Abstract
We report the zircon Hf-O isotopic data for mafic enclaves from the Taihang Yanshanian intermediate to felsic plutons, and use them, along with the petrological, whole-rock chemical and Nd-Sr isotopic data, to reveal the petrogenesis of mafic enclaves. Mafic enclaves show magmatic textures and are finer-grained than host rocks. In places they are highly elongated due to stretching within the partially crystallized, convective felsic magma, but show no solid-state deformation. These data suggest that mafic enclaves and host rocks were co-existing, but compositionally distinct magmas. The mafic enclaves contain abundant hydrous minerals such as hornblende and biotite, with pyroxene relict being surrounded by hornblende reaction rim. Plagioclase xenocrysts from mafic enclaves show a complicated compositional and textural disequilibrium. Comparison between mafic enclaves and the immediate host rocks suggests that the two rock units are compositionally correlated. The ɛ Nd values of mafic enclaves are generally higher than the host rocks, though the Sr isotopic ratios of the two rock units are indistinguishable. Zircons from a single enclave sample show a significant variation in Hf isotopic compositions, with ɛ Hf =.10–−22, suggesting an origin through magma mixing between mafic and felsic magmas. This is supported by the relatively large variation of zircon O isotopic ratios (δ 18O = 5.5‰–7.8‰) of the mafic enclaves. The petrogenesis of mafic enclaves could be described as below. Evolved basaltic magma (via fractionation of olivine and pyroxene) first mixed with crustally derived granitic melts in depths, forming a hybrid magma; then the hybrid magma broke up into discrete lumps upon entering the above felsic magma. Subsequently, the enclave-forming magma experienced a double mechanical transfer of plagioclase, and inward chemical transfer of fluid and Na, P, Y, Nb and Pb at the contacts with host felsic magmas.
Similar content being viewed by others
References
Noyes H J, Frey F A, Wones D R. A tale of two plutons: Geochemical evidence bearing on the origin and differentiation of the Red Lake and Eagle Peak plutons, Central Sierra Nevada, California. J Geol, 1983, 91: 487–509
Chappell B W, White A J R, Wyborn D. The importance of residual source material (restite) in granite petrogenesis. J Petrol, 1987, 28: 1111–1138
Chappell B W, White A J R. I- and S-type granites in the Lachlan Fold Belt. Trans R Soc Edinb Earth Sci, 1992, 83: 1–26
Vernon R H. Microgranitoid enclaves: Globules of hybrid magma quenched in a plutonic environment. Nature, 1984, 304: 438–439
Dorais M J, Whitney J A, Roden M F. Origin of mafic enclaves in the Dinkey Creek Pluton, Central Sierra Nevada batholith, California. J Petrol, 1990, 31: 853–881
Blundy J D, Sparks R S J. Petrogenesis of mafic inclusions in granitoids of the Adamelo Massif, Italy. J Petrol, 1992, 33: 1039–1104
Perugini D, Poli G, Christofides G, et al. Magma mixing in the Sithonia plutonic complex, Greece: Evidence from mafic microgranular enclaves. Mineral Petrol, 2003, 78: 173–200
Wiebe R A, Smith D, Sturn M, et al. Enclaves in the Cadillac mountain granite (Coastal Maine): Samples of hybrid magma from the base of the chamber. J Petrol, 1997, 38: 393–426
Barbarin B. Mafic magmatic enclaves and mafic rocks associated with some granitoids of the central Sierra Nevada batholith, California: Nature, origin, and relations with the hosts. Lithos, 2005, 80: 155–177
Feeley T C, Wilson L F, Underwood S J. Distribution and compositions magmatic inclusions in the Mount Helen dome, Lassen volcanic center, California: Insights into magma chamber processes. Lithos, 2008, 106: 173–189
Bussy F. Enclaves of the Late Miocene Monte Capanne granite, Elba Island, Italy. In: Didier J, Barbarin B, eds. Enclaves and Granite Petrology. Volume 13, Developments in Petrology. Amsterdam: Elsevier, 1991. 167–178
Debon F. Comparative major element chemistry in various “gmicrogranular enclave-plutonic host” pairs. In: Didier J, Barbarin B, eds. Enclaves and Granite Petrology. Volume 13, Developments in Petrology. Amsterdam: Elsevier, 1991. 293–312
Orsini J B, Cocirta C, Zorpi M J. Genesis of mafic microgranular enclaves through differentiation of basic magmas, mingling and chemical exchanges with their host granitoid magmas. In: Didier J, Barbarin B, eds. Enclaves and Granite Petrology. Volume 13, Developments in Petrology. Amsterdam: Elsevier, 1991. 445–464
Seaman S J, Ramsey P C. Effects of magma mingling in the granites of Mount Desert Island, Maine. J Geol, 1992, 100: 395–409
Tepper J H, Kuehner S M. Geochemistry of mafic enclaves and host granitoids from the Chilliwack batholith, Washington: Chemical exchange processes between coexisting mafic and felsic magmas and implications for the interpretation of enclave chemical traits. J Geol, 2004, 112: 349–367
Ferla P, Meli C. Evidence of magma mixing in the “Daly Gap” of alkaline suites: A case study from the enclaves of Pantelleria (Italy). J Petrol, 2006, 47: 1467–1507
Yang J H, Wu F Y, Wilde S A, et al. Tracing magma mixing in granite genesis: in situ U-Pb dating and Hf-isotope analysis of zircons. Contrib Mineral Petrol, 2007, 153: 177–190
Chen B, Chen Z C, Jahn B M. Origin of mafic enclaves from the Taihang Mesozoic orogen, north China craton. Lithos, 2009, 110: 343–358
Chen B, Tian W, Zhai M G, et al. Zircon U-Pb geochronology and geochemistry of Mesozoic magmatism in the Taihang Mountains and other places of the North China Craton, with implications for petrogenesis and geodynamic setting (in Chinese). Acta Petrol Sin, 2005, 21(1): 13–24
Zhao Y, Xu G, Zhang S H, et al. The Yanshan movement and change of tectonic system in East Asia. Earth Sci Front, 2004, 11: 319–328
Liu L, Chen B, Liu A K. Petrogenesis of the Zijingguan mafic pluton, northern Taihang orogen: Constraints from petrology and geochemistry (in Chinese with English abstract). Earth Sci, 2009, 34: 165–178
Vernon R H. Interpretation of microstructures of microgranitoid enclaves. In: Didier J, Barbarin B, eds. Enclaves and Granite Petrology. Volume 13, Developments in Petrology. Amsterdam: Elsevier, 1991. 277–291
Kumar S, Rino V, Pal A B. Field evidence of magma mixing from microgranular enclaves hosted in Palaeoproterozoic Malanjkhand granitoids, central India. Gondwana Res, 2004, 7: 539–548
Chen B, Zhai M G, Shao J A. Petrogenesis and significance of the Mesozoic North Taihang complex: Major and trace element evidence. Sci China D-Earth Sci, 2003, 46(9): 941–953
Chen B, Zhai M G. Geochemistry of late Mesozoic lamprophyre dykes from the Taihang Mountains, north China, and implications for the sub-continental lithospheric mantle. Geol Mag, 2003, 140: 87–93
Chen B, Jahn B M, Zhai M G. Sr-Nd isotopic characteristics of the Mesozoic magmatism in the Taihang-Yanshan orogen, north China craton, and implications for Archean lithosphere thinning. J Geol Soc London, 2003, 160: 963–970
Wu F Y, Yang Y H, Xie L W, et al. Hf isotopic compositions of the standard zircons and baddeleyites used in U-Pb geochronology. Chem Geol, 2006, 234: 105–126
Xu Y G., Wu X Y, Luo Z Y, et al. Zircon Hf isotope compositions of middle Jurassic-Early Cretaceous intrusions in Shandong Province and its implications. Acta Petrol Sin, 2007, 23: 307–316
Chen B, Tian W, Jahn B M, et al. Zircon SHRIMP U-Pb ages and in situ Hf isotopic analysis for the Mesozoic intrusions from in south Taihang, north China craton: Evidence for hybridization between mantle-derived magmas and crustal components. Lithos, 2008, 102: 118–137
Li X H, Li W X, Wang X C, et al. The role of mantle-derived magma in generating the early Yanshanian granitoids from Nanling, S China: Constrains from zircon in situ Hf-O isotopic analyses. Sci China Ser D-Earth Sci, 2009, 52(9): 1262–1278
Hawkesworth C J, Kemp A I S. Using hafnium and oxygen isotopes in zircons to unravel the record of crustal evolution. Chem Geol, 2006, 226: 144–162
Janousek V, Braithwaite C J R, Bowesb D R. Magma-mixing in the genesis of Hercynian calc-alkaline granitoids: An integrated petrographic and geochemical study of the Sa’zava intrusion, Central Bohemian Pluton, Czech Republic. Lithos, 2004, 78: 67–99
Donaire T, Pascual E, Pin C, et al. Microgranular enclaves as evidence of rapid cooling in granitoid rocks: The case of the Los Pedroches granodiorite, Iberian Massif, Spain. Contrib Mineral Petrol, 2005, 149: 247–265
Johnston A D, Wyllie P J. Interaction of granitic and basaltic magmas: Experimental observations on contamination processes at 10 kbar with H2O. Contrib Mineral Petrol, 1988, 98: 352–362
Watson E B, Jurewicz S R. Behavior of alkalis during diffusive interaction of granitic xenoliths with basaltic magma. J Geol, 1984, 92: 121–131
Langmuir C H, Vocke R D, Hanson G N. A general mixing equation with applications to Icelandic basalts. Earth Planet Sci Lett, 1978, 37: 380–392
Zindler A, Staudigel H., Batiza R. Isotope and trace element geochemistry young Pacific seamounts: Implications for the scale of upper mantle heterogeneity. Earth Planet Sci Lett, 1984, 70: 175–195
Jahn B M, Ernst W G. Late Archean Sm-Nd isochron age for mafic-ultramafic supracrustal amphibolites from the northeastern Sino-Korean Craton, China. Precambrain Res, 1990, 46: 295–306
Jahn B M, Auvray B, Cornichet J, et al. 3.5 Ga old amphibolites from eastern Hebei Province, China: Field occurrence, petrology, Sm-Nd isochron age and REE geochemistry. Precambrain Res, 1987, 34: 311–346
Geng Y S, Shen Q H, Zhang Z Q. Sm-Nd isotope age and its geological significance of epimetamorphic rock series in the Qinglong area, eastern Hebei Province (in Chinese). Regional Geol China, 1999, 18: 271–276
Valley J W, Lackey J S, Cavosie A J, et al. 4.4 billion years of crustal maturation: Oxygen isotope ratios of magmatic zircon. Contrib Mineral Petrol, 2005, 150: 561–580
Author information
Authors and Affiliations
Corresponding author
Additional information
Supported by National Natural Science Foundation of China (Grant Nos. 40625005 and 40821002) and National Basic Research Program of China (Grant No. 2006CB403501)
Rights and permissions
About this article
Cite this article
Chen, B., He, J. & Ma, X. Petrogenesis of mafic enclaves from the north Taihang Yanshanian intermediate to felsic plutons: Evidence from petrological, geochemical, and zircon Hf-O isotopic data. Sci. China Ser. D-Earth Sci. 52, 1331–1344 (2009). https://doi.org/10.1007/s11430-009-0130-z
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/s11430-009-0130-z