2022, Vol. 38
2. 成都理工大学沉积地质研究院, 成都 610059
2. Institution of Sedimentary Geology, Chengdu University of Technology, Chengdu 610059, China
罗斯造山带(Ross Orogenic Belt)位于南极横断山脉(Transantarctic Mountains)，是古太平洋板块早古生代向西俯冲在南极东冈瓦纳大陆形成的大型增生造山带。东冈瓦纳被动陆缘在早古生代向活动陆缘转变，引发洋弧增生和大陆弧岩浆持续作用以及区域变质作用，保存完好的侵入体和变质岩系，由此记录了古太平洋板块西倾俯冲并形成陆内造山带的详细过程(图 1b)(Cawood, 2005; Cawood and Buchan, 2007; Paulsen et al., 2007; Elliot and Fanning, 2008; Vaughan and Pankhurst, 2008; Goodge, 2020)。早古生代罗斯造山带受到广泛的长英质、镁铁质岩浆侵入，这些岩浆在南极横断山脉地区广泛侵入形成的深成岩体统称为花岗岩港侵入体(Granite Harbour Intrusive; Gunn and Warren, 1962)，岩石类型主要为岛弧性质的高钾钙碱性花岗岩、闪长岩、碱性花岗岩等(Borg et al., 1987; Vetter and Tessensohn, 1987; Rocchi et al., 1998; 2011, 2015; Federico et al., 2006, 2009; Giacomini et al., 2007)。北维多利亚地(Northern Victoria Land)位于南极横断山脉最北端(图 1b)，广泛分布早古生代花岗岩港侵入体侵入岩，构造-岩浆活动长期活跃(图 1a)。前人关于北维多利亚地当今威尔逊地体(Wilson Terrance)、鲍尔斯地体(Bowers Terrance)、罗伯逊湾地体(Robertson Terrance)平行北西走向的地体并置成因和闭合时限仍持不同观点(Borg et al., 1987; Federico et al., 2009; Rocchi et al., 2011)。该区域构造演化早期类似现今西太平洋大陆边缘构造模式(Goodge, 2020)，古生代经历岛弧增生和弧陆碰撞(Rocchi et al., 2011)，最终于泥盆纪沿兰特曼断裂带发生闭合(Capponi et al., 1999; Federico et al., 2006; Palmeri et al., 2012)。由于南极大陆几乎都被冰雪覆盖，仅有限的地质露头无法对其进行精确的地质区域划分，罗斯造山带广泛岩浆作用和地体增生的构造演化过程和模式仍然缺乏清晰认识，因此该地区花岗质岩石的研究对厘清俯冲带结构、俯冲板片性质、俯冲物质源区具有重要意义。
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图 1 南极洲北维多利亚地大地构造图(据Läufer et al., 2011; Di Vincenzo and Rocchi, 1999; Estrada et al., 2016; Chen et al., 2019; Goodge, 2020修改) 图中标记了罗斯造山带和北维多利亚地在南极大陆的相对位置(据Boger, 2011; Rossetti et al., 2011). LaFZ-兰特曼断裂带; LYFZ-闰年断裂带; O'K-奥凯恩峡谷.难言岛位于北维多利亚地的坎贝尔冰川和普里斯特利冰川之间，主要岩性为威尔逊变质杂岩和花岗岩港侵入体 Fig. 1 Geological and tectonic sketch map of Northern Victoria Land (NVL), Antarctica (modified after Läufer et al., 2011; Vincenzo and Rocchi, 1999; Estrada et al., 2016; Chen et al., 2019; Goodge, 2020) The inset shows the location of the Ross Orogenic Belt and NVL in Antarctica (after Boger, 2011; Rossetti et al., 2011). LaFZ-Lanterman Fault Zone; LYFZ-Leap Year Fault Zone; O'K-O'Kane Canyon. Inexpressible Island lies between Campbell Gacier and Priestley Glacier in Northern Victoria Land, composed of Wilson metamorphic complex and Granite Harbour intrusive |
本文对北维多利亚地威尔逊地体难言岛出露的闪长质岩石进行了详细野外地质调查研究和取样，并选取典型岩石进行U-Pb地质年代学、地球化学和同位素分析。结合前人在北维多利亚地不同岩浆活动的侵入时代和源区演化，探讨了难言岛闪长质岩石成因和大地构造背景，为探讨罗斯造山带北维多利亚地壳-幔相互作用和造山带构造演化提供新的证据。
1 地质背景北维多利亚地位于南极横断山脉的北部(图 1b)，主要由三个以断层为界的地体组成(Bradshaw and Laird, 1983; Weaver et al., 1984; Kleinschmidt and Tessensohn, 1987; Tessensohn and Henjes-Kunst, 2005)：代表东冈瓦大陆地壳性质的威尔逊地体(Wilson Terrane)、鲍尔斯地体(Bowers Terrane)和罗伯逊湾地体(Robertson Bay Terrane)(图 1a)。威尔逊地体由一套变质碎屑岩系列，包括一些残余多相变质麻粒岩混杂岩体组成(Talarico and Castelli, 1995)，这些混杂岩在早古生代的罗斯造山运动中经历了低压型的低级至高级变质作用(Palmeri et al., 1994)；基底由寒武系低级到高级变质沉积岩组成，具有绿片岩相向角闪岩相过渡的特征(Palmeri et al., 2012)，变质岩系记录了西威尔逊地体低压高温变质作用和东威尔逊中压变质作用(Grew et al., 1984; Schüssler et al., 2004; Talarico et al., 2004)。鲍尔斯地体以兰特曼-马里纳缝合带与西部的威尔逊地体相接(图 1a)，由格拉斯哥组的拉斑玄武岩和钙碱性岛弧岩浆岩(Weaver et al., 1984；Estrada and Jordan, 2003)与磨拉石建造组成(Henjes-Kunst and Schüssler, 2003)。罗伯逊湾地体由一套早-中奥陶世(Estrada et al., 2016)低级浊积岩序列组成(Henjes-Kunst and Schüssler, 2003)。罗斯运动时期，富钾、强至弱过铝质的钙碱性岩浆大量侵入到威尔逊地层当中(Ghezzo et al., 1987; Vetter and Tessensohn, 1987; Armienti et al., 1990)，主要为S型和I型花岗岩(Borg et al., 1987; Vetter and Tessensohn, 1987; Rocchi et al., 2015)。前人研究表明，该区后碰撞岩浆侵入作用大约为515~481Ma，峰期岩浆作用为495~490Ma(Bomparola et al., 2007; Rocchi et al., 2015)。
2 样品及岩相学特征本文研究的闪长质岩石构成了难言岛主要侵入体杂岩(图 2)，位于东经163°35′~163°46′，南纬74°50′~74°57′之间, 面积约50km2，呈南北方向延伸。北面为普里斯特利冰川，南面为南森冰盖，特拉诺瓦湾位于难言岛东面。东部海湾大部分基岩覆盖积雪和浅层松散的砂砾(Chen et al., 2019)。岛上遍布第四纪冰川作用形成的砾石，使得基岩出露和辨识难度增加。主要的岩石出露点集中分布于南部较低海拔的定军山、北部望鹅岭，以及西部较高海拔的青龙山(图 2)。南部低海拔定军山发育宽约5m的闪长质岩墙，岩墙整体呈近北东走向，沿走向延伸约300m(图 3a)。北部望鹅岭、青龙山发育长英质和闪长质混杂岩体(图 3b, c)。
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图 2 难言岛及周边区域地质简图和样品采集点(据Chen et al., 2019修改) Fig. 2 Geological map of Inexpressible Island and around area and sample locations (modified after Chen et al., 2019) |
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图 3 难言岛闪长质岩石岩野外地质照片和镜下照片 (a)定军山闪长质岩墙野外出露情况；(b)望鹅岭闪长质包体野外特征；(c)青龙山闪长质岩体野外特征；(d)闪长质岩石中含副矿物磷灰石、榍石；(e)闪长质岩石中黑云母交代的自形角闪石斑晶，基质为斜长石和石英；(f)闪长质岩石中斜长石与角闪石交生. Pl-斜长石；Qtz-石英；Bt-黑云母；Kfs-钾长石；Hbl-角闪石；Ttn-榍石；Ap-磷灰石 Fig. 3 Field and microscopic characteristics of the Inexpressible Island dioritic rocks (a) occurrence of Dingjunshan diorite dyke; (b) occurrence of Wangeling diortic rocks; (c) occurrence of Qinglongshan dioritic rocks; (d) apatite and titanite in diorite intrusions; (e) a biotite metasomatism surrounds the euhedral hornblende phenocryst; (f) plagioclase intersects with hornblende in dioritic rocks. Pl-plagioclase; Qtz-quartz; Bt-biotite; Kfs-orthoclase; Hbl-hornblende; Ttn-titanite; Ap-apatite |
定军山闪长岩墙样品(DJS-8、9、10、11、12、16，GPS位置：74°55′12.36″S、163°41′39.48″E)普遍呈半自形细粒结构，组成矿物主要为斜长石(60%)，黑云母(20%)、角闪石次之，可见少量的钾长石(2%)和石英，为闪长岩。斜长石可见环带结构，包裹少量磷灰石包体；角闪石呈半自形柱状或他形粒状，与黑云母交生；石英多分布于自形斜长石间隙中；钾长石主要为他形粒状；可见微细粒自形柱状磷灰石及磷灰石包体，例如DJS-10镜下可见微细粒的磷灰石沿着晶面析出(图 3d)。DJS-11石英含量高于5%，但其具有较少的钾长石，其镜下可见局部较多的他形榍石，正交偏光显微镜下呈现高级干涉色。DJS-12为闪长玢岩。具斑状结构，斑晶主要成分为斜长石、角闪石次之，可见少量的钾长石斑晶，斑晶总体占比约10%。角闪石多呈半自形柱状，且外围被黑云母交代。基质成分主要成分类似于斑晶，为斜长石、黑云母以及角闪石，结晶细小，粒径多在0.1mm左右，结晶程度接近，基质总含量为90%(图 3e)。DJS-16为细粒闪长岩，局部呈斑状结构，成分以斜长石为主，角闪石和黑云母次之，含少量石英。局部可见结晶较粗的斜长石与角闪石交生(图 3f)。角闪石多呈半自形柱状或他形粒状，较多的角闪石呈粗粒，与斜长石交生，且角闪石常被黑云母交代，基质中亦可见较多微细粒的角闪石。黑云母呈片状分布于基质当中。
青龙山的细粒闪长岩样品QLS-2(GPS位置：74°53′51.36″S、163°40′48.36″E)，具半自形细粒结构，块状构造。岩石主要成分为斜长石50%~60%、黑云母20%、石英1%~5%、角闪石小于1%。斜长石偶见环带结构，部分斜长石可见内部蚀变形成的净边结构；角闪石呈半自形-他形粒状，多与黑云母交生；部分斜长石发育强烈绢云母化。
采自望鹅岭的样品WEL-6(GPS位置：74°53′51.00″S、163°40′45.12″E)，二长闪长岩，具半自形细粒结构，块状构造。岩石成分主要为斜长石，黑云母、角闪石次之，可见少量石英，局部可见副矿物榍石。斜长石多呈自形-半自形柱状，其粒径多为0.1~0.7mm，聚片双晶现象十分普遍，有时可见环带结构，部分斜长石内部发生蚀变构成净边结构，斜长石含量约为60%；黑云母呈片状，半自形，片径范围0.1~0.5mm，其含量约为30%；角闪石多呈半自形柱状或他形粒状，且多与黑云母交生，粒径范围0.1~0.4mm，其含量约为5%。石英多呈他形粒状，多分布于自形斜长石间隙之中，其粒径范围0.2~0.5mm，干涉色为一级灰白，正低突起，无解理，含量约为5%；榍石少见，多呈他形粒状与黑云母、角闪石交生。文中使用的矿物名称缩写据文献(Kretz, 1983; 沈其韩, 2009)。
3 分析方法在详细的野外及手标本观察、薄片鉴定基础上，对上述样品进行了全岩主微量元素分析，并对DJS-8、QLS-2、WEL-6进行了全岩Sr-Nd同位素、锆石U-Pb年代学和锆石Hf同位素分析。本文所有样品分析和前处理都在武汉上谱分析公司完成。
3.1 锆石U-Pb定年锆石U-Pb同位素定年和微量元素含量分析的主检设备为安捷伦电感耦合等离子体质谱仪(Agilent 7700)。详细的仪器参数和分析流程见文献(Zong et al., 2017)。GeolasPro激光剥蚀系统由COMPexPro 102 ArF 193nm准分子激光器和MicroLas光学系统组成。本次分析的激光束斑和频率分别为32μm和5Hz。U-Pb同位素定年和微量元素含量处理中采用2个锆石标准91500和玻璃标准物质NIST610作外标分别进行同位素和微量元素分馏校正，2个锆石标样GJ-1分析是作为未知样品来监控数据分析质量，推荐值引自GeoRem(http://georem.mpch-mainz.gwdg.de/)。单次时间分辨分析数据包括大约20~30s空白信号和50s样品信号。对分析数据的离线处理(包括对样品和空白信号的选择、仪器灵敏度漂移校正、元素含量及U-Pb同位素比值和年龄计算)采用软件ICPMSDataCal(Liu et al., 2008, 2010)完成。锆石样品的U-Pb年龄谐和图绘制和年龄加权平均计算采用Isoplot/Ex_ver3(Ludwig, 2003)完成。
锆石阴极发光图像拍摄的仪器为高真空扫描电子显微镜(JSM-IT100)，配备有GATAN MINICL系统。工作电场电压为10.0~13.0kV，钨灯丝电流为80~85μA。
3.2 全岩元素地球化学主量元素采用波长色散X射线荧光光谱仪(ZSXPrimus Ⅱ(XRF)分析测定，依据国标GB/T14506.28—2010标准，检测项目包括SiO2、Al2O3、Fe2O3T、MgO、CaO、Na2O、K2O、TiO2、P2O5、MnO、烧失量。微量元素利用Agilent 7700e ICP-MS分析测试，分析方法依据GB/T 14506.3—2010硅酸盐岩石化分析方法，分析精度优于10%。具体的分析流程和原理见文献(Liu et al., 2008)。
3.3 全岩Sr-Nd同位素全岩Sr-Nd同位素前处理在配备100级操作台的千级超净室完成。样品处理：(1)将200目样品置于105℃烘箱中烘干12小时；(2)准确称取粉末样品50~200mg置于Teflon溶样弹中；(3)依次缓慢加入1~3mL高纯HNO3和1~3mL高纯HF；(4)将Teflon溶样弹放入钢套，拧紧后置于190℃烘箱中加热24小时以上；(5)待溶样弹冷却，开盖后置于140℃电热板上蒸干，然后加入1mL HNO3并再次蒸干；(6)用1.5mL的HCl(2.5M)溶解蒸干样品，待上柱分离。化学分离：用离心机将样品离心后，取上清液上柱。柱子填充AG50W树脂。用2.5M HCl淋洗去除基体元素。最终用2.5M HCl将Sr从柱上洗脱并收集。收集的Sr溶液蒸干后等待上机测试。树脂残留物质通过4.0M HCl淋洗可获得REE溶液。接收的REE溶液蒸干后以0.18M HCl淋洗去除基体元素，最后用0.3M HCl可以将Nd从柱上洗脱并收集。对于高Rb的样品，经过AG50W树脂分离后，还进行二次Sr特效树脂分离。一次分离获得的溶液首先转换为3M HNO3介质，然后样品上柱。柱子填充Sr特效树脂。用3M HNO3淋洗去除干扰元素。最终用MQ H2O将Sr从柱上洗脱并收集。收集的Sr溶液蒸干后等待上机测试。Sr-Nd同位素分析采用美国Thermo Fisher Scientific公司的MC-ICP-MS(Neptune Plus)，仪器配备9个法拉第杯接收器。
BCR-2(玄武岩)和RGM-2(流纹岩)(USGS)被选择作为Sr-Nd同位素分析流程监控标样，两个样品分别代表了基性岩和酸性岩，具有显著的物理化学差异。数据表明，本实验流程可以对样品进行有效分离，分析准确度和精密度满足高精度的Sr-Nd-Pb同位素分析。
3.4 锆石Hf同位素原位微区锆石Hf同位素比值测试利用激光剥蚀多接收杯等离子体质谱(LA-MC-ICP-MS)完成。激光剥蚀系统为Geolas HD(Coherent，德国), MC-ICP-MS为Neptune Plus(Thermo Fisher Scientific，德国)。分析过程同时配备了信号平滑装置以提高信号稳定性和同位素比值测试精密度(Hu et al., 2012a)。载气使用氦气，并在剥蚀池之后引入少量氮气以提高Hf元素灵敏度(Hu et al., 2012b)。分析采用Neptune Plus新设计高性能锥组合。前人研究表明，对于Neptune Plus的标准锥组合，新设计的X截取锥和Jet采样锥组合在少量氮气加入的条件下能分别提高Hf、Yb和Lu的灵敏度5.3倍、4.0倍和2.4倍。激光输出能量可以调节，实际输出能量密度为~7.0J/cm2。采用单点剥蚀模式，束斑直径为44μm。详细仪器操作条件和分析方法可参照文献(Hu et al., 2012b)。为确保分析数据的可靠性，91500和GJ-1两个国际锆石标准与实际样品同时分析。91500用于进行外标校正以进一步优化分析测试结果，GJ-1作为第二标样监控数据校正质量。91500和GJ-1的外部精密度(2SD)优于0.000020，测试值与推荐值在误差范围内一致。
4 分析结果 4.1 锆石U-Pb定年为了精确限定闪长质岩浆作用的时空侵入序列，以及研究岩浆演化源区特征的差异性和继承性，我们对难言岛3个闪长质岩石样品进行了锆石U-Pb年代学研究(表 1)。
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表 1 北维多利亚地难言岛闪长质岩石LA-ICP-MS锆石U-Pb测年结果 Table 1 LA-ICP-MS zircon U-Pb isotopic data for dioritic rocks in Inexpressible Island, NVL |
青龙山闪长岩(QLS-2)的锆石具有较为清晰的亮暗振荡环带，具有薄的振荡边(图 4a)，大多透明无色，呈半自形-自形的柱状或粒状。锆石颗粒平均长约为110μm，宽约50μm。未对锆石核心进行年代学分析，但锆石的振荡年龄群具有普遍一致的谐和年龄，我们分析了19个锆石点位，分带清晰的锆石的一致年龄为498.7±3.2Ma(MSWD=1.7，N=19)(图 5a, b)，锆石Th/U比值为0.29~1.17，比值波动较大，但综合分析属于岩浆锆石。
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图 4 难言岛闪长质岩石锆石CL图像，示锆石靶点的U-Pb年龄(206Pb/238U)及同位素测点位置 Fig. 4 Cathodoluminescence (CL) images showing texture and analytical spot of the Inexpressible Island dioritic rocks |
望鹅岭二长闪长岩(WEL-6)锆石具有典型的中性岩浆锆石特征，普遍为他形粒状，Th/U比值0.11~1.02，没有显著的振荡环带或弱分带(图 4b)。我们对18个锆石进行了年代学分析，获得的加权平均谐和年龄为500.4±1.2Ma(MSWD=6.9，N=18) (图 5c, d)。
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图 5 难言岛闪长质岩石锆石U-Pb谐和年龄曲线图和加权平均年龄图 Fig. 5 Zircon U-Pb data of Inexpressible Island dioritic rocks |
定军山闪长岩墙(DJS-8)的锆石颗粒普遍长约100μm，宽约60~80μm，呈半自形-自形，发育较明显的振荡环带，Th/U比值为0.35~0.91，为岩浆成因锆石(图 4c)。对20个锆石进行了原位分析，其中10个锆石点位获得了较为可靠的一致年龄，加权平均谐和年龄为501.5±1.6Ma(MSWD=0.27，N=12)(图 5e, f)。
4.2 全岩元素地球化学难言岛闪长质岩石主量、微量元素分析结果见表 2，8个样品的SiO2变化范围为54.80%~60.83%，都具有高的K2O含量(3.12%~4.05%)。AR(碱度)为1.80~2.11；K2O/Na2O>1, 里特曼指数为2.67~3.68，属于高钾钙碱性岩石。在侵入岩TAS图解上(图 6a)落入二长闪长岩至二长岩区域，靠近二长岩与闪长岩边界。在SiO2-K2O图解中(图 6b)，所有样品均落入超钾质岩石区域，靠近高钾钙碱性岩附近；铝饱和指数A/CNK=0.77~0.85(图 6c)，属准铝质、弱过铝质系列。岩石总体具有较高的TiO2、MgO、Fe2O3T、P2O5含量。
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表 2 北维多利亚地难言岛闪长质岩石地球化学组成(主量元素：wt%; 稀土和微量元素：×10-6) Table 2 Geochemical compositions of the dioritic rocks, Inexpressible Island (major element: wt%; trace elements: ×10-6) |
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图 6 难言岛闪长质岩石地球化学图解 (a)TAS图解(Middlemost, 1994)；(b)K2O-SiO2图(Peccerillo and Taylor, 1976)；(c)A/NK-A/CNK图(Maniar and Piccoli, 1989). 阿尔伯特辉长岩、弗杰泰申闪长岩石以及两角闪长岩数据据Di Vincenzo and Rocchi, 1999；Rocchi et al., 2009, 2015 Fig. 6 Diagrams of geochemical compositions of the Inexpressible Island dioritic rocks (a) total alkali vs. silica (TAS) diagram (middlemost, 1994); (b) K2O vs. SiO2 diagram (Peccerillo and Taylor, 1976); (c) A/NK vs. A/CNK diagram (Maniar and Piccoli, 1989). Data sources: the Abbott gabbro (Di Vincenzo and Rocchi, 1999), the Vegetation diorites (Rocchi et al., 2009) and Morozumi diorite (Rocchi et al., 2015) |
在N-MORB标准化微量元素蛛网图中(图 7a)，难言岛闪长质岩石显著富集大离子亲石元素，亏损高场强元素如Nb、Ta、Ti，呈现明显负异常。难言岛闪长质岩石的稀土总量较高(ΣREE=338.4×10-6~458.8×10-6)，在球粒陨石标准化图解中(图 7b)表现为右倾轻稀土富集、重稀土相对亏损(LREE/HREE=4.00~4.51)的特征，轻、重稀土之间分馏明显，(La/Yb)N=12.99~14.60，(La/Sm)N=3.28~3.46；δEu=0.62~0.71，为中等-弱Eu负异常。
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图 7 难言岛闪长质岩石正常洋中脊玄武岩标准化微量元素蛛网图(a，标准化值据Sun and McDonough, 1989)和球粒陨石标准化稀土元素配分图(b，标准化值据Boynton, 1984) 数据来源: 阿尔伯特辉长岩(Di Vincenzo and Rocchi, 1999)；弗杰泰申煌斑岩(Rocchi et al., 2009)；泰格尔弧辉长岩(Bracciali et al., 2009)；两角闪长岩(Rocchi et al., 2015) Fig. 7 N-MORB-normalized trace element spider diagrams (a, normalization values after Sun and McDonough, 1989) and chondrite-normalization REE patterns (b, normalization values after Boynton, 1984) of Inexpressible Island dioritic rocks Data sources: the Abbott gabbro (Di Vincenzo and Rocchi, 1999); the Vegetation lamprophyres from central Victoria Land (Rocchi et al., 2009); the Tiger gabbro from the Tiger magmatic arc (Bracciali et al., 2009); Morozumi diorite samples from Wilson Terrance (Rocchi et al., 2015) |
闪长质岩石的全岩Sr-Nd同位素成分测定结果见表 3，我们通过对应样品的平均U-Pb年龄进行校正计算，获得闪长质岩浆初始同位素组成。难言岛闪长质岩石87Sr/86Sr为0.713440~0.713540，143Nd/144Nd为0.511972~0.511982；εNd(t)为-7.1~-7.4(图 8)，初始Sr值为0.709521~0.709795。根据U-Pb定年结果校正获得(87Sr/86Sr)i范围0.7095~0.7098，(143Nd/144Nd)t范围0.511502~0.511629，Nd模式年龄tDM为1.67~1.70Ga，显示古老的下地壳源区特征。
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表 3 北维多利亚地难言岛闪长质岩石全岩Sr-Nd同位素分析结果 Table 3 Whole-rock Sr-Nd isotopic compositions for the dioritic rocks from Inexpressible Island |
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图 8 难言岛闪长质岩石Sr-Nd图解 对比数据为威尔逊弧490~500Ma花岗杂岩体(据Rocchi et al., 2015)：阿尔伯特辉长岩组成以及与深部地壳熔体混合趋势，弗杰泰申淡色花岗岩组成以及与变沉积上地壳熔体混合趋势(Di Vincenzo and Rocchi, 1999; Rocchi et al., 2015)；伊里萨尔花岗岩和岩墙(Rocchi et al., 2009)；泰格尔洋弧早期侵入体，如泰格尔辉长岩(Bracciali et al., 2009)；两角侵入岩(Rocchi et al., 2015)；花岗岩港侵入体杂岩(GHI)I型、S型花岗岩演化趋势(Armienti et al., 1990) Fig. 8 εNd(500Ma) vs. ISr(500Ma) plot of the dioritic rocks from Inexpressible Island Data for comparison of intrusive complexes emplaced at around 490~500Ma in the Wilson arc (after Rocchi et al., 2015): The Abbott gabbro and its hybridization trend with melts from the deep crust, Vegetation leucogranites and their hybridization trend with melts from metasedimentary upper crust (Di Vincenzo and Rocchi, 1999; Rocchi et al., 2015); The Irizar granites and dykes (Rocchi et al., 2009); Intrusive rocks emplaced earlier in the Tiger oceanic arc, i.e. Tiger gabbro (Bracciali et al., 2009); The intrusive rocks of Morozumi mafic-intermediate (Rocchi et al., 2015); The I-type and S-type granites of GHI (Armienti et al., 1990) |
本次分析共获得47个锆石Hf同位素数据。从表 4中可以看出，3个闪长质岩石样品的锆石群Th/U比值均>0.1，Th/U平均值为0.51，Th与U之间正相关性较好。根据三个不同时空分布关系的锆石群年龄峰判断，难言岛闪长质岩石样品接近同期形成于约500Ma。εHf(t)比值(图 9)为-10.7~-6.3，Hf同位素具有较老的地壳模式年龄，tDM、tDMC分别为1331~1515Ma、1847~2118Ma，暗示初始岩浆可能起源于富集源区。
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表 4 难言岛闪长质岩石锆石Hf同位素测试结果 Table 4 Zircon Hf isotope compositions of dioritic rocks from Inexpressible Island |
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图 9 难言岛闪长质岩石锆石Hf同位素随时间分布图(底图据Wang et al., 2018) Fig. 9 Hf isotopic compositions vs. ages of the Inexpressible Island dioritic rocks (after Wang et al., 2018) |
Bomparola and Ghezzo(2007)对登山家山脉东部的钙碱性花岗岩进行Rb-Sr假等时线定年获得610Ma年龄。威尔逊地体东部两角闪长岩测得锆石U-Pb年龄为496.7±6.8Ma(Rocchi et al., 2015)；弗杰泰申单元煌斑岩、石英闪长岩、花岗闪长岩侵位时间在521~487Ma之间。难言岛闪长质岩侵入体中，定军山含角闪石斑晶闪长质岩墙锆石记录了501.5±1.6Ma年龄(Di Vincenzo and Rocchi, 1999; Rocchi et al., 2009; Hagen-Peter and Cottle, 2016)，望鹅岭和青龙山闪长质包体分别记录了500.4±1.2Ma和498.7±3.2Ma年龄，这三者年龄在误差限内基本一致(图 5)，王伟等(2014)研究表明难言岛石英闪长岩侵位年龄最晚至482±4.2Ma。结合岩石学特征，混杂斑块状的闪长岩包体和近N-E、N-N-E走向的岩墙指示了同期不同产状的侵位形态，表明岩浆被动侵位。综合前人结果，北维多利亚地难言岛闪长质岩浆作用是晚寒武世罗斯造山作用的产物。前人报道的弗杰泰申岛和难言岛区域出露的长英质岩体成分为碱性、准铝质或强过铝质花岗岩(Rocchi, 2004)，闪长质岩体与这些浅色花岗岩从毫米级到米级以不同的形态接触。前人通过斜长石-黑云母-石榴子石-白云母地质压力计估算获得过铝质花岗岩在0.2GPa下形成(Ghent and Stout, 1981)，弗杰泰申闪长质岩石通过地质压力计获取结果一致(Anderson and Smith, 1995)，这表明岩浆在浅部地壳快速冷却结晶。此外镜下研究没有发现难言岛闪长质岩石矿物结晶同变形结构和构造，且结晶较差。暗示了岩浆快速向地壳浅部运移结晶的历史。
难言岛高钾钙碱性闪长质岩石呈现典型的Nb、Ta、Ti负异常，在Nb-Y图中(图 10a)，难言岛闪长质岩石落入板内岩浆作用区域，在Zr-104×Ga/Al图解中(图 10b)也落在A型花岗岩的区域内，在Rb-(Nb+Y)图解中(图 10c)落在后碰撞花岗岩区域(Whalen et al., 1987)。结合微量元素特征和构造环境判别图解，表明难言岛晚寒武世闪长质岩浆作用侵位于后碰撞构造伸展环境下，属于A型花岗岩。Loiselle and Wones (1979)定义了产生于裂谷带和稳定陆内环境中非造山或者称为A型花岗岩，指出A型花岗岩具有碱性(alkaline)、无水(anhydrous)、非造山(anorogenic)的特征。前人认为这类花岗岩是非地壳成因的，而是遭受改造的幔源碱性玄武岩分离结晶形成(fractionation)(Bonin, 2007)。事实是大多数花岗岩在确定了源区的条件下，岩石普遍具有继承性，早先岩浆发生过混合或更复杂的过程改变其组分，从化学组成上具有普遍的重叠关系。准铝质花岗岩浆的起源被认为与俯冲带板片的性质密切相关，主要发育在洋-陆俯冲体系中的大陆板块边缘，也可以产于碰撞后或造山后环境(Boger, 2004; 2011)。这些花岗岩具有典型的岛弧花岗岩的地球化学和同位素特征，前人研究表明可由幔源镁铁质岩浆和地壳深熔岩浆的混合作用形成，表现为岩浆作用常含有镁铁质包体；或者高度准铝质的岩石经部分熔融产生，如俯冲板片(Martin, 1987)和镁铁质下地壳(Wedepohl, 1991)部分熔融作用，形成英云闪长质到低钾花岗闪长质岩石，如后太古宙准铝质花岗岩(Roberts and Clemens, 1993)。以上结果表明，虽然壳源物质显著影响部分熔融产生的熔体性质，但无论是地壳深熔作用还是直接由地幔岩浆分离结晶作用，都受到幔源物质或熔体与大陆地壳多次直接或间接反应。这也反应出北维多利亚地花岗岩I型、S型分类沿俯冲带平行分布(Vetter et al., 1987; Borg and DePaolo, 1991)的俯冲带岩浆动力学意义。此外，随着对A型岩浆岩的深入研究，有的A型花岗岩不仅具有准铝质系列岩石特征，还显示高钾的特征(Sun et al., 2011)，指示俯冲带岩石圈地幔源区的额外富集。
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图 10 难言岛闪长质岩石构造环境判别图解 (a) Nd-Y图解和(b) Zr-104×Ga/Al图解(Whalen et al., 1987)；(c)Rb-(Nb+Y)图解(Pearce et al., 1984) Fig. 10 Tectonic environment diagrams of the rocks in Inexpressible Island dioritic rocks (a) Nd vs. Y and (b) Zr vs. 104×Ga/Al diagrams (Whalen et al., 1987); (c) Rb vs. Nb+Y diagram (Pearce et al., 1984) |
难言岛闪长质岩石的SiO2值在54.03%~60.10%之间，相比较两角闪长岩(图 6)具有更高的总碱含量，整体比弗杰泰申煌斑岩、阿尔伯特辉长岩(Di Vincenzo and Rocchi, 1999; Rocchi et al., 2009, 2015)具有更高的Si2O含量，闪长质岩石整体演化程度较低，K2O-SiO2图解显示岩石具有超钾质组成(3.06%~3.9%)。超钾质特征和高的MgO(3.13%~3.98%)、Cr、Ni含量(表 2)与初始地幔熔体的特征相似。全岩球粒陨石标准化稀土元素显示出难言岛闪长质岩石整体呈轻稀土富集，具有微弱的Eu负异常，富集大离子亲石元素，相对于N-MORB强烈亏损Nb、Ta元素，图中可见与前人研究弗杰泰申煌斑岩一致的分布曲线(图 7a)。相比于阿尔伯特辉长岩，Nb、Ta、Ti相对弱亏损，弗杰泰申煌斑岩更加亏损Nb、Ta。泰格尔辉长岩(Bracciali et al., 2009)和难言岛闪长质岩石具有相似程度富集的Sr、Ti。岩石整体表现为准铝质，实验岩石学表明，镁铁质下地壳物质部分熔融产生的熔体为准铝质且K2O/Na2O比值< 1；压力大于1.5GPa时，产生的熔体为过铝质且K2O/Na2O比值>1的富钾埃达克质熔体(Rapp and Watson, 1995；Skjerlie and Patiño Douce, 2002)，这表明岩浆具有更深的源区或者其它的富集机制。难言岛闪长质岩石K2O/Na2O比值>1，但Sr、Y元素含量显示出岛弧岩浆源区性质，显然不是镁铁质下地壳部分熔融产生的。难言岛闪长质岩石样品的Nb/U和Ce/Pb平均值为12.93和6.88，相比于大陆地壳平均Nb/U和Ce/Pb(分别为10和4，Hofmann et al., 1986)更为富集，暗示难言岛闪长质岩浆源区与俯冲带地壳物质贡献密切相关。此外，高场强元素能够在岩浆作用和后期流体蚀变作用中稳定的保存下来，保留来自源区的特征(Rocchi et al., 2009)。难言岛闪长质岩石Zr/Hf比值为44.9~41.7，高于原始地幔的Zr/Hf比值36.25(Sun and McDonough, 1989)，表明源区在产生难言岛闪长质岩石熔体之前就已经富集(Goodgeand Fanning, 2012)，这与前人对非流体活动性元素区分源区的富集机制的结果相吻合(Rocchi, 2009)。前人运用同化混染和分离结晶(AFC)模型(DePaolo, 1981)，模拟计算获得弗杰泰申单元闪长质源区熔体可能的微量元素和同位素组成(Rocchi et al., 2009)，其岩浆源区很可能是俯冲交代的岩石圈地幔。前人模拟初始物质(详细模拟参数见Di Vincenzoand Rocchi, 1999；Rocchi et al., 2015)成分为高铝安第斯山玄武岩，其相比于N-MORB更富集。罗斯造山带尚无玄武岩浆作用的可靠报道，所以难言岛闪长质岩石的源区不可能来自新生镁铁质下地壳部分熔融。综合以上，表明早古生代闪长质岩浆源区是先前遭受俯冲组分交代的弧下大陆岩石圈地幔，可能的熔体富集机制(Di Vincenzoand Rocchi, 1999)包括：(1)俯冲壳源沉积物地幔楔交代富集；(2)壳-幔界面可能存在的长期同化混染-分离结晶(R-AFC)的岩浆源区(O'Hara, 1977)。放射性同位素组成方面，闪长质岩石总体具有(87Sr/86Sr)i范围0.7095~0.7098，(143Nd/144Nd)t范围0.511502~0.511629(表 3)，εNd(t)值为-7.1~-7.3，壳源花岗岩εNd(t)值一般为负值，通常εNd(t)偏离零值的程度越大，代表陆源物质组分的对源区贡献越多。此外SiO2与εNd(t)具有弱相关关系，这可能是岩浆从源区上升到地壳浅部与围岩同化混染作用的结果(图略)。对比前人研究北维多利亚地岩浆活动的Sr-Nd同位素双曲线同化混染演化路径，结果发现不同时期花岗质岩浆作用校正到初始年龄的Sr-Nd同位素特征显示出明显从闪长质岩石出发的同化混染分离结晶趋势，这与广泛的花岗岩港侵入体I、S型花岗岩(Armienti et al., 1990)演化一致(图 9)，这表明难言岛闪长质岩石组成可能是岩浆源区演化的结果。
综合以上特征，作者认识到难言岛闪长质岩石与弗杰泰申煌斑岩、阿尔伯特辉长岩、两角花岗岩岩浆源区以及侵位时代、构造环境密切相关，且其寄主围岩发育相似的变形结构特征，表明其岩浆源区的相似性。结合微量元素特征以及同位素特征，难言岛闪长质岩石来自于先前富集的大陆岩石圈地幔部分熔融，晚寒武世难言岛构造环境为板内伸展。
5.3 地质意义罗斯造山带北维多利亚地在晚古生代俯冲碰撞构造体制的形态是理解古太平洋板块持续向西汇聚产生大量同-后构造钾质、钙碱性岩浆岩的关键。罗斯造山带从南维多利亚地沿横贯南极山脉向北，岩浆岩持续记录的U-Pb年龄逐渐变年轻，表明罗斯造山带整体斜向俯冲构造体制(Rowell and Rees, 1989; Goodge et al., 1991; Janosy and Wilson, 1995; Encarnación and Grunow, 1996; Goodge and Dallmeyer, 1996; Storey et al., 1996; Rocchi et al., 1998; Goodge, 2002)。这与兰特曼约480Ma威尔逊地体和鲍尔斯地体发育的左旋走滑剪切韧性缝合带的特征相一致(Capponi et al., 1999; Federico et al., 2010)。前人认为罗斯造山带晚期板内伸展岩浆作用是冈瓦纳大陆外侧地体拼合而引发俯冲板块之间短暂耦合的结果(Cawood and Buchan, 2007)。早古生代北维多利亚地存在共轭板块俯冲构造(图 11a)，主要观点认为北维多利亚地洋内弧-大陆弧俯冲汇聚区域构造体制沿罗斯造山带延伸到南维多利亚地，由从主俯冲带弧前-弧后分离开的交替俯冲形态(Foster et al., 2005)过渡为单一的弧前俯冲(Rocchi et al., 2011)，进而在之后的弧陆碰撞时期即晚寒武世发生鲍尔斯弧-弧后与威尔逊大陆弧拼贴(Rocchi et al., 2011)(图 11b)。北维多利亚地榴辉岩相变质作用发生在不晚于530Ma，同时伴随530~520Ma钙碱性岩浆侵入事件，表明该阶段为活动大陆边缘向碰撞造山带转变时期(Godard and Palmeri, 2013; Di Vincenzo et al., 2016)。威尔逊绿片岩相记录了升温升压过程以及峰期近等压降温区域变质过程，这一低压(2~5kbar)相系顺时针P-T轨迹表明北维多利亚地早古生代地壳缩短、减薄发生再伸展的多期构造演化过程，这可能与泰格尔弧辉长岩浆作用相关的洋盆闭合有关(Bracciali et al., 2009)。兰特曼山脉榴辉岩记录的二阶段榴辉岩化温度和年龄与外侧岛弧向冈瓦纳陆缘增生的时限吻合(Di Vincenzo et al., 2016)。证据支持了北维多利亚地洋洋俯冲到洋陆俯冲，最终弧陆对接碰撞的构造历史(Rocchi et al., 2011)。北维多利亚地(Northern Victoria Land)晚寒武世伊里萨尔花岗岩和和弗杰泰申煌斑岩归因于伸展环境下软流圈地幔上涌，软流圈地幔上涌的机制可能是罗斯造山带弧陆碰撞榴辉岩折返过程中板块回撤作用(图 11c)或造山带减薄作用。
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图 11 北维多利亚地中寒武世至早奥陶世构造演化图(据Rocchi et al., 2009, 2011; Goodge, 2002修改) (a)中寒武世早期伸展事件，海沟后退、弧前伸展、弧后伸展和弧后张开, 鲍尔斯火山弧继续开始俯冲; (b)鲍尔斯弧后系统的增生，弧陆碰撞(超)高压俯冲/逆冲作用; (c)造山晚期，榴辉岩快速折返，发生碰撞后钾质岩浆作用 Fig. 11 Cambrian-Early Ordovician tectonic evolution sketch of Northern Victoria Land (modified after Rocchi et al., 2009, 2011; Goodge, 2002) (a) early Middle Cambrian extensional event, with trench retreat, forearc boudinage, arc migration, and backarc(s) and onset of the Bowers volcanic arc at Middle Cambrian period; (b) Bowers arc backarc system with (ultra)high-pressure subduction/underthrusting of part of the Bowers arc complex; (c) late orogenic stage with fast exhumation of eclogites, sediment shed to the northeast and post-collisional potassic magmatism |
(1) 罗斯造山带花岗岩港侵入体在难言岛形成的闪长质岩石年龄为498.7~501.5Ma。表现为高钾钙碱性、准铝质特点。结合微量元素构造判别图解，认为闪长质岩石为罗斯造山带后碰撞伸展环境下快速侵位的A型花岗岩。为造山带伸展环境下古老岩石圈地幔部分熔融产物。
(2) 难言岛闪长质岩石整体演化程度较低，岩石具有超钾质组成(3.06%~3.90%)和较高的SiO2、MgO、Cr、Ni含量，锆石εHf(t)值为-10.7~-6.3。综合初始岩浆高Sr、低Nd特征，表明岩浆来自俯冲物质交代富集的大陆岩石圈地幔。
(3) 北维多利亚地难言岛晚寒武世闪长质岩浆作用是在古太平洋板块西倾俯冲南极冈瓦纳大陆的构造格架下形成的。多俯冲构造体系致使弧陆碰撞，伴随弧地壳增生引起俯冲板片回撤作用，软流圈地幔上涌使早先俯冲交代富集的岩石圈地幔发生部分熔融，并产生岛弧特征的超钾闪长质岩浆作用，伸展环境下从源区快速侵位到地壳浅部形成难言岛晚寒武时期的A型花岗岩。
致谢 感谢中国第34次南极科学考察队对本研究涉及的野外地质考察和样品采集的支持；感谢匿名审稿人在文章评审过程中提出的宝贵意见。
Anderson JL and Smith DR. 1995. The effects of temperature and fO2 on the Al-in-hornblende barometer. American Mineralogist, 80(5-6): 549-559 DOI:10.2138/am-1995-5-614
|
Armienti P, Ghezzo C, Innocenti F, Manetti P, Rocchi S and Tonarini S. 1990. Isotope geochemistry and petrology of granitoid suites from Granite Harbour Intrusives of the Wilson Terrane, North Victoria Land, Antarctica. European Journal of Mineralogy, 2(1): 103-124 DOI:10.1127/ejm/2/1/0103
|
Bonin B. 2007. A-type granites and related rocks: Evolution of a concept, problems and prospects. Lithos, 97(1-2): 1-29 DOI:10.1016/j.lithos.2006.12.007
|
Blichert-Toft J and Albarède F. 1998. The Lu-Hf isotope geochemistry of chondrites and the evolution of the mantle-crust system. Earth and Planetary Science Letters, 148(1-2): 243-258
|
Boger SD and Miller JM. 2004. Terminal suturing of Gondwana and the onset of the Ross-Delamerian Orogeny: The cause and effect of an Early Cambrian reconfiguration of plate motions. Earth and Planetary Science Letters, 219: 35-48 DOI:10.1016/S0012-821X(03)00692-7
|
Boger SD. 2011. Antarctica: Before and after Gondwana. Gondwana Research, 19(2): 335-371
|
Bomparola RM and Ghezzo C. 2007. Inside the Granite Harbour Intrusives of northern Victoria Land: Timing and origin of the intrusive sequence. In: U.S. Geological Survey and the National Academies. 10th International Symposium on Antarctic Earth Sciences. USGS of-2007-1047, Extended Abstract 043
|
Bomparola RM, Ghezzo C, Belousova E, Griffin WL and O'Reilly SY. 2007. Resetting of the U-Pb zircon system in Cambro-Ordovician intrusives of the deep freeze range, Northern Victoria Land, Antarctica. Journal of Petrology, 48(2): 327-364 DOI:10.1093/petrology/egl064
|
Borg SG, Stump E, Chappell BW, McCulloch MT, Wyborn D, Armstrong RL and Holloway JR. 1987. Granitoids of northern Victoria Land, Antarctica: Implications of chemical and isotopic variations to regional crustal structure and tectonics. American Journal of Science, 287(2): 127-169 DOI:10.2475/ajs.287.2.127
|
Borg SG and DePaolo DJ. 1991. A tectonic model of the Antarctic Gondwana margin with implications for southeastern Australia: Isotopic and geochemical evidence. Tectonophysics, 196(3-4): 339-358 DOI:10.1016/0040-1951(91)90329-Q
|
Boynton WV. 1984. Cosmochemistry of the rare earth elements: Meteorite studies. Developments in Geochemistry, 2: 63-114
|
Bracciali L, Di Vincenzo G, Rocchi S and Ghezzo C. 2009. The Tiger gabbro from Northern Victoria Land, Antarctica: The roots of an island arc within the Early Palaeozoic margin of Gondwana. Journal of the Geological Society, 166(4): 711-724 DOI:10.1144/0016-76492008-098
|
Bradshaw JD and Laird MG. 1983. The pre-Beacon geology of Northern Victoria Land: A review. Antarctic Earth Science: 98-101
|
Cawood PA. 2005. Terra Australis Orogen: Rodinia breakup and development of the Pacific and Iapetus margins of Gondwana during the Neoproterozoic and Paleozoic. Earth-Science Reviews, 69(3-4): 249-279 DOI:10.1016/j.earscirev.2004.09.001
|
Cawood PA and Buchan C. 2007. Linking accretionary orogenesis with supercontinent assembly. Earth-Science Reviews, 82(3-4): 217-256 DOI:10.1016/j.earscirev.2007.03.003
|
Capponi G, Crispini L and Meccheri M. 1999. Structural history and tectonic evolution of the boundary between the Wilson and Bowers terranes, Lanterman Range, Northern Victoria Land, Antarctica. Tectonophysics, 312: 249-266 DOI:10.1016/S0040-1951(99)00174-2
|
Chen H, Wang W and Zhao Y. 2019. Constraints on Early Paleozoic magmatic processes and tectonic setting of Inexpressible Island, Northern Victoria Land, Antarctica. Advances in Polar Science, 30(1): 52-69
|
DePaolo DJ. 1981. Trace element and isotopic effects of combined wall rock assimilation and fractional crystallization. Earth and Planetary Science Letters, 53(2): 189-202 DOI:10.1016/0012-821X(81)90153-9
|
Di Vincenzo G and Rocchi S. 1999. Origin and interaction of mafic and felsic magmas in an evolving late orogenic setting: The Early Paleozoic Terra Nova Intrusive Complex, Antarctica. Contributions to Mineralogy and Petrology, 137(1-2): 15-35 DOI:10.1007/s004100050579
|
Di Vincenzo G, Horton F and Palmeri R. 2016. Protracted (~30Ma) eclogite-facies metamorphism in Northern Victoria Land (Antarctica): Implications for the geodynamics of the Ross/Delamerian Orogen. Gondwana Research, 40: 91-106 DOI:10.1016/j.gr.2016.08.005
|
Elliot DH and Fanning CM. 2008. Detrital zircons from Upper Permian and Lower Triassic Victoria Group sandstones, Shackleton Glacier region, Antarctica: Evidence for multiple sources along the Gondwana plate margin. Gondwana Research, 13(2): 259-274 DOI:10.1016/j.gr.2007.05.003
|
Estrada S and Jordan H. 2003. Early Paleozoic Island arc volcanism in the Bowers Terrane of Northern Victoria Land, Antarctica. Geologisches Jahrbuch, B95: 183-207
|
Estrada S, Läufer A, Eckelmann K, Hofmann M, Gärtner A and Linnemann U. 2016. Continuous Neoproterozoic to Ordovician sedimentation at the East Gondwana margin Implications from detrital zircons of the Ross Orogen in Northern Victoria Land, Antarctica. Gondwana Research, 37: 426-448 DOI:10.1016/j.gr.2015.10.006
|
Encarnación J and Grunow A. 1996. Changing magmatic and tectonic styles along the paleo-Pacific margin of Gondwana and the onset of Early Paleozoic magmatism in Antarctica. Tectonics, 15(6): 1325-1341 DOI:10.1029/96TC01484
|
Federico L, Capponi G and Crispini L. 2006. The Ross orogeny of the Transantarctic Mountains: A Northern Victoria Land perspective. International Journal of Earth Sciences, 95(5): 759-770 DOI:10.1007/s00531-005-0063-5
|
Federico L, Crispini L, Capponi G and Bradshaw JD. 2009. The Cambrian Ross Orogeny in Northern Victoria Land (Antarctica) and New Zealand: A synthesis. Gondwana Research, 15(2): 188-196 DOI:10.1016/j.gr.2008.10.004
|
Federico L, Crispini L and Capponi G. 2010. Fault-slip analysis and transpressional tectonics: A study of Paleozoic structures in Northern Victoria Land, Antarctica. Journal of Structural Geology, 32(5): 667-684 DOI:10.1016/j.jsg.2010.04.001
|
Foster DA, Gray DR and Spaggiari C. 2005. Timing of subduction and exhumation along the Cambrian East Gondwana margin, and the formation of Paleozoic back arc basins. Geological Society of America Bulletin, 117(1-2): 105-116
|
Ghent ED and Stout MZ. 1981. Geobarometry and geothermometry of plagioclase-biotite-garnet-muscovite assemblages. Contributions to Mineralogy and Petrology, 76(1): 92-97 DOI:10.1007/BF00373688
|
Ghezzo C, Baldelli C, Biagini R, Carmignani L, Di Vincenzo G, Gosso G, Lelli A, Lombardo B, Montrasio A, Pertusati PC and Salvini F. 1987. Granitoids from the David Glacier-Aviator Glacier segment of the Transantarctic Mountains, Victoria Land, Antarctica. Memorie Della Societa Geologica Italiana, 33: 143-159
|
Giacomini F, Tiepolo M, Dallai L and Ghezzo C. 2007. On the onset and evolution of the Ross-orogeny magmatism in North Victoria Land, Antarctica. Chemical Geology, 240(1-2): 103-128 DOI:10.1016/j.chemgeo.2007.02.005
|
Godard G and Palmeri R. 2013. High-pressure metamorphism in Antarctica from the Proterozoic to the Cenozoic: A review and geodynamic implications. Gondwana Research, 23(3): 844-864 DOI:10.1016/j.gr.2012.07.012
|
Goodge JW, Borg SG, Smith BK and Bennett VC. 1991. Tectonic significance of Proterozoic ductile shortening and translation along the Antarctic margin of Gondwana. Earth and Planetary Science Letters, 102(1): 58-70 DOI:10.1016/0012-821X(91)90017-C
|
Goodge JW and Dallmeyer RD. 1996. Contrasting thermal evolution within the Ross orogen, Antarctica: Evidence from mineral 40Ar/39Ar. The Journal of Geology, 104(4): 435-458 DOI:10.1086/629838
|
Goodge JW. 2002. From Rodinia to Gondwana: Supercontinent evolution in the Transantarctic Mountains. In: Proceedings of the 8th International Symposium on Antarctic Earth Sciences. Wellington, New Zealand: Royal Society of New Zealand, 61-74
|
Goodge JW, Fanning CM, Norman MD and Bennett VC. 2012. Temporal, isotopic and spatial relations of Early Paleozoic Gondwana-margin arc magmatism, central Transantarctic Mountains, Antarctica. Journal of Petrology, 53(10): 2027-2065 DOI:10.1093/petrology/egs043
|
Goodge JW. 2020. Geological and tectonic evolution of the Transantarctic Mountains, from ancient craton to recent enigma. Gondwana Research, 80: 50-122 DOI:10.1016/j.gr.2019.11.001
|
Gunn BM and Warren G. 1962. Geology of Victoria Land between the Mawson and Mulock Glaciers. Antarctica: New Zealand Geological Survey Bulletin, 71
|
Grew ES, Kleinschmidt G and Schubert W. 1984. Contrasting metamorphic belts in North Victoria Land. Antarctica. Geologisches Jahrbuch, B60: 253-264
|
Hagen-Peter G and Cottle JM. 2016. Synchronous alkaline and subalkaline magmatism during the Late Neoproterozoic-Early Paleozoic Ross orogeny, Antarctica: Insights into magmatic sources and processes within a continental arc. Lithos, 262: 677-698 DOI:10.1016/j.lithos.2016.07.032
|
Henjes-Kunst F and Schüssler U. 2003. Metasedimentary units of the Cambro-Ordovician Ross Orogen in Northern Victoria Land and Oates Land: Implications for their provenance and geotectonic setting from geochemical and Nd-Sr isotope data. Terra Antartica, 10: 105-128
|
Hofmann AW, Jochum KP, Seufert M and White WM. 1986. Nb and Pb in oceanic basalts: New constraints on mantle evolution. Earth and Planetary Science Letters, 79(1-2): 33-45 DOI:10.1016/0012-821X(86)90038-5
|
Hu ZC, Liu YS, Gao S, Xiao SQ, Zhao LS, Günther D, Li M, Zhang W and Zong KQ. 2012a. A "wire" signal smoothing device for laser ablation inductively coupled plasma mass spectrometry analysis. Spectrochimica Acta, 78: 50-57 DOI:10.1016/j.sab.2012.09.007
|
Hu ZC, Liu YS, Gao S, Liu WG, Zhang W, Tong XR, Lin L, Zong KQ, Li M, Chen HH, Zhou L and Yang L. 2012b. Improved in situ Hf isotope ratio analysis of zircon using newly designed X skimmer cone and jet sample cone in combination with the addition of nitrogen by laser ablation multiple collector ICP-MS. Journal of Analytical Atomic Spectrometry, 27(9): 1391-1399 DOI:10.1039/c2ja30078h
|
Janosy RJ and Wilson TJ. 1995. Tectonic setting of the Early Paleozoic dike swarm in Southern Victoria Land. VII International Symposium on Antarctic Earth Sciences, Siena (Italy): September 1995. 10-15. Abstracts, 212
|
Kleinschmidt G and Tessensohn F. 1987. Early Paleozoic westward directed subduction at the Pacific margin of Antartica. In: Gondwana Six: Structure, Tectonics, and Geophysics. Washington, D.C. : AGU, 40: 89-105
|
Kretz R. 1983. Symbols for rock-forming minerals. American Mineralogist, 68(1-2): 277-279
|
Liu YS, Hu ZC, Gao S, Günther D, Xu J, Gao CG and Chen HH. 2008. In situ analysis of major and trace elements of anhydrous minerals by LA-ICP-MS without applying an internal standard. Chemical Geology, 257: 34-43 DOI:10.1016/j.chemgeo.2008.08.004
|
Liu YS, Gao S, Hu ZC, Gao CG, Zong KQ and Wang DB. 2010. Continental and oceanic crust recycling-induced melt-peridotite interactions in the Trans-North China Orogen: U-Pb dating, Hf isotopes and trace elements in zircons of mantle xenoliths. Journal of Petrology, 51: 537-571 DOI:10.1093/petrology/egp082
|
Ludwig KR. 2003. ISOPLOT 3.00: A Geochronological Toolkit for Microsoft Excel. Berkeley, California: Berkeley Geochronology Center, 1-39
|
Loiselle MC and Wones DR. 1979. Characteristics and origin of anorogenic granites. Abstracts of Papers to be Presented at the Annual Meetings of the Geological Society of America and Associated Societies, San Diego, California, November 5-8, 11: 468
|
Maniar PD and Piccoli PM. 1989. Tectonic discrimination of granitoids. Geological Society of America Bulletin, 101(5): 635-643 DOI:10.1130/0016-7606(1989)101<0635:TDOG>2.3.CO;2
|
Martin H. 1987. Petrogenesis of Archaean trondhjemites, tonalites, and granodiorites from eastern Finland: Major and trace element geochemistry. Journal of Petrology, 28(5): 921-953 DOI:10.1093/petrology/28.5.921
|
Middlemost EAK. 1994. Naming materials in the magma/igneous rock system. Earth-Science Reviews, 37(3-4): 215-224 DOI:10.1016/0012-8252(94)90029-9
|
O'Hara MJ. 1977. Geochemical evolution during fractional crystallization of a periodically refilled magma chamber. Nature, 266(5602): 503-507 DOI:10.1038/266503a0
|
Palmeri R, Pertusati PC, Ricci CA and Talarico F. 1994. Late Proterozoic (?)-Early Paleozoic evolution of the active Pacific margin of Gondwana: Evidence from the southern Wilson Terrane (Northern Victoria Land, Antarctica). Terra Antartica, 1(1): 5-9
|
Palmeri R, Sandroni S, Godard G and Ricci CA. 2012. Boninite-derived amphibolites from the Lanterman-Mariner suture (Northern Victoria Land, Antarctica): New geochemical and petrological data. Lithos, 140-141: 200-223 DOI:10.1016/j.lithos.2012.02.001
|
Paulsen TS, Encarnación J, Grunow AM, Layer PW and Watkeys M. 2007. New age constraints for a short pulse in Ross orogen deformation triggered by East-West Gondwana suturing. Gondwana Research, 12(4): 417-427 DOI:10.1016/j.gr.2007.05.011
|
Pearce JA, Harris NBW and Tindle AG. 1984. Trace element discrimination diagrams for the tectonic interpretation of granitic rocks. Journal of Petrology, 25(4): 956-983 DOI:10.1093/petrology/25.4.956
|
Peccerillo A and Taylor SR. 1976. Geochemistry of Eocene calc-alkaline volcanic rocks from the Kastamonu area, Northern Turkey. Contributions to Mineralogy and Petrology, 58(1): 63-81 DOI:10.1007/BF00384745
|
Rapp RP and Watson EB. 1995. Dehydration melting of metabasalt at 8~32kbar: Implications for continental growth and crust-mantle recycling. Journal of Petrology, 36(4): 891-931 DOI:10.1093/petrology/36.4.891
|
Roberts MP and Clemens JD. 1993. Origin of high-potassium, talc-alkaline, I-type granitoids. Geology, 21(9): 825-828 DOI:10.1130/0091-7613(1993)021<0825:OOHPTA>2.3.CO;2
|
Rocchi S, Tonarini S, Armienti P, Innocenti F and Manetti P. 1998. Geochemical and isotopic structure of the Early Palaeozoic active margin of Gondwana in Northern Victoria Land, Antarctica. Tectonophysics, 284(3-4): 261-281 DOI:10.1016/S0040-1951(97)00178-9
|
Rocchi S, Di Vincenzo G and Ghezzo C. 2004. The Terra Nova intrusive complex (Victoria Land, Antarctica). Terra Antartica Reports, 10: 1-51
|
Rocchi S, Di Vincenzo G, Ghezzo C and Nardini I. 2009. Granite-lamprophyre connection in the latest stages of the Early Paleozoic Ross Orogeny (Victoria Land, Antarctica). Geological Society of America Bulletin, 121(5-6): 801-819 DOI:10.1130/B26342.1
|
Rocchi S, Bracciali L, Di Vincenzo G, Gemelli M and Ghezzo C. 2011. Arc accretion to the Early Paleozoic Antarctic margin of Gondwana in Victoria Land. Gondwana Research, 19(3): 594-607 DOI:10.1016/j.gr.2010.08.001
|
Rocchi S, Di Vincenzo G, Dini A, Petrelli M and Vezzoni S. 2015. Time-space focused intrusion of genetically unrelated arc magmas in the Early Paleozoic Ross-Delamerian Orogen (Morozumi Range, Antarctica). Lithos, 232: 84-99 DOI:10.1016/j.lithos.2015.06.006
|
Rossetti F, Vignaroli G, Di Vincenzo G, Gerdes A, Ghezzo C, Theye T and Balsamo F. 2011. Long-lived orogenic construction along the paleo-Pacific margin of Gondwana (Deep Freeze Range, North Victoria Land, Antarctica). Tectonics, 30(4): TC4008
|
Rowell AJ and Rees MN. 1989. Early Palaeozoic history of the upper Beardmore Glacier area: Implications for a major Antarctic structural boundary within the Transantarctic Mountains. Antarctic Science, 1(3): 249-260 DOI:10.1017/S0954102089000374
|
Shen QH. 2009. The recommendation of a systematic list of mineral abbreviations. Acta Petrologica et Mineralogica, 28(5): 495-500 (in Chinese with English abstract)
|
Skjerlie KP and Patiño Douce AE. 2002. The fluid-absent partial melting of a zoisite-bearing quartz eclogite from 1.0 to 3.2GPa: Implications for melting in thickened continental crust and for subduction-zone processes. Journal of Petrology, 43(2): 291-314 DOI:10.1093/petrology/43.2.291
|
Steiger RH and Jäger E. 1977. Subcommission on geochronology: Convention on the use of decay constants in geochronology and cosmochronology. Earth and Planetary Science Letters, 36(3): 359-362 DOI:10.1016/0012-821X(77)90060-7
|
Storey BC, Macdonald DIM, Dalziel IWD, Isbell JL and Millar IL. 1996. Early Paleozoic sedimentation, magmatism, and deformation in the Pensacola Mountains, Antarctica: The significance of the Ross orogeny. Geological Society of America Bulletin, 108(6): 685-707 DOI:10.1130/0016-7606(1996)108<0685:EPSMAD>2.3.CO;2
|
Sun SS and McDonough WF. 1989. Chemical and isotopic systematics of oceanic basalts: Implications for mantle composition and processes. In: Saunders AD and Norry MJ (eds. ). Magmatism in the Ocean Basins. Geological Society, London, Special Publications, 42(1): 313-345
|
Sun Y, Ma CQ, Liu YY and She ZB. 2011. Geochronological and geochemical constraints on the petrogenesis of Late Triassic aluminous A-type granites in southeast China. Journal of Asian Earth Sciences, 42(6): 1117-1131 DOI:10.1016/j.jseaes.2011.06.007
|
Schüssler U, Henjes-Kunst F, Talarico F and Flöttmann T. 2004. High-grade crystalline basement of the northwestern Wilson Terrane at Oates Coast: New petrological and geochronological data and implications for its tectonometamorphic evolution. Terra Antartica, 11: 15-34
|
Talarico F and Castelli D. 1995. Relict granulites in the Ross orogen of Northern Victoria Land (Antarctica): I. Field occurrence, petrography and metamorphic evolution. Precambrian Research, 75(3-4): 141-156
|
Talarico FM, Palmeri R and Ricci CA. 2004. Regional metamorphism and P-T evolution of the Ross Orogen in Northern Victoria Land (Antarctica): A review. Periodico di Mineralogia, 73: 185-196
|
Tessensohn F and Henjes-Kunst F. 2005. Northern Victoria Land terranes, Antarctica: Far-travelled or local products?. Geological Society, London, Special Publications, 246(1): 275-291 DOI:10.1144/GSL.SP.2005.246.01.10
|
Vaughan APM and Pankhurst RJ. 2008. Tectonic overview of the West Gondwana margin. Gondwana Research, 13(2): 150-162
|
Vetter U and Tessensohn F. 1987. S- and I-type granitoids of North Victoria Land, Antarctica, and their inferred geotectonic setting. Geologische Rundschau, 76(1): 233-243 DOI:10.1007/BF01820585
|
Vervoort JD and Blichert-Toft J. 1999. Evolution of the depleted mantle: Hf isotope evidence from juvenile rocks through time. Geochimica et Cosmochimica Acta, 63(3-4): 533-556 DOI:10.1016/S0016-7037(98)00274-9
|
Wang H, Wang SH, Xu ZW, Fu B, Zhao ZX, Li ZG, Dong YH, Tang LM and Li J. 2018. Geochemical and Sr-Nd-Pb-Hf-O isotopic compositions of the Tiezhai complex: Implications for lithosphere destruction of the North China Craton. Gondwana Research, 61: 203-221 DOI:10.1016/j.gr.2018.04.020
|
Wang W, Hu JM, Chen H, Yu GW, Zhao Y and Liu XC. 2014. LA-ICP-MS zircon U-Pb ages and geological constraint of intrusive rocks from the Inexpressible Island, Northern Victoria Land, Antarctica. Geological Bulletin of China, 33(12): 2023-2031 (in Chinese with English abstract)
|
Weaver SD, Bradshaw JD and Laird MG. 1984. Geochemistry of Cambrian volcanics of the Bowers Supergroup and implications for the Early Palaeozoic tectonic evolution of Northern Victoria Land, Antarctica. Earth and Planetary Science Letters, 68(1): 128-140 DOI:10.1016/0012-821X(84)90145-6
|
Wedepohl KH. 1991. Chemical composition and fractionation of the continental crust. Geologische Rundschau, 80(2): 207-223
|
Whalen JB, Currie KL and Chappell BW. 1987. A-type granites: Geochemical characteristics, discrimination and petrogenesis. Contributions to Mineralogy and Petrology, 95(4): 407-419 DOI:10.1007/BF00402202
|
Zong KQ, Klemd R, Yuan Y, He ZY, Guo JL, Shi XL, Liu YS, Hu ZC and Zhang ZM. 2017. The assembly of Rodinia: The correlation of early Neoproterozoic (ca. 900Ma) high-grade metamorphism and continental arc formation in the southern Beishan Orogen, southern Central Asian Orogenic Belt (CAOB). Precambrian Research, 290: 32-48
|
沈其韩. 2009. 推荐一个系统的矿物缩写表. 岩石矿物学杂志, 28(5): 495-500. |
王伟, 胡健民, 陈虹, 于根旺, 赵越, 刘晓春. 2014. 南极北维多利亚地难言岛侵入岩LA-ICP-MS锆石U-Pb年龄及其地质意义. 地质通报, 33(12): 2023-2031. |