岩石地球化学-郭进辉

1、中国科学院研究生院 中国科学院地质与地球物理研究所 岩石地球化学 郭敬辉 82998541（新办公楼541） ,理解地球内部的方法,地质,地球物理技术,物理化学实验模拟,地球化学,提纲 第一章 绪论 现代全球构造体系中的岩石成因问题 第二章 岩石地球化学研究方法的理论基础,第三章 地壳和上地幔的主要构成岩类及其地球化学 上地幔的岩石学组成、结构及地球化学特征，地幔的不均一性和地幔端元； 不同构造环境的地壳结构，下地壳的岩石学组成及地球化学特征； 上地壳主要岩类的地球化学特征。,第四章 大洋地壳的形成演化与地球化学过程 洋中脊、蛇绿岩、大洋地壳的生长机制与地幔对流； 洋岛、大洋高原的岩石地球化学

2、特征与地幔柱构造； 岛弧及活动大陆边缘主要岩石组合的地球化学特征，俯冲消减带的岩浆发生机制与地球化学特征的联系。,第五章 大陆地壳的形成演化与地球化学过程 大陆岩石圈地幔的基本组成特征，拆沉作用与富集地幔的形成机制； 埃达克岩，科马提岩、片麻岩的成因与太古宙大陆生长机制； 大陆碰撞造山带，同碰撞与碰撞后岩浆活动：类型、地球化学及成因机制； 大陆裂谷带的岩浆活动类型及地球化学特征 大火成岩省的岩石地球化学特征,第六章 新全球构造与地球系统中的圈层相互作用 第七章研究实例1: 太古宙大陆地壳生长机制 第八章研究实例2: 花岗岩类成因与大地构造 第九章 研究实例3: 中国东部中新生代岩石圈加厚、减薄

3、与转型,对岩石地球化学的思考框架,要面对哪些特定的科学问题? 主要采用哪些方法、理论和技术？ 成功解决了哪些科学问题？ 哪些理论、方法、成果可以作为学科发展的标志？,1、上地幔的性质和相关过程,第三章 地壳和上地幔的主要构成岩类及其地球化学,地球的圈层结构,地球各主要圈层的体积和质量,地壳的厚度是地幔的0.59；体积是地幔的0.9；质量是0.6。 因此，地幔的微小变化会导致地壳的巨大变化,地幔的形成,地球早期的核幔分离,地幔橄榄岩包体 太行山南部鹤壁,地幔橄榄岩包体 河北张家口大麻坪,上地幔的化学和标准矿物组成 - 地幔包体资料,二辉橄榄岩,不同深度地幔的矿物组成和密度,上地幔,下地幔,过渡带

4、,上地幔矿物相关系,亏损地幔的贡献大洋地壳的形成,拉斑玄武岩,富集地幔的贡献大洋岛的形成,碱性玄武岩,地幔柱构造 Plume Tectonics,2、不同构造环境的地壳结构， 下地壳的岩石学组成及地球化学特征,第三章 地壳和上地幔的主要构成岩类及其地球化学,大陆地壳一般结构,地壳结构的类型： 1 速度结构、2 岩石学结构、 3 成分结构、4 流变学结构,上部地壳，Upper crust 中部地壳，Middle crust 上部下地壳，Upper lower crust 最下地壳，lowermost continental crust,大陆地壳的9种结构（Vp速度）类型,中国不同构造单元地壳的结

5、构(Vp速度),中国东部地壳的平均速度结构（Vp）,大别山造山带地壳速度结构（王椿镛等，1997）,世界著名造山带地壳断面对比图,大陆地壳的岩石学结构,实例：,上部地壳：沉积岩，火山岩 中部地壳：变质沉积岩，混合岩，花岗岩 上部下地壳：中性麻粒岩，斜长角闪岩 最下地壳：基性麻粒岩，辉长岩，辉石岩,要区分形成、赋存的不同条件,Sawyer EW, 1998,JP,Zegers and LeRoex et al. (1983) J. Petrol., 24, 267-318.,结论： MORBs 源区不止一种类型 大洋盆地之下的地幔是不均匀的 N-MORBs，上部的，亏损地幔 E-MORBs，深部

6、的，富集地幔 T-MORBs， 混合的，可能发生在岩浆上升过程中，或者发生在岩浆上升到浅部的岩浆房之后,MORB 的成因,板块伸展，张开 地幔物质向上运移，进入伸展带 上升的地幔物质发生减压熔融 形成N-MORB 的部分熔融发生在亏损上地幔 60-80 km 深度，继承了亏损的微量元素和同位素特征,After Zindler et al. (1984) Earth Planet. Sci. Lett., 70, 175-195. and Wilson (1989) Igneous Petrogenesis, Kluwer.,发生部分熔融的区域宽度大约 100 km，但是熔体通常汇集于扩张脊下宽

7、度大约3-8 km的区域 在上地幔大约25-35 km的深度，熔体blobs从原岩中分离出来，直到这时，熔体一直与残留相（方辉橄榄岩）保持平衡。 然后，熔体迅速迁移到扩张脊之下1-2 km深度，形成轴部的岩浆房,After Zindler et al. (1984) Earth Planet. Sci. Lett., 70, 175-195. and Wilson (1989) Igneous Petrogenesis, Kluwer.,MORB 的成因,深部的富集地幔源区，也可能被动地上移，形成一个plume，产生 E-MORB型岩浆,After Zindler et al. (1984)

8、Earth Planet. Sci. Lett., 70, 175-195. and Wilson (1989) Igneous Petrogenesis, Kluwer.,扩张脊的岩浆房,最初的模式 在岩浆房，由于分离结晶作用，演化出MORB岩浆 岩浆房的结晶分异作用，由于其下面新鲜的、原始的MORB岩浆的周期性添加，而得到缓和 分异的岩浆，沿着岩浆房顶部的伸展和断裂上行，造成水下喷发，形成枕状熔岩，并留下席状岩墙杂岩,From Byran and Moore (1977) Geol. Soc. Amer. Bull., 88, 556-570.,扩张脊的岩浆房,岩浆房顶部和边部，发生结晶作

9、用，形成层状的辉长岩 (layer 3) 较重的橄榄石和辉石晶体，沉入岩浆房底部，形成超镁铁质岩 (layer 4),From Byran and Moore (1977) Geol. Soc. Amer. Bull., 88, 556-570.,现代的模式之一：快速扩张脊,After Perfit et al. (1994) Geology, 22, 375-379.,Dike-like mush zone and a smaller transition zone beneath the well-developed rift valley The bulk of the body is

10、well below the liquidus temperature, so convection and mixing is far less likely than at fast ridges,After Sinton and Detrick (1992) J. Geophys. Res., 97, 197-216.,现代的模式之二：慢速扩张脊,Nisbit and Fowler (1978) suggested that numerous, small, ephemeral magma bodies occur at slow ridges (“infinite leek”) Slo

11、w ridges are generally less differentiated than fast ridges No continuous liquid lenses, so magmas entering the axial area are more likely to erupt directly to the surface (hence more primitive), with some mixing of mush,After Sinton and Detrick (1992) J. Geophys. Res., 97, 197-216.,沉积物,熔岩,岩墙杂岩,辉长岩，

12、正在岩浆房结晶,层状堆晶橄榄岩,亏损的方辉橄榄岩,上升的熔融体,洋中脊的结构,洋中脊的岩浆活动,这个洋中脊结构与蛇绿岩套相同吗？,洋洋 岛弧 (IA) 洋陆 大陆弧或活动大陆边缘 (ACM),Principal subduction zones associated with orogenic volcanism and plutonism. Triangles are on the overriding plate. PBS = Papuan-Bismarck-Solomon-New Hebrides arc. SAfter Wilson (1989) Igneous Petrogenesi

13、s, Allen Unwin/Kluwer.,不同构造环境岩石组合的差别,After Wilson (1989). Igneous Petrogenesis. Unwin Hyman - Kluwer,岛弧岩浆活动,岛弧岩浆活动的时空变化,1) 岛弧火山岩存在成分极性，从俯冲带向岛弧方向，依次出现拉斑玄武岩浆系列、钙碱性岩浆系列和碱性岩浆系列 2) 岛弧岩浆岩的岩石类型多样，主元素有较大的变化范围。 3) 岛弧拉斑玄武岩微量元素以Nb、Zr、Ti的负异常为特征。 4) 岛弧拉斑玄武岩来自富集地幔楔，俯冲的大洋地壳脱水造成富集地幔楔。 5) 岛弧岩浆活动伴随有同化作用，结晶分异作用，混染作用等等

14、,Schematic cross section through a typical island arc after Gill (1981), Orogenic Andesites and Plate Tectonics. Springer-Verlag. HFU= heat flow unit (4.2 x 10-6 joules/cm2/sec),俯冲带结构,岛弧的岩石成因机制,A proposed model for subduction zone magmatism with particular reference to island arcs. Dehydration of sl

15、ab crust causes hydration of the mantle (violet), which undergoes partial melting as amphibole (A) and phlogopite (B) dehydrate. From Tatsumi (1989), J. Geophys. Res., 94, 4697-4707 and Tatsumi and Eggins (1995). Subduction Zone Magmatism. Blackwell. Oxford.,俯冲板片脱水造成LIL, 10Be, B, 等富集，并形成富集的Nd, Sr, P

16、b同位素组成 地幔楔造成HFS亏损,钙碱系列的母岩浆是高铝玄武岩, 一种典型地发育在俯冲带环境的玄武岩 一些高Mg (8wt% MgO) 高Al的玄武岩可能是原始岩浆结晶产物，包括一些安山岩，但是大多数熔岩具有高度演化的成分，不可能是元素岩浆结晶产物 广泛发育的低Mg (17wt% Al2O3) 玄武岩可能是原始拉斑玄武岩岩浆在较深的位置结晶分异的产物 分离结晶作用在不同的深度都有发育,岛弧岩浆活动,岛弧岩浆活 动综合图示,主元素和岩浆系列,拉斑系列Tholeiitic (MORB, OIT) 碱性系列 (OIA) 钙碱系列 ( 限于 SZ),Data compiled by Terry Pl

17、ank (Plank and Langmuir, 1988) Earth Planet. Sci. Lett., 90, 349-370.,a. 硅碱图 b. AFM c. FeO*/MgO 对SiO2 30岛弧和大陆弧的1946个分析数据，主要是火山岩,钙碱系列的细分,用K2O 作为指标 3 个亚系列,The three andesite series of Gill (1981) Orogenic Andesites and Plate Tectonics. Springer-Verlag. Contours represent the concentration of 2500 anal

18、yses of andesites stored in the large data file RKOC76 (Carnegie Institute of Washington).,K2O-SiO2 diagram distinguishing high-K, medium-K and low-K series. Large squares = high-K, stars = med.-K, diamonds = low-K series from Table 16-2. Smaller symbols are identified in the caption. Differentiatio

19、n within a series (presumably dominated by fractional crystallization) is indicated by the arrow. Different primary magmas (to the left) are distinguished by vertical variations in K2O at low SiO2. After Gill, 1981, Orogenic Andesites and Plate Tectonics. Springer-Verlag.,AFM diagram distinguishing

20、tholeiitic and calc-alkaline series. Arrows represent differentiation trends within a series.,FeO*/MgO vs. SiO2 diagram distinguishing tholeiitic and calc-alkaline series.,如果加上拉斑玄武岩系列，有6个亚系列,3个最常见,Combined K2O - FeO*/MgO diagram in which the Low-K to High-K series are combined with the tholeiitic vs

21、. calc-alkaline types, resulting in six andesite series, after Gill (1981) Orogenic Andesites and Plate Tectonics. Springer-Verlag. The points represent the analyses in the appendix of Gill (1981).,Low-K 拉斑系列,Med-K 钙碱系列,Hi-K 混合系列,拉斑系列和钙碱系列的分异演化,From Winter (2001) An Introduction to Igneous and Metam

22、orphic Petrology. Prentice Hall.,钙碱系列显示连续的SiO2增长，没有Fe 的富集,Skaergrd 侵入体，拉斑系列,无变化,拉斑系列和钙碱系列的分异演化,空间变化（极性） 从海沟向岛弧方向：low-K拉斑系列 钙碱系列 碱性系列 时间变化 早期拉斑系列 晚期钙碱系列 最晚期碱性系列普遍发育,微量元素,REEs,REE diagrams for some representative Low-K (tholeiitic), Medium-K (calc-alkaline), and High-K basaltic andesites and andesites

23、. An N-MORB is included for reference (from Sun and McDonough, 1989). After Gill (1981) Orogenic Andesites and Plate Tectonics. Springer-Verlag.,同一岩浆系列的REE配分型式相似，高度不同，起因于Ol, Plag, Pyx结晶分离作用 low-K TH 源于DM REE甚至可以低于 MORB 其他岛弧岩浆系列具有正常的REE配分型式 岛弧岩浆系列起源于不均一的地幔源区 HREE 平坦，源区无石榴石,MORB-normalized spider diag

24、rams for selected island arc basalts. Using the normalization and ordering scheme of Pearce (1983) with LIL on the left and HFS on the right and compatibility increasing outward from Ba-Th. Data from BVTP. Composite OIB from Fig 14-3 in yellow.,Winter (2001) An Introduction to Igneous and Metamorphi

25、c Petrology. Prentice Hall. Data from Sun and McDonough (1989) In A. D. Saunders and M. J. Norry (eds.), Magmatism in the Ocean Basins. Geol. Soc. London Spec. Publ., 42. pp. 313-345.,微量元素MORB标准化的不相容元素配分型式,OIB具有特征的隆起,IAB: HFS - LIL 解耦 LIL是亲流体的元素,在俯冲带，什么原因造成了流体主导的环境？,问题二,同位素,Nd-Sr isotopic variation

26、in some island arc volcanics. MORB and mantle array from Figures 13-11 and 10-15. After Wilson (1989), Arculus and Powell (1986), Gill (1981), and McCulloch et al. (1994). Atlantic sediment data from White et al. (1985).,New Britain, Marianas, Aleutians, and South Sandwich的火山岩落在非常小的DM区域 大部分岛弧带火山岩地幔源

27、区不均一,Variation in 207Pb/204Pb vs. 206Pb/204Pb for oceanic island arc volcanics. Included are the isotopic reservoirs and the Northern Hemisphere Reference Line (NHRL) proposed in Chapter 14. The geochron represents the mutual evolution of 207Pb/204Pb and 206Pb/204Pb in a single-stage homogeneous res

28、ervoir. Data sources listed in Wilson (1989).,1. DM (亏损地幔) = N-MORB 源区,After Zindler and Hart (1986), Staudigel et al. (1984), Hamelin et al. (1986) and Wilson (1989).,地幔源区 / 储库 / 端元 Mantle Reservoirs,2. BSE (Bulk Silicate Earth)总体硅酸盐地球或原始均一库 CHUR,After Zindler and Hart (1986), Staudigel et al. (198

29、4), Hamelin et al. (1986) and Wilson (1989).,4. EM II 富集地幔II， 87Sr/86Sr较高 ( 0.720, 高于任何合理的地幔源区,After Zindler and Hart (1986), Staudigel et al. (1984), Hamelin et al. (1986) and Wilson (1989).,3. EM I 富集地幔I， 87Sr/86Sr 较低,5. PREMA (PREvalent MAntle) 主体地幔,After Zindler and Hart (1986), Staudigel et al.

30、 (1984), Hamelin et al. (1986) and Wilson (1989).,After Wilson (1989) Igneous Petrogenesis. Kluwer.,6. HIMU (HIgh m value) 高m值地幔,After Wilson (1989) Igneous Petrogenesis. Kluwer. Data from Hamelin and Allgre (1985), Hart (1984), Vidal et al. (1984).,实际存在的地幔端元有4个,地幔端元的特征,DMM，一般在地幔的最上部，亏损不相容元素，代表地壳从 地

31、幔分异后的残留物 HIMU，地幔与再循环洋壳的混合，由于洋低热液作用或俯冲带的脱水作用，造成Pb的流失和m值升高 EM I和EM II 可能分别来自地幔与下地壳和上地壳的混合,地幔端元的特征,与岛弧岩浆岩的差别： 厚的硅铝壳显著的地壳混染 岩浆上升慢岩浆分异更强 地壳熔融,活动大陆边缘岩浆活动火山岩,Map of western South America showing the plate tectonic framework, and the distribution of volcanics and crustal types. NVZ, CVZ, and SVZ are the nor

32、thern, central, and southern volcanic zones. After Thorpe and Francis (1979) Tectonophys., 57, 53-70; Thorpe et al. (1982) In R. S. Thorpe (ed.), (1982). Andesites. Orogenic Andesites and Related Rocks. John Wiley and Harmon et al. (1984) J. Geol. Soc. London, 141, 803-822. Winter (2001) An Introduc

33、tion to Igneous and Metamorphic Petrology. Prentice Hall.,Schematic diagram to illustrate how a shallow dip of the subducting slab can pinch out the asthenosphere from the overlying mantle wedge. Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,AFM and K2O vs. SiO2

34、diagrams (including Hi-K, Med.-K and Low-K types of Gill, 1981; see Figs. 16-4 and 16-6) for volcanics from the (a) northern, (b) central and (c) southern volcanic zones of the Andes. Open circles in the NVZ and SVZ are alkaline rocks. Data from Thorpe et al. (1982,1984), Geist (personal communicati

35、on), Deruelle (1982), Davidson (personal communication), Hickey et al. (1986), Lpez-Escobar et al. (1981), Hrmann and Pichler (1982). Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,主元素和岩浆系列,Chondrite-normalized REE diagram for selected Andean volcanics. NVZ (6 sam

36、ples, average SiO2 = 60.7, K2O = 0.66, data from Thorpe et al. 1984; Geist, pers. comm.). CVZ (10 samples, ave. SiO2 = 54.8, K2O = 2.77, data from Deruelle, 1982; Davidson, pers. comm.; Thorpe et al., 1984). SVZ (49 samples, average SiO2 = 52.1, K2O = 1.07, data from Hickey et al. 1986; Deruelle, 19

37、82; Lpez-Escobar et al. 1981). Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,微量元素REE,MORB-normalized spider diagram (Pearce, 1983) for selected Andean volcanics. NVZ (6 samples, average SiO2 = 60.7, K2O = 0.66, data from Thorpe et al. 1984; Geist, pers. comm.). C

38、VZ (10 samples, ave. SiO2 = 54.8, K2O = 2.77, data from Deruelle, 1982; Davidson, pers. comm.; Thorpe et al., 1984). SVZ (49 samples, average SiO2 = 52.1, K2O = 1.07, data from Hickey et al. 1986; Deruelle, 1982; Lpez-Escobar et al. 1981). Winter (2001) An Introduction to Igneous and Metamorphic Pet

39、rology. Prentice Hall.,微量元素不相容元素,Sr vs. Nd isotopic ratios for the three zones of the Andes. Data from James et al. (1976), Hawkesworth et al. (1979), James (1982), Harmon et al. (1984), Frey et al. (1984), Thorpe et al. (1984), Hickey et al. (1986), Hildreth and Moorbath (1988), Geist (pers. comm),

40、 Davidson (pers. comm.), Wrner et al. (1988), Walker et al. (1991), deSilva (1991), Kay et al. (1991), Davidson and deSilva (1992). Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,Sr-Nd同位素,208Pb/204Pb vs. 206Pb/204Pb and 207Pb/204Pb vs. 206Pb/204Pb for Andean volca

41、nics plotted over the OIB fields from Figures 14-7 and 14-8. Data from James et al. (1976), Hawkesworth et al. (1979), James (1982), Harmon et al. (1984), Frey et al. (1984), Thorpe et al. (1984), Hickey et al. (1986), Hildreth and Moorbath (1988), Geist (pers. comm), Davidson (pers. comm.), Wrner e

42、t al. (1988), Walker et al. (1991), deSilva (1991), Kay et al. (1991), Davidson and deSilva (1992). Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,Pb同位素,87Sr/86Sr, D7/4, D8/4, and d18O vs. Latitude for the Andean volcanics. D7/4 and D8/4 are indices of 207Pb and 2

43、08Pb enrichment over the NHRL values of Figure 17-7 (see Rollinson, 1993, p. 240). Shaded areas are estimates for mantle and MORB isotopic ranges from Chapter 10. Data from James et al. (1976), Hawkesworth et al. (1979), James (1982), Harmon et al. (1984), Frey et al. (1984), Thorpe et al. (1984), H

44、ickey et al. (1986), Hildreth and Moorbath (1988), Geist (pers. comm), Davidson (pers. comm.), Wrner et al. (1988), Walker et al. (1991), deSilva (1991), Kay et al. (1991), Davidson and deSilva (1992). Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,同位素,Relative fr

45、equency of rock types in the Andes vs. SW Pacific Island arcs. Data from 397 Andean and 1484 SW Pacific analyses in Ewart (1982) In R. S. Thorpe (ed.), Andesites. Wiley. New York, pp. 25-95. Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,岩石类型的比例岛弧vs.大陆边缘,Schematic

46、 cross sections of a volcanic arc showing an initial state (a) followed by trench migration toward the continent (b), resulting in a destructive boundary and subduction erosion of the overlying crust. Alternatively, trench migration away from the continent (c) results in extension and a constructive

47、 boundary. In this case the extension in (c) is accomplished by “roll-back” of the subducting plate. An alternative method involves a jump of the subduction zone away from the continent, leaving a segment of oceanic crust (original dashed) on the left of the new trench. Winter (2001) An Introduction

48、 to Igneous and Metamorphic Petrology. Prentice Hall.,俯冲带的变化,Time-averaged rates of extrusion of mafic (basalt and basaltic andesite), andesitic, and silicic (dacite and rhyolite) volcanics (Priest, 1990, J. Geophys. Res., 95, 19583-19599) and Juan de Fuca-North American plate convergence rates (Ver

49、planck and Duncan, 1987 Tectonics, 6, 197-209) for the past 35 Ma. The volcanics are poorly exposed and sampled, so the timing should be considered tentative. Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,火山物质平均溢出量与时间的关系,Major plutons of the North American Cordil

50、lera, a principal segment of a continuous Mesozoic-Tertiary belt from the Aleutians to Antarctica. After Anderson (1990, preface to The Nature and Origin of Cordilleran Magmatism. Geol. Soc. Amer. Memoir, 174. The Sr 0.706 line in N. America is after Kistler (1990), Miller and Barton (1990) and Arms

51、trong (1988). Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,活动大陆边缘岩浆活动侵入岩,北美,Major plutons of the South American Cordillera, a principal segment of a continuous Mesozoic-Tertiary belt from the Aleutians to Antarctica. After USGS.,南美,Schematic cross section of the

52、 Coastal batholith of Peru. The shallow flat-topped and steep-sided “bell-jar”-shaped plutons are stoped into place. Successive pulses may be nested at a single locality. The heavy line is the present erosion surface. From Myers (1975) Geol. Soc. Amer. Bull., 86, 1209-1220.,秘鲁海岸岩基侵入构造示意图,Harker-type

53、 and AFM variation diagrams for the Coastal batholith of Peru. Data span several suites from W. S. Pitcher, M. P. Atherton, E. J. Cobbing, and R. D. Beckensale (eds.), Magmatism at a Plate Edge. The Peruvian Andes. Blackie. Glasgow. Winter (2001) An Introduction to Igneous and Metamorphic Petrology.

54、 Prentice Hall.,秘鲁海岸岩基主元素,Chondrite-normalized REE abundances for the Linga and Tiybaya super-units of the Coastal batholith of Peru and associated volcanics. From Atherton et al. (1979) In M. P. Atherton and J. Tarney (eds.), Origin of Granite Batholiths: Geochemical Evidence. Shiva. Kent. Winter (

55、2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,秘鲁海岸岩基 REE,Initial 87Sr/86Sr ranges for three principal segments of the Coastal batholith of Peru (after Beckinsale et al., 1985) in W. S Pitcher, M. P. Atherton, E. J. Cobbing, and R. D. Beckensale (eds.), Magmatism at a Pla

56、te Edge. The Peruvian Andes. Blackie. Glasgow, pp. 177-202. . b. 207Pb/204Pb vs. 206Pb/204Pb data for the plutons (after Mukasa and Tilton, 1984) in R. S. Harmon and B. A. Barreiro (eds.), Andean Magmatism: Chemical and Isotopic Constraints. Shiva. Nantwich, pp. 235-238. ORL = Ocean Regression Line

57、for depleted mantle sources (similar to oceanic crust). Winter (2001) An Introduction to Igneous and Metamorphic Petrology. Prentice Hall.,秘鲁海岸岩基 同位素,Schematic diagram illustrating (a) the formation of a gabbroic crustal underplate at an continental arc and (b) the remelting of the underplate to gen

58、erate tonalitic plutons. After Cobbing and Pitcher (1983) in J. A. Roddick (ed.), Circum-Pacific Plutonic Terranes. Geol. Soc. Amer. Memoir, 159. pp. 277-291.,秘鲁海岸岩基 岩浆演化模式,Schematic cross section of an active continental margin subduction zone, showing the dehydration of the subducting slab, hydrat

59、ion and melting of a heterogeneous mantle wedge (including enriched sub-continental lithospheric mantle), crustal underplating of mantle-derived melts where MASH processes may occur, as well as crystallization of the underplates. Remelting of the underplate to produce tonalitic magmas and a possible zone of crustal anatexis is also shown. As magm