JY. 2015. Structure, geochronology, and petrogenesis of the Late Triassic Puziba granitoid dikes in the Mianlue Suture Zone, Qinling Orogen, China. The Geological Society of America Bulletin, 127: 1831-1854. DOI:10.1130/B31249.1
Yang LQ, Gao X and He WY. 2015. Late Cretaceous porphyry metallogenic system of the Yidun arc, SW China. Acta Petrologica Sinica, 31(11): 3155-3170.
Yang LQ, Deng J, Guo LN, Wang ZL, Li XZ and Li JL. 2016a. Origin and evolution of ore fluid, and gold deposition processes at the giant Taishang gold deposit, Jiaodong Peninsula, eastern China. Ore Geology Reviews, 72: 585-602. DOI:10.1016/j.oregeorev.2015.08.021
Yang LQ, Deng J, Guo RP, Guo LN, Wang ZL, Chen BH and Wang XD. 2016b. World-class Xincheng gold deposit:An example from the giant Jiaodong Gold Province. Geoscience Frontiers, 7: 419-430. DOI:10.1016/j.gsf.2015.08.006
Yang LQ, Deng J, Wang ZL, Guo LN, Li RH, Groves DI, Danyushevskiy L, Zhang C, Zheng XL and Zhao H. 2016c. Relationships between gold and pyrite at the Xincheng gold deposit, Jiaodong Peninsula, China:Implications for gold source and deposition in a brittle epizonal environment. Economic Geology, 111: 105-126. DOI:10.2113/econgeo.111.1.105
Yang LQ, Deng J, Wang ZL, Zhang L, Goldfarb RJ, Yuan WM, Weinberg RF and Zhang RZ. 2016d. Thermochronologic constraints on evolution of the Linglong Metamorphic Core Complex and implications for gold mineralization:A case study from the Xiadian gold deposit, Jiaodong Peninsula, eastern China. Ore Geology Reviews, 72: 165-178. DOI:10.1016/j.oregeorev.2015.07.006
Yang LQ, Deng J, Dilek Y, Meng JY, Gao X, Santosh M, Wang D and Yan H. 2016e. Melt source and evolution of I-type granitoids in the SE Tibetan Plateau:Late Cretaceous magmatism and mineralization driven by collision-induced transtensional tectonics. Lithos, 245: 258-273. DOI:10.1016/j.lithos.2015.10.005
Yang LQ, Dilek Y, Wang ZL, Weinberg RF and Liu Y. 2017a. Late Jurassic, high Ba-Sr Linglong granites in the Jiaodong Peninsula, East China: Lower crustal melting products in the Eastern North China Craton. Geological Magazine, doi. 10. 1017/S0016756816001230
Yang LQ, Guo LN, Wang ZL, Zhao RX, Song MC and Zheng XL. 2017b. Timing and mechanism of gold mineralization at the Wang'ershan gold deposit, Jiaodong Peninsula, eastern China. Ore Geology Reviews, 88: 491-510. DOI:10.1016/j.oregeorev.2016.06.027
Yang LQ, Gao X and Shu QH. 2017c. Multiple Mesozoic porphyry-skarn Cu (Mo-W) systems in Yidun Terrane, East Tethys:Constraints from zircon U-Pb and molybdenite Re-Os geochronology. Ore Geology Reviews, 90: 813-826. DOI:10.1016/j.oregeorev.2017.01.030
Yang LQ, Deng J, Gao X, He WY, Meng JY, Santosh M, Yu HJ, Yang Z and Wang D. 2017d. Timing of formation and origin of the Tongchanggou porphyry-skarn deposit:Implications for Late Cretaceous Mo-Cu metallogenesis in the southern Yidun Terrane, SE Tibetan Plateau. Ore Geology Reviews, 81: 1015-1032. DOI:10.1016/j.oregeorev.2016.03.015
Yang SH, Zhou MF, Lightfoot PC, Malpas J, Qu WJ, Zhou JB and Kong DY. 2012. Selective crustal contamination and decoupling of lithophile and chalcophile element isotopes in sulfide-bearing mafic intrusions:An example from the Jingbulake intrusion, Xinjiang, NW China. Chemical Geology, 302: 106-118.
Yang Y, Luo TY, Huang ZL, Yang ZS, Tian SH and Qian ZK. 2010. Sulfur and lead isotope compositions of the Narusongduo silver-lead deposit in Tibet:Implications for the sources of plutons and metals in the deposit. Acta Mineralogica Sinica, 30(3): 311-318.
Zhang XS. 2005. Mafic-ultramafic rocks, metallogenetic series and prospecting targeting in the Jinping-Song Da rift. Ph. D. Dissertation. Kunming: Kunming University of Science and Technology, 1-263 (in Chinese with English summary)
Zhang ZW, Tang QY, Li C, Wang YL and Ripley EM. 2017. Sr-Nd-Os-S isotope and PGE geochemistry of the Xiarihamu magmatic sulfide deposit in the Qinghai-Tibet Plateau, China. Mineralium Deposita, 52(1): 51-68. DOI:10.1007/s00126-016-0645-0
Zhou MF, Arndt NT, Malpas J, Wang CY and Kennedy AK. 2008. Two magma series and associated ore deposit types in the Permian Emeishan large igneous province, SW China. Lithos, 103(3): 352-368.
邓军, 葛良胜, 杨立强. 2013. 构造动力体制与复合造山作用:兼论三江复合造山带时空演化. 岩石学报, 29(4): 1099-1114.
邓军, 王长明, 李文昌, 杨立强, 王庆飞. 2014. 三江特提斯复合造山与成矿作用研究态势及启示. 地学前缘, 21(1): 52-64.
邓军, 王庆飞, 李龚健. 2016. 复合造山和复合成矿系统:三江特提斯例析. 岩石学报, 32(8): 2225-2247.
韩梅梅. 2017. 四川杨柳坪岩浆型铜镍硫化物矿床成矿作用研究. 硕士学位论文. 北京: 中国地质大学: 1-62 http://cdmd.cnki.com.cn/Article/CDMD-11415-1017126148.htm
李宏博. 2012. 峨眉山大火成岩省地幔柱动力学: 基性岩墙群、地球化学及沉积地层学证据. 博士学位论文. 北京: 中国地质大学, 1-176 http://cdmd.cnki.com.cn/Article/CDMD-11415-1012364506.htm
卢宜冠, 赵凯, 熊伊曲, 李坡, 杜达洋, 袁明伟. 2014. 滇西金宝山铂钯矿床元素地球化学. 岩石学报, 30(9): 2681-2694.
马言胜, 陶琰, 朱飞霖, 王兴阵. 2009. 金宝山铂-钯矿和力马河镍矿的硫同位素组成特征及地质意义. 矿物岩石地球化学通报, 28(2): 123-127.
陶琰, 胡瑞忠, 漆亮, 屈文俊, 储著银, 苟体忠. 2010. 云南金宝山铂钯矿Sr-Nd-Os同位素组成:岩浆成因及演化分析. 矿物岩石, 30(2): 60-67.
王生伟, 孙晓明, 廖震文, 周邦国, 罗茂金, 郭阳, 蒋小芳, 朱华平, 马东, 沈战武. 2012. 云南金宝山铂钯矿床铂族元素地球化学及找矿意义. 矿床地质, 31(6): 1259-1276.
熊伊曲, 杨立强, 邵拥军, 赵凯, 李坡, 卢宜冠, 杜达洋. 2015. 滇西南墨江金厂金镍矿床金、镍赋存状态及成矿过程探讨. 岩石学报, 31(11): 3309-3330.
杨立强, 刘江涛, 张闯, 王庆飞, 葛良胜, 王中亮, 张静, 龚庆杰. 2010. 哀牢山造山型金成矿系统:复合造山构造演化与成矿作用初探. 岩石学报, 26(6): 1723-1739.
杨立强, 邓军, 赵凯, 刘江涛, 葛良胜, 周道卿, 李士辉, 曹宝宝. 2011a. 滇西大坪金矿床地质特征及成因初探. 岩石学报, 27(12): 3800-3810.
杨立强, 邓军, 赵凯, 刘江涛. 2011b. 哀牢山造山带金矿成矿时序及其动力学背景探讨. 岩石学报, 27(9): 2519-2532.
杨立强, 邓军, 王中亮, 张良, 郭林楠, 宋明春, 郑小礼. 2014. 胶东中生代金成矿系统. 岩石学报, 30(9): 2447-2467.
杨立强, 高雪, 和文言. 2015. 义敦岛弧晚白垩世斑岩成矿系统. 岩石学报, 31(11): 3155-3170.
杨勇, 罗泰义, 黄智龙, 杨竹森, 田世洪, 钱宽志. 2010. 西藏纳如松多银铅矿S、Pb同位素组成:对成矿物质来源的指示. 矿物学报, 30(3): 311-318.
张学书. 2005. 金平-黑水河裂谷基性-超基性岩特征、成矿系列及成矿预测. 博士学位论文. 昆明: 昆明理工大学, 1-263 http://cdmd.cnki.com.cn/article/cdmd-10674-2007124994.htm