深部过程对埃达克质岩石成分的制约
The role of deep processes controls on variation of compositions of adakitic rocks
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摘要: 埃达克岩、太古宙TTG和中国东部广泛出露的燕山期埃达克质中酸性火山-侵入岩在岩石地球化学特征方面有许多相似之处，也有一些显著的差异。与典型的埃达克岩相比，太古宙TTG具有相对高Si和低Mg^#的特点：中国东部埃达克质岩石多表现为低Mg^#贫A120，和高K特征。埃达克岩相对高Mg^#是由于俯冲洋壳部分熔融产生的原生埃达克岩熔体受到了地幔橄榄岩的混染，太古宙TTG多无明显的地幔混染印记，反映其可能主要形成于下地壳底侵玄武岩的部分熔融，而与洋壳俯冲没有直接联系。中国东部埃达克质岩石相对低Mg^#畜K，暗示其可能是下地壳底侵玄武岩部分熔融或拆沉-熔融的产物，而幔源富钾熔体的混合、壳内分异和混染过程都有可能影响其成分特征中国东部部分地区的高镁埃达克质岩石可能揭示了下地壳拆沉一熔融和地幔混染过程。钾质埃达克岩的源区可能是被小比例软流圈熔体交代富集的底侵玄武岩层(增厚的下地壳)。结合燕山期岩浆作用和构造转换的特点来看，埃达克岩的形成是中国东部晚中生代岩石圈强烈减薄和大规模岩浆作用产物的一部分，这一重大构造体制的转换可能与地幔柱上涌对岩石圈的侵蚀和导致的伸展作用有关。Abstract: There are many geochemical similarities and significant dissimilarities among Adakite, early Archaean TTG suites and Yanshanian intermediate-acid magamtic rocks (" adakitic rocks" or potassic adakite) in eastern China. Simple geochemical parameters, such as silica content, Mg# and K2O content, show that TTG and "adakitic rocks" from eastern China are distinct from adakite, suggesting that they experienced different deep processes. Comparing with slab-melting generated adakite, the early Archaean TTG suites have higher SiO2 and lower Mg# and, potassic adakite from eastern China show lower Mg# and higher K2O. The higher-Mg# adakites imply that the ocean slab melting generated pristine adakite melts interacted with the mantle wedge. There is little convincing evidence for a direct mantle component in TTG, implying that accommodate TTG production through melting of hydrous basaltic material at the base of thickened crust, without modern-style subduction processes. The potassic adakite from eastern China may predominately experienced partial melting of underplated basaltic rocks (lower Mg# potassic adakite) , or delimitation-melting of lower crust and interacted with mantle peridotite ( higher Mg# potassic adakite), and followed assimilation and contamination of crustal intermediate-acid rocks. Potassic adakite might be generated from a basaltic underplated layer that was metasomated by small melt fractions from asthenosphere mantle. Adakitic magmatism is then an accompanying product of Yanshannian lithosphere thinning and magmatism, which may be related to a upwelling of mantle plume.
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Key words:
- Adakite /
- Archean TTG /
- Thickened crust /
- Crust delaminating and melting /
- Deep processes /
- Mantle plume
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[1] ［1］Arth J G andHanson G N. 1975. Geochemistry and origin of the early Precambrian crust of northern Minnesota. Geochim. Cosmochim.Acta, 39: 325 - 362
[2] ［2］Atherton M P and Petford. 1993. Generation of sodium-rich magmas from newly underplated basaltic crust. Geology, 4:596 -600
[3] ［3］Barker F and Arth J G. 1976. Generation of trondjhemitic-tonalitic liquids and Archaean bimodal trondjhemite-basalt suites. Geology,4: 596 - 600
[4] ［4］Barker F. 1979. Trondhjemites, Dacites. Andesite Related Rocks.Elsevier. Amsterdam, 1-321
[5] ［5］Barnes C G, Marnes, M A and Kistler R W. 1992. Petrology of the Caribou Moutain pluton, Klamath Mountains, California, Jouml of Petrol. , 33: 95 - 124
[6] ［6］Barnes, C G, Petersen, S. W. , Kistler, et al. , 1996. Source and tectonic implications of tonalite-trondhjemite magmatism in the Klamath Mountains. Contrib. Mineral. Petrol. ,123:40-60
[7] ［7］Beard J S, Bergantz G W, Defant M J and Drummond M S. 1993. Origin and emplacement of low-K silicic magmas in subduction setting.Penrose Conference Report, Geol. Soc, Am. Today, 3: 38
[8] ［8］Beate B, Monzier M, Spikings R, Cotton J, Silva J, Bourdon E and Eissen J P. 2001. Mio-Pliocene adakite generation related to flat subduction in southern Ecuador: the Quimsacocha volcanic center.Earth Planet. Sci. Lett. , 192:561 -570
[9] ［9］Bebout G E and Barton M D. 1993. Metasomatism during subduction:products and possible paths in the Catalina schish, California.Chem. Geol. , 108:61 -92
[10] ［10］Castillo P R, Janney P E and Solidum R U. 1999. Petrology and geochemistry of Camiguin island, southern Philippines: insights to the source of adakites and other lavas in a complex arc setting.Contrib. Mineral. Petrol. , 134:33 -51
[11] ［11］Condie K C. 1981. Archaean Greenstone Belts, Elsevier. Amsterdam, 1-434
[12] ［12］Defant M J and Drummond M S. 1990. Derivation of some modern arc magmas by melting of young subduction lithosphere. Nature, 662-665
[13] ［13］Defant M J, Xu J F, Wang Q, Xiao L. 2002, Adakite: Some variation on a theme. Acta Petrologica Sinica, 18(2): 129 -142
[14] ［14］Deng J F, Zhao G C and Zhao H L. 2000. Yanshanian igneous petrotectonic assemblage and orogenic-deep process in east China.Geological Review, 46:41 -48 (in Chinese with English abstract)
[15] ［15］Dong S W, Wu X H, Wu Z H, et al. 2000. On tectonic seesawing of the east Asia continent-global implication of the Yanshanian movement,Geological Review, 46 ( 1 ): 8 - 13 ( in Chinese with English abstract)
[16] ［16］Drummond M S and Defant M J. 1990. A model for trondhjemite-tonalitedacite genesis and crustal growth via slab melting: Archean to modern comparisons. J. Geophy. s Res. , 95:21503 ～21521
[17] ［17］Gao S and Jin Z M. 1997. Delamination and its dynamic implications for crust-mantle evolution. Geological Science and Technology Information, 16( 1 ): 1 -8 (in Chinese with English abstract)
[18] ［18］Gao S, Liu Y S, Yuan H L. 2001. Geochemistry of Jurassic-Cretaceous High-Mg adakite from North China Craton Suggests Delamination of Eclogitic Lower Crust. Beijing, China, Symposium on adakite-like rocks and their geodynamic significance (abstract), 82-82
[19] ［19］Ge X Y, Li X H, Chen Z G, et al. 2002. Geochemical characteristics and petrogenesis of the Yanshanian high-Sr / low-Y intermediatefelsic igneous rocks from eastern China: constraints on crustal thickness of eastern China, Chinese Science Bulletin, 47 ( 6 ): 474-480 (in Chinese with English abstract)
[20] ［20］Gill J B. 1981. Orogenic Andesite and Plate Tectonics. New York:Springer-Verlag, 1 - 390
[21] ［21］Gormet L P and Silver L T. 1987. REE variations across the peninsular ranges batholith: Implications for batholithic petrogenesis andcrustal growth in magmatic arcs. J. Petrology, 28:75 -125
[22] ［22］Gonzalez-Partida E, Levresse G, Carrillo-Chavez A, Cheilletz A, Gasquet D and Jones D. 2003. Paleocene adakite Au-Fe bearing rocks,Mezcala, Mexico: evidence from geochemical characteristics.Journal of Geochemical Exploration, 4105: 1 - 16
[23] ［23］Gutscher M A, Maury R, Eissen J P and Bourdon E. 1999. Can slab melting be caused by flat subduction?. Geology 28,535 -538
[24] ［24］Gutscher M A, Olivet J L, Aswlanian D, Eissen J P and R Maury. 1999. The "lost Inca Plateau": cause of flat subduction beneath Peru?Earth Planet. Sci. Lett. 171:335-341
[25] ［25］Hou Z Q, Mo X X, Gao Y F, Qu X M, MengX J. 2003. Adakite, a possible host rock for porphyry copper deposits: case studies of porphyry copper belts in Tibetan Plateau and in northem Chile.Mineral Deposits, 22 (1): 1-12. ( in Chinese with English abstract)
[26] ［26］Kamber B S, Ewart A, Collerson K D, Bruce M C. and McDonald G D.2002. Fluid-mobile trace element constraints on the role of slab melting and implications for Archean crustal growth models. Contrib.Mineral, Petrol. , 144, 38-56
[27] ［27］Kay R W and Kay S M. 1991. Creation and destruction of lower continental crust. Geologiche Rundschau, 80: 259 - 278
[28] ［28］Kay R W. 1978. Aleutian magnesium andesites: melts from subducted Pacific oceanic crust. J. Volcanol. Geotherm. Res. , 4:117 -132
[29] ［29］Kay S M, Ramos V A and Marques M. 1993. Evidence in Cerro Pampa Volcanic Rocks for Slab-Melting Prior to Ridge-Trench Collision in Southern South America. J. Geology, 101: 703 -714
[30] ［30］Kimura G, Takahashi M and M. Kono. 1990. Mesozoic collisionextrusion tectonics in eastern Asia. Tectonophysics, 181: 15 -23
[31] ［31］Mao J R, Su Y X, Chen S Y. 1990. Felsic intrusions and mineralization in the middle and lower part of Yangtz River. Beijing: Geological Publishing House, 1 -191 (in Chinese with English abstract)
[32] ［32］Martin H. 1986. Effect of steeper Archaean geothermal gradient on geochemistry of subduction-zone magmas. Geology, 14: 753 - 756
[33] ［33］Martin H. 1987. Petrogenesis of Archaean trondhjemites, tonalities, and granodiorites from eastern Finland: major and trace element geochemistry. J. Petrol. , 18 (5): 921 -953
[34] ［34］Martin H. 1999. Adakitic magmas: modern analogues of Archaean granitoids. Lithos, 46: 411 - 429
[35] ［35］McKenzie D. 1989. Some remarks on the movement of small melt fractions in the mantle. Earth Planet. Sci. Lett. , 95:53 -72
[36] ［36］Menzies M. A. and Xu Y. G. 1998. Geodynamics of the North China Craton. In Mantle Dynamics and Plate Interactions in East Asia(eds. M. F. J. Flower, S. L. Chung, C. H. Lo, and T. Y.Lee), 155 165. American Geophysical Union, Geodynamics Series 27
[37] ［37］Muir R J, Weaver S D, Bradshaw J D, Eby G N and Evans J A. 1995. The Cretaceous separation point batholith, New Zealand: granitiod magmas formed by melting of mafic lithosphere. Journal of Geological Society, London, 152:689-701
[38] ［38］Mungall J E. 2002. Roasting the mantle: slab melting and the genesis of major Au and Au-rich Cu deposits. Geology, 30:915 -918
[39] ［39］Nelson K D. 1992. Are crustal thickness variation in old mountain belts like the Appalachians a consequence of lithospheric delamination?.Geology, 20: 498 - 502
[40] ［40］Peacock S M. Rushmer T, Thompson A B. 1994. Partial melting of subducting oceanic crust. Earth Planet. Sci. Lett. , 121: 227 -244
[41] ［41］Petford N and Atherton M. 1996. Na-rich partial melts from newly underplated basaltic crust: the Cordillera Blanca Batholith, Peru.Journal of Petrology, 37: 491 - 521
[42] ［42］Petford N and Kerry G. 2001. Partial melting of mafic ( amphibolitic)lower crust by periodic influx of basaltic magma. Earth and Planetary Science Letters, 193(3 -4): 483 -499
[43] ［43］Rapp P R, Shimizu N, Norman M D, Applegate. 1999. Reaction between slab-derived melts and peridotite in the mantle wedge: experimental constraints at 3.8 GPa. Chem. Geol. , 160:335 -356
[44] ［44］Rapp P R. 1997. Heterogeneous source regions for Archean granitoids.In: (de.) Wit M J, Ashwal L D, ed. Greenstone Belts. Oxford:Oxford University Press, 35 - 37
[45] ［45］Rapp R P and Watson E B. 1995. Dehydration melting of metabasalt at 8-32 kbar: implications for continental growth and crust-mantle recycling. J. Petrol., 36:891 -931
[46] ［46］Rapp R P, Watson E B, Miller C F. 1991. Partial melting of amphibolite /eclogite and the origin of Archean trondhjemites and tonalities.Preeambrian Research, 51: 1 - 25
[47] ［47］Rapp R P, Xiao L, Shimizu N. 2002. Experimental Constraints on the Origin of Potassium-rich Adakites in Eastern China. Acta Petrological Siniea, 18 ( 3 ): 293 - 302
[48] ［48］Sajona F G and Maury R C. 1998. Association of adakites with gold and copper mineralization in the Philipiines: Paris, Academie de Scieneos Comptes Rendus, Sciences de a Terre et les Planetes, 326:27 - 34
[49] ［49］Sen C and Dunn T. 1994. Dehydration melting of a basaltic composition amphibolite at 1. 5 and 2.0 GPa: implications for the origin of adakites. Contrib. Mineral. Petrol., 117:394 ～409
[50] ［50］Shao J A, Mu B L, Zhang L Q. 2000. Deep geological process and its shallow response during Mesozoic transfer of tectonic frameworks in eastern China. Geological Review, 46 (1): 32 - 39 (in Chinese with English abstract)
[51] ［51］Smithies R H. 2000. The Arehaean tonalite-trondhjemite-granodiorite(TTG) series is not an analogue of Cenozoic adakite. Earth and Planetary Science Letters, 182(1): 115 -125
[52] ［52］Sorensen S S and Barton M D. 1987. Metasomatism and partial melting in a subduction complex: Catalina schist, southern California.Geology, 15:115-118
[53] ［53］Sorensen S S. 1988. Petrology of amphibolite-faeies mafic and ultramafie rocks from Catalina schist, southern California metamorphism and magmatisation in a subduction zone metamorphic setting. J.Metamorph. Geol. , 6:405-435
[54] ［54］Stem C R and Kilian R. 1996. Role of the subducted slab, mantle wedge and continental crust in the generation of adakites from the Andean Austral Volcanic Zone. Contrib Mineral Petrol, 123:263 -281
[55] ［55］Tao K Y, Gao T J, Lu Z G. 1988. The basement structure of volcanic rocks, volcano-intrusion and their metallogenesis, Beijing:Geological Publishing House, 1 -43 (in Chinese with English abstract)
[56] ［56］Thieblemont D, Stein G, Lescuyer J L. 1997. Gisements epithermaux et porphyriques: la connexion adakite. Earth Planet. Sci. Lett,. 325:103-109
[57] ［57］Wang Q Xu J, Zhao Z. 200la. The summary and comment on research on a new kind of igneous rock-adakite, Advance in Earth Science,16 (2): 201 - 208 ( in Chinese with English abstract)
[58] ［58］Wang Q, Zhao Z H, Xu J F, Li X H, Bao Z W. Xiong X L, Liu Y M.2002. Petrogenesis and metallogenesis of the Yanshanian adakitelike rocks in the Eastern Yangtze Block. Science in China (D), 46(Supplement): 164 - 176
[59] ［59］Wang Q, Zhao Z, Xiong X, Xu J. 2001b. The melting of mafic lower crust: evidence from the Shaxi adakitic sodic quartz dioriteporphyrites in Anhui Province, China. Geochimica, 30(4): 353 -362 (in Chinese with English abstract)
[60] ［60］Wang Y and Zhang Q. 2001. A granitoid complex from Badaling area,North China: composition, geochemical characteristics and its implications. Acta Petrologica Sinica, 17, 533 - 540. (in Chinese with English abstract)
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