岩石学报  2018, Vol. 34 Issue (6): 1539-1556   PDF    
苏鲁超高压变质带胡家林超镁铁质岩成因及构造意义
谢志鹏1,2 , 王建2 , HATTORI Keiko3 , 薛传东1 , 钟军伟1 , 王泽利4     
1. 昆明理工大学国土资源工程学院, 昆明 650093;
2. 吉林大学地球科学学院, 长春 130061;
3. 渥太华大学地球科学系, 渥太华 K1N 6N5;
4. 山东科技大学地球科学与工程学院, 青岛 266590
摘要:胡家林超镁铁质杂岩体产于苏鲁超高压变质带中部,纯橄岩和(石榴)单斜辉石岩呈不连续透镜体产于蛇纹石化橄榄岩中。纯橄岩遭受了部分蛇纹石化(烧失量=6.6%~13.2%),全岩富集强相容元素(Ni、Cr、Co)和Ir族PGE(IPGE;Ir、Os、Ru)及高IPGE/PPGE值,亏损Al、Ti、V,具高Mg#橄榄石(Fo=91.7~92.4)和高Cr#(0.68~0.76)尖晶石。纯橄岩高耐熔地球化学及矿物化学特征和古老的大陆岩石圈地幔相一致,表明其原岩来源于弧前地幔,代表了华北克拉通古老的大陆岩石圈地幔残留。(石榴)单斜辉石岩全岩呈相对低含量的强相容元素(Cr、Ni、Co)和IPGE,高含量的Al、Ti、V和流体迁移元素(Sr、Pb和Ba),球粒陨石标准化REE配分图呈明显"上凸"型,具低Mg#橄榄石(Fo=76.6~76.8)和低Al2O3(< 2.76%)和高SiO2(54.56%~56.87%)的单斜辉石。全岩组成和矿物化学表明其原岩为俯冲带内超镁铁质火成堆晶岩,最初岩浆由地幔岩高程度部分熔融的熔体和俯冲带中富H2O流体和/或熔体构成。(石榴)单斜辉石岩原岩曾被地幔流带入扬子大陆俯冲板片和上覆地幔楔之间的俯冲通道,经历了超高压变质作用和生成大量石榴石。(石榴)单斜辉石岩在折返过程中,与大陆岩石圈地幔楔剥离的蛇纹石化橄榄岩及纯橄岩相结合,形成超镁铁质杂岩体,整体被低密度的俯冲板片(主要由花岗质片麻岩和变质沉积岩组成)裹挟,折返至地壳浅部。
关键词: 苏鲁超高压变质带     铂族元素(PGE)     纯橄岩     (石榴)单斜辉石岩     岩石成因    
The petrogenesis and tectonic implication of Hujialin ultramafic rocks in the Sulu ultrahigh-pressure metamorphic belt, eastern China
XIE ZhiPeng1,2, WANG Jian2, HATTORI Keiko3, XUE ChuanDong1, ZHONG JunWei1, WANG ZeLi4     
1. Faculty of Land Resources Engineering, Kunming University of Science and Technology, Kunming 650093, China;
2. College of Earth Sciences, Jilin University, Changchun 130061, China;
3. Department of Earth Sciences, University of Ottawa, Ottawa K1N 6N5, Canada;
4. College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao 266590, China
Abstract: The Hujialin ultramafic complex in the central region of Sulu ultrahigh-pressure (UHP) metamorphic belt mainly consists of discontinuous lenses of garnet-bearing clinopyroxenite and dunite surrounded by marginal serpentinized peridotites. Dunite samples, which are partially hydrated (LOI=6.6%~13.2%), contain high concentrations of compatible elements (Ni, Cr, Co) and IPGE with high ratios (up to 8.8) of IPGE/PPGE, low concentrations of Al, Ti, V in bulk rocks, olivine in dunite shows high Fo (91.7~92.4) and Cr-spinel displays high Cr# (0.68~0.76). The high refractory geochemical characteristics and mineral chemistries of dunite samples are similar to that of the ancient subcontinental lithospheric mantle, suggesting that dunites originated from forearc mantle, and represented the relic of the ancient subcontinental lithospheric mantle. Garnet-bearing clinopyroxenites show relatively low concentrations of compatible elements (Ni, Cr, Co) and IPGE, high concentrations of Al, Ti, V, and fluid-mobile elements (Sr, Pb and Ba) in buck rocks. They show convex chondrite-normalized REE patterns, low Fo (76.6~76.8) in olivine, low Al2O3 (< 2.76%) and high SiO2 (54.56%~56.87%) in clinopyroxene. The bulk rock compositions and mineral chemistry suggest garnet-bearing clinopyroxenite is initially cumulate of subduction-related ultramafic melt, and the parental magma was formed by the melt from high degree of partial melting of mantle rocks and H2O-rich fluids/melt from subduction zone. The protoliths of garnet-bearing clinopyroxenite was individually incorporated into the subduction channel between the Yangtze subducted plate and overlying North China Craton by a mantle flow and then underwent UHP metamorphism. Garnet-bearing clinopyroxenite probably physically mixed with serpentinized peridotite lenses off-scraped from the overlying subcontinental lithospheric mantle (SCLM) wedge in the exhumation process, and both of them were coerced by low-density subducted slab (granitic gneiss and metamorphosed sedimentary rocks) and exhumed to the surface together.
Key words: Sulu ultrahigh-pressure metamorphic belt     Platinum group elements     Dunite     Garnet-bearing clinopyroxenite     Petrogenesis    

苏鲁超高压变质带形成于早中生代扬子大陆与华北克拉通之间的深俯冲与碰撞过程,是典型构造岩浆混杂岩带(或拼合带)发展起来的陆-陆碰撞造山带(Yang et al., 2003; Li et al., 2008; Zheng, 2008)。变质带出露大量成群或成带展布的超镁铁质岩块和透镜体,岩性有石榴橄榄岩、石榴辉石岩和尖晶石橄榄岩(Zhang et al., 2000, 2009a)。超镁铁质岩的岩石成因、构造环境及地球动力学背景研究,近年来取得了丰硕成果(Zhang et al., 2000, 2005; Zheng et al., 2008; Ye et al., 2000, 2009),Zhang et al. (2000)将其成因划分为二类:(1)源于上地幔或大陆岩石圈地幔,侵入到俯冲板片内,并经历了深俯冲和超高压变质作用;(2)扬子大陆携带的超镁铁质岩,在遭受超高压变质作用前已侵入大陆壳的地幔橄榄岩或基性熔岩堆晶体。(1)类超镁铁质岩主要分布在苏鲁超高压变质带和大别饶八寨地区,绝大多数具有与华北克拉通大陆岩石圈地幔岩相似的岩石地球化学和矿物化学特征(Zhang et al., 2005, 2009a; Yang et al., 2009);(2)类超镁铁质岩主要分布在大别造山带,具有一定变化的矿物化学和地球化学特征,被认为是经历了交代作用和(或)地壳混染作用的地幔橄榄岩或超镁铁质火成堆晶岩(Zheng et al., 2008),如碧溪岭岩体和毛屋岩体。此外,苏鲁东海地区大陆超深钻主孔中也见有这种堆晶成因的超镁铁岩(Li et al., 2011)。变质带中超镁铁质岩绝大多数为石榴橄榄岩和石榴辉石岩,它们被认为在金刚石的稳定压力区间发生了重结晶作用(Okay, 1994; Zhang et al., 2000, 2009a)。变质带中出露的尖晶石相橄榄岩(纯橄岩、方辉橄榄岩和少量二辉橄榄岩),普遍代表了大陆岩石圈地幔残留,并可能具有不同的构造演化过程(Chen et al., 2009; Xie et al., 2013)。

胡家林超镁铁质杂岩体构造侵入花岗质片麻岩中,主体为蛇纹石化橄榄岩,包括不连续产出的纯橄岩和单斜辉石岩及(石榴)单斜辉石岩透镜体(图 1)。胡家林(石榴)单斜辉石岩的岩石成因和构造演化过程存在一定争议,可供参照的岩石成因有:(1)橄榄岩与玄武质熔体交代反应产物(Zhang and Liou, 2003);(2)源自上地幔的一种辉石岩(Chen and Xu, 2005)和(3)地幔来源的岛弧岩浆的堆晶岩(Yang, 2006)。绝大多数研究认同(石榴)单斜辉石岩的原岩曾俯冲到地幔深度并经历了超高压变质作用,但(石榴)单斜辉石岩透镜体如何与尖晶石相橄榄岩共同出现,以及它们如何抬升至地表等问题仍未解决。此外,胡家林纯橄岩的岩石成因及其构造演化过程研究仍然有待深入。

图 1 苏鲁超高压变质带中胡家林地区镁铁-超镁铁质岩分布图(a, 据Zhang and Liou, 2003修改)和采样位置图(b) Fig. 1 Map showing distribution of mafic-ultramafic rocks at Hujialin region of Sulu ultrahigh-high pressure belt (a, modified after Zhang and Liou, 2003) and sampling locations of Hujialin ultramafic complex (b)

本文选择苏鲁超高压变质带中胡家林地区的纯橄岩和(石榴)单斜辉石岩为研究对象,在岩石地球化学和矿物化学研究的基础上,探讨其岩石成因、构造演化过程和扬子大陆与上覆华北克拉通间俯冲通道的属性。

1 地质背景

大别-苏鲁造山带是华北克拉通与扬子大陆之间的一条陆-陆碰撞造山带,也是中国中东部一条巨型的超高压变质带(Yang et al., 2003; Zheng, 2008),苏鲁超高压变质带作为其东半部,北部以郯庐断裂和烟台-五莲断裂为界与华北克拉通相连,南部以嘉山-响水断裂为界与扬子大陆相通。变质带中高压-超高压变质岩主体为花岗质片麻岩和少量但广泛出露的榴辉岩、变质沉积岩(大理岩及变质石英岩)和石榴石相超镁铁质岩,其遭受的超高压变质作用与三叠纪(240~220Ma)扬子大陆边缘俯冲到华北克拉通东南缘下部的构造事件紧密相关(Liu et al., 2004; Zheng, 2008)。区域内花岗质片麻岩的全岩Hf、O同位素特征及锆石U-Pb模式年龄,证实其与扬子大陆新元古代中期的岩浆岩(780~740Ma)具有同源性(Zheng, 2008; Tang et al., 2008)。石榴橄榄岩和石榴辉石岩中超高压变质矿物和出溶矿物组合,表明其曾随大陆地壳俯冲被带到地幔深部,深度可达200km以上(Ye et al., 2000; Zhang et al., 2009b, 2010)。

胡家林位于苏鲁超高压变质带中部日照市附近,区内花岗质片麻岩中出露大量镁铁-超镁铁质岩透镜体和岩块,大者可延伸至几千米,小者仅几十米,其长轴方向基本与区域片麻理构造线方向一致(图 1a)。胡家林超镁铁质杂岩体主要由蛇纹岩和蛇纹石化橄榄岩组成,纯橄岩和(石榴)单斜辉石岩呈不连续透镜体产于其内,最大的(石榴)单斜辉石岩透镜体大小为100m×225m。纯橄岩样品采集于超镁铁质岩体北部,(石榴)单斜辉石岩采集于岩体北部和南部(图 1b)。

2 岩石学

胡家林超镁铁质岩体共采集样品14块。纯橄岩样品(HJL1、HJL2、HJL3和HJL4)全岩烧失量为6.6%~13.2%(表 1),岩相学显示其均遭受部分蛇纹石化。纯橄岩手标本呈绿黄色和等粒状结构(粒径0.5~1.0mm),矿物组合为橄榄石(半自形晶;粒径0.5~1.0mm;70%~80%),蛇纹石(≤20%)和铬尖晶石(他形-半自形晶;粒径0.2~1.0mm;≤5%)(图 2a)。橄榄石颗粒边部蚀变为蛇纹石和细粒磁铁矿,内部未见任何包裹体。铬尖晶石颗粒边部见次生磁铁矿环带(图 2b)。少量细粒硫化物(镍黄铁矿和磁黄铁矿)分散在蛇纹石中,暗示硫化物多为蛇纹石化过程的产物。样品HJL3(烧失量=13.2%)遭受了更高程度的蛇纹石化。

表 1 苏鲁超高压变质带中胡家林超镁铁质岩全岩化学组成(主量元素:wt%;稀土和微量元素:×10-6;铂族元素: ×10-9) Table 1 Bulk-rock chemical compositions of Hujialin ultramafic rocks from the Sulu UHP metamorphic belt (major elements: wt%; trace elements: ×10-6; platinum group elements: ×10-9)

图 2 胡家林超镁铁质岩的薄片显微照片和背散射电子图像 (a)纯橄岩中尖晶石、橄榄石及边部蛇纹石化显微照片(HJL1);(b)纯橄岩中铬尖晶石的背散射电子图像(HJL2);(c)纯橄岩中硫化物(镍黄铁矿和磁黄铁矿)的背散射电子图像(HJL4);(d)粗粒单斜辉石包裹橄榄石及边部为细粒单斜辉石与磁铁矿或钛铁矿的显微照片及(HJL6);(e)单斜辉石包裹橄榄石的背散射电子图像(HJL6);(f)石榴石包裹单斜辉石和磁铁矿显微照片(HJL8);(g)石榴石及边部角闪石与绿泥石显微照片(HJL7);(h)斑晶单斜辉石及边部细粒单斜辉石和磁铁矿(或钛铁矿)显微照片(HJLII-3);(i)斑晶单斜辉石出溶石榴石、磁铁矿和钛铁矿的背散射电子图像(HJLII-3). Ol-橄榄石;Serp-蛇纹石;Sp-尖晶石;Pn-镍黄铁矿;Po-磁黄铁矿;Cpx-为单斜辉石;Grt-石榴石;Ilm-钛铁矿;Mag-磁铁矿;Clc-绿泥石;Amp-角闪石 Fig. 2 Photomicrographs and back-scattered electron image of Hujialin ultramafic rocks

基于(石榴)单斜辉石岩矿物组合及百分含量,将其划分成3类。Ⅰ类样品(HJL6)无石榴石,矿物组合主要包括粗粒单斜辉石(半自形晶-他形;粒径0.5~1.0mm;~10%),细粒单斜辉石(他形;粒径≤0.3mm,~80%)、磁铁矿和钛铁矿(粒径0.1~0.3mm;< 10%)和少量蚀变矿物(绿泥石或角闪石)。粗粒单斜辉石包裹少量细粒橄榄石(图 2e),边部被细粒单斜辉石、磁铁矿和钛铁矿包围(图 2d)。Ⅱ类样品(HJL8、HJL9、HJL11、HJLⅡ-1和HJLⅡ-5)手标本可见淡红色石榴石颗粒,矿物组合有石榴石巨晶(最大粒径为2.0cm;20%~40%)、单斜辉石(他形;粒径0.2~1.0mm;50%~60%)、磁铁矿和钛铁矿(粒径0.2~0.8mm;< 15%)。石榴石巨晶包裹有细粒单斜辉石、磁铁矿和钛铁矿(图 2f)。Ⅲ类样品(HJL7、HJLⅡ-3、HJLⅡ-6和HJLⅡ-7)矿物组合为磁铁矿及钛铁矿(粒径0.1~0.3mm;30%~40%)、斑状单斜辉石(HJL7和HJLⅡ-3;粒径1.0~2.5mm)、细粒单斜辉石(粒径≤0.3mm;40%~50%)、石榴石残斑(粒径2~0.5mm;≤10%)和绿色富Al尖晶石(≤2%)(图 2g, h)。石榴石残斑边部由角闪石、绿泥石和绿帘石包围(图 2g),斑状单斜辉石包裹大量呈片状或条带状产出的出溶矿物,如石榴石、单斜辉石、磁铁矿和钛铁矿(图 2i)。

3 分析方法

全岩化学分析前,除去样品边缘风化部分。主量元素测试在加拿大渥太华大学的Philips PW2400型XRF上完成。通过测定标样MRG-1和Sy-2获得样品测试的准确度(accuracy)为:Al2O3,±0.039%;MgO,±0.28%;Cr,±3.4%;Ni,±4.0%,其它主、微量元素的测试精度和准确度分别优于1%和10%,详细的样品处理过程和仪器操作流程同Wang et al. (2008a, b)。微量元素分析在中国科学院地球化学研究所矿床地球化学国家重点实验室完成,首先称取50mg样品,用酸溶样制成溶液,然后在ICP-MS(仪器型号为PE ELAN DRC-e)上用内标法进行测定,分析精度优于10%。详细的样品消解处理过程和仪器操作流程同Qi et al. (2000)。全岩主量元素和微量元素的分析结果见表 1。铂族元素(PGE)通过使用190Os、191Ir、99Ru、194Pt和105Pd混合稀释剂的同位素稀释技术测定。样品的PGE和混合稀释剂被事先提取到一个Ni珠中,并在浓硝酸中溶解。具体的测试流程见文献(Hattori and Guillot, 2007; Yuan et al., 2007)。PGE的质量比值在渥太华大学的Agilent HP-4500 ICP-MS上测得。PGE的本底测试显示,1g本底助熔剂中PGE贡献分别为:Ir为0.003ng,Os为0.007ng,Pt为0.003ng,Pd为0.035ng和Ru为0.005ng。与样品中的PGE质量分数相比,本底的贡献可以忽略不计,因而无需做本底校正。测试精度通过测定标样TDB-1和JP1获得,标样测试结果与文献(Meisel and Moser, 2004)的测试结果相当。全岩铜(Cu)和硫(S)元素测试在渥太华大学的Varian Vista-Pro ICP-OES上测试获得,通过重复测试5个样品,Cu和S测试精度分别优于11%和7%。

矿物成分测定在卡尔顿大学CAMEBAX MBX型电子探针上完成。测试条件:20s/元素,15kV加速电压,20nA电子束电流。探针原始数据校正运用硅灰石(Si和Ca)、合成尖晶石(Al)、合成氧化铬(Cr)、镁橄榄石(Mg)、合成MnTiO3(Mn和Ti)、金属钒(V)、钠长石(Na)、铁橄榄石(Fe)和合成Fe2O3。尖晶石中的Fe3+质量分数由矿物化学计量法获得。单一样品中同一种矿物成分无明显变化,典型矿物成分列于表 2表 3

表 2 苏鲁超高压变质带中胡家林纯橄岩的代表矿物成分(wt%) Table 2 Compositions of selected minerals in Hujialin dunites from the Sulu UHP metamorphic belt (wt%)

表 3 苏鲁超高压变质带中(石榴)单斜辉石岩的代表矿物成分(wt%) Table 3 Compositions of selected minerals in Hujialin garnet-bearing clinopyroxenites from the Sulu UHP metamorphic belt (wt%)
4 分析结果 4.1 全岩化学成分

纯橄岩与原始地幔估算值(McDonough and Sun, 1995)相比,亏损Al2O3(0.28%~0.40%),CaO(0.43%~0.85%)和TiO2(0.02%~0.03%),富集强相容元素(Ni=1683×10-6~1931×10-6、Cr=2307×10-6~4443×10-6、Co≥107×10-6)、MgO(Mg#=100×Mg/(Mg+Fe)=89.3~92.1)和流体迁移元素(Pb和Sr)(表 1)。纯橄岩全岩具明显的轻稀土(LREE)富集、重稀土(HREE)亏损((La/Yb)N=12~54)及流体迁移元素(Pb和Sr)富集的特征(图 3a图 4a)。全岩高含量的Ir族PGE(IPGE;Os=1.1×10-9~7.8×10-9、Ir=1.7×10-9~3.6×10-9、Ru=2.1×10-9~11.2×10-9)及IPGE/PPGE值(最高达8.8)(表 1),显示其原始地幔标准化Ni-PGE-Cu分布模式与华北克拉通岩石圈地幔橄榄岩(Zheng et al., 2005)相似,而与莱芜超镁铁质火成堆晶成因的纯橄岩(Wang et al., 2012a)完全不同(图 5a)。

图 3 胡家林纯橄岩(a)和(石榴)单斜辉石岩(b)球粒陨石标准化稀土元素配分图(标准化值据McDonough and Sun, 1995) (a)喜马拉雅橄榄岩引自Deschamps et al .(2010)图 4a同;(b)多米尼加岛弧堆晶石榴橄榄岩引自Hattori et al. (2010b) Fig. 3 Chondrite-normalized REE patterns of Hujialin dunite (a) and garnet-bearing clinopyroxenite (b) (normalization values after McDonough and Sun, 1995)

图 4 胡家林石纯橄岩原始地幔标准化微量元素配分图(a, 标准化值据McDonough and Sun, 1995)和(石榴)单斜辉石岩MORB标准化微量元素配分图(b,c, 标准化值据Arevalo and McDonough, 2010) Fig. 4 Primitive mantle-normalized trace element spidergrams of Hujialin dunite (a, normalization values after McDonough and Sun, 1995) and MORB-normalized trace element spidergrams of garnet-bearing clinopyroxenite (b, c, normalization values after Arevalo and McDonough, 2010)

图 5 胡家林超镁铁质岩原始地幔标准化的Ni-PGE-Cu分布图(标准化值据McDonough and Sun, 1995) 莱芜纯橄岩引自Wang et al. (2012a);鹤壁和信阳地幔捕虏体引自Zheng et al. (2005);乌拉尔-阿拉斯加型辉石岩引起Garuti et al. (1997);Sanbagawa单斜辉石岩引自Hattori et al. (2010a) Fig. 5 The primitive mantle-normalized Ni-PGE-Cu distribution patterns for Hujialin ultramafic rocks (normalization values after McDonough and Sun, 1995)

(石榴)单斜辉石岩全岩具高含量的CaO(15.0%~20.3%)和Al2O3(3.13%~13.32%),低含量的强相容元素(Cr=52×10-6~1673×10-6、Ni=98×10-6~514×10-6和Co=41×10-6~92×10-6)和Na2O(≤1.28%)。MgO(8.8%~20.8%)含量与Fe2O3T、Al2O3和TiO2呈负相关(图 6),全岩Mg#值与Zr、V呈负相关,与Cr、Ni呈正相关(图 7)。相比大洋中脊玄武岩(MORB;Arevalo and McDonough, 2010),样品富集流体迁移元素(Sr、Pb和Ba),轻度亏损LREE,强烈亏损HREE((La/Yb)N=1.6~13.2)和高场强元素(Nb、Zr、Y)(图 4b, c)。样品全岩∑REE为球粒陨石估算值(McDonough and Sun, 1995)的18~63倍(表 1),球粒陨石标准化REE配分图呈明显的“上凸”型(图 3b),Ⅰ类和Ⅱ类单斜辉石岩全岩具轻微的Eu正异常(Eu/Eu*=1.08~1.32)。

图 6 胡家林超镁铁质岩全岩主要氧化物含量-MgO对比图解 PM为原始地幔值(据McDonough and Sun, 1995);MORB为洋中脊玄武岩值(据Arevalo and McDonough, 2010);CCSD主孔石榴辉石岩引自Zeng et al. (2009);俯冲带地区蛇绿岩带中辉石岩引自Melcher et al. (2002)Parlak et al. (2002) Fig. 6 The diagrams of major element oxides vs. MgO for Hujialin ultramafic rocks

图 7 胡家林超镁铁质岩全岩微量元素-Mg#对比图解 PM为原始地幔值(据McDonough and Sun, 1995);MORB为洋中脊玄武岩值(据Arevalo and McDonough, 2010);俯冲带地区蛇绿岩带中辉石岩引自Melcher et al. (2002)Parlak et al. (2002);图例同图 6 Fig. 7 The diagrams of trace elements vs. Mg# for Hujialin ultramafic rocks

(石榴)单斜辉石岩呈低含量的IPGE(Os=0.1×10-9~1.1×10-9、Ir=0.1×10-9~2.3×10-9、Ru=0.1×10-9~1.4×10-9)和分异的IPGE/PPGE值(0.03~3.37)(表 1)。原始地幔标准化Ni-PGE-Cu分布模式与Sanbagawa变质带中堆晶成因的单斜辉石岩(Hattori et al., 2010a)和乌拉尔-阿拉斯加型辉石岩(Garuti et al., 1997)类似(图 5b, c)。样品与原始地幔估算值(S=250×10-6)相比,明显亏损S元素(8.8×10-6~55.3×10-6),表明其原岩为S不饱和。Ⅰ类单斜辉石岩相对富集Mg、Cr、Ni和亏损Al、Ti、V。Ⅲ类石榴单斜辉石岩相比Ⅱ类单斜辉石岩,具高含量的Fe、Ti、Co,低含量的Si、Ca和Mg(表 1图 6),这与其高比重的磁铁矿、钛铁矿和低比重的单斜辉石相一致。

4.2 矿物化学

橄榄石  纯橄岩中橄榄石的Fo(Fo=100×Mg/(Mg+Fe))为91.7~92.4,NiO为0.36%~0.41%,CaO≤0.02%(表 2)。橄榄石成分与华北克拉通古老的大陆岩石圈地幔中的橄榄石成分(Zheng et al., 2001, 2006; Ying et al., 2006; Xu et al., 2010)相当,明显不同于新生代大陆岩石圈地幔中的橄榄石成分(Zheng et al., 2006; Ying et al., 2006; Wang et al., 2012b)(图 8a, b)。单斜辉石岩(样品HJL6)中橄榄石呈低的Fo值(76.6~76.8)和NiO(0.25%~0.26%),橄榄石成分位于超基性熔岩结晶分异的演化趋势线上(图 8a),暗示其为火成岩结晶产物。

图 8 胡家林超镁铁质岩中橄榄石和尖晶石成分对比图 古老的大陆岩石圈地幔引自Zheng et al. (2001, 2006),Ying et al. (2006)Xu et al. (2010);新生代大陆岩石圈地幔引自Zheng et al. (2001, 2006)Ying et al. (2006)Wang et al. (2012a);深海橄榄岩引自Dick and Bullen (1984) (a, c, d)和Arai (1994) (b);马里亚纳弧前橄榄岩引自Ishii et al. (1992);喜马拉雅弧前蛇纹岩引自Hattori and Guillot (2007);(b)中N为测试矿物个数 Fig. 8 The comparison diagram of the compositions of olivine and spinel in Hujialin ultramafic rocks

单斜辉石  (石榴)单斜辉石岩中单斜辉石均为透辉石,呈高的MgO(15.12%~17.57%)和SiO2(54.56%~56.87%),低的TiO2(0.02%~0.29%)和Al2O3(≤2.76%)(表 3)。透辉石因偏低的Al2O3,与榴辉岩中变质单斜辉石成分明显不同。透辉石四面体间隙位(tetrahedral site)中Al含量低于4%,结合低的TiO2,明显不同于MORB中的单斜辉石成分,而与乌拉尔-阿拉斯加型辉石岩(Helmy and El Mahallawi, 2003; Pettigrew and Hattori, 2006)中辉石成分接近(图 9a)。透辉石可能为原生普通辉石出溶石榴石、磁铁矿和钛铁矿后的残留,因而具偏低的Al2O3和TiO2含量。基于矿物比重和矿物成分,Yang (2006)曾估算了原生普通辉石的化学成分,其与岛弧堆晶岩中单斜辉石成分相当(图 9)。

图 9 胡家林(石榴)单斜辉石岩中单斜辉石成分对比图(a, 据Loucks 1990; b, 据Le Bas, 1962) 乌拉尔-阿拉斯加型超镁铁质侵入岩引自Helmy and El Mahallawi (2003)Pettigrew and Hattori (2006) Fig. 9 The comparison diagram of the compositions of clinopyroxene in Hujialin garnet-bearing clinopyroxenites (a, after Loucks 1990; b, after Le Bas, 1962)

尖晶石  纯橄岩单一样品中,铬尖晶石的核部成分无明显变化(表 2),呈极低的YFe3+(YFe3+=Fe3+/(Fe3++Al3++Cr3+)=0.05~0.12)和TiO2(≤0.36%),表明其核部具原生铬尖晶石成分。尖晶石是反映地幔部分熔融程度的敏感矿物,反映在尖晶石的Cr#(=Cr/(Cr+Al))值上。纯橄岩中铬尖晶石核部具高Cr#(0.68~0.76)和低XMg#(=Mg/(Mg+Fe2+)=0.33~0.40)(表 2),与马里亚纳弧前橄榄岩(Ishii et al., 1992)和喜马拉雅弧前橄榄岩(Hattori and Guillot, 2007)中尖晶石成分相似,明显不同于深海橄榄岩中尖晶石成分(Dick and Bullen, 1984)(图 8c, d)。铬尖晶石的高Cr#反映了纯橄岩原岩的高耐熔性。(石榴)单斜辉石岩中铬磁铁矿成分具较大变化(表 3),呈偏高的YFe3+(≥0.74)、Cr2O3(12.2%~13.4%)和分异的TiO2

石榴石  Ⅱ类石榴单斜辉石岩和Ⅲ类单斜辉石岩中石榴石成分明显不同(表 3),Ⅱ类石榴单斜辉石岩中石榴石巨晶,组分为Prp27-36Alm20-23Gro40-53Spe0-1(Prp-镁铝榴石;Alm-铁铝榴石;Gro-钙铝榴石;Spe-锰铝榴石;Andra-钙铁榴石)。Ⅲ类石榴单斜辉石岩中石榴石残留和出溶石榴石,呈高的钙铝榴石组分,为Prp17-22Alm19-21Gro55-60Spe1

5 讨论 5.1 胡家林镁铁-超镁铁质岩的原岩与成因 5.1.1 纯橄岩

全球典型造山带中纯橄岩成因主要有3种:(1)超镁铁质火成堆晶岩(Kelemen et al., 1995);(2)橄榄岩-熔体反应的产物(Kelemen, 1990)和(3)高程度部分熔融后地幔残留(Hattori et al., 2010a)。华北克拉通东部晚中生代闪长岩和辉长岩中的纯橄岩捕虏体,其成因也存在一定争议(Xu et al., 2008, 2012; Wang et al., 2012a)。

纯橄岩一致高Fo值(91.7~92.4)橄榄石和高Cr#值(0.68~0.76)尖晶石,与橄榄石-尖晶石地幔序列图中耐熔橄榄岩的矿物化学成分相当,远离深海橄榄岩和新生代大陆岩石圈地幔橄榄岩成分区,与古老的大陆岩石圈地幔橄榄岩成分区重叠(图 8b),意味着纯橄岩很可能为华北克拉通古老的大陆岩石圈地幔橄榄岩。上述推断与其全岩高含量的相容元素(Ni、Cr和Co)和极低含量的Al、Ca、V相一致(表 1图 6图 7)。耐熔性地幔橄榄岩也可能来自大洋岩石圈,但深海橄榄岩耐熔程度相对偏低,橄榄石Fo值一般低于92(Seyler et al., 2007),尖晶石Cr#极少超过0.60(Dick and Bullen, 1984)。在尖晶石的二元(Cr#-XMg图 9d)成分图解中,纯橄岩与马里亚纳弧前橄榄岩(Ishii et al., 1992; Cr#≤0.82)和喜马拉雅弧前橄榄岩(Hattori and Guillot, 2007; Cr#≤0.84)成分区基本重叠,表明其来源很可能为弧前地幔橄榄岩。

高Cr#值的尖晶石也出现在超镁铁质火成堆晶中,但纯橄岩高IPGE含量和高IPGE/PPGE值排除了这种可能性。部分熔融过程中,IPGE为强耐熔组分,易滞留于地幔残留,而PPGE却优先进入熔体中(Righter et al., 2004; Brenan et al., 2005)。据此,超镁铁质火成堆晶岩一般具低含量的IPGE和低IPGE/PPGE值(Hattori et al., 2010a; Wang et al., 2012a)。高含量的IPGE也可能与高百分含量的硫化物有关,因PGE在硫化物和硅酸盐矿物间具高的分配系数(>1000)(Crocket et al., 1997),但纯橄岩相比原始地幔估算值,亏损S(19.8×10-6~64.5×10-6表 1),其次,样品中硫化物大多数为部分蛇纹石化过程中被引进来的(图 2c),这意味着纯橄岩中PGE元素主要赋存于硅酸矿物中或以合金形式存在,如南美洲Pali Aike火山岩区中地幔橄榄岩捕虏体(Wang et al., 2008a)。纯橄岩的PGE含量和原始地幔标准化分布模式与莱芜超镁铁质火成堆晶的纯橄岩(Wang et al., 2012a)明显不同,但与鹤壁和信阳的橄榄岩捕虏体相似(Zheng et al., 2005)(图 5a)。在Ir-Ir/(Pt+Pb)图解中,纯橄岩与地幔橄榄岩成分区重叠,明显不同于超镁铁质火成堆晶岩(图 10)。方辉橄榄岩与熔体交代反应形成纯橄岩的可能性同样不被支持,因橄榄石呈一致高的Fo值和NiO,交代反应形成的橄榄石常具变化的Mg和Ni含量(Wang et al., 2008b; Xu et al., 2010)。橄榄石中CaO含量为温度的重要参数,岩浆岩中橄榄石常具有高的CaO(>0.10%; De Hoog et al., 2010),而本次测试的橄榄石呈极低的CaO(≤0.02%),这与大陆岩石圈地幔来源的推断相一致。需要说明的是,流体交代作用对地幔岩中强耐熔组分IPGE的影响微乎其微(Hattori and Guillot, 2007; Wang et al., 2012b),但对PPGE具有一定的影响,因Pd和Pt在含水流体中具相对偏高的活动性(刘庆等, 2007; Hattori and Cameron, 2004)。纯橄岩全岩一致偏低的PPGE及低程度的蛇纹石化作用(≤20%),表明交代流体对PPGE的影响程度也很低。

图 10 胡家林超镁铁质岩Ir/(Pt+Pd)-Ir图解 地幔橄榄岩和超镁铁质堆晶岩引自Hattori and Guillot (2007);深海橄榄岩引自Rehkämper et al. (1999);莱芜纯橄岩引自Wang et al. (2012a);Sanbagawa单斜辉石岩引自Hattori et al. (2010a);原始地幔估算值引自McDonough and Sun (1995) Fig. 10 Diagram of Ir/(Pt+Pd) vs. Ir for Hujialin ultramafic rocks

纯橄岩全岩富集流体迁移元素(Pb和Sr)和LREE的特征(图 3a图 4a),可能与其遭受了不同程度的蛇纹石化有关,高耐熔地幔橄榄岩本应亏损这些不相容元素,因部分熔融过程中,它们优先进入熔体。流体迁移元素和LREE的富集过程很可能发生在地幔楔橄榄岩的蛇纹石化过程中,因在一定温度-压力条件下,特别是从角闪岩相-蓝片岩相到榴辉岩相的相变过程中,俯冲板片及上覆沉积物将释放大量富H2O流体和流体迁移元素(Iwamori, 1998; Rüpke et al., 2004),释放的富H2O流体及流体迁移元素往往富集在上覆地幔楔蛇纹石化橄榄岩中(Hattori and Guillot, 2003)。Pb等元素也可能来自折返过程中的花岗质片麻岩的释放,但橄榄岩全岩极低含量的碱性元素(Na、K和Rb)排除了这种可能性(表 1),因为折返中的蛇纹石化作用往往导致橄榄岩成比例的富集碱性元素。据此,纯橄岩遭受的蛇纹石化作用应发生在地幔楔部位,这与全球其它俯冲带地区蛇纹岩的情形相一致(Hattori and Guillot, 2003; Saumur et al., 2010)。

鉴于橄榄石高的Fo值、铬尖晶石的高Cr#值和全岩一致高含量的强相容元素(Ni、Cr、Co)和IPGE及Ni-PGE-Cu分布模式图等证据,胡家林纯橄岩的原岩为弧前地幔橄榄岩,来源于华北克拉通古老的大陆岩石圈地幔,并于地幔楔部位遭受了部分蛇纹石化作用。

5.1.2 (石榴)单斜辉石岩

(石榴)单斜辉石岩与原始地幔估算值(McDonough and Sun, 1995)相比,明显亏损IPGE和Cr、Ni(图 5b, c图 7)。IPGE在地幔矿物和熔体间具高分配系数(D),部分熔融过程中易于保留在地幔残留中(Puchtel and Humayun, 2001; Righter et al., 2004)。因此,地幔残留常富集IPGE(Wang et al., 2008b; Saumur et al., 2010),而基性熔体堆晶岩则亏损IPGE(Hattori and Hart, 1997; Wang et al., 2012a)。在Ir-Ir/(Pt+Pb)图解中,样品远离地幔橄榄岩成分区,而与超镁铁质堆晶岩的成分区接近(图 10)。全岩分异的IPGE/PPGE值(0.03~3.37)可能与存在壳源流体或熔体参与有关,因PPGE在富流体的环境下可以被活化(刘庆等, 2007; Hattori and Cameron, 2004)。全岩低含量的IPGE表明其原岩非地幔岩,很可能为超镁铁质熔体的堆晶岩,这与全岩亏损Cr和Ni元素相一致,因其对地幔岩矿物为相容元素,倾向于保留在残余地幔岩中。全岩球粒陨石标准化配分图的明显“上凸”型(图 3b),也印证了其原岩很可能为火成堆晶岩(Gonzaga et al., 2010)。(石榴)单斜辉石岩全岩组分位于俯冲带蛇绿岩带中辉石岩(Melcher et al., 2002; Parlak et al., 2002)和高Ti、高Fe玄武质岩浆的结晶辉石岩(Zeng et al., 2009)之间(图 6),结合全岩高Fe和Ti的地球化学特征,表明其原岩非等同于单一地幔橄榄岩的熔体,而很可能为经历了差异化结晶分异的岛弧岩浆。

(石榴)单斜辉石岩堆晶岩成因的推断从矿物化学得到进一步证实,单斜辉石包裹的橄榄石呈低的Fo值和NiO,在Fo-NiO图解中,它们远离地幔橄榄岩区域,投在了超基性熔岩结晶分异的演化趋势线上(图 8a)。测试的单斜辉石成分与乌拉尔-阿拉斯加型辉石岩(Helmy and El Mahallawi, 2003; Pettigrew and Hattori, 2006)中辉石成分接近,而且估算的原生普通辉石成分与岛弧堆晶岩中单斜辉石成分相当(Loucks, 1990; Le Bas, 1962)(图 9)。

(石榴)单斜辉石岩全岩与MORB估算值(Arevalo and McDonough, 2010)相比,富集流体迁移元素(Pb、Sr和Ba),轻度亏损LREE和强烈亏损高场强元素(Nb、Zr、Y)(图 4b, c)。上述地球化学特征,非单一的地幔岩熔体经结晶堆积能够解释,因无论何种比例的橄榄岩和辉石,均不能分异REE和高场强元素(Hattori et al., 2010a)。据此,作者推测地幔岩熔体曾与壳源流体或熔体发生机械混合,在差异化的岩浆演化后,结晶堆积形成了(石榴)单斜辉石岩的原岩。壳源流体或熔体的来源可能为俯冲陆壳板片在高压-超高压变质作用下,释放的富H2O流体以及由此产生的地壳熔体(Zheng et al., 2011)。上述推断得到了高天山等(2015)研究成果证实,胡家林(石榴)单斜辉石岩的Sr-Nd-Pb同位素组成为亏损地幔与地壳流体或熔体之间的混合构成。

Ⅰ类单斜辉石岩(样品HJL6)缺乏高压变质指示矿物(石榴石),可能与其全岩偏低的Al2O3含量(3.13%)有关,其全岩相对偏高的Mg、Ni、Cr,偏低的Al、Ti和REE,意味着其原岩为演化程度较低的岛弧岩浆。Ⅱ类和Ⅲ类石榴单斜辉石岩中的石榴石很可能是在深俯冲过程中,由单斜辉石和尖晶石变质生成,这与石榴石颗粒包裹有大量单斜辉石和磁铁矿或钛铁矿粒状包裹体相一致(图 2f)。此外,石榴石优先结合HREE(Green et al., 2000),假设石榴石形成于岩浆岩阶段,石榴石矿物及全岩将富集HREE。含10%石榴石的超镁铁质火成堆晶岩,其全岩将呈明显高含量的HREE(Hattori et al., 2010b),研究样品均强烈亏损HREE(Yb=0.31×10-6~0.81×10-6; (La/Yb)N>1.6),表明石榴石非岩浆岩阶段产物,而很可能为后期变质产物。Ⅲ类石榴单斜辉石岩相对呈偏低的Mg、Cr和Ni,偏高的Fe、Ti和REE(表 1图 3b图 6图 7),表明其原岩可能为演化程度较高的岛弧岩浆。Ⅰ类和Ⅱ类单斜辉石岩全岩的Eu正异常,暗示其原岩中存在少量斜长石,因斜长石优先结合Eu变为Eu2+,而全岩高含量的Ca和Al与其原岩可能存在斜长石一致。基于岩相学和地球化学分析及估算的原生单斜辉石组分,胡家林(石榴)单斜辉石岩原岩的矿物组合主要为普通辉石和尖晶石及少量斜长石。深俯冲过程中,普通辉石因压力分解为透辉石、钛铁矿和磁铁矿等,同时单斜辉石、尖晶石和斜长石发生变质作用,形成富Al与富Ca的石榴石。

综上,胡家林(石榴)单斜辉石岩原岩很可能为俯冲带中超镁铁质火成堆晶岩,原始岩浆很可能由地幔橄榄岩高程度部分熔融的熔体和壳源流体或熔体构成,并经历了差异化的结晶分异。超高压变质作用前,其原岩矿物组合可能为普通辉石和尖晶石和少量斜长石。

5.2 胡家林超镁铁质岩构造意义

(石榴)单斜辉石岩的构造过程经历了3个阶段:(1)俯冲带超镁铁质熔体的结晶堆积过程;(2)纳入俯冲通道并经历超高压变质作用;(3)折返-抬升过程。第(1)阶段岛弧岩浆的物理化学环境难以估计,因样品中缺乏原生的单斜辉石(普通辉石)。Yang (2006)依据火成岩阶段存在富Al尖晶石和缺乏石榴石及斜长石,推测其原岩可能位于壳-幔边界的深度。第(2)阶段(石榴)单斜辉石岩的原岩被地幔牵引流带入俯冲通道,经历了深俯冲过程及超高压变质作用,消耗了单斜辉石、尖晶石等矿物,生成大量石榴石(钙铝榴石组分为主)(图 2f)(Hiramatsu and Hirajima, 1995; Yang, 2006)。基于平衡结构中单斜辉石-石榴石的Fe-Mg置换数据,(石榴)单斜辉石岩原岩遭受的最高温-压条件为P≥5.0GPa;T≥750℃(Chen and Xu, 2005; Yang, 2006),表明其曾俯冲到地幔深部(接近150km)。第(3)阶段(石榴)单斜辉石岩折返-抬升,经历了低角闪岩-绿片岩相退变质作用,证据有石榴石边部的退变质矿物(角闪石、绿泥石及绿帘石)(图 2g)。锆石U-Pb年龄(~220Ma)(Gao et al., 2004),代表其遭受的流体交代与板片折返年龄,这与区域花岗质片麻岩退变质年龄相一致(Liu et al., 2004; Zhao et al., 2006)。实验岩石学显示,石榴石组分中镁铝榴石的溶解度将随压力增加而显著降低(一定温度条件)或随温度降低而略有增加(一定压力条件)(Akaogi and Akimoto, 1977)。斑晶单斜辉石中出溶石榴石相比斑晶石榴石具有偏低镁铝榴石组分,表明矿物出溶发生在增压和/或降温环境中(Zhang et al., 2011)。

(石榴)单斜辉石岩如何与尖晶石相橄榄岩结合,一起抬升至地壳浅部,存在2种可能性。(1)(石榴)单斜辉石岩的原岩在地幔楔部位与无水橄榄岩相结合,被地幔流带入扬子大陆与上覆华北克拉通之间的俯冲通道内,一同经历了深俯冲和超高压变质作用。在折返过程中,尖晶石橄榄岩与俯冲通道内富H2O流体发生蛇纹石化。纯橄岩中缺乏超高压变质指示矿物,如变质橄榄岩中的石榴石(Zhang et al., 2000; Ye et al., 2009),可能与其全岩极低含量的Al和Ca有关(表 1)。多尼米加岛弧岩浆堆晶成因的石榴橄榄岩具有相似的构造演化过程(Hattori et al., 2010b)。然而,这种可能性并不被支持。深俯冲过程中,地幔楔橄榄岩很难保持无水状态,因俯冲板片不间断释放大量富H2O流体(Hattori and Guillot, 2003; Rüpke et al., 2004),特别是从角闪岩相-蓝片岩相到榴辉岩相的相变过程中。一旦橄榄岩发生蛇纹石化生成大量蛇纹石矿物,蛇纹石矿物在高压条件下(~5GPa)不稳定,将脱水重结晶成镁橄榄石石和顽火辉石(Ulmer and Trommsdorff, 1995; Wunder et al., 2001)。本次研究的纯橄岩内并未发现重结晶镁橄榄石和顽火辉石,因为重结晶镁橄榄石常呈低Fo值(< 90)(De Hoog et al., 2011)和包裹磁铁矿,而研究样品中橄榄石呈一致高Fo值(≥91.7)和无任何包裹体。据此,胡家林纯橄岩未经历深俯冲和超高压变质作用。(2)(石榴)单斜辉石岩的原岩单独被地幔流带入俯冲通道,并经历了超高压变质作用,变质形成大量石榴石。在折返-抬升过程中,(石榴)单斜辉石岩与俯冲带上覆地幔楔剥离的蛇纹石化地幔橄榄岩混合,形成了超镁铁质杂岩体。它们与折返板片相结合,一同折返至地壳浅部(图 11a)。这种可能性与石榴单斜辉石透镜体和周围蛇纹石化橄榄岩的尖锐接触关系相一致,对胡家林超镁铁质杂岩体的构造演化过程的阐释也更为合理。梭罗树镁铁-超镁铁质杂岩体(图 1a),与胡家林超镁铁质杂岩体具有相似的岩性组合(龚冰等, 2005),暗示其具有相似的构造演化过程。

图 11 胡家林超镁铁质岩俯冲与折返模式示意图(a,据Warren et al., 2008; Li and Gerya, 2009修改)及俯冲或折返大陆板片与上覆地幔楔的界面模拟图(b,据Guillot et al., 2009; Zheng, 2012修改) Fig. 11 Schematic models for the subduction and exhumation of the Hujialin ultramafic complex in the continental subduction channel (a, modified after Warren et al., 2008; Li and Gerya, 2009) and interface interaction along the continental subduction channel (b, modified after Guillot et al., 2009; Zheng, 2012)

苏鲁-大别地区超镁铁质杂岩体普遍发育石榴石相超镁铁质岩和尖晶石橄榄岩,如东海和仰口地区超镁铁质杂岩体(Zhang et al., 2005; Ye et al., 2009)和和大别饶八寨超镁铁质岩体(Tsai et al., 2000; Zheng et al., 2008)。石榴橄榄岩和尖晶石橄榄岩普遍具有大陆岩石圈地幔属性(Zhang et al., 2000, 2009b; Yang et al., 2009; Ye et al., 2009; Xie et al., 2013),而石榴辉石岩的原岩常为俯冲带内基性熔体的堆晶岩(Zheng et al., 2008; Zhang et al., 2010)。

扬子大陆俯冲边缘与上覆华北克拉通间的俯冲通道,主体可能由非均匀变质的陆壳板片和不同程度变质、蚀变或熔体交代反应的镁铁-超镁铁质岩构成,即俯冲通道内主体岩性由下部的陆源变质岩(花岗质片麻岩、榴辉岩和变质沉积岩)和上部的非均匀变质和蚀变的石榴橄榄岩、石榴辉石岩、基性榴辉岩、尖晶石橄榄岩和辉石岩构成(图 11b)。这与全球典型俯冲带地区内俯冲板片与上覆地幔楔间的界面岩性组合相一致(Guillot et al., 2009; Zheng, 2012)。华北克拉通与扬子大陆间的古特提斯洋闭合和洋壳俯冲-消减后,扬子大陆边缘开始深俯冲,并经历一系列非均匀的高压-超高压变质作用(许志琴等, 2005; Zheng, 2008)。大量动力学数字模型表明,扬子俯冲陆壳板片(花岗质片麻岩和变质沉积岩)的低密度特征,导致其与扬子大陆其它岩石圈相脱耦(Li and Gerya, 2009; Warren et al., 2008)(图 11a),脱耦的陆壳板片携带大量镁铁-超镁铁质岩透镜体及岩块,一共折返至地壳浅部。胡家林超镁铁质杂岩体很可能是在地幔楔浅部(尖晶石相深度),被脱耦的陆壳板片相裹挟,整体抬升至地壳浅部。

6 结论

胡家林纯橄岩全岩呈高含量IPGE和富集强相容元素(Ni、Cr、Co),具高Fo值(91.7~92.4)橄榄石和高Cr#(0.68~0.76)铬尖晶石,表明其为经历了高程度部分熔融作用的地幔橄榄岩,代表了华北克拉通古老的大陆岩石圈地幔残留,并于地幔楔部位遭受了部分蛇纹石化。(石榴)单斜辉石岩呈低含量IPGE和强相容元素,富集流体迁移元素(Pb、Sr和Ba),轻度亏损LREE和强烈亏损高场强元素,具低Fo值(76.6~76.8)橄榄石,证实其原岩为俯冲带中地幔熔体与壳源流体或熔体形成的岛弧岩浆堆晶岩,原始岩浆曾经历了不同程度的岩浆分异,原岩矿物组合主要为普通辉石和尖晶石及少量斜长石。

(石榴)单斜辉石岩原岩曾单独被地幔流体带入俯冲通道,经历超高压变质作用,其在折返过程中与地幔楔剥离的蛇纹石化橄榄岩及纯橄岩相结合,形成超镁铁质杂岩体。扬子大陆俯冲板片与上覆地幔楔间界面很可能由下部的陆源变质岩(花岗质片麻岩、榴辉岩和变质沉积岩)和上部的非均匀变质及蚀变的石榴橄榄岩,石榴辉石岩、基性榴辉岩、尖晶石橄榄岩和辉石岩构成。低密度的俯冲陆壳物质与其它俯冲岩石圈间的脱耦作用,致使其裹挟大量镁铁-超镁铁质岩透镜体及岩体,一同折返至地壳浅部。

致谢 渥太华大学的Smita Mohanty与Nimal DeSilva、卡尔顿大学的Peter Jones和中国科学院地球化学研究所黄小文博士为本文涉及的测试分析提供了技术帮助;同时,审稿专家对本文提出了宝贵的修改意见;在此一并致以衷心的感谢!
参考文献
Akaogi M and Akimoto S. 1977. Pyroxene-garnet solid-solution equilibria in the systems Mg4Si4O12-Mg3Al2Si3O12 and Fe4Si4O12-Fe3Al2Si3O12 at high pressures and temperatures. Physics of the Earth and Planetary Interiors, 15(1): 90-106. DOI:10.1016/0031-9201(77)90013-9
Arai S. 1994. Characterization of spinel peridotites by olivine-spinel compositional relationships: Review and interpretation. Chemical Geology, 113(3-4): 91-204.
Arevalo R Jr and McDonough WF. 2010. Chemical variations and regional diversity observed in MORB. Chemical Geology, 271(1-2): 70-85. DOI:10.1016/j.chemgeo.2009.12.013
Brenan JM, McDonough WF and Ash R. 2005. An experimental study of the solubility and partitioning of iridium, osmium and gold between olivine and silicate melt. Earth and Planetary Science Letters, 237(3-4): 855-872. DOI:10.1016/j.epsl.2005.06.051
Chen J and Xu ZQ. 2005. Pargasite and ilmenite exsolution texture in clinopyroxenes from Hujialing garnet-pyroxenite, Su-Lu UHP terrane, central China: A geodynamic implication. European Journal of Mineralogy, 17(6): 895-903. DOI:10.1127/0935-1221/2005/0017-0895
Chen SZ, Yang JS and Li TF. 2009. Petrological investigation of the Ganyu peridotite in the Sulu ultrahigh-pressure terrane, eastern China. Tectonophysics, 475(2): 383-395. DOI:10.1016/j.tecto.2009.03.004
Crocket JH, Fleet ME and Stone WE. 1997. Implications of composition for experimental partitioning of platinum-group elements and gold between sulfide liquid and basalt melt: The significance of nickel content. Geochimica et Cosmochimica Acta, 61(19): 4139-4149. DOI:10.1016/S0016-7037(97)00234-2
De Hoog JCM, Gall L and Cornell DH. 2010. Trace-element geochemistry of mantle olivine and application to mantle petrogenesis and geothermobarometry. Chemical Geology, 270(1-4): 196-215. DOI:10.1016/j.chemgeo.2009.11.017
De Hoog JCM, Janak M, Vrabec M and Hattori K. 2011. Ultramafic cumulates of oceanic affinity in an intracontinental subduction zone: Ultrahigh-pressure garnet peridotites from Pohorje (Eastern Alps, Slovenia). In: Dobrzhinetskaya LF, Faryad SW, Wallis S and Cuthbert S (eds. ). Ultrahigh-Pressure Metamorphism: 25 Years after the Discovery of Coesite and Diamond. Amsterdam: Elsevier, 399-439
Deschamps F, Guillot S, Godard M, Chauvel C, Andreani M and Hattori K. 2010. In situ characterization of serpentinites from forearc mantle wedges: Timing of serpentinization and behavior of fluid-mobile elements in subduction zones. Chemical Geology, 269(3-4): 262-277. DOI:10.1016/j.chemgeo.2009.10.002
Dick HJB and Bullen T. 1984. Chromian spinel as a petrogenetic indicator in abyssal and alpine-type peridotites and spatially associated lavas. Contributions to Mineralogy and Petrology, 86(1): 54-76. DOI:10.1007/BF00373711
Gao TS, Chen JF, Xie Z, Yang SH and Yu G. 2004. Zircon SHRIMP U-Pb age of garnet olivine pyroxenite at Hujialin in the Sulu terrane and its geological significance. Chinese Science Bulletin, 49(20): 2198-2204. DOI:10.1007/BF03185788
Gao TS, Chen JF and Xie Z. 2015. Petrology and geochemistry of ultramafic rocks at Hujialin, Sulu Orogen.Bulletin of Mineralogy . Petrology and Geochemistry, 34(3): 601-618.
Garuti G, Fershtater G, Bea F, Montero P, Pushkarev EV and Zaccarini F. 1997. Platinum-group elements as petrological indicators in mafic-ultramafic complexes of the central and southern Urals: Preliminary results. Tectonophysics, 76(1-4): 181-194.
Gong B, Zheng YF, Chen B and Wu YB. 2005. Zircon U-Pb age, Lu-Hf and O isotope geochemistry of Triassic meta-ultramafic rocks at Hujialin and Suoluoshu in the Sulu orogenic belt. Acta Geoscientica Sinica, 26(S1): 67-69.
Gonzaga RG, Lowry D, Jacob DE, LeRoex A, Schulze D and Menzies MA. 2010. Eclogites and garnet pyroxenites: Similarities and differences. Journal of Volcanology and Geothermal Research, 190(1-2): 235-247. DOI:10.1016/j.jvolgeores.2009.08.022
Green TH, Blundy JD, Adam J and Yaxley GM. 2000. SIMS determination of trace element partition coefficients between garnet, clinopyroxene and hydrous basaltic liquids at 2~7.5GPa and 1080~1200℃. . Lithos, 53(3-4): 165-187.
Guillot S, Hattori KH, Agard P, Schwartz S and Vidal O. 2009. Exhumation processes in oceanic and continental subduction contexts: A review. In: Lallemand S and Funiciello F (eds. ). Subduction Zone Geodynamics. Berlin Heidelberg: Springer, 175-205
Hattori K, Walls S, Enami M and Mizukami T. 2010a. Subduction of mantle wedge peridotites: Evidence from the Higashi-akaishi ultramafic body in the Sanbagawa metamorphic belt. The Island Arc, 19(1): 192-207. DOI:10.1111/iar.2010.19.issue-1
Hattori KH and Hart SR. 1997. PGE and Os isotopic signatures for ultramafic rocks from the base of the Talkeetna island arc, Alaska. Eos (Transactions, American Geophysical Union), 78(17): 339.
Hattori KH and Guillot S. 2003. Volcanic fronts form as a consequence of serpentinite dehydration in the forearc mantle wedge. Geology, 31(6): 525-528. DOI:10.1130/0091-7613(2003)031<0525:VFFAAC>2.0.CO;2
Hattori KH and Cameron EM. 2004. Using the high mobility of palladium in surface media in exploration for platinum group element deposits: Evidence from the Lac des Iles Region, northwestern Ontario. Economic Geology, 99(1): 157-171.
Hattori KH and Guillot S. 2007. Geochemical character of serpentinites associated with high- to ultrahigh-pressure metamorphic rocks in the Alps, Cuba, and the Himalayas: Recycling of elements in subduction zones. Geochemistry, Geophysics, Geosystems, 8(9): Q09010.
Hattori KH, Guillot S, Saumur BM, Tubrett MN, Vidal O and Morfin S. 2010b. Corundum-bearing garnet peridotite from northern Dominican Republic: A metamorphic product of an arc cumulate in the Caribbean subduction zone. Lithos, 114(3-4): 437-450. DOI:10.1016/j.lithos.2009.10.010
Helmy HM and El Mahallawi MM. 2003. Gabbro Akarem mafic-ultramafic complex, Eastern Desert, Egypt: A Late Precambrian analogue of Alaskan-type complexes. Mineralogy and Petrology, 77(1-2): 85-108. DOI:10.1007/s00710-001-0185-9
Hiramatsu N and Hirajima T. 1995. Petrology of the Hujialin garnet clinopyroxenite in the Su-Lu ultrahigh-pressure province, eastern China. The Island Arc, 4(4): 310-323. DOI:10.1111/iar.1995.4.issue-4
Ishii T, Robinson PT, Maekawa H and Fiske R. 1992. Petrological studies of peridotites from diapiric serpentinite seamounts in the Izu-Ogasawara-Mariana forearc, Leg 125. In: Fryer P, Pearce JA and Stokking LB (eds. ). Proceedings of the Ocean Drilling Program, Scientific Results. College Station, Texas: Ocean Drilling Program, 445-485
Iwamori H. 1998. Transportation of H2O and melting in subduction zones. Earth and Planetary Science Letters, 160(1-2): 65-80. DOI:10.1016/S0012-821X(98)00080-6
Kelemen PB. 1990. Reaction between ultramafic rock and fractionating basaltic magma I.Phase relations, the origin of calc-alkaline magma series, and the formation of discordant dunite. . Journal of Petrology, 31(1): 51-98.
Kelemen PB, Shimizu N and Salters VJM. 1995. Extraction of mid-ocean-ridge basalt from the upwelling mantle by focused flow of melt in dunite channels. Nature, 375(6534): 747-753. DOI:10.1038/375747a0
Le Bas MJ. 1962. The role of aluminum in igneous clinopyroxenes with relation to their parentage. American Journal of Science, 260(4): 267-288. DOI:10.2475/ajs.260.4.267
Li TF, Yang JS and Zhang RY. 2008. Geochemical characteristics, UHP metamorphic age, and genesis of the Hujialing garnet clinopyroxenite, Sulu terrane, China. International Geology Review, 50(1): 48-60. DOI:10.2747/0020-6814.50.1.48
Li XP, Yang JS, Robinson P, Xu ZQ and Li TF. 2011. Petrology and geochemistry of UHP-metamorphosed ultramafic-mafic rocks from the main hole of the Chinese Continental Scientific Drilling project (CCSD-MH), China: Fluid/melt-rock interaction: Mafic-ultramafic complex from CCSD-MH. Journal of Asian Earth Sciences, 42(4): 661-683. DOI:10.1016/j.jseaes.2011.01.010
Li ZH and Gerya TV. 2009. Polyphase formation and exhumation of high- to ultrahigh-pressure rocks in continental subduction zone: Numerical modeling and application to the Sulu ultrahigh-pressure terrane in eastern China. Journal of Geophysical Research: Solid Earth, 114(B9): B09406.
Liu FL, Xu ZQ, Liou JG and Song B. 2004. SHRIMP U-Pb ages of ultrahigh-pressure and retrograde metamorphism of gneisses, south-western Sulu terrane, eastern China. Journal of Metamorphic Geology, 22(4): 315-326. DOI:10.1111/j.1525-1314.2004.00516.x
Liu Q, Hou QL, Zhou XH, Xie LW, Ni SQ and Wu YD. 2007. Platinum-group element geochemistry of ultramafic rocks in Maowu, Dabie Mountains. Geology in China, 24(5): 818-814.
Loucks RR. 1990. Discrimination of ophiolitic from nonophiolitic ultramafic-mafic allochthons in orogenic belts by the Al/Ti ratio in clinopyroxene. Geology, 18(4): 346-349. DOI:10.1130/0091-7613(1990)018<0346:DOOFNU>2.3.CO;2
McDonough WF and Sun SS. 1995. The composition of the Earth. Chemical Geology, 120(3-4): 223-253. DOI:10.1016/0009-2541(94)00140-4
Meisel T and Moser J. 2004. Reference materials for geochemical PGE analysis: New analytical data for Ru, Rh, Pd, Os, Ir, Pt and Re by isotope dilution ICP-MS in 11 geological reference materials. Chemical Geology, 208(1-4): 319-338. DOI:10.1016/j.chemgeo.2004.04.019
Melcher F, Meisel T, Puhl J and Koller F. 2002. Petrogenesis and geotectonic setting of ultramafic rocks in the Eastern Alps: Constraints from geochemistry. Lithos, 65(1-2): 69-112. DOI:10.1016/S0024-4937(02)00161-5
Okay AI. 1994. Sapphirine and Ti-clinohumite in ultra-high-pressure garnet-pyroxenite and eclogite from Dabie Shan, China. Contributions to Mineralogy and Petrology, 116(1-2): 145-155. DOI:10.1007/BF00310696
Parlak O, Höck V and Delaloye M. 2002. The supra-subduction zone Pozanti-Karsanti ophiolite, southern Turkey: Evidence for high-pressure crystal fractionation of ultramafic cumulates. Lithos, 65(1-2): 205-224. DOI:10.1016/S0024-4937(02)00166-4
Pettigrew NT and Hattori KH. 2006. The Quetico intrusions of western superior province: Neo-Archean examples of Alaskan/Ural-type mafic-ultramafic intrusions. Precambrian Research, 149(1-2): 21-42. DOI:10.1016/j.precamres.2006.06.004
Puchtel IS and Humayun M. 2001. Platinum group element fractionation in a komatiitic basalt lava lake. Geochimica et Cosmochimica Acta, 65(17): 2979-2993. DOI:10.1016/S0016-7037(01)00642-1
Qi L, Hu J and Gregoire DC. 2000. Determination of trace elements in granites by inductively coupled plasma mass spectrometry. Talanta, 51(3): 507-513. DOI:10.1016/S0039-9140(99)00318-5
Rehkämper M, Halliday AN, Alt J, Fitton JG, Zipfel J and Takazawa E. 1999. Non-chondritic platinum-group element ratios in oceanic mantle lithosphere: Petrogenetic signature of melt percolation?. Earth and Planetary Science Letters, 172(1-2): 65-81. DOI:10.1016/S0012-821X(99)00193-4
Righter K, Campbell AJ, Humayun M and Hervig RL. 2004. Partitioning of Ru, Rh, Pd, Re, Ir, and Au between Cr-bearing spinel, olivine, pyroxene and silicate melts. Geochimica et Cosmochimica Acta, 68(4): 867-880. DOI:10.1016/j.gca.2003.07.005
Rüpke LH, Morgan JP, Hort M and Connolly JAD. 2004. Serpentine and the subduction zone water cycle. Earth and Planetary Science Letters, 223(1-2): 17-34. DOI:10.1016/j.epsl.2004.04.018
Saumur BM, Hattori KH and Guillot S. 2010. Contrasting origins of serpentinites in a subduction complex, northern Dominican Republic. Geological Society of America Bulletin, 122(1-2): 292-304. DOI:10.1130/B26530.1
Seyler M, Lorand JP, Dick HJB and Drouin M. 2007. Pervasive melt percolation reactions in ultra-depleted refractory harzburgites at the Mid-Atlantic Ridge, 15° 20'N: ODP hole 1274A. Contributions to Mineralogy and Petrology, 153(3): 303-319. DOI:10.1007/s00410-006-0148-6
Tang J, Zheng YF, Wu YB, Gong B, Zha XP and Liu XM. 2008. Zircon U-Pb age and geochemical constraints on the tectonic affinity of the Jiaodong terrane in the Sulu orogen, China. Precambrian Research, 161(3-4): 389-418. DOI:10.1016/j.precamres.2007.09.008
Tsai CH, Liou JG and Ernst WG. 2000. Petrological characterization and tectonic significance of retrogressed garnet peridotites, Raobazhai area, North Dabie Complex, east-central China. Journal of Metamorphic Geology, 18(2): 181-192. DOI:10.1046/j.1525-1314.2000.00237.x
Ulmer P and Trommsdorff V. 1995. Serpentine stability to mantle depths and subduction-related magmatism. Science, 268(5212): 858-861. DOI:10.1126/science.268.5212.858
Wang J, Hattori KH, Li JP and Stern CR. 2008a. Oxidation state of Paleozoic subcontinental lithospheric mantle below the Pali Aike volcanic field in southernmost Patagonia. Lithos, 105(1-2): 98-110. DOI:10.1016/j.lithos.2008.02.009
Wang J, Hattori KH and Stern CR. 2008b. Metasomatic origin of garnet orthopyroxenites in the subcontinental lithospheric mantle underlying Pali Aike volcanic field, southern South America. Mineralogy and Petrology, 94(3-4): 243-258. DOI:10.1007/s00710-008-0017-2
Wang J, Hattori K, Xu WL, Yang YQ, Xie ZP, Liu JL and Song Y. 2012a. Origin of ultramafic xenoliths in high-Mg diorites from east-central China based on their oxidation state and abundance of platinum group elements. International Geology Review, 54(10): 1203-1218. DOI:10.1080/00206814.2011.628206
Wang J, Liu JL, Hattori K, Xu WL, Xie ZP and Song Y. 2012b. Behavior of siderophile and chalcophile elements in the subcontinental lithospheric mantle beneath the Changbaishan volcano, NE China. Acta Geologica Sinica, 86(2): 407-422. DOI:10.1111/j.1755-6724.2012.00669.x
Warren CJ, Beaumont C and Jamieson RA. 2008. Formation and exhumation of ultra-high-pressure rocks during continental collision: Role of detachment in the subduction channel. Geochemistry, Geophysics, Geosystems, 9(4): Q04019.
Wunder B, Wirth R and Gottschalk M. 2001. Antigorite: Pressure and temperature dependence of polysomatism and water content. European Journal of Mineralogy, 13(3): 485-495. DOI:10.1127/0935-1221/2001/0013-0485
Xie ZP, Hattori K and Wang J. 2013. Origins of ultramafic rocks in the Sulu Ultrahigh-pressure terrane, eastern China. Lithos, 178: 158-170. DOI:10.1016/j.lithos.2012.12.003
Xu WL, Hergt JM, Gao S, Pei FP, Wang W and Yang DB. 2008. Interaction of adakitic melt-peridotite: Implications for the high-Mg# signature of Mesozoic adakitic rocks in the eastern North China Craton. Earth and Planetary Science Letters, 265(1-2): 123-137. DOI:10.1016/j.epsl.2007.09.041
Xu WL, Yang DB, Gao S, Pei FP and Yu Y. 2010. Geochemistry of peridotite xenoliths in Early Cretaceous high-Mg# diorites from the central orogenic block of the North China Craton: The nature of Mesozoic lithospheric mantle and constraints on lithospheric thinning. Chemical Geology, 270(1-4): 257-273. DOI:10.1016/j.chemgeo.2009.12.006
Xu ZQ, Zeng LS, Liang FH and Qi XX. 2005. A dynamic model for sequential subduction and exhumation of a continental slab: Age constraints on the timing of exhumation of the Sulu HP-UHP metamorphic terrane. Acta Petrologica et Mineralogica, 24(5): 357-368.
Yang JJ. 2006. Ca-rich garnet-clinopyroxene rocks at Hujialin in the Su-Lu terrane (eastern China): Deeply subducted arc cumulates?. Journal of Petrology, 47(5): 965-990. DOI:10.1093/petrology/egi102
Yang JS, Xu ZQ, Dobrzhinetskaya LF, Green Ⅱ HW, Pei XZ, Shi RD, Wu CL, Wooden JL, Zhang JX, Wan YS and Li HB. 2003. Discovery of metamorphic diamonds in central China: An indication of a >4000-km-long zone of deep subduction resulting from multiple continental collisions. Terra Nova, 15(6): 370-379. DOI:10.1046/j.1365-3121.2003.00511.x
Yang JS, Li TF, Chen SZ, Wu CL, Robinson PT, Liu DY and Wooden JL. 2009. Genesis of garnet peridotites in the Sulu UHP belt: Examples from the Chinese continental scientific drilling project-main hole, PP1 and PP3 drillholes. Tectonophysics, 475(2): 359-382. DOI:10.1016/j.tecto.2009.02.032
Ye K, Cong BL and Ye DN. 2000. The possible subduction of continental material to depths greater than 200km. Nature, 407(6805): 734-736. DOI:10.1038/35037566
Ye K, Song YR, Chen Y, Xu HJ, Liu JB and Sun M. 2009. Multistage metamorphism of orogenic garnet-lherzolite from Zhimafang, Sulu UHP terrane, E.China: Implications for mantle wedge convection during progressive oceanic and continental subduction. . Lithos, 109(3-4): 155-175.
Ying JF, Zhang HF, Kita N, Morishita Y and Shimoda G. 2006. Nature and evolution of Late Cretaceous lithospheric mantle beneath the eastern North China Craton: Constraints from petrology and geochemistry of peridotitic xenoliths from Jünan, Shandong Province, China. Earth and Planetary Science Letters, 244(3-4): 622-638. DOI:10.1016/j.epsl.2006.02.023
Yuan HL, Gao S, Rudnick RL, Jin ZM, Liu YS, Puchtel IS, Walker RJ and Yu RD. 2007. Re-Os evidence for the age and origin of peridotites from the Dabie-Sulu ultrahigh pressure metamorphic belt, China. Chemical Geology, 236(3-4): 323-338. DOI:10.1016/j.chemgeo.2006.10.009
Zeng LS, Liang FH, Chen ZY, Liu FL and Xu ZQ. 2009. Metamorphic garnet pyroxenite from the 540~600m main borehole of the Chinese Continental Scientific Drilling (CCSD) project. Tectonophysics, 475(2): 396-412. DOI:10.1016/j.tecto.2009.02.043
Zhang RY, Liou JG, Yang JS and Yui TF. 2000. Petrochemical constraints for dual origin of garnet peridotites from the Dabie-Sulu UHP terrane, eastern-central China. Journal of Metamorphic Geology, 18(2): 149-166. DOI:10.1046/j.1525-1314.2000.00248.x
Zhang RY and Liou JG. 2003. Clinopyroxenite from the Sulu ultrahigh-pressure terrane, eastern China: Origin and evolution of garnet exsolution in clinopyroxene. American Mineralogist, 88(10): 1591-1600. DOI:10.2138/am-2003-1022
Zhang RY, Liou JG, Zheng JP, Yui TF, Griffin WL and O'Reilly SY. 2005. Petrogenesis of the Yangkou ultramafic complex with rhythmic layering structure from the Sulu UHP terrane, China. American Mineralogist, 90(5-6): 801-813. DOI:10.2138/am.2005.1706
Zhang RY, Liou JG and Ernst WG. 2009a. The Dabie-Sulu continental collision zone: A comprehensive review. Gondwana Research, 16(1): 1-26. DOI:10.1016/j.gr.2009.03.008
Zhang RY, Liou JG, Zheng JP, Griffin WL, Yang YH and Jahn BM. 2009b. Petrogenesis of eclogites enclosed in mantle-derived peridotites from the Sulu UHP terrane: Constraints from trace elements in minerals and Hf isotopes in zircon. Lithos, 109(3-4): 176-192. DOI:10.1016/j.lithos.2008.08.002
Zhang RY, Jahn BM, Liou JG, Yang JS, Chiu HY, Chung SL, Li TF and Lo CH. 2010. Origin and tectonic implication of an UHP metamorphic mafic-ultramafic complex from the Sulu UHP terrane, eastern China: Evidence from petrological and geochemical studies of CCSD-Main Hole core samples. Chemical Geology, 276(1-2): 69-87. DOI:10.1016/j.chemgeo.2010.05.021
Zhang RY, Liou JG, Huberty JM, Xu HF, Maki K, Jahn BM and Iizuka Y. 2011. Origin and metamorphic evolution of garnet clinopyroxenite from the Sulu UHP terrane, China: Evidence from mineral chemistry and microstructures. In: Dobrzhinetskaya LF, Faryad SW, Wallis S and Cuthbert S (eds. ). Ultrahigh-Pressure Metamorphism: 25 Years after the Discovery of Coesite and Diamond. Amsterdam: Elsevier, 151-185
Zhao ZF, Zheng YF, Gao TS, Wu YB, Chen B, Chen FK and Wu FY. 2006. Isotopic constraints on age and duration of fluid-assisted high-pressure eclogite-facies recrystallization during exhumation of deeply subducted continental crust in the Sulu orogen. Journal of Metamorphic Geology, 24(8): 687-702. DOI:10.1111/jmg.2006.24.issue-8
Zheng JP, O'Reilly SY, Griffin WL, Lu FX, Zhang M and Pearson NJ. 2001. Relict refractory mantle beneath the eastern North China block: Significance for lithosphere evolution. Lithos, 57(1): 43-66. DOI:10.1016/S0024-4937(00)00073-6
Zheng JP, Sun M, Zhou MF and Robinson P. 2005. Trace elemental and PGE geochemical constraints of Mesozoic and Cenozoic peridotitic xenoliths on lithospheric evolution of the North China Craton. Geochimica et Cosmochimica Acta, 69(13): 3401-3418. DOI:10.1016/j.gca.2005.03.020
Zheng JP, Griffin WL, O'Reilly SY, Yang JS, Li TF, Zhang M, Zhang RY and Liou JG. 2006. Mineral chemistry of peridotites from Paleozoic, Mesozoic and Cenozoic lithosphere: Constraints on mantle evolution beneath eastern China. Journal of Petrology, 47(11): 2233-2256. DOI:10.1093/petrology/egl042
Zheng JP, Sun M, Griffin WL, Zhou MF, Zhao GC, Robinson P, Tang HY and Zhang ZH. 2008. Age and geochemistry of contrasting peridotite types in the Dabie UHP belt, eastern China: Petrogenetic and geodynamic implications. Chemical Geology, 247(1-2): 282-304. DOI:10.1016/j.chemgeo.2007.10.023
Zheng YF. 2008. A perspective view on ultrahigh-pressure metamorphism and continental collision in the Dabie-Sulu orogenic belt. Chinese Science Bulletin, 53(20): 3081-3104.
Zheng YF, Xia QX, Chen RX and Gao XY. 2011. Partial melting, fluid supercriticality and element mobility in ultrahigh-pressure metamorphic rocks during continental collision. Earth-Science Reviews, 107(3-4): 342-374. DOI:10.1016/j.earscirev.2011.04.004
Zheng YF. 2012. Metamorphic chemical geodynamics in continental subduction zones. Chemical Geology, 328: 5-48. DOI:10.1016/j.chemgeo.2012.02.005
高天山, 陈江峰, 谢智. 2015. 苏鲁造山带中胡家林超镁铁质岩岩石地球化学特征. 矿物岩石地球化学通报, 34(3): 601-618.
龚冰, 郑永飞, 陈斌, 吴元保. 2005. 苏鲁地体胡家林和梭罗树三叠纪变质超基性岩U-Pb、Lu-Hf和O同位素地球化学研究. 地球学报, 26(S): 67-69.
刘庆, 侯泉林, 周新华, 谢烈文, 倪善芹, 武昱东. 2007. 大别造山带毛屋超镁铁岩的铂族元素研究. 中国地质, 34(5): 818-814.
许志琴, 曾令森, 梁凤华, 戚学祥. 2005. 大陆板片多重性俯冲与折返的动力学模式——苏鲁高压-超高压变质地体的折返年龄限定. 岩石矿物学杂志, 24(5): 357-368.