Journal of Earth Science, Vol. 23, No. 3, p. 277284, June 2012 ISSN 1674-487X Printed in China DOI: 10.1007/s12583-012-0253-6

The Neoarchean Ophiolite in the North China Craton: Early Precambrian Plate Tectonics and

Scientific Debate

Timothy M Kusky* Three Gorges Research Center for Geo-hazards, Ministry of Education, China University of Geosciences, Wuhan

430074, China; State Key Laboratory of Geological Processes and Mineral Resources, China University of Geosciences, Wuhan 430074, China

Mingguo Zhai () State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics,

Chinese Academy of Sciences, Beijing 100029, China

ABSTRACT: Archean greenstone belts and their possible inclusion of fragments of ophiolites is an im-portant research subject, since it is correlated with the nature of early oceanic crust, and can yield in-formation on the nature of early planetary lithospheres, the origin of TTG (tonalite-trondhjemite- granodiorite) continental crust, the formation of early cratons and continents, and is related to when plate tectonics started in the Earths evolutionary history. This article briefly reviews the North China cratons Archean ophiolite argument and proposes further studies aimed at understanding the genera-tion of greenstone belts and Archean ophiolites, and suggests some key scientific questions that remain to be answered. KEY WORDS: Archean, ophiolite, greenstone belt, North China craton.

INTRODUCTION

Understanding the early history of the Earth is one of the major challenges to the Earth Science community. Early crust formation is represented by massive tonalite-trondhjemite-granodiorite (TTG), and its peak formation time is about 2.7 Ga. The formation of this stage of TTG is generally considered to be re-lated to mantle plumes (e.g., Condie, 1997), although

This study was supported by the National Natural Science

Foundation of China (Nos. 91014002, 40821061), and Ministry of Education of China (No. B07039).

*Corresponding author: tkusky@gmail.com China University of Geosciences and Springer-Verlag Berlin

Heidelberg 2012

Manuscript received January 12, 2012.

Manuscript accepted March 5, 2012.

other models suggest that the TTG terranes may have formed from partial melting of shallowly subducted buoyant oceanic slabs (e.g., Tappe et al., 2011; Rapp and Watson, 1995; Rapp et al., 1991). However, some cratons preserve a tectonic framework of high-grade granulite-gneiss and greenstone belts formed in the Early Archean. Greenstone belts consist of low-grade metamorphic volcanic-sedimentary rocks which are typically exposed as linear fold belts around high-grade rocks (e.g., Kusky and Vearncombe, 1997). For the tectonic setting of greenstone belt rocks, there are different opinions including intracontinental rifts, island arcs, back-arc basinsmall ocean basin com-binations, although these models are not mutually ex-clusive. These different ideas led to a debate of whether plate tectonics existed in the Archean and when did plate tectonics begin to operate (e.g., Stern,

Timothy M Kusky and Mingguo Zhai 278

2007). Archean ophiolite discrimination is one of the

main bases to explore the issues of whether or not plate tectonics existed in the Archean and when did plate tectonics begin to operate, thus many scientists have been dedicated to this study for many years. There are a number of papers related to this aspect published in international journals. Precambrian Ophiolites and Related Rocks edited by Kusky (2004) focused on Archean and Proterozoic ophiolites, and also discussed the oceanic crust evolution model which changes with time. The assumed oldest ophio-lite is from the Isua supracrustal rocks in West Greenland (Furnes et al., 2009, 2007a, b), with an isotopic age of ~3.8 Ga. The ophiolites that are as-sumed to be around 3.02.7 Ga age include the 3.0 Ga ophiolite of Olondo in the Aldan Shield, East Siberia, 2.8 Ga SSZ-type ophiolite of the North Karelian belt in the NE Baltic Shield, Russia, and 2.7 Ga ophiolites in the Slave craton, Canada, and Zimbabwe (Cocoran et al., 2004; Hofmann and Kusky, 2004; Puctel, 2004; Shchipansky et al., 2004; Kusky, 1998, 1991, 1990, 1989; Kusky and Kidd, 1992), and 2.5 Ga ophiolites in the North China craton (NCC). All above ophiolites are still controversial, mainly because of their differ-ences compared to the rock association, occurrence and geochemistry of modern spreading ridges. Since documentation of Archean ophiolites is a key scien-tific issue, the debate and further research will con-tinue and its progress will promote the understanding of early continental evolution and the beginning of plate tectonics. GENERAL CHARACTERISTICS OF GREENSTONE BELTS AND OPHIOLITES Greenstone Belt

Generally, the term greenstone belt refers to a supracrustal rock belt distributed in linear to arcuate zones in Precambrian shields. Greenstone belts typi-cally contain products of several generations of mafic volcanic-sedimentary rocks. The main rocks consist of basalts, komatiites, intermediate-acidic calc-alkaline volcanic rocks and sedimentary rocks, gabbros and diabases, and minor serpentinized ultramafic rocks (e.g., de Wit and Ashwal, 1997). Metamorphic grades range from sub-greenschist to granulite, with

greenschist-amphibolite facies being most characteris-tic. The chlorite, epidote, actinolite and other meta-morphic minerals give the rocks their characteristic dark green color. A complete set of strata of green-stone belt rocks is typically comprised of early vol-canic rocks and later clastic sedimentary rocks or vol-canic clastic sedimentary rocks, which are mainly tur-bidites. Underlying volcanic/plutonic rocks are mainly ultramafic-mafic rocks also in some cases including komatiites. Overlying volcanic rocks are typically calc-alkaline volcanic rocks. There are generally ul-tramafic lenses underlying the greenstone belt, which are explained to represent fragments of ancient mantle. Greenstone belts are structurally complex with a com-plex series of deformation events, yet many exhibit a broad synclinal shape surrounding high-grade gneiss-granulite zones, formed in the late stages of deformation of these belts (e.g., Kusky and Vearn-combe, 1997). Ophiolite

An ophiolite is a rock suite that consists of ser-pentinized ultramafic rocks, a mafic intrusive complex, mafic lavas and marine sediments. The classical Penrose (Anonymous, 1972) representative ophioli-tic sequence includes, from base upward, peridotites, gabbros, sheeted dikes, mafic lavas and marine sedi-ments, in which peridotites and gabbros can be re-peated several times. During deformation and meta-morphism, peridotites are generally serpentinized with a density reduction, and then can be easily uplifted and undergo plastic deformation and significant structural displacement. Overlying the igneous rocks are pelitic and sandy rocks, which may be intercalated with chert and limestone. Many ophiolitic rocks from around the world have similar sequences, which can be compared with sequences of current ocean floors, so ophiolites are generally thought to be fragments of oceanic crust attached to the continental margin or is-land arc. However, the integrity of ophiolitic se-quences is always damaged because of the subduction of oceanic crust, tectonic emplacement that forms overthrust nappes, and in most cases just some sec-tions of the sequence or mixed rocks from hybrid ac-cumulation can be observed. The origin of ophiolite is generally interpreted to be generated by the emplace-

The Neoarchean ophiolite in the North China Craton: Early Precambrian Plate Tectonics and Scientific Debate 279

ment of oceanic lithosphere which is formed because of ocean floor spreading along a mid oceanic ridge, or spreading in a fore-arc environment (e.g., Dilek and Furnes, 2011; Robinson et al., 2008). There are close relations between ophiolites and the evolution of oce-

anic lithosphere, therefore, research on ophiolite composition, components and origin is the main way to understand the structure, change, and dynamics of oceanic lithosphere. Recent work (e.g., Dilek and Furnes, 2011; Kusky et al., 2011) shows that there is a

Table 1 Criteria for Recognition of a Rock Sequence as an Ophiolite

Indicator Importance Status in Phanerozoic

ophiolites

Status in Dongwanzi Conclusion

Full Penrose sequence In order

Diagnostic Rare, about 10% Suggested, needs Documentation

And verification.

Not conclusive

Podiform chromites w/

nodular textures

Diagnostic About 15% Present Diagnostic

Full sequence

dismembered

Convincing About 30%50% Dismembered units

Present

Convincing

3 or 4 of 7 main units

present

Typical for accepting

Phanerozoic. Ophiolite

About 80% 6 of 7 units known

Dikes still not convincing Uncertain (age)

Convincing

Sheeted dikes Distinctive, nearly diagnostic About 10% Suggested, age needs Verification

Not conclusive

Mantle tectonites Distinctive About 20%30% Present Distinctive Cumulates Present, not distinctive About 70% Present Supportive

Layered gabbro Typical About 70% Present Supportive Pillow lavas Typical not distinctive About 85% Present Supportive

Chert, deep water seds Typical About 85% Present Supportive Co-magmatic dikes and

gabbro

Necessary, rare to observe About 15% Present Distinctive

High-T silicate defm. ins inclus. in melt pods

Rare, but distinctive About 10% Present Distinctive

Basal thrust fault Necessary (except in rare

cases), not diag.

About 60% Present Supportive

Dynamothermal

sole

Distinctive, almost diagnostic About 15% Not determined Inconclusive

Sea floor metamor Distinctive All Present Supportive

Hydrothermal vents black smoker type

Distinctive Rare Present Strongly supports

Ophiolites are defined on the basis of field relationships and the overall rock sequence. Many workers have added chemical criteria to the ways to recognize and distinguish between different types of ophiolites. Some of the more

common traits are

MORB chem. Common About 40% Present Distinctive

Arc tholeiite chem. Common About 60% Present Distinctive Flat REE Distinctive About 65% Present Distinctive

Calc-alkaline chem. Common About 25% Present in some units InconclusiveBoninite chem. Distinctive About 40% Uncertain Inconclusive

Timothy M Kusky and Mingguo Zhai 280

much greater variation in young ophiolites and oce-anic lithosphere than proposed by the Penrose defini-tion (Anonymous, 1972), and workers in ancient Pre-cambrian shields need to appreciate the variation in Phanerozoic ophiolites and modern oceanic litho-sphere, when interpreting the tectonic setting of mafic/ ultramafic/sedimentary sequences in greenstone belts.

Because ophiolites are mostly dismembered and disordered fragments, there are different criteria and descriptions in formal research for how to determine whether or not a rock sequence may be an ophiolite. Kusky (2004) presented a list of criteria for determin-ing whether or not a rock sequence is an ophiolite or not. This list is modified and reproduced above (also after Kusky et al., 2011) where geologists can com-pare the different indicators of ophiolitic characteris-tics of a rock sequence against well-known Phanero-zoic ophiolites, to determine how well their sequence of rocks compares to established ophiolite sequences. The main problem is that even if a rock sequence had a sea-floor spreading ridge origin, it is typically dis-membered and only partly preserved because of the structural and metamorphic consequences of the em-placement process. It has to be asked, how many of the characteristics of a full Penrose-style ophiolite are needed to recognize a rock sequence as having a sea-floor spreading origin? In Table 1, the presence or absence of different units in the Archean Dongwanzi- Zunhua ophiolite belt of the North China craton are compared to typical Phanerozoic ophiolites, but these columns can be replaced with the rocks present in any other given rock sequence to see how well it compares to other recognized ophiolites.

PREVIOUS AND FURTHER STUDY OF ARCHEAN OPHIOLITES IN THE NCC

As originally reported in Science (Kusky et al., 2001), a group of circa 2.5 Ga mafic/ultramafic rocks in eastern Hebei, China, was interpreted to represent one of the worlds oldest, most complete yet dismem-bered and metamorphosed ophiolite sequences. This sequence was named the Dongwanzi ophiolite and has been the focus of much scientific debate since the original proposal (Kusky and Li, 2010, 2008, 2002; Kusky et al., 2007; Zhao et al., 2007; Zhang et al., 2003; Zhai et al., 2002). The main focus point of the

debate is documenting if rocks in this belt have ge-netic relationships with each other. The ophiolite belt was later (Li et al., 2002) extended to the south to the Zunhua area (Fig. 1) to include a group of ophiolite- like fragments in high grade mlange, including podi-form chromites, and the belt has since been referred to as the Dongwanzi-Zunhua ophiolite belt (e.g., Kusky and Li, 2010). The Dongwanzi ophiolite, in the origi-nal reconnaissance maps and definition of Kusky et al. (2001) included three belts of rocks, namely the northern, central, and southern zones. In these belts, the sequence of rocks was suggested to grade upwards from tectonized harzburgites, through lower crustal ultramafic and mafic cumulates, into a thick gabbro unit, then into a unit of metamorphosed mafic amphi-bolites that locally include remnants of pillow lavas and dike complexes.

One of the most contentious issues has been the age of the relatively small central belt of the Dong-wanzi ophiolite. Kusky et al. (2001) interpreted this belt to be part of the main ophiolite preserved in the southeastern belt, but stated that the central belt is in-truded by several generations of younger intrusions, and in 2004 (Kusky et al., 2004) dated these younger intrusions as circa 300 Ma. Later, Zhao et al. (2007) confirmed that gabbro, leucogabbro and mafic dikes of only the central belt of the Dongwanzi complex are later intrusions, and considered that Kusky et al. re-garded this rockmass as a part of the Archean Dong-wanzi complex by mistake. Based on the new data, there are at least two current possible interpretations to explain this discrepancy. One possibility is that Zhao et al. (2007) only dated the younger intrusions in the central belt, and missed the older rocks. The other in-terpretation is that the zircons that Kusky et al. (2001) dated may have been old xenocrystic cores caught in younger intrusions. Therefore, until further work can resolve this ambiguity, Kusky et al. abandon the cor-relation of the central belt with the main southeastern belt of the Dongwanzi-Zunhua mafic-ultramafic belt. Yet they emphasize that most of the data and interpre-tation of the Dongwanzi-Zuhua belt as ophiolitic comes from the southeastern belt, and its extensions to Palaeoarchean terrains along strike which contain ex-tensively serpentinized ultramafic rocks from Qinglong, Zunhua, Zhangjiakou of Hebei, Miyun of

The Neoarchean ophiolite in the North China Craton: Early Precambrian Plate Tectonics and Scientific Debate 281

Beijing to some areas of Shanxi-Henan (Fig. 1, Polat and Kusky, 2007). They consider that there once ex-isted a relatively large scale ophiolite belt of ~2.5 Ga,

hence to explain the Neoarchean tectonic evolution of the North China craton.

Shanghai

Wuhan

Xinyang

Songpan

Xian

Qingdao

DuolunBayan Obo

Jiayuguan

Changchun

Taiyuan

Beijing

120o

Ogch

eon

bel

t

Sulu

bel

t

Imjingangbelt

North Hebei orogenic belt

Westernblock

Eastern

block

Tan

lufa

ult

Datong-Wuqi

faultCentral China orogen

Qinling-Dabie belt

Khondalites andS-type granite(2.2 1.9 Ga)-

Thrust boundary

Fault

*

0 400 km

Yellow Sea

Jiaoliaobelt

City

1.8 Ga granulites

Proterozoic granite(1.9 Ga)

Paleoproterozoicorogenic beltArchean orogenicbelt

COB

13

4

5

6

2.5 Ga ophioliticfragments

* ***

* *****

****

**

*

*

****

2

* * **

Beijing

130oE

30

o3

5o

40

oN

110o

90o

Datong-Wuqi

Figure 1. Tectonic sketch map of the North China craton (modified after Kusky et al., 2007) showing the eastern and western blocks separated by the central orogenic belt (COB). Note the location of suggested Archean ophiolitic fragments in the central orogenic belt. Proposed ophiolitic fragments include 1. Dong-wanzi; 2. Zunhua; 3. West Liaoning; 4. North Taihang; 5. Wutaishan; 6. South Taihang.

Since the initial report in 2001 of the possible

Archean ophiolite in North China, it has led to wide-spread concern of scholars at home and abroad. In this period, Li and Kusky (2003) have led two interna-tional field trips to the Dongwanzi-Zunhua belt. The problems concerned are also about the interpretations of mantle peridotite, gabbro, sheeted dike complex, pillow lava, podiform chromite, and geochemistry of igneous rocks besides the ages of mafic-ultramafic rocks in the Dongwanzi area. Respective evidence has been presented for different opinions (Zhang et al., 2003; Kusky et al., 2010, 2004; Zhao et al., 2007; Polat et al., 2006; Huang et al., 2004; Li et al., 2002). However, because these Precambrian rocks experi-enced complicated metamorphism and deformation, and were overprinted by later magmatism, the re-

search is very complicated when compared to the Phanerozoic, so far, there still exist many differences in interpretations.

To these different views, there are three main as-pects which need to be emphasized. The first one is detailed geological research, including making formal detailed geological maps and geochronology research on some terrains, and to map, date, and reject later in-trusions as not being part of the Archean complex. At the same time, we suggest that different researchers can have the chance to do the field investigation to-gether and discuss problems on the spot, to avoid the variance in the object of study and sample collection.

The second one is understanding and discussion to the concept of ophiolites. For example, the origin of podiform chromites; so far podiform chromites are

Timothy M Kusky and Mingguo Zhai 282

only known from ophiolites, but deep mantle rocks from other environments are rarely preserved so we can not be sure if they can form in different tectonic environments. The significance of pillow lava, and geochemical indication, identification and formation mechanism of sheeted dikes as well as the relationship between the rate of extension and the rate of magma supply, and the change of geochemical characteristics of rocks in metamorphic processes all need to be carefully assessed as to whether they are unique to ophiolites, or if ophiolites may have different charac-teristics between older and younger ages.

The last one is the recognition to Archean oce-anic crust, for example, if old oceanic crust was thicker and hotter than that of the Mesoproterozoic and younger times. If there are disparities in physics and geochemical characteristics, what are the similari-ties and differences of the formation environment of Archean greenstone belts with arcs or oceanic basins, and what is the relationship between the formation of TTG and possible old oceanic crust? Study of possible Archean ophiolites will yield clues about if the amal-gamation mechanism of micro-continental blocks in the Palaeo-Mesoarchean NCC is the same or similar to plate tectonics. ENDING REMARKS

In short, the Early Precambrian ophiolite is a very active scientific issue, its meaning is the charac-ter and recognition of the Early Precambrian oceanic crust, when did plate tectonics begin to work in the evolution of Earths history, and are there any differ-ences of evolutionary mechanism between the conti-nent and the ocean. The problem of the possible Ar-chean ophiolite within the North China craton had been discussed very early, and the article of Kusky et al. (2001) on the Dongwanzi ophiolite has triggered a great interest among domestic and foreign scholars. Different views of the controversy impetus the Pre-cambrian research of North China to a certain extent, showing the importance of this research topic. There are also different views from the two authors of this paper. Timothy M Kusky emphasizes that this belt contains most of the ingredients that a typical ophio-lite should include, although it is controversial. The existing data still supports this interpretation that it

might be the oldest, most integral yet dismembered and metamorphosed Archean oceanic crust and mantle fragment in the world. Mingguo Zhai (e.g., Zhai et al., 2005) emphasizes more about the differences of the Archean oceanic crust and the oceanic crust after that, considering the genetic relationship between the for-mation of the huge amount of TTG rocks and the ul-tramafic rocks. The North China craton is one of the oldest cratons in the world, with a variety of rock types, colorful geological phenomenon, and a complex geological record of the events. The NCC is the ideal place to study early Precambrian geology. This paper calls for researchers to give more study on Precam-brian North China, especially on Archean ophiolites, Paleoproterozoic high pressure-high temperature and ultra-high temperature granulites, Precambrian min-eral deposits and other key scientific issues, so as to make innovative contributions to earth science. ACKNOWLEDGMENTS

Funds were provided by the National Natural Science Foundation of China (Nos. 91014002, 40821061) and Ministry of Education of China (No. B07039). REFERENCES CITED Anonymous, 1972. Ophiolites. Geotimes, 17: 2415 Cocoran, P. L., Mueller, W. U., Kusky, T. M., 2004. Inferred

Ophiolites in the Archean Slave Craton. In: Kusky, T. M.,

ed., Precambrian Ophiolites and Related Rocks. Develop-ments in Precambrian Geology, 13: 363404

Condie, K. C., 1997. Plate Tectonics and Crustal Evolution (4th Edition). Elsevier, Burlington

de Wit, M. J., Ashwal, L. D., 1997. Greenstone Belts. Oxford Science Publications, Clarendon Press, Oxford. 809

Dilek, Y., Furnes, H., 2011. Ophiolite Genesis and Global Tectonics: Geochemical and Tectonic Fingerprinting of

Ancient Oceanic Lithosphere. Geological Society of America Bulletin, 123(34): 387411, doi:10.1130/ B30446.1

Furnes, H., de Wit, M. J., Staudigel, H., et al., 2007a. A Vestige

of Earths Oldest Ophiolite. Science, 315(5819): 17041707, doi:10.1126/science.1139170

Furnes, H., de Wit, M. J., Staudigel, H., et al., 2007b. Response to Comments on A Vestige of Earths Oldest Ophiolite.

Science, 318(5851), doi: 10.1126/science.1144231

The Neoarchean ophiolite in the North China Craton: Early Precambrian Plate Tectonics and Scientific Debate 283

Furnes, H., Rosing, M., Dilek, Y., et al., 2009. Isua Su-

pracrustal Belt (Greenland)A Vestige of a 3.8 Ga Su-prasubduction Zone Ophiolite, and the Implications for

Archean Geology. Lithos, 113(12): 115132 Hofmann, A., Kusky, T. M., 2004. The Belingwe Greenstone

Belt: Ensialic or Oceanic? In: Kusky, T. M., Precambrian Ophiolites and Related Rocks. Developments in Precam-brian Geology, 13: 487538

Huang, X. N., Li, J. H., Kusky, T. M., et al., 2004. Microstruc-

tures of the Zunhua 2.50 Ga Podiform Chromite, North China Craton and Implications for the Deformation and

Rheology of the Archean Oceanic Lithospheric Mantle (Chapter 10). In: Kusky, T. M., ed., Precambrian Ophio-

lites and Related Rocks. Developments in Precambrian Geology, 13: 321337

Kusky, T. M., 1989. Accretion of the Archean Slave Province. Geology, 17: 6367

Kusky, T. M., 1990. Evidence for Archean Ocean Opening and Closing in the Southern Slave Province. Tectonics, 9(6): 15331563, doi:10.1029/TC009i006p01533

Kusky, T. M., 1991. Structural Development of an Archean

Orogen, Western Point Lake, Northwest Territories. Tec-tonics, 10(4): 820841, doi:10.1029/91TC00765

Kusky, T. M., 1998. Tectonic Setting and Terrane Accretion of the Archean Zimbabwe Craton. Geology, 26(2): 163166, doi:10.1130/0091-7613(1998)0262.3. CO; 2

Kusky, T. M., 2004. Precambrian Ophiolites and Related Rocks: Introduction. In: Kusky, T. M., Precambrian Ophiolites

and Related Rocks. Developments in Precambrian Geol-ogy, 13: 135, doi:10.1016/S0166-2635(04)13027-2

Kusky, T. M., Kidd, W. S. F., 1992. Remnants of an Archean Oceanic Plateau, Belingwe Greenstone Belt, Zimbabwe,

Geology, 20(1): 4346, doi:10.1130/0091-7613(1992) 0202.3.CO;2

Kusky, T. M., Li, J. H., 2010. Origin and Emplacement of Ar-chean Ophiolites of the Central Orogenic Belt, North

China Craton. Journal of Earth Science, 21(5): 744781, doi:10.1007/s12583-010-0119-8

Kusky, T. M., Li, J. H., 2002. Is the Dongwanzi Complex an Archean Ophiolite? Response to Zhai, M. G., Zhao, G. C.,

Zhang, Q., Science, 295(5557): 923, doi:10.1126/science.295.5557.923a

Kusky, T. M., Li, J. H., 2008. Discussion of U-Pb Zircon Age Constraints on the Dongwanzi Ultramafic-Mafic Body,

North China, Confirm It Is not an Archean Ophiolite.

Earth and Planetary Science Letters, 273: 227230 Kusky, T. M., Li, J. H., Glass, A., et al., 2004. Origin and Em-

placement of Archean Ophiolites of the Central Orogenic

Belt, North China Craton (Chapter 7). In: Kusky, T. M., ed., Precambrian Ophiolites and Related Rocks. Develop-ments in Precambrian Geology, 13: 223274

Kusky, T. M., Li, J. H., Tucker, R. D., 2001. The Archean

Dongwanzi Ophiolite Complex, North China Craton: 2.505 Billion Year Old Oceanic Crust and Mantle. Science, 292: 11421145, doi:10.1126/science.1059426

Kusky, T. M., Vearncombe, J., 1997. Structure of Archean

Greenstone Belts (Chapter 3). In: de Wit, M. J., Ashwal, L. D., eds., Tectonic Evolution of Greenstone Belts. Oxford Monograph on Geology and Geophysics, 95128

Kusky, T. M., Wang, L., Dilek, Y., et al., 2011. Application of

the Modern Ophiolite Concept with Special Reference to Precambrian Ophiolites. Science China (Sers. D), 54(3): 315341, doi:10.1007/s11430-011-4175-4

Kusky, T. M., Windley, B. F., Zhai, M. G., 2007. 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 Lon-don Special Publication, 280: 134, doi:10.1144/SP280.10305-8719/07/$15

Li, J. H., Kusky, T. M., 2003. A Field Trip Guidebook to the Dongwanzi Ophiolite and Zunhua Mantle Tectonites and

Podiform Chromites. Interridge Program of NSF Li, J. H., Kusky, T. M., Huang, X., 2002. Neoarchean Podiform

Chromitites and Harzburgite Tectonite in Ophiolitic Me-lange, North China Craton, Remnants of Archean Oceanic

Mantle. GSA Today, 12(7): 411 Polat, A., Herzberg, C., Munker, C., et al., 2006. Geochemical

and Petrological Evidence for a Suprasubduction Zone Origin of Neoarchean (ca. 2.5 Ga) Peridotites, Central

Orogenic Belt, North China Craton. Bulletin of the Geo-logical Society of America, 118(78): 771784, doi:10.1130/B25845.1

Polat, A., Kusky, T. M., 2007. Discussion of Geochemistry of

the Late Archean (ca. 2.552.50 Ga) Volcanic and Ophio-litic Rocks in the Wutaishan Greenstone Belt, Central

Orogenic Belt, North China Craton: Implications for Geodynamic Setting and Continental Growth. Reply to

Zhao, G., Kroner, A., Geological Society of America Bul-letin, 119: 490492

Puchtel, I. S., 2004. 3.0 Ga Olondo Greenstone Belt in the

Timothy M Kusky and Mingguo Zhai 284

Aldan Shield, E. Siberia. In: Kusky, T. M., ed., Precam-

brian Ophiolites and Related Rocks. Developments in Precambrian Geology, 13: 405424, doi:10.1016/S0166-2635(04)13013-2

Rapp, R. P., Watson, E. B., 1995. Dehydration Melting of Me-

tabasalt at 832 kbar: Implications for Continental Growth and Crust-Mantle Recycling. Journal of Petrology, 36(4): 891931, doi:10.1093/petrology/36.4.891

Rapp, R. P., Watson, E. B., Miller, C. F., 1991. Partial Melting

of Amphibolite/Eclogite and the Origin of Archean Trondhjemites and Tonalites. Precambrian Research, 51(14): 125

Robinson, P. T., Malpas, J., Dilek, Y., et al., 2008. The Sig-

nificance of Sheeted Dike Complexes in Ophiolites. GSA Today, 18(11): 410

Shchipansky, A. A., Samsonov, A. V., Bibikova, E. V., 2004. 2.8 Ga Boninite-Hosted Partial Suprasubduction Zone

Ophiolite Sequences from the North Karelian Greenstone Belt, NE Baltic Shield, Russia. In: Kusky, T. M., ed., Pre-

cambrian Ophiolites and Related Rocks. Developments in Precambrian Geology, 13: 425486, doi:10.1016/S0166- 2635(04)13014-4

Stern, R. J., 2007. When and How Did Plate Tectonics Begin?

Theoretical and Empirical Considerations. Chinese Sci-ence Bulletin, 52(5): 578591,

doi:10.1007/s11434-007-0073-8

Tappe, S., Smart, K. A., Pearson, D. G., et al., 2011. Craton Formation in Late Archean Subduction Zones Revealed by

First Greenland Eclogites. Geology, 39(12): 11031106, doi:10.1130/G32348.1

Zhai, M. G., Guo, J. H., Liu, W. J., 2005. Neoarchean to Pa-leoproterozoic Continental Evolution and Tectonic History

of the North China Craton: A Review. Journal of Asian Earth Sciences, 24: 547561

Zhai, M. G., Zhao, G. C., Zhang, Q., 2002. Is the Dongwanzi Complex an Archean Ophiolite? Science, 295(5557): 923, doi:10.1126/science.295.5557.923a

Zhang, Q., Ni, Z. Y., Zhai, M. G., 2003. Comments on the Ar-

chean Ophiolites in Eastern Hebei. Earth Sci. Front., 10(4): 429437 (in Chinese with English Abstract)

Zhao, G. C., Sun, M., Wilde, S. A., 2005. Late Archean to Pa-leoproterozoic Evolution of the North China Craton: Key

Issues Revisited. Precambrian Research, 136: 177202, doi:10.1016/j.precamres.2004.10.002

Zhao, G. C., Wilde, S. A., Li, S. Z., et al., 2007. U-Pb Zircon Age Constraints on the Dongwanzi Ultramafic-Mafic

Body, North China, Confirm It Is not an Archean Ophio-lite. Earth and Planetary Science Letters, 255(12): 8593, doi:10.1016/j.epsl.2006.12.007