Figure
1.
Geology map of the western margin of Yangtze plate, Dahongshan district.
| Citation: | Hongxiang Zhang, Congqiang Liu, Zhifang Xu, Zhilong Huang. Characteristics of Paleoproterozoic Subduction System in Western Margin of Yangtze Plate. Journal of Earth Science, 2000, 11(1): 56-65.
|
Paleoproterozoic subduction strongly occurred in the western margin of Yangtze plate. The basalticandesite volcanics of Ailaoshan Group and Dibadu Formation had been formed during paleo QinghaiTibet oceanic plate subduction under the paleoYangtze plate. Their trace element geochemistry suggests that their forming environments are continentalmarginarc and back arcbasin respectively. Consequently, the Paleoproterozoic subduction system in the western margin of Yangtze plate was established. Ailaoshan Group and Dibadu Formation came from an enriched mantle source that was contaminated by crustal sediments carried by subducted slab, and formed the Paleoroterozoic metamorphic basement of western margin of Yangtze plate. Ailaoshan Group is actually western boundary of Yangtze plate.
Debate centered on Proterozoic tectonic style and crustal evolution has existed for a long time. The customary view believed that the Proterozoic undeveloped solid plate could not put into effect on the subduction because of the high heat flow in the earth, and the continental crustal growth was dominated by mafic magma vertical underplating (Wyborn, 1988; Etheridge et al., 1987). However, many observations recently obtained from Proterozoic mobile zones in the world suggests that Proterozoic crust could have grown by lateral accretion in island-arc regimes. This accretion style is major process of the Phanerozoic crustal growth (Windley, 1995; Zhao, 1994; Kroner, 1987; Park, 1985; Condie, 1982; Lewry, 1981; Hoffman, 1980). The buoyancy of oceanic lithosphere is a major mechanism for Phanerozoic subduction because of the cold plate. Nevertheless, the buoyancy was not enough to drive the plate subduct in Proterozoic due to the high heat flow in the earth, and the viscous drag may be the dominating impetus of subduction (Hargraves, 1981).
Zhang (1993) and Zhong and Shi (1993) suggested that "Three Rivers" orogenic belt and Qinghai-Tibet plateau to the east of Yangtze plate result from the collision between Yangtze plate and Eastern Tethys tectonic region (including original Tethys Ocean, paleo-Tethys Ocean and new-Tethys Ocean) since Mesozoic. Whereas, little work has been done about the Precambrian geology in the western margin of Yangtze plate. Where is the western boundary of Yangtze plate? How was the tectonic style, continental accretion and mantle characteristics of Yangtze plate? The answer is the key to unraveling the whole tectonic and magmatic evolution of the western margin of Yangtze plate. To investigate further and constrain these questions more completely, we present the geochemical study of the Paleoproterozoic Ailaoshan Group and Dibadu Formation.
The Paleo-Middle Proterozoic Dahongshan Group (DG) is a set of volcanism-deposit cycle composed of limestone, sandstone and basalt, in which basalt stand for the Paleo-Middle Proterozoic volcanism in the west mobile belt of Yangtze plate. The age of the volcanics is about 1 700 Ma (Rb-Sr isochrons) and 1 900 Ma (single zircon U-Pb) (Feng, 1989). DG is conformable contacted with its basement-Dibadu Formation (DF). They constitute the lower unit of Yangtze plate. DF is dominated by a set of basaltic-andesite volcanics and limestone-sandstone. Because of later metamorphism, magmatization and small outcrop, the original deposited structure is difficult to observe. Although the stratigraphic studies show that DF is in the same stratigraphic horizon with its neighbor geological unit—Ailaoshan Group (AG) (Sun et al., 1993; Qian and Shen, 1990), it is questionable whether they belong to the same tectonic unit (Yangtze tectonic region) (Fig. 1).
AG is composed of greenschist-amphibolite facies metamorphic basaltic-andesite-acid-tuff volcanics and sandstone-limestone. Sm-Nd isochron age of 1 600-2 000 Ma was obtained for AG volcanics (Zhai et al., 1990). Both AG and DF show the characteristics of arc or spreading basin volcanic and deposited petrologic formation. AG is constituted of two types of metamorphic rock series. The eastern part is Paleoproterozoic hypometamorphic rocks that is called narrowly AG in this paper, which is stratigraphically related with DF although they are separated by the Honghe fault. The western part is epizonal metamorphic rocks represented by Permian Shuanggou ophiolite suite, which was thought to be the suture line of paleo-Tethys Ocean (Huang et al., 1993; Zhang et al., 1988). These two metamorphic rock series are separated by Ailaoshan fault.
Debate existed on the AG tectonic location. One view proposes that the Panxi rift should be the western boundary of Yangtze plate and AG the outer accretion (Liu et al., 1996). Another view suggests AG should be crystalline basement of Yangtze plate (Cong et al., 1993). The above divergence is the key to discuss the whole tectonic and magmatic evolution history of western margin in Yangtze plate.
AG is greenschist-amphibolite facies metamorphic rock. The major metamorphic minerals are Ca-rich plagioclase and hornblende. Some clinopyroxenes occur in some samples. DF is composed of granulite and amphibolite. The major metamorphic minerals of DF are hornblende and albite. A few quartzes occur in the granulites with augen structure, which might result from later silicification. When we selected samples in fieldwork, granulite samples with silicification were kicked off. On the bases of some facts including palimpsest volcanics structure, the porphyroid slaty plagioclase under microscope and non-orientation array of metamorphic minerals, the original rocks of these two groups were defined as volcanics. Some mantle-derived samples were picked up, which had been metamorphosed into amphibolites. All the 12 samples of AG and DF (AG1-AG7 and DF1-DF5) are analyzed for major and trace elements systematically. The analysis processes are accomplished in the resources environment analysis lab in Institute of Geochemistry, Chinese Academy of Science. Major elements are analyzed by wet chemistry, and trace elements are analyzed by ICP-MS. Overall, the precision of major element and trace element analyses are better than 2 %-5 % and +5 %, respectively. The results are given in Table 1.
|
DownLoad:
CSV
The amphibolites have basalt-like major element compositions. The TAS diagram (total-alkali-silica diagram) is useful in defining the original rock types of low-middle metamorphic volcanics including amphibolites (Le Bas et al., 1986). The original rocks of DF and AG amphibolites are basaltic basic-metabasic volcanics in TAS diagram, and some samples with high alkali fall in the field of trachy-basalt (figure is omitted).
In order to further confirm the rock classification, we use the immobile elements (IEs) such as high field-strengthen elements (HFSEs) and P2O5 and TiO2. In the diagram of w (Zr) /w (P2O5) -w (Nb) /w (Y) (Fig. 2a), most samples fall in tholeiite field except for DF4. In the diagram of w (Nb) /w (Y) -w (Zr) /w (TiO2) (Fig. 2b), samples of DF and AG7 fall on the boundary of basanite. These observations suggest that most samples belong to tholeiites. Although some samples have a little higher alkali, it is not high enough so that they can be called basanite.
The mass fractions of MgO of most samples vary in the typical basalt range (5.23 %-7.70 % for AG and 6.2 %-7.3 % for DF). Those of TiO2 (0.84 %-1.57 %) and P2O5 (0.06 %-0.68 %) are lower, which is close to that of the tholeiite in some Proterozoic mobile belts (Halden, 1991; Pharoah and Brewer, 1990; Bergh and Torske, 1988; Condie, 1986; Geringer et al., 1986). The mass fractions of CaO of AG (8.80 %-13.08 %) are higher than those of DF (< 8.8 %), which depend on clinopyroxene and olivine crystallization facies in crystalline differentiation processes (Halden, 1991). The mineralogic study of AG indicates that the high contents of CaO be due to a few clinopyroxenes and Ca-rich hornblendes and plagioclases. The total alkali (K2O+Na2O) (3.75 %-5.18 %) is higher than that of AG (2.75 %-4.65 %). In the major element tectonic diagram (Fig. 2c, d), most samples (AG or DF) fall in the area of olivinelatite, and three samples in the calc-alkaline basalt and island arc low-K tholeiite, showing the trend of magma differentiation. Moreover, the Al2O3 mass fractions of DF are higher (15.42 %-17.32 %), which indicates that the island arc had developed mature.
According to the primary mantle-normalized spider-diagram (Hoffman, 1988), most samples have similar patterns and are enriched in large ion lithophile elements (LILEs) as well as light rare earth elements (LREEs) and depleted in high field strength elements (HFSEs), which is a typical feature of island-arc basalts (Fig. 3b, c). LILEs of AG and DF are over 100-1 000 times and HFSEs (Nb, Ta, Zr, Hf and Ti) are about 10 times higher than primary mantle. Cs and Sr might be disturbed by later metamorphism. Zr and Hf of DF are less depleted than those of AG, even show a Zr-Hf positive anormaly in contrast to Sr depletion, while other HFSEs (Nb, Ta, Ti) are strongly depleted. LREEs of DF are less enriched with w (La) n of 39.18-51.79 and HREEs are more depleted. REEs patterns are smooth and the deplation degree of MREEs and HREEs like that of MORB. REEs differentiation extents of DF are stronger (w (La) n/w (Yb) n=6.88-13.14) than those of AG (w (La) n/w (Yb) n=3.25-8.23). Both AG and DF have less negative Eu anomaly that was attributed to magmatic differentiation. The intensively Pb enrichment is a typical character of subduction-related basalts (Liu et al., 1995). The similarity of AG, DF and modern continental margin arc basalts (CMA) (e.g., Fig. 3a: Indonesia arc) in trace elements except for Cs, Rb and Ba suggests that they might be formed in similar tectonic environments and the local metamorphism did not affect Th and U strongly.
The nature of the mantle sources can be obtained from isotopic studies of mantle-derived rocks. However, these ratios provide rather limited geochemical information, as the involved elements have similar geochemical properties and behaviors, which may not be strongly fractionated by mantle processes. Ratios between trace elements that have different geochemical proprieties and behaviors (e.g., ratios between REEs, LILEs and HFSEs) will be more strongly fractionated by mantle processes, and may provide important additional information about the nature of magma source.
DF and AG show an apparent decoupling characteristics of intensively LILEs enrichment and HFSEs depletion (Fig. 3). The subduction process is considered viable to explain this signature. The enrichment of these elements was superimposed onto the mantle source through the subduction process. A subducted slab-derived fluid phase enriched in the LILEs would have strong influence on the LILEs abundance of the partial melts without visible effects on IEs. In general, the pronounced depletions in HFSEs are indicative of subduction-related mantle sources (McCulloch and Gamble, 1991; Pearce, 1983). Condie (1986) and Halden (1991) argued that these kinds of basalts could be formed in back-arc basin or island arc environments. Both AG and DF are analogous to the amphibolites from eastern Finland Outokumpa Assemblage and Australia Entia, which have been argued for continental marginal-arc and back-arc basin settings (Zhao and Cooper, 1992; Pharaoh and Brewer, 1990; Sivell and Forden, 1988; Park, 1988).
The slab subduction is an important mechanism of crust-mantle recycle in Proterozoic. Fluids released from the dehydration of subducted slab would lower the melting point of mantle lherzolite to induce lower-temperature partial melting. Then, mantle enrichment occurred during the mantle metasomatism by subducted slab-derived fluids/melts that were highly enriched in LILEs and LREEs. The residue, enriched in HFSEs, isolated and cumulated into the deeper mantle (even to asthenosphere, 400-700 km) (Thompson, 1992), which could form the mantle source for OIBs and CFBs.
Trace element variations provide a method of tectonic discrimination of rocks from different suits. HFSEs and REEs are generally immobile during weathering, hydrothermal alteration and greenschist to amphibolite metamorphism, so they can reflect the original features of the volcanics (Pearce, 1982; Pearce and Norry, 1979; Winchester and Floryd, 1976). Some inter-element ratios of HFSEs do not change significantly with degrees of partial melting or crystal fractionation (unless phases rich in these elements are involved) (Hoffman, 1997; Pharaoh and Pearce, 1984).
Major elements of the samples suggest that they could not form in the within-plate tectonic environment. By comparison with typical tectonic settings, the forming environment of AG and DF could be defined further by IEs ratio diagrams (Fig. 4). Most samples from DF and AG fall in the range of IABs in thew (Zr) -w (Ti) diagram of Pearce (1982), and their w (Ti) /w (Zr) is lower than 50. One sample from DF and one from AG fall on the boundary between IAB and WPB (Fig. 4a). It has been discussed in the above section that Th had not been disturbed heavily in local metamorphism. In the w (Zr) /w (Nb) -w (Th) /w (La) diagram, most samples from DF and AG fall in the field of CMA (Fig. 4b). However, in the w (Ta) /w (Yb) -w (Th) /w (Yb) diagram (Fig. 4c), the samples of AG fall in CMA, while those of DF mostly fall on the boundary of CMA and tend to WPB. The difference between DF and AG could be attributed to the discrepancy on the degree of partial melting and the tectonic setting. Some IE ratios of amphibolites from AG, DF and those of typical tectonic setting basalts are listed in Table 2. The ratios of w (Zr) /w (Nb), w (La) /w (Nb), w (Th) /w (Nb), w (Ta) /w (Yb), w (Th) /w (Yb), w (Ta) /w (Th), w (Pb) /w (Ce) and w (Th) /w (La) of AG and DF are very similar to those of Indonesia CMA basalts. Back arc basin basalts were found to have island arc-like trace elements geochemical features (Shervais, 1982). In summary, the trace element compositions of DF and AG amphibolites show clear arc-type affinities (especially CMA), suggesting an island arc or back-arc basin origin.
On the bases of regional tectonic environment and geochemical features of AG and DF amphibolites, the Paleoproterozoic subduction system can be established in western margin of Yangtze plate (Fig. 5a). The northeastward subduction of pre-Tythes filled plate (we call it paleo-Qinghai-Tibet oceanic plate in this paper) under paleo-Yangtze plate resulted in the dehydration of subducted slab and initiated mantle lherzolite partial melting. Metasomatism of sub-arc mantle by fluids/melts enriched in LILEs and LREEs had induced the large-scale partial melting to form basalts with continental-margin-arc characteristics (CMA-AG). At the same time, accompanying the extension of back-arc-basin, decompression melting took place under the influence of continental margin arc magma enriched in LILEs, and back arc basin basalt formed (DF). The plane diagram of plate collision evolution is illustrated in Fig. 5b. Although MREEs-HREEs patterns of AG and DF is like that of modern oceanic ridge basalts, due to the limited oceanic basin development, the back arc basin did not evolve to ocean at the end.
The arc-related features of AG and DF suggest plate subduction in western margin of Yangtze plate should have had already taken place in Paleoproterozoic and the large-scale lateral extension had formed with the island arc development. Although the customary ensialic rifting model interpreting the continental extension in Proterozoic mobile belt was sustained by some scholars and the model can successfully explain some Proterozoic basalts (Etheridge et al., 1987), there still existed some difficulties. In the modern continental ensialic rifting districts, basalts are mostly alkaline and transitional types. These basalts were enriched in the LREEs, HFSEs and remarkably different from arc-type basalts, suggesting low-degree partial melting of enriched mantle sources probably within garnet stability field. Some rocks may have positive Nb anomaly, resembling plume-related oceanic island basalt. Most importantly, no basalts with arc signatures have been found in ensialic rift zones (Zhao, 1994). Therefore, if the Proterozoic mobile zones developed within a preexisting continental crust and no oceanic crust subduction, it would be expected that most of the volcanics found in such mobile zones should strongly have geochemical affinities to within-plate basalts, and few of them should display arc-type geochemical signatures. However, studies of many Proterozoic mobile zones provided contrary evidence. It is the arc signatures that dominate the mafic volcanics in the Proterozoic mobile zones (Halden, 1991; Pharaoh and Brewer, 1990; Park, 1988; Sivell and Forden, 1988; Condie, 1986). In fact, the mechanism of Archean-Proterozoic greenstone belts proved to be unanimous by most scholars: the formation of greenstone is related to subduction and island-arc accretion (Windley, 1995).
An argument about the AG location has existed for a long time. In fact, the result has been achieved from above discussion. AG was formed in the continental margin arc due to the collision between paleo-Yangtze plate and paleo-Qinghai-Tibet ocean plate in Paleoproterozoic, and attached to Yangtze tectonic field.
HFSEs and REEs are all highly incompatible elements in basaltic-andesite system, the ratios of them are generally not significantly fractionated during partial melting or crystallization and are the same as the value of the mantle source (Holm, 1985). So they can be used to constrain the mantle source of AG and DF amphibolites. The values of w (Ta) /w (Nb), w (Zr) /w (Ta), w ((Zr) /w (Hf), w (La) /w (Sm) and w (La) /w (Ce) of AG amphibolites are close to those of DF amphibolites (Table 2), which suggests that the mafic volcanics in AG and DF should come from the same mantle source. Therefore, it can be concluded that AG should belong to the Yangtze tectonic field and stand for the western boundary of Yangtze plate. Both AG and DF are the Paleoproterozoic metamorphic basements in the western margin of Yangtze plate.
|
DownLoad:
CSV
As tholeiites are considered to be generated by relatively large degree of partial melting (Jaques and Green, 1980), the HFSE ratios (e.g., w (Zr) /w (Nb)) of tholeiites are believed to approach that of their mantle sources. Typical type—N-MORBs formed in depleted mantle have the w (Zr) /w (Nb) of 40-50, which are significantly higher than the chondritic value of 16-18. Oceanic island tholeiites derived from enriched mantle always have lower w (Zr) /w (Nb) ratio than the chondritic value. In this case, the variation of w (Zr) /w (Nb) in tholeiites reflects the depletion degree of mantle source, and the higher w (Zr) /w (Nb) ratio, the higher depletion of mantle origin. The w (Zr) /w (Nb) ratios of DF and AG (19.23 and 11.40 respectively) are similar to or lower than chondritic value, which implies that they could have derived from enriched mantle.
Mantle enrichments are usually related to the mantle fluid metasomatism derived from subducted slab or original mantle degasification and dehydration, and all types of mantle fluids are enriched in LILEs and LREEs. Using HFSEs to discuss mantle origin characteristics is a common way in the trace elements geochemistry. Zhao (1994) suggested that thew (Ti) /w (Zr) ratio of the mantle-derived magmas could be used to trace their source features and assess the crustal contamination, and low w (Ti) /w (Zr) value could result from crustal contamination. This also applies to the w (Zr) /w (Y), w (Zr) /w (Nb), w (Y) /w (Nb) and w (Ti) /w (Y) ratios.
AG and DF are strongly depleted in Ti (Fig. 3). The w (Ti) /w (Zr) ratios of DF and AG (11-17 and 20-40 respectively) are close to those of granites and post-Archean shales (~20 and 30 respectively). Furthermore, that the amphibolites have low Ti, Y and high w (Zr) /w (Y) also suggests mantle contamination. So contamination by siliceous melts derived from subducted slab with sediments could occur in the mantle source of AG and DF. In conclusion, the mafic volcanics of DF and AG could have been derived from enriched mantle contaminated by crustal sediments in subduction belt.
The Paleoproterozoic subduction of paleo-Qinghai-Tibet oceanic plate under paleo-Yangtze plate initiated the mafic volcanics represented by AG and DF amphibolites in continental margin arc and back arc basin setting respectively. AG is actually the western boundary of Yangtze plate. The mafic volcanics in AG and DF were originated from enriched mantle that was contaminated by subducted slab-derived fluids and melts.
| Bergh S G, Torske T, 1988. Palaeovolcanology and Tectonic Setting of a Proterozoic Metatholeiitic Sequence near the Baltic Shield Margin, Northern Norway. Precambrian Res, 39: 227-246 doi: 10.1016/0301-9268(88)90021-6 |
| Clague D A, Frey F A, 1982. Petrology and Trace Element Geochemistry of the Honolulu Volcanics, Oahu: Implications for the Oceanic Mantle below Hawaii. J Petrol, 23: 447-504 doi: 10.1093/petrology/23.3.447 |
| Condie K C, 1986. Geochemistry and Tectonic Setting of Early Proterozoic Supracrustal Rocks in the Southwestern United State. J Geol, 94: 845-864 doi: 10.1086/629091 |
| Condie K C, 1982. Plate-Tectonics Model for Proterozoic Continental Accretion in the Southwestern United States. Geology, 10: 37- 42 https://pubs.geoscienceworld.org/gsa/geology/article-abstract/10/1/37/203370/Plate-tectonics-model-for-Proterozoic-continental |
| Cong B L, Wu G Y, Zhang Q, 1993. The Petrologic Note of the PaleoTythes Evolution in West Yunnan Province of China. In: IGCP 321th Chinese Work Group, ed. IGCP 31th. Beijing: Geology Publishing House. 65-68 (in Chinese) |
| Dupuy C, Barsczus HG, Dostal J, et al, 1989. Subducted and Recycled Lithosphere as the Mantle Source of Ocean Island Basalts from Southern Polynesia, Central Pacific. Chem Geol, 77: 1-18 doi: 10.1016/0009-2541(89)90010-7 |
| Dupuy C, Barsczus H G, Liotard J M, et al, 1988. Trace Element Evidence for the Origin of Ocean Island Basalts: An Example from the Austral Islands. Contrib Mineral Petrol, 98: 293-302 doi: 10.1007/BF00375180 |
| Etheridge M A, Rutland RW R, Wyborn L A I, 1987. Orogenesis and Tectonic Process in the Early to Middle Proterozoic of Northern Australia. In: Kroner A, ed. Proterozoic Lithospheric Evolution. Am Geophy Union, Geodyn Ser, Washington D C, 17: 131-147 |
| Feng B Z, 1989. On the Pre-Precambrian Basement and Its Mineralization of Yangtze Plate Western Margin. Acta Geologica Sinica, 4: 338-347 (in Chinese) |
| Geringer G J, Botha B J V, Pretorius J J, et al, 1986. Calc-Alkaline Volcanism along the Eastern Margin of the Namaqua Mobile Belt, South Africa— A Possible Middle Proterozoic Volcanic Arc. Precambrian Res, 33: 139-170 doi: 10.1016/0301-9268(86)90019-7 |
| Halden N M, 1991. Existence of Marginal Basin within the CircumSuperior Belt: Geochemical Evidence from the Churchill-Superior Boundary in Manitoba, Canada. Precambrian Res, 49: 167-183 doi: 10.1016/0301-9268(91)90061-E |
| Hargraves R B, 1981. Precambrian Tectonic Style: A Liberal Uniformitarian Interpretation. In: Kroner A, ed. Precambrian Plate Tectonics. Developments in Precambrian Geology 4. New York: Elsevier. 20-54 |
| Hoffman A W, 1988. Chemical Differentiation of the Earth: The Relationship between Mantle, Continental Crust and Oceanic Crust. Earth Planet Sci Lett, 90: 297-314 doi: 10.1016/0012-821X(88)90132-X |
| Hoffman P E, 1980. Wopmay Orogen: A Wilson Cycle of the Proterozoic Age in the Northwest of Canadian Shield. In: Strangway D W, ed. The Continental Crust and Its Mineral Deposits. Geol Assoc Can Spec Pap, 20: 523-549 |
| Hoffman A W, 1997. Mantle Geochemistry: The Message from Oceanic Volcanism. Nature, 385: 219-229 doi: 10.1038/385219a0 |
| Hole M J, Kempton P D, Millar I L, 1993. Trace Element and Isotopic Characteristics of Small-Degree Melts of the Asthenosphere: Evidence from the Alkalic Basalts of the Antarctic Peninsula. Chem Geol, 109: 51-68 doi: 10.1016/0009-2541(93)90061-M |
| Holm P E, 1985. The Geochemical Fingerprints of Different Tectonomagmatic Environments Using Hydromagmatophils Element Abundance of Tholeiitic Basalts and Basalts Andersites. Geology, 51: 303-323 https://www.sciencedirect.com/science/article/pii/0009254185901391 |
| Hoogewerff J A, Van Bergen M J, Vroon P Z, et al, 1997. U-Series, Sr-Nd-Pb Isotope and Trace Element Systematic across an Active Island Arc— Continental Collision Zone: Implication for Element Transfer at the Slab-Wedge Interface. Geochim Cosmochim Acta, 61(5): 1057-1072 doi: 10.1016/S0016-7037(97)84621-2 |
| Huang Z X, Han S, Dong J, et al, 1993. Rare Earth Element Geochemistry of Shuanggou Ophiolites from Xinping County, Yunnan Province. Acta Petrologica Mineralogica, 3: 205-211 (in Chinese) |
| Jaques A L, Green D H, 1980. Anhydrous Melting of Perodotite at 0-15 kbar Pressure and the Genesis of Tholeiitic Basalts. Contrib Mineral Petrol, 73: 287-310 doi: 10.1007/BF00381447 |
| Kroner A, 1987. Proterozoic Lithospheric Evolution. Geodynamics Series, 17: 1-269 doi: 10.1029/88EO00138 |
| Le Bas M J, Le Maitre R W, Streckeisen A, et al, 1986. A Chemical Classification of Volcanic Rocks Based on the Total Alkali-Silica Diagram. J Petrol, 27(3): 745-750 doi: 10.1093/petrology/27.3.745 |
| Lewry J F, 1981. Lower Proterozoic Arc— Microcontinent Collision Tectonics in the Western Churchill Province. Nature, 294: 69- 72 doi: 10.1038/294069a0 |
| Liu Z C, Li F Y, Zhong HK, et al, 1996. The Tectonic Evolution and Origin in the West Margin of Yangtze Plate. Chengdu: Electronic Technology University Publishing House (in Chinese). 1-255 |
| Liu, C Q, Xie G H, Masuda A, 1995. Geochemistry of Cenozoic Basalts from Eastern China— I. Major Element and Trace lement Compositions: Petrogenesis and Characteristics of Mantle Source. Geochimica, 1: 1-19 (in Chinese) |
| McCulloch M T, Gamble J A, 1991. Geochemical and Geodynamical Constraints on Subduction Zone Magmatism. Earth Planet Sci Lett, 102: 358-374 doi: 10.1016/0012-821X(91)90029-H |
| Michard A, Montifny R, Schlich R, 1986. Geochemistry of the Mantle Beneath the Rodriguez Triple Junction and the Southeast Indian Ridge. Earth Planet Sci Lett, 78: 104-114 doi: 10.1016/0012-821X(86)90176-7 |
| Nguyen H, Flower M F J, Carlson RW, 1996. Major, Trace Element and Isotopic Compositions of Vietnameses Basalts: Interaction of Hydrous EMI-Rich Asthenosphere with Thinned Eurasian Lithosphere. Geochim Cosmochim Acta, 22: 4329-4351 https://www.sciencedirect.com/science/article/pii/S0016703796002475 |
| Palacz Z A, Saunders A D, 1986. Coupled Trace Element and Isotope Enrichment in the Cook-Austral-Samaro Islands, Southwest Pacific. Earth Planet Sci Lett, 79: 270-280 doi: 10.1016/0012-821X(86)90185-8 |
| Park A F, 1985. Accretion Tectonism in the Proterozoic Svecokarelides of the Baltic Shield. Geology, 13: 725-729 https://pubs.geoscienceworld.org/gsa/geology/article-abstract/13/10/725/203720/Accretion-tectonism-in-the-Proterozoic |
| Park A F, 1988. Nature of the Early Proterozoic Outokumpu Assemblage, Eastern Finland. Precambrian Res, 38: 131-146 doi: 10.1016/0301-9268(88)90088-5 |
| Pearce J A, 1976. Statistical Analysis of Major Elements Patterns in Basalts. J Petrol, 17: 15-43 doi: 10.1093/petrology/17.1.15 |
| Pearce J A, Norry M J, 1979. Petrogenetic Implications of Ti, Zr, Y and Nb Variations in Volcanic Rocks. Contrib Mineral Petrol, 69: 33-47 doi: 10.1007/BF00375192 |
| Pearce J A, 1983. Role of the Slab-Continental Lithosphere in Magma Genesis at Active Continental Margin. In: Hawkesworth C J, Norry M J, eds. Continental Basalts and Mantle Xenoliths. Nanywich: Shiva Publishing House. 158-185 |
| Pearce J A, 1982. Trace Element Characteristics of Lavas from Destructive Plate Boundaries. In: Thorpe R S, ed. Andesites. New York: Wiley. 525-548 |
| Peate D W, Pearce J A, Hawkesworth C J, et al, 1997. Geochemical Variations in Vanuatu Arc Lavas: The Role of Subducted Material and a Variable Mantle Wedge Composition. J Petrol, 38 (10): 1331-1358 doi: 10.1093/petroj/38.10.1331 |
| Pharaoh T C, Brewer T S, 1990. Spatial and Temporal Diversity of Early Proterozoic Volcanic Sequences— Comparisons between the Batlic and Laurentian Shield. Precambrian Res, 47: 169-189 doi: 10.1016/0301-9268(90)90037-Q |
| Pharaoh T C, Pearce J A, 1984. Geochemical Evidence for the Geotectonic Setting of Early Proterozoic Metavolcanic Sequences in Lapland. Precambrian Res, 25: 283-308 doi: 10.1016/0301-9268(84)90037-8 |
| Qian J H, Shen Y R, 1990. The Paleo-Volcanics Iron-Copper Deposits in Yunnan Province. Beijing: Geology Publishing House. 1-80 (in Chinese) |
| Roden M F, Frey F A, Clague D A, 1984. Geochemistry of Tholeiitic and Alkalic Lavas from the Koolau Range, Oahu, Hawaii: Implication for Hawaiian Volcanism. Earth Planet Sci Lett, 69: 141-158 doi: 10.1016/0012-821X(84)90079-7 |
| Shervais J W, 1982. Ti-V Plots and the Petrogenesis of Modern and Ophiolitic Lavas. Earth Planet Sci Lett, 59: 101-118 doi: 10.1016/0012-821X(82)90120-0 |
| Sivell W J, Forden J D, 1988. Amphibolites from the Entia Genesis Complex, Eastern Arunta Inlier: Geochemical Evidence for a Proterozoic Transition from Extensional to Compressional Tectonics. Precambrian Res, 38: 235-255 doi: 10.1016/0301-9268(88)90004-6 |
| Sun K X, Li Z W, Yang X K, 1993. Characteristics and Stratigraphic Horizons of Chahe Metamorphic Rock Assemblage of Middle to High-Grade in Yuanjiang County. Yunnan Geology, 1: 21-29 (in Chinese) |
| Taylor R N, Nesbit R W, 1998. Isotopic Characteristics of Subduction Fluids in an Intra-Oceanic Setting, Izu-Bonin Arc, Japan. Earth Planet Sci Lett, 164: 79-98 doi: 10.1016/S0012-821X(98)00182-4 |
| Thompson A B, 1992. Water in the Earth' s Upper Mantle. Nature, 23: 295-302 https://www.nature.com/articles/358295a0 |
| Winchester J A, Floryd P A, 1976. Geochemical Magma Type Discrimination Application to Altered and Metamorphosed Basic Igneous Rocks. Earth Planet Sci Lett, 28: 459-469 doi: 10.1016/0012-821X(76)90207-7 |
| Windley B F, 1995. The Evolving Continents. New York, Chichester: Wiley. 1-526 |
| Wyborn L A I, 1988. Petrology, Geochemistry and Origin of a Major Australian 1 880- 1 840 Ma Felsic Volcano-Plutonic Suits: A Model for Intracontinental Felsic Magma Generation. Precambrian Res, 40 /41: 37-60 doi: 10.1016/0301-9268(88)90060-5 |
| Zhai M G, Cong B L, Qiao G S, et al, 1990. Sm-Nd and Rb-Sr Geochronology of Metamorphic Rocks from SW Yunnan Orogenic Zones. Acta Petrologica Sinica, 4: 1-11 (in Chinese) https://www.sciencedirect.com/science/article/pii/S1342937X05703403 |
| Zhang Q, Zhang K W, Li D Z, et al, 1988. A Preliminary Study of Shuanggou Ophiolite in Xinping County, Yunnan Province. Acta Petrologica Sinica, 4: 37-47 (in Chinese) https://en.cnki.com.cn/Article_en/CJFDTOTAL-YSXB198804004.htm |
| Zhang Q, 1993. Where is Chinese Paleo-Tythes Ophiolite Complex? In: IGCP 321th Chinese Work Group, ed. IGCP 321th. Beijing: Geology Publishing House. 21-23 |
| Zhao J X, Cooper J A, 1992. The Atnarpa Igneous Complex, S. E. Arunta Inlier, Central Australia: Implications for Subduction at an Early - Mid Proterozoic Continental Margin. Precambrian Res, 56: 227-253 |
| Zhao J X, 1994. Geochemical and Sm-Nd Isotopic Study of Amphibolites in the Southern Arunta Inlier, Central Australia: Evidence for Subduction at a Proterozoic Continental Margin. Precambrian Res, 65: 71-94 https://www.sciencedirect.com/science/article/pii/0301926894901007 |
| Zhong D L, Shi L, 1993. Discussion about Divergent Gondwana-Land and Asia Continent Accretion from the Evolution of" Three River" District and Neighbor Tythes Belt. In: IGCP 321th Chinese Work Group, ed. IGCP 321th. Beijing: Geology Publishing House. 5-8 (in Chinese) |
Figures(5) / Tables(2)
Copyright © 2013-2020 Journal of Earth Science 鄂ICP备15021562号-2
Tel: +86-27-67885075 Fax: +86-27-67885075 E-mail: xbb@cug.edu.cn
Address: Editorial Office of Journal, China University of Geosciences, Yujiashan, Wuhan, Hubei 430074, P. R. China
Supported by:
Beijing Renhe Information Technology Co. Ltd
E-mail:
info@rhhz.net
Hongxiang Zhang, Congqiang Liu, Zhifang Xu, Zhilong Huang. Characteristics of Paleoproterozoic Subduction System in Western Margin of Yangtze Plate. Journal of Earth Science, 2000, 11(1): 56-65.
|
|
DownLoad:
CSV
DownLoad:
DownLoad:
