Origin and emplacement of Archean ophiolites of the central orogenic belt, North China craton
Timothy M. Kusky, Jianghai Li
Journal of Earth Science ›› 2010, Vol. 21 ›› Issue (5) : 744-781.
Origin and emplacement of Archean ophiolites of the central orogenic belt, North China craton
Understanding Archean crustal and mantle evolution hinges upon identification and characterization of oceanic lithosphere. We report and update here more than 10 years work on a complete, yet dismembered and metamorphosed Archean ophiolite sequence in the North China craton, in the Dongwanzi (东湾子)-Zunhua (遵化) structural belt and correlatives in the Wutaishan (五台山) area. Banded iron formation structurally overlies several tens of meters of variably deformed pillow lavas, mafic flows, and picritic amphibolites. These are in structural contact with a 2 km thick mixed gabbro and dike complex with gabbro screens, exposed discontinuously along strike for more than 20 km. The dikes consist of metamorphosed diabase, basalt, Hb-Cpx-gabbro, and pyroxenite. The dike/gabbro complex is underlain by several kilometers of mixed isotropic and foliated gabbro, which preserve compositional layering approximately 2 km below the dike complex, and then over several hundred meters merge into strongly compositionally layered gabbro and olivine-gabbro. The layered gabbro becomes mixed with layered pyroxenite/gabbro marking a transition zone into cumulate ultramafic rocks including serpentinized dunite, pyroxenite and wehrlite, and finally into strongly deformed and serpentinized olivine and orthopyroxene-bearing ultramafic rocks interpreted as depleted mantle harzburgite tectonites. A U/Pb zircon age of 2.505 Ga from gabbro of the Dongwanzi ophiolite makes it one of the world’s oldest recognized, laterally-extensive complete ophiolite sequences, though older dismembered ophiolites are recognized in South Africa and Greenland, extending back to 3.8 Ga. This age is confirmed by a ca. 2.6 Ga Re-Os isochron from chromites from the belt, and a number of dated 2.5–2.4 Ga cross-cutting younger igneous units. The Dongwanzi ophiolite is one of the largest well-preserved greenstone belts in the central orogenic belt that divides the North China craton into eastern and western blocks. More than 1 000 other fragments of gabbro, pillow lava, sheeted dikes, harzburgite, and podiform-chromite bearing dunite occur as tectonic blocks (tens to hundreds of meters long) in a biotite-gneiss and BIF matrix, intruded by tonalite and granodiorite, in the Zunhua structural belt. Blocks in this metamorphosed Archean ophiolitic mélange preserve deeper levels of oceanic mantle than the Dongwanzi ophiolite. The ophiolite-related mélange marks a suture zone across the North China craton, traced for more than 1 600 km along the central orogenic belt. Many of the chromitite bodies are localized in dunite envelopes within harzburgite tectonite, and have characteristic nodular and orbicular chromite textures, known elsewhere only from ophiolites. The chromites have variable but high chrome numbers (Cr/(Cr+Al)=0.74−0.93) and elevated P, also characteristic of suprasubduction zone ophiolites. The high chrome numbers, coupled with TiO2<0.2 wt.% and V2O5<0.1 wt.% indicate high degrees of partial melting from a very depleted mantle source and primitive melt for the chromite. A Re-Os isochron from the chromites indicates an age of 2.6 Ga, showing that they are the same age as the Dongwanzi ophiolite. The range in initial Os isotopic compositions in the chromites in these ophiolitic blocks is small and well within the range seen in modern ophiolites. The ultramafic and ophiolitic blocks in the Zunhua mélange are therefore interpreted as dismembered and strongly deformed parts of the Dongwanzi ophiolite. We suggest the name “Dongwanzi-Zunhua ophiolite belt” for these rocks. Geochemical and structural features of the Dongwanzi ophiolite suggest that it formed in a forearc environment and was incorporated in an accretionary prism soon after it formed. Neoarchean and Paleoproterozoic (2.50 and 1.90 Ga) high-pressure granulites form a belt more than 700 km long along the western side of the central orogenic belt. Several Neoarchean sedimentary basins consisting of conglomerate, greywacke, and shale are located along the eastern side of the central orogenic belt, and are interpreted as remnants of a foreland basin. The three belts record the Neoarchean subduction and collision between an arc terrane and eastern blocks of the North China craton in the Neoarchean, and further deformation and metamorphism in the Paleoproterozoic related to collisions on the northern margin of the already amalgamated North China craton.
North China craton / Archean / ophiolite / Proterozoic / mélange / podiform chromite
|
|
Anonymous, 1972. Penrose Field Conference on Ophiolites. Geotimes, 17(12): 24–25
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
De-Wit, M. J., 2004. Archean Greenstone Belts do Contain Fragments of Ophiolites, In: Kusky, T. M., ed., Precambrian Ophiolites and Related Rocks. Developments in Precambrian Geology, 13: 599–614
|
|
|
|
|
Dilek, Y., 2003. Ophiolite Concept and Its Evolution. In: Dilek, Y., Newcomb, S., eds., Ophiolite Concept and the Evolution of Geological Thought. Geological Society of America Special Paper, 373: 1–16
|
|
|
|
|
|
|
|
|
Edwards, S. J., Pearce, J. A., Freeman, J., 2000. New Insights Concerning the Influence of Water during the Formation of Podiform Chromitite. In: Dilek, Y., Moores, E., Elthon, D., et al., eds., Ophiolites and Oceanic Crust, New Insights from Field Studies and the Ocean Drilling Program. Geological Society of America Special Paper, 349: 139–148
|
|
|
|
|
|
|
Furnes, H., De-Wit, M. J., Staudigel, H., et al., 2007b. Response to Comments on “A Vestige of Earth’s Oldest Ophiolite”. Science, 318(5851), doi: 10.1126/science.1144231
|
|
|
|
|
|
Griffin, W. L., Zhang, A., O’Reilly, S. Y., et al., 1998. Phanerozoic Evolution of the Lithosphere beneath the Sino-Korean Craton. In: Conference on Mantle Dynamics and Plate Interactions in East Asia. A.G.U. Geodynamics, 27: 107–126
|
|
|
|
|
|
|
Holtzman, B., 2000. Gauging Stress from Mantle Chromitite Pods in the Oman Ophiolite. In: Dilek, Y., Moores, E. M., Elthon, D., et al., eds., Ophiolites and Oceanic Crust: New Insights from Field Studies and the Ocean Drilling Program. Geological Society of America Special Paper, 349: 149–158
|
Huang, X. N., Li, J. H., Kusky, T. M., et al., 2004. Microstructures of the Zunhua 2.50 Ga Podiform Chromite, North China Craton and Implications for the Deformation and Rheology of the Archean Oceanic Lithospheric Mantle. In: Kusky, T. M., ed., Precambrian Ophiolites and Related Rocks. Developments in Precambrian Geology, 13:321–337
|
Huson, R., Kusky, T. M., Li, J. H., 2004. Geochemical and Petrographic Characteristics of the Central Belt of the Archean Dongwanzi Ophiolite Complex. In: Kusky, T. M., ed., Precambrian Ophiolites and Related Rocks. Developments in Precambrian Geology, 13: 283–320
|
|
|
|
|
|
|
Johnson, P. R., Kattan, F. H., Al-Saleh, A. M., 2004. Neoproterozoic Ophiolites in the Arabian Shield: Field Relations and Structure. In: Kusky, T. M., ed., Precambrian Ophiolites and Related Rocks. Developments in Precambrian Geology, 13: 129–162
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Kusky, T. M., Li, J. H., 2002. Is the Dongwanzi Complex an Archean Ophiolite? Response to Zhai, M., Zhao, G., Zhang, Q.. Science, 295(5557)
|
|
|
Kusky, T. M., Glass, A., Tucker, R., 2007a. Structure, Cr-Chemistry, and Age of the Border Ranges Ultramafic-Mafic Complex: A Suprasubduction Zone Ophiolite Complex. In: Ridgway, K. D., Trop, J. M., Glen, J. M. G., et al., eds., Tectonic Growth of a Collisional Continental Margin: Crustal Evolution of Southern Alaska. Geological Society of America Special Paper, 207–225
|
Kusky, T. M., Windley, B. F., Zhai, M. G., 2007b. Tectonic Evolution of the North China Block: From Orogen to Craton to Orogen. In: Zhai, M. G., Windley, B. F., Kusky, T. M., et al., eds., Mesozoic Sub-continental Lithospheric Thinning under Eastern Asia. Geological Society of London Special Publication, 280: 1–34
|
Kusky, T. M., Li, J. H., Santosh, M., 2007c. The Paleoproterozoic North Hebei Orogen: North China Craton’s Collisional Suture with the Columbia Supercontinent. In: Zhai, M. G., Xiao, W. J., Kusky, T. M., et al., eds., Tectonic Evolution of China and Adjacent Crustal Fragments. Special Issue of Gondwana Research, 12(1–2): 4–28
|
Kusky, T. M., Zhi, X. C., Li, J. H., et al., 2007d. Chondritic Osmium Isotopic Composition of Archean ophiolitic Mantle, North China Craton. In: Zhai, M. G., Xiao, W. J., Kusky, T. M., et al., eds., Tectonic Evolution of China and Adjacent Crustal Fragments. Special Issue of Gondwana Research, 12(1–2): 67–76
|
Kusky, T. M., Polat, A., 1999. Growth of Granite-Greenstone Terranes at Convergent Margins and Stabilization of Archean Cratons. In: Marshak, S., Van Der Pluijm, B. A., Hamburger, M., eds., The Tectonics of Continental Interiors. Tectonophysics, 305(1–3): 43–73
|
Kusky, T. M., Santosh, M., 2009. The Columbia Connection in North China. In: Reddy, S. M., Mazumder, R., Evans, D. A. D., et al., eds., Palaeoproterozoic Supercontinents and Global Evolution. Geological Society of London Special Publication, 323: 49–71
|
Kusky, T. M., Vearncombe, J., 1997. Structure of Archean Greenstone Belts. In: De-Wit, M. J., Ashwal, L. D., eds., Tectonic Evolution of Greenstone Belts. Oxford Monograph on Geology and Geophysics, 35: 95–128
|
|
|
|
|
Li, J. H., Kusky, T. M., 2007a. World’s Largest Known Precambrian Fossil Black Smoker Chimneys and Associated Microbial Vent Communities, North China: Implications for Early Life. In: Zhai, M. G., Xiao, W. J., Kusky, T. M., et al., eds., Tectonic Evolution of China and Adjacent Crustal Fragments. Special Issue of Gondwana Research, 12(1–2): 84–100
|
|
Li, J. H., Kusky, T. M., 2007b. A Late Archean Foreland Fold and Thrust Belt in the North China Craton: Implications for Early Collisional Tectonics. In: Zhai, M. G., Xiao, W. J., Kusky, T. M., et al., eds., Tectonic Evolution of China and Adjacent Crustal Fragments. Special Issue of Gondwana Research, 12(1–2): 47–66
|
|
Li, J. H., Kusky, T. M., Niu, X. L., et al., 2004. Neo-Archean Massive Sulfide of Wutai Mountain, North China: A Black Smoker Chimney and Mound Complex within 2.50-Ga-Old Oceanic Crust. In: Kusky, T. M., ed., Precambrian Ophiolites and Related Rocks. Developments in Precambrian Geology, 13: 339–362
|
|
|
|
|
|
|
|
|
Menzies, M. A., Fan, W. M., Zhang, M., 1993. Palaeozoic and Cenozoic Lithoprobes and the Loss of >120 km of Archaean Lithosphere, Sino-Korean Craton, China. In: Prichard, H. M., Alabaster, T., Harris, N. B., et al., eds., Magmatic Processes and Plate Tectonics. Geological Society Special Publications, 76: 71–81
|
|
|
|
Nicolas, A., Al-Azri, H., 1991. Chromite-Rich and Chromite-Poor Ophiolites: The Oman Case. In: Peters, T. J., Nicolas, A., Coleman, R. G., eds., Ophiolite Genesis and Evolution of the Oceanic Lithosphere. Petrology and Structural Geology, 5: 261–274
|
Nicolas, A., Boudier, F., 2000. Large Mantle Upwellings and Related Variations in Crustal Thickness in the Oman Ophiolite. In: Dilek, Y., Moores, E. M., Elthon, D., et al., eds., Ophiolites and Oceanic Crust: New Insights from Field Studies and the Ocean Drilling Program. Geological Society of America Special Paper, 349: 67–73
|
|
|
|
|
Peltonen, P., Kontinen, A., 2004. The Jormua Ophiolite: A Mafic-Ultramafic Complex from an Ancient Ocean-Continent Transition Zone. In: Kusky, T. M., ed., Precambrian Ophiolites and Related Rocks. Developments in Precambrian Geology, 13: 35–72
|
Peng, P., Zhai, M. G., Guo, J. H., et al., 2007. Nature of Mantle Source Contributions and Crystal Differentiation in the Petrogenesis of the 1.78 Ga Mafic Dikes in the Central North China Craton. In: Zhai, M. G., Xiao, W. J., Kusky, T. M., et al., eds., Tectonic Evolution of China and Adjacent Crustal Fragments. Gondwana Research, 12(1–2): 29–46
|
|
|
|
|
|
|
|
|
Reed, C., 2002. Chimneys from an Ancient Ocean. Geotimes, 23
|
Regional Geological Survey Team of Hebei Geology and Mineral Resources Bureau, 1988. Regional Geology Survey Reports of Xiabancheng Breadth, Breadth and Taipingzhai Breadth. 1: 50 000 (in Chinese)
|
|
|
|
Scott, D. J., St. Onge, M. R., Lucas, S. B., et al., 1991. Geology and Chemistry of the Early Proterozoic Purtuniq Ophiolite, Cape Smith Belt, Northern Quebec, Canada. In: Peters, T. J., ed., Ophiolite Genesis and Evolution of the Oceanic Lithosphere. Petrology and Structural Geology, 5: 817–849
|
|
|
Shervais, J., 2003. Ophiolites and Oceanic Crust, New Insights from Field Studies and the Ocean Drilling Program. In: Dilek, Y., Moores, E., Elthon, D., et al., eds., Geological Society of America Special Paper, 349: 552
|
|
|
Stern, R. J., Johnson, P. R., Kroener, A., et al., 2004. Neoproterozoic Ophiolites of the Arabian-Nubian Shield. In: Kusky, T. M., ed., Precambrian Ophiolites and Related Rocks. Developments in Precambrian Geology, 13: 95–128
|
|
|
Sylvester, P. J., Harper, G. D., Byerly, G. R., et al., 1997. Volcanic Aspects. In: De-Wit, M. J., Ashwal, L. D., eds., Greenstone Belts. Oxford Monographs on Geology and Geophysics, 35: 55–90
|
Thayer, T. P., 1969. Gravity Differentiation and Magmatic Re-emplacement of Podiform Chromite Deposits. In: Magmatic Ore Deposits. Economic Geology Monographs, 4: 132–146
|
|
|
|
|
|
|
|
|
|
|
|
|
|
|
Wilks, M. E., Harper, G. D., 1997. Wind River Range, Wyoming Craton. In: De-Wit, M. J., Ashwal, L. D., eds., Greenstone Belts. Oxford Monograph on Geology and Geophysics, 35: 508–516
|
|
|
|
|
|
|
|
|
|
|
|
|
Zhao, G., Kröner, A., 2002, Introduction. In: Kröner, A., Zhao, G. C., Wilde, S. A., et al., eds., Late Archean to Paleoproterozoic Lower to Upper Crustal Section in the Hengshan-Wutaishan Area of North China. Guidebook for Penrose Conference Field Trip. 1–2
|
|
|
|
|
|
|
|
|
|
/
〈 |
|
〉 |