First Evidence of the Cambrian Basement in Upper Peninsula of Thailand and Its Implication for Crustal and Tectonic Evolution of the Sibumasu Terrane

Gondwana Research 24 (2013) 1031–1037

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GR letter First evidence of the Cambrian basement in Upper Peninsula of Thailand and its implication for crustal and tectonic evolution of the Sibumasu terrane

Yu-Ling Lin a, Meng-Wan Yeh b,⁎, Tung-Yi Lee a, Sun-Lin Chung c, Yoshiyuki Iizuka d, Punya Charusiri e a Department of Earth Sciences, National Taiwan Normal University, Taipei 116, Taiwan b Center for General Education, National Taiwan Normal University, Taipei 106, Taiwan c Department of Geosciences, National Taiwan University, Taipei 106, Taiwan d Institute of Earth Sciences, Academia Sinica, Taipei 115, Taiwan e Department of Geology, Faculty of Science, Chulalongkorn University, Bangkok 10330, Thailand article info abstract

Article history: Although the Sibumasu terrane in Asia was previously considered to be composed of Phanerozoic rocks with Received 10 December 2012 Cambrian crystalline basement, no reliable or direct radiometric dating evidences of such crystalline basement Received in revised form 14 May 2013 was ever reported. Our new in-situ zircon U/Pb dating of the Khao Tao orthogneiss yields a concordant age of Accepted 14 May 2013 501.5 ± 7.5 Ma (2σ), which provides the ﬁrst robust evidence for the Cambrian crust in Upper Peninsula of Available online 10 June 2013 C Thailand. The zircon εHf(T) values range from +3.7 to −6.1 with model ages (T DM)of1244–1827 Ma, suggests Handling Editor: G.C. Zhao a mixed crust-mantle source. The chemical similarity and spatial continuity of the Khao Tao orthogneiss with other pre-Neotethys marginal Eurasian and Sibumasu granitoids indicate the linear paleogeographic association Keywords: under a similar magmatic arc-related regime along the Gondwana India–Australia margin as part of the Sibumasu terrane Pan-African Orogeny system. Gondwana tectonic © 2013 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. Zircon U–Pb age Hf isotopic ratio

1. Introduction occurrence of high grade tectonothermal event associated with the development of Pan-African orogeny (Wilde et al., 2003; Zhou et The 500–600 Ma Pan-African Orogeny system is considered to be al., 2011). Whereas the zircon ages obtained from the Tibet and one of the world's largest orogenic belts and crustal building episodes Tengchong–Baoshan terrane represent the magmatism crystalliza- over the past 1000 Myrs. Signiﬁcant amounts of igneous, metamor- tion ages and the presence of Pan-African crystalline basement with- phic, and deformation activities occurred during this period (Kröner in these regions (Cawood et al., 2007; Song et al., 2007; Liu et al., and Stern, 2004; Collins and Pisarevsky, 2005). The collision of 2009; Zhu et al., 2012). about 7–8 Australia-sized Neoproterozoic continents formed numer- Many palaeogeographic models (Metcalfe, 2011) and biostrati- ous mobile belts surrounding older cratons, and Andean-type active graphic correlation suggested that the Sibumasu terrane, which con- margins along the Australia–Antarctica–South America segment of stituted part of the eastern Cimmerian Continent, was separated the Gondwana margin (Cawood et al., 2007), which resulted to a from Gondwana margin (Ueno, 2003; Wang et al., 2013). Thus a wide distribution of Pan-African aged continental crust across the Cambrian basement is suspected to lie beneath the Permian sedimen- globe (Fig. 1). tary rocks of the Sibumasu terrane (Brum et al., 1970). Yet, other than Although Asia represents one third of the current continental crust, the core regions of inherited zircons of the crystalline rocks within Pan-African aged continental crust fragments are merely reported from the Three Pagodas shear zone and the Khlong Marui shear zone three major regions of the Central Asian Orogenic Belt (Wilde et al., (Kanjanapayont et al., 2012; Nantasin et al., 2012), and detrital zir- 2003; Zhou et al., 2011), Cathaysia Block (Li et al., 2011), and Tibet cons within paragneiss from Laem Khet, SE of Rayong in Thailand (Cawood et al., 2007; Zhu et al., 2012) and Tengchong–Baoshan terrane (Geard, 2008). No reliable isotope date older than Permian for (Song et al., 2007; Liu et al., 2009). The zircon ages obtained from the the basement of Sibumasu terrane in Thailand has been reported Central Asian Orogenic Belt and the Cathaysia Block indicated the (Nantasin et al., 2012) until the current study. The lack of Pan- African crust in Indochina peninsula may be due to two reasons: that the Indochina Peninsula is a complex collage of the Tengchong– ⁎ Corresponding author at: Center for General Education, 162, HePing East Road, Section 1, Taipei 106, Taiwan. Tel.: +886 2 7734 6390. Baoshan terrane, Sibumasu terrane, Inthanon suture zone, Sukhothai E-mail address: [email protected] (M.-W. Yeh). terrane, Chanthaburi terrane and Indochina terrane (Ueno and

1342-937X/$ – see front matter © 2013 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved. http://dx.doi.org/10.1016/j.gr.2013.05.014 1032 Y.-L. Lin et al. / Gondwana Research 24 (2013) 1031–1037

Pan- Africa 60ºS 30ºS Equator Orogeny Belt Magmatic arc along proto- Tethyan margin 546 531 proto-Tethyan Distribution of intra-oceanic 530 547 Ocean juvenile arcs (Rino et al., 2008). Kuunga orogen 990-950 & 600-500 Ma (Duan et al., 2011) South Pole East African orogen Qiangtang 650-550 Ma 553 (Duan et al., 2011) 492 501 480 Sibumasu Locations of Cambrian 487 arc-related granites Africa 500 India 502 Khao Tao (This study) Tengchong-Baoshan 495 (Liu et al., 2009; Song et al., 2007) Central Lhasa (Zhu et al., 2012) New Namche-Barwa Guinea (Zhang et al., 2012) South Northwest Himalaya Antarctica (Miller et al., 2001) America Iran (Ramezani amd Tucker, Australia 2003) Turkey (Ustaomer et al., 2009)

Fig. 1. Reconstruction of Cambrian palaeogeographic map showing distribution of Pan-African orogenic belts within Gondwana (modiﬁed after Rino et al., 2008; Duan et al., 2011; Metcalfe, 2011). Circles with age (Ma) with various colors mark the locations of previously reported Cambrian granitoids along the proto-Tethyan margin whereas the red full circle marks the age data of current study. A linear distribution that corresponds to the subduction trend between proto-Tethyan oceanic crust and Gondwana can be established.

Hisada, 2001; Sone and Metcalfe, 2008; Hara et al., 2009). This makes crystalline rocks of the Hua Hin Group, with Quaternary sedimentary investigating the basement of these blocks difficult. Moreover, the old cover. The Hua Hin Group can be further divided into the meta- crust either was reworked into Mesozoic and Cenozoic continental sedimentary Pranburi and orthogneissic Khao Tao formations that crust, or underwent intense metamorphism during the amalgamation of underwent an amphibolite facies metamorphism (Sinclair, 1997). The Asia (Mitchell, 1981; Searle et al., 2012). Our new in-situ zircon U–Pb Khao Tao formation was previously interpreted as an I-type granite geochronology and Hf isotope analysis results of the Khao Tao (Sinclair, 1997) that was crystallized at 210 ± 4 Ma during the orthogneiss from Upper Peninsula of Thailand provide the first robust Sibumasu–Indochina collision (Putthapiban and Suensilpong, 1978). evidence for the presence of Cambrian crust and confirm the tectonic Cobbing et al. (1992) interpreted the Khao Tao Formation to have significance of the Cimmerian continent. formed within an island arc-related setting which experienced subse- quent deformation and metamorphism during the Early Paleogene 2. Geological background collision of India and Eurasia. This is supported by a biotite K/Ar age of 63 ± 4 Ma (Beckinsale et al., 1979). Thailand is composed of four parallel tectonic units: Sibumasu terrane, Inthanon zone, Sukhothai zone, and Indochina terrane from 3. Analytical method and results west to east (Fig. 2a; Ueno and Hisada, 2001; Sone and Metcalfe, 2008; Hara et al., 2009). Both Sibumasu and Indochina terranes U/Pb geochronology is a powerful technique for extracting source were part of Gondwana that got detached separately during the Early information from zircon grains (Scherer et al., 2007). Due to the consid- Permian (Metcalfe, 1999; Ridd, 2009, 2012) and during the Silurian– erable amount of high field strength elements (HFSE) within zircon, it Devonian (Metcalfe, 1999; Barber et al., 2011) respectively. The can also be used to evaluate crustal residence and growth via Hf isotope Inthanon zone is composed of complex mixtures of lower Paleozoic to analysis (Hawkesworth and Kemp, 2006). The combination of U/Pb dat- Devonian–Triassic oceanic sediments and ocean-floor basalt. That is ing with Hf isotope analysis of zircons reveals not only the crystalline considered as the accretionary complex when the Paleotethys closed ages but also the relative contributions of juvenile (directly mantle- due to the amalgamation of Sibumasu and Indochina terranes during derived) crust versus recycled continental crust (Scherer et al., 2007). Middle to Late Triassic time (Barr and Macdonald, 1999). Whereas the Zircons were separated from ~1 kg sample using conventional heavy- Sukhothai zone is interpreted as an island arc that collided onto Indochina liquid and magnetic separation techniques. Most zircon crystals are terrane as the back arc basin closed during the Permian to Triassic time colorless, euhedral and prismatic in shape and around 200 μminsize. (Sone and Metcalfe, 2008). Cathodoluminescence (CL) electron micrographs of individual zircon The sample TM0628 (E99.9787°, N12.4558°) is composed of feld- grains were taken at the Institute of Earth Sciences, Academia Sinica, spars, biotite, chlorite, quartz with minor hornblende. It was collected Taipei to examine the internal structures in order to select suitable from Kao Tao formation (Fig. 2b) which is situated at the southern positions for U–Pb isotope determinations. section of the Sibumasu terrane within the Hua Hin area, 200 km All zircon grains show oscillatory zoning without alteration rims south of Bangkok. This region is mostly composed of metamorphic in CL electron micrographs (Fig. 3a). Among them, 17 zircon grains Y.-L. Lin et al. / Gondwana Research 24 (2013) 1031–1037 1033

E85° E95° E105° (a) Qaidam North (b) 5km Kunlun China Qam do– Simao Songpan N12.50° 474 Qiangtang Ganzi 532 501492 492 482 501 Khao Tao N30° Lhasa

492 530 506 490 GULF OF 499 478 508 496495 THAILAND 480 499 502 487 LITHOLOGY 470 Tengchong-Baoshan Q Coastal deposits 500 Q Fluvial deposits 470 India We 499 South 502 T Cataclastic China st Burma TR Gneiss

i O Dolomitic Limestone N12.30° N20° a non th C Khao Tao gneiss a Pre - Metasediments C nth I M Sukho P S Z Indochina E99.8° E99.9° E100° Tibet: 470~532 Ma T P (Zhu et al., 2012; S Z (c) Zhang et al., 2012) Chant 502 Tengchong-Baoshan: S (b) ha i buri N10° 470~490 Ma b (Liu et al., 2009; um Song et al., 2007)

asu Khao Tao:502 Ma (This study)

Western igneous province 0° (SW Thailand-E Burma) Central igneous province (N Thailand -W Malaya)

Eastern igenous province 0 250 500km (E Malaya)

Fig. 2. (a) Tectonic subdivision of Thailand and adjacent regions of Asia (modiﬁed after Sone and Metcalfe, 2008; Metcalfe, 2011; Searle et al., 2012). The locations of Cambrian granitoids are labeled with circles and ages (Ma) with various color matching that of Fig. 1. The red full circle marks the location of the Khao Tao orthogneiss. A linear distribution can be established from Tibet, Tengchong–Baoshan terrane, and Sibumasu terrane, as part of the Cimmerian continent. (b) Simpliﬁed geological map of Khao Tao and adjacent area in Upper Peninsula of Thailand (after Sinclair, 1997). (c) Outcrop photograph of Khao Tao orthogneiss.

were selected for LA-ICP-MS U/Pb dating using an Agilent 7500 s al. (2006). During the analysis, 176Hf/177Hf and 176Lu/177Hf ratios for quadruple ICP-MS (inductively coupled plasma mass spectrometer) the standard zircon 91500 were 0.282300 ± 0.000030 (2σ, n = 24) with a New Wave UP213 laser ablation system at the National Taiwan and 0.00030 respectively, which are similar to the commonly accept- University, Taipei. The GJ-1 zircons were used as standard for instru- ed 176Hf/177Hf ratio of 0.282302 ± 0.00008 and 0.282306 ± 0.00008 mental drift correction, which yielded an average 207Pb/206Pb age of (2σ) determined by the solution method (Goolaerts et al., 2004). The

606.2 Ma during experiments. This age is very close to the standard εHf(T) values from these magmatic zircons of the Khao Tao gneiss C age of 608.5 Ma by TIMS analyses provided in Jackson et al. (2004). scatter from +4.1 to −6.5, corresponding to (T DM) model ages of Harvard reference zircon 91500 and Australian Mud Tank Carbonatite between 1244 Ma and 1827 Ma (Fig. 3b, Table 2). zircon MT were utilized as secondary standards for measurement quality control. Operating conditions and analytical procedures 4. Discussion were the same as those reported in Chiu et al. (2009). The data obtained from 21 spots fall within 441–545 Ma, and are generally 4.1. Cambrian basement in Southeast Asia concordant around 501.5 ± 7.5 Ma of 206Pb/238U age (2σ, MSWD = 1.5; Fig. 3a, Table 1). The analyzed spots have relatively high Th/U SE Asia has three major granitic provinces: (i) the Triassic (212– values of 0.17 to 1.72 (av. 0.74), suggesting that these analyzed zircons 214 Ma) Western Thailand-Myanmar province, (ii) the Triassic are typical of magmatic zircons (Schaltegger et al., 1999), and the (210–215 Ma) North Thailand–West Malaya Main Range province, results should represent the time of crystallization for the protolith. and (iii) the Cretaceous (80 Ma) East Malaya province (Fig. 2a; 176Hf/177Hf isotopic ratio analysis was conducted at the exact Searle et al., 2012 and references therein). These granite provinces same spots for age dating utilizing the Neptune MC-ICP-MS with a are associated with the subduction and accretion of island arc ter- larger beam diameter (60 μm) and a laser repetition rate of 10 Hz ranes and plates during progressive closure of the Devonian to Middle at 100 mJ. The detailed analytical method was described in Wu et Triassic Paleo-Tethys (Fig. 2a; Metcalfe, 2000; Searle et al., 2012 and 1034 Y.-L. Lin et al. / Gondwana Research 24 (2013) 1031–1037 (a) (b) data-point error ellipses are 2σ 20 box heights are 2σ 550 Weighted average age 560 Detrital zircon of Australia (Kemp et al., 2006) 0.090 = 495.9±6.1 Ma (2σ) NW Argentina (Hauser et al., 2011) DM 530 N = 10, MSWD = 1.14 CL (Zhu et al., 2012)

510 Concordia Age TC (Liu et al., 2009) 540 C = 501.5±7.5 Ma 10 KT (This study) TDM =1.0 Ga 0.086 490

470 520 U 0.082 450 CHUR 238 500 0 (T) Pb/ Hf

ε C 206 TDM =2.0 Ga 0.078 480 -10 0.074 460

440 0.070 -20 0.54 0.58 0.62 0.66 0.70 0.74 300 400 500 600 700 800 900 207Pb/235U U-Pb age (Ma)

Fig. 3. (a) Zircon U–Pb concordia diagram with selected Cathode luminescence (CL) electron micrographs for Khao Tao orthogneiss. The orange circles indicate the positions of LA-ICP-MS U–Pb dating analysis. A concordant age of 501 ± 7.5 Ma, and an average age of 495.5 ± 6.1 Ma with MSWD = 1.5 were calculated. The ages do not indicate any duplicable spatial variation from core to rim. (b) Plots of εHf(T) values with error bar versus U–Pb age of zircons from Khao Tao orthogneiss (red full circle) and other previously reported Cambrian granitoids (Kemp et al., 2006; Liu et al., 2009; Hauser et al., 2011; Zhu et al., 2012). The wide range of εHf(T) values indicates that most of these zircons have a crust-mantle mixture source except for zircons from Tengchong–Baoshan terrane, which show an intense signal of crust origin (Maniar and Piccoli, 1989).

references therein). The lack of exposure due to heavy weathering and derived from interaction of late Proterozoic crust and mantle. Other dense vegetation along with the strong overprinting of the dominant than the negative εHf(T) of the monzogranite in Tengchong–Baoshan crustal forming Indosinian orogeny leads the long proposed Cambrian terrane (Liu et al., 2009), the Late Cambrian magmatism within most basement of Sibumasu terrane unfound previously (Hansen and Cimmerian micro-continental blocks of the Lhasa terrane (Zhu et al., Wemmer, 2011). 2012), NW Argentina (Hauser et al., 2011), and Australia (Kemp et al., The protolith of Khao Tao orthogneiss was previously inferred as an 2006) all showed similar geochemical signatures of a wide range of extensional granitic plutonium formed during the Triassic subduction of εHf(T) from positive to negative values (Fig. 3c) and crystallized within Sibumasu beneath the Indochina terranes (Pongsapich et al., 1980). This arc-related settings. interpretation is further modiﬁed by the new geochronology and Based on the similar geochronology age and geochemistry data of geochemistry data reported herein. The U/Pb zircon age of 501.5 Ma εHf(T) value, a continuous Pan-African orogenic system can be linked from this study suggests that the Khao Tao gneiss could represent the along the Proto-Tethyan margin of Gondwana extending from Turkey, Cambrian basement of Sibumasu terrane. The Lansang gneiss further Iran, NW Himalaya, Namche Barwa, central Lhasa, Tengchong to central NW of Khao Tao showed a considerable amount of inherited zircons Sibumasu (Fig. 1; Miller et al., 2001; Ramezani and Tucker, 2003; with a minimum U/Pb age of 1530 Ma (Ahrendt et al., 1993), which is Cawood et al., 2007; Liu et al., 2009; Ustaömer et al., 2009; Saki, 2010; similar to the Hf model age (1244 Ma to 1827 Ma) of Khao Tao gneiss. Zhang et al., 2012; Zhu et al., 2012). This series of early Paleozoic arc- Although no early Paleozoic event was ever reported in the Malay related magmatism along the India–Australian margin of Gondwana Peninsula, the mid-Proterozoic component in several plutons in the generated granitic bodies sourced from a mixture of mantle and West Coast Province of Malay Peninsula was also supported by U/Pb zir- mid-Proterozoic continental crust. These granites made up part of the con dating and Sm/Nd results (Liew and Page, 1985). Other than similar basement in the present Lhasa terrane, Namche Barwa Complex, Hf model ages, a ~500 Ma peak of detrital zircons separated from river Tengchong–Baoshan terrane, and Sibumasu terrane, as part of the sands and paragneiss, and inherited zircons were identiﬁed throughout Cimmerian continent that rifted away from Australia and Antarctica Thailand and Malay Peninsula (Sevastjanova et al., 2011; Kanjanapayont during the Early Permian according to the palaeogeographic recon- et al., 2012; Nantasin et al., 2012). Therefore, the distribution of mid- struction by correlating the early Permian cool-water fauna and Late Proterozoic and the Cambrian crust component of Sibumasu terrane Carboniferous–Early Permian glacial-marine diamictites (Metcalfe, can be reasonably further stretched from Thailand to Malaysia Peninsula 1988, 2006), and amalgamated to Indochina and Asia during the Triassic (Dunning et al., 1995). (Mitchell, 1981; Searle et al., 2012).

4.2. Tectonic signiﬁcances 5. Conclusions

Besides the Khao Tao orthogneiss within Sibumasu, synchronous The in-situ zircon U/Pb age of 501.5 ± 7.5 Ma (2σ) obtained from magmatic events are also reported from magmatic bodies along various the Khao Tao gneiss, Thailand offers the ﬁrst tangible geochronology ev- terranes. That includes the Tengchong–Baoshan terrane, the Greater idence of the Early-Paleozoic basement of Sibumasu. The Hf model age

Himalayan sequence (GHS), Lesser Himalayan sequence (LHS), the (1244 Ma to 1827 Ma) and wide range of εHf(T) values between +4.1 Lhasa terrane, the Namche Barwa Complex, Iran, and Turkey (Fig. 1; to −6.5 of zircons suggest that the protolith of the Khao Tao gneiss Miller et al., 2001; Ramezani and Tucker, 2003; Cawood et al., 2007; was derived from a mixing source of late Proterozoic crust and mantle. Liu et al., 2009; Ustaömer et al., 2009; Saki, 2010; Zhang et al., 2012; The consistent magmatic U/Pb zircon and Hf model ages, together

Zhu et al., 2012 and references therein). The Hf model age (1244 Ma with similar εHf(T) values of granites from Namche Barwa Complex, to 1827 Ma) and wide spread of εHf(T) value (+4.1 to −6.5) of zircons Tengchong–Baoshan terrane, and Sibumasu terrane, indicate their suggest that the magma formed the protolith of Khao Tao orthogneiss close spatial association with similar arc-related tectonic setting. This Table 1 LA-ICP-MS zircon U–Pb isotope data for Khao Tao orthogneiss.

Spot U238 Th 232 Th/U Measured ratios Ratios corrected for common lead Age (Ma) ppm ppm 207 Pb/206 Pb ± 1σ 207 Pb/235 Pb ± 1σ 206 Pb/238 Pb ± 1σ 207 Pb/206 Pb ± 1σ 207 Pb/235 Pb ± 1σ 206 Pb/238 Pb ± 1σ 206 Pb/ 207 Pb/ .L i ta./Gnwn eerh2 21)1031 (2013) 24 Research Gondwana / al. et Lin Y.-L. 238 Pb ± 1σ 206 Pb ± 1σ

01 586.0 428.0 0.7304 0.05905 0.00127 0.64836 0.01366 0.07964 0.00158 0.05905 0.00054 0.64836 0.01366 0.07964 0.00158 494 9 507 8 02 446.5 263.3 0.5896 0.05842 0.00128 0.63178 0.01351 0.07845 0.00156 0.05842 0.00055 0.63178 0.01351 0.07845 0.00156 487 9 497 8 02C 1318.2 720.9 0.5468 0.05803 0.00123 0.65121 0.01349 0.0814 0.00161 0.05803 0.00053 0.65121 0.01349 0.0814 0.00161 504 10 509 8 03 1497.8 2580.6 1.7229 0.05788 0.00123 0.62101 0.01289 0.07783 0.00154 0.05788 0.00053 0.62101 0.01289 0.07783 0.00154 483 9 490 8 04 342.8 306.1 0.8929 0.05865 0.00131 0.62752 0.01371 0.07761 0.00154 0.05865 0.00056 0.62752 0.01371 0.07761 0.00154 482 9 495 9 05 356.1 209.2 0.5874 0.05881 0.00133 0.64662 0.01429 0.07975 0.00159 0.05881 0.00057 0.64662 0.01429 0.07975 0.00159 495 9 506 9 06 497.9 578.0 1.1608 0.05965 0.00136 .58166 0.01296 0.07074 0.00141 0.05965 0.00058 0.58166 0.01296 0.07074 0.00141 441 8 466 8 07 433.3 509.2 1.1752 0.05827 0.00128 0.65372 0.01412 0.08137 0.00163 0.05827 0.00055 0.65372 0.01412 0.08137 0.00163 504 10 511 9 07C 973.5 741.4 0.7616 0.05798 0.00124 0.66184 0.01392 0.08279 0.00165 0.05798 0.00053 0.66184 0.01392 0.08279 0.00165 513 10 516 9 08 1275.7 508.4 0.3985 0.0576 0.0012 0.64062 0.0135 0.0807 0.0016 0.05762 0.00053 0.64062 0.01345 0.08065 0.00161 500 10 503 8 09 244.0 175.5 0.7192 0.0576 0.0013 0.6384 0.0145 0.0804 0.0016 0.05761 0.00057 0.6384 0.01448 0.08038 0.00162 498 10 501 9 10 226.6 168.4 0.7433 0.05906 0.00137 0.67031 0.01529 0.08232 0.00167 0.05906 0.00059 0.67031 0.01529 0.08232 0.00167 510 10 521 9 11 1322.4 490.7 0.3711 0.05714 0.00123 0.62318 0.01335 0.07911 0.00159 0.05714 0.00054 0.62318 0.01335 0.07911 0.00159 491 9 492 8 12 405.2 213.6 0.5271 .05865 .00133 .62311 .01396 .07706 .00156 0.05865 0.00057 0.62311 0.01396 0.07706 0.00156 479 9 492 9 12C 915.8 710.3 0.7755 0.05818 0.00128 0.64894 0.01418 0.0809 0.00164 0.05818 0.00056 0.64894 0.01418 0.0809 0.00164 501 10 508 9

13 245.3 228.9 0.9335 0.05796 0.00138 0.63522 0.01504 0.0795 0.00163 0.05796 0.0006 0.63522 0.01504 0.0795 0.00163 493 10 499 9 – 14 384.4 143.1 0.3722 0.05668 0.00128 0.60423 0.01334 0.07733 0.00155 0.05668 0.00055 0.60423 0.01334 0.07733 0.00155 480 9 480 8 1037 15 141.3 105.1 0.7438 0.05933 0.00147 0.68496 0.01654 0.08374 0.0017 0.05933 0.00063 0.68496 0.01654 0.08374 0.0017 518 10 530 10 16 367.6 170.3 0.4633 0.05725 0.0013 0.69633 0.01552 0.08821 0.00177 0.05725 0.00056 0.69633 0.01552 0.08821 0.00177 545 10 537 9 17 846.6 1005.4 1.1876 0.05604 0.00126 0.63566 0.014 0.08228 0.00165 0.05604 0.00054 0.63566 0.014 0.08228 0.00165 510 10 500 9

Corrected for common Pb: 204/206 = 0.0625, 207/206 = 0.9618, 208/206 = 2.229. Corrected for U-dependent calibration bias by 2.0% per 1000 ppm U above 2500 ppm U. Note: c = core. The bold spot numbers highlight the analysis used in the concordia age calculations. 1035 1036 Y.-L. Lin et al. / Gondwana Research 24 (2013) 1031–1037

Table 2 Zircon Hf isotope analysis for Khao Tao orthogneiss.

Spot Inferred age ±1 s 176Hf/177Hf ±2 s 176Lu/177Hf ±2 s 176Hf/177Hf(T) 176Hf/177Hf CHUR(T) εHf(T) ±2 s T(DM) 1 Ma T(DM) 2 Ma

01 494 9 0.28252 3E-05 0.00299 2E-04 0.282495 0.282464 1.08 1.07 1089 1395 02C 504 10 0.28240 3E-05 0.00457 2E-04 0.282356 0.282458 −3.60 1.10 1330 1698 03 483 9 0.28266 3E-05 0.00699 3E-04 0.282597 0.282471 4.45 1.14 996 1172 04 482 9 0.28247 3E-05 0.00240 4E-05 0.282452 0.282472 −0.71 1.00 1143 1499 05 495 9 0.28232 3E-05 0.00151 1E-05 0.282301 0.282464 −5.76 0.94 1340 1828 06 441 8 0.28244 3E-05 0.00150 9E-05 0.282426 0.282498 −2.52 0.97 1165 1583 07 504 10 0.28249 3E-05 0.00195 1E-04 0.282469 0.282458 0.40 0.98 1108 1446 07C 513 10 0.28248 3E-05 0.00333 2E-04 0.282443 0.282452 −0.32 1.07 1170 1498 08 500 10 0.28241 3E-05 0.00234 1E-04 0.282389 0.282461 −2.52 0.95 1231 1627 09 498 10 0.28247 2E-05 0.00269 3E-05 0.282441 0.282462 −0.72 0.87 1162 1512 10 510 10 0.28240 3E-05 0.00205 1E-04 0.282380 0.282454 −2.64 0.89 1239 1642 11 491 9 0.28245 3E-05 0.00231 9E-06 0.282431 0.282466 −1.24 0.92 1171 1539 12 479 9 0.28249 3E-05 0.00341 6E-05 0.282457 0.282474 −0.59 1.17 1154 1489 12C 501 10 0.28247 2E-05 0.00204 2E-05 0.282453 0.282460 −0.25 0.75 1134 1484 13 493 10 0.28239 2E-05 0.00127 2E-05 0.282376 0.282465 −3.14 0.82 1229 1661 14C 480 9 0.28232 3E-05 0.00241 7E-05 0.282302 0.282473 −6.07 1.06 1362 1836 14 537 10 0.28246 4E-05 0.00431 2E-04 0.282416 0.282437 −0.77 1.59 1228 1544 15 518 10 0.28258 4E-05 0.00294 9E-05 0.282555 0.282449 3.74 1.34 997 1244 16 545 10 0.28246 3E-05 0.00264 9E-05 0.282438 0.282432 0.18 1.07 1164 1490 17 510 4 0.28282 3E-05 0.00267 2E-04 0.282810 0.282652 5.57 1.05 642 879

series of late Cambrian magmatism along the India–Australian margin Geard, A.K., 2008. Geology of the Klaeng Region (Southeast Thailand): Lithology, Struc- of Gondwana generated suites of granite bodies sourced from a mixture ture and Geochronology, School of Earth Sciences. (Unpublished BSc Honours thesis) University of Tasmania, Hobart. of mantle and mid-Proterozoic continental crust. These granitoid bodies Goolaerts, A., Mattielli, N., de Jong, J., Weis, D., Scoates, J.S., 2004. Hf and Lu isotopic refer- form the basement of the current Turkey, Iran, Lhasa terrane, Namche ence values for the zircon standard 91500 by MC-ICP-MS. Chemical Geology 206, 1–9. Barwa Complex, Tengchong–Baoshan terrane, and Sibumasu terrane Hansen, B.T., Wemmer, K., 2011. Age and evolution of the basement rocks in Thailand. In: Ridd, M.F., Barber, A.J., Crow, M.J. (Eds.), The Geology of Thailand. Geological So- at the margin of Gondwana during early Paleozoic. Therefore, this ciety, London, pp. 19–32. study further confirmed the geochronology continuity of early Paleozo- Hara, H., Wakita, K., Ueno, K., Kamata, Y., Hisada, K., Charusiri, P., Charoentitirat, T., ic granitoid belt extending from Upper Peninsula of Thailand to Turkey. Chaodumrong, P., 2009. Nature of accretion related to Paleo-Tethys subduction recorded in northern Thailand: constraints from melange kinematics and illite crystallinity. Gondwana Research 16, 310–320. Hauser, N., Matteini, M., Omarini, R.H., Pimentel, M.M., 2011. Combined U–Pb and Lu– Acknowledgments Hf isotope data on turbidites of the Paleozoic basement of NW Argentina and petrology of associated igneous rocks: implications for the tectonic evolution of western Gondwana between 560 and 460 Ma. Gondwana Research 19, 100–127. The authors wish to thank the National Science Council of Taiwan for Hawkesworth, C.J., Kemp, A.I.S., 2006. Using hafnium and oxygen isotopes in zircons to the financial support (NSC 98-2116-M-003-003, and NSC 99-2116- unravel the record of crustal evolution. Chemical Geology 226, 144–162. fi M-003-005). Greg Shellnutt is thanked for the helpful discussion on Jackson, S.E., Pearson, N.J., Grif n, W.L., Belousova, E.A., 2004. The application of laser ablation-inductively coupled plasma-mass spectrometry to in situ U–Pb zircon the geochemical data and English proofreading. geochronology. Chemical Geology 211, 47–69. Kanjanapayont, P., Klötzli, U., Thöni, M., Grasemann, B., Edwards, M.A., 2012. Rb–Sr, Sm–Nd, and U–Pb geochronology of the rocks within the Khlong Marui shear zone, southern Thailand. Journal of Asian Earth Sciences 56, 263–275. References Kemp, A.I.S., Hawkesworth, C.J., Paterson, B.A., Kinny, P.D., 2006. Episodic growth of the Gondwana supercontinent from hafnium and oxygen isotopes in zircon. Nature Ahrendt, H., Chonglakmani, C., Hansen, B.T., Helmcke, D., 1993. Geochronological cross 439, 580–583. section through northern Thailand. Journal of Southeast Asian Earth Sciences 8, Kröner, A., Stern, R.J., 2004. Pan-African orogeny. In: Selley, R.C., Cocks, L.R.M., Plimer, 207–217. I.R. (Eds.), Encyclopedia of Geology, pp. 1–12. Barber, A.J., Ridd, M.F., Crow, M.J., 2011. The origin, movement and assembly of the pre- Li, L.-M., Sun, M., Wang, Y., Xing, G., Zhao, G., Lin, S., Xia, X., Chan, L., Zhang, F., Wong, J., Tertiary tectonic units of Thailand. In: Ridd, M.F., Barber, A.J., Crow, M.J. (Eds.), The 2011. U–Pb and Hf isotopic study of zircons from migmatised amphibolites in the Geology of Thailand. Geological Society, London, pp. 507–537. Cathaysia Block: implications for the early Paleozoic peak tectonothermal event in Barr, S.M., Macdonald, A.S., 1999. Toward a late Paleozoic–early Mesozoic model for Southeastern China. Gondwana Research 19, 191–201. Thailand. Journal of Thai Geosciences 1, 11–22. Liew, T.C., Page, R.W., 1985. U–Pb zircon dating of granitoid plutons from the west-coast Beckinsale, R.D., Suensilpong, S., Nakapadungrat, S., Walsh, J.N., 1979. Geochronology province of Peninsular Malaysia. Journal of the Geological Society 142, 515–526. and geochemistry of granite magmatism in Thailand in relation to a plate tectonic Liu, S., Hu, R., Gao, S., Feng, C., Huang, Z., Lai, S., Yuan, H., Liu, X., Coulson, I.M., Feng, G., model. Journal of the Geological Society 136, 529–540. Wang, T., Qi, Y., 2009. U–Pb zircon, geochemical and Sr–Nd–Hf isotopic constraints Brum, F., von Braun, E., Hahn, L., Hess, A., Koch, K.E., Krause, G., Quarsh, H., Siebenhuner, on the age and origin of Early Palaeozoic I-type granite from the Tengchong– M., 1970. On the geology of northern Thailand. Beihefte zum Geologischen Jahrbuch Baoshan Block, Western Yunnan Province, SW China. Journal of Asian Earth 102, 1–24. Sciences 36, 168–182. Cawood, P.A., Johnson, M.R.W., Nemchin, A.A., 2007. Early Palaeozoic orogenesis along Maniar, P.D., Piccoli, P.M., 1989. Tectonic discrimination of granitoids. Geological Society the Indian margin of Gondwana: tectonic response to Gondwana assembly. Earth of America Bulletin 101, 635–643. and Planetary Science Letters 255, 70–84. Metcalfe, I., 1988. Origin and assembly of south-east Asian continental terranes. Chiu, H.-Y., Chung, S.-L., Wu, F.-Y., Liu, D., Liang, Y.-H., Lin, I.J., Iizuka, Y., Xie, L.-W., Geological Society, London, Special Publications 37, 101–118. Wang, Y., Chu, M.-F., 2009. Zircon U–Pb and Hf isotopic constraints from eastern Metcalfe, I., 1999. Gondwana dispersion and Asian accretion: an overview. In: Metcalfe, Transhimalayan batholiths on the precollisional magmatic and tectonic evolution I. (Ed.), Gondwana Dispersion and Asian Accretion (IGCP 321 Final Results in southern Tibet. Tectonophysics 477, 3–19. Volume). A.A. Balkema, Rotterdam, pp. 9–28. Cobbing, E.J., Pitfield, P.E.J., Derbyshire, D.P.F., Mallick, D.I.J., 1992. The granites of the Metcalfe, I., 2000. The Bentong–Raub Suture Zone. Journal of Asian Earth Sciences 18, Southeast Asian tin belt. Overseas Memoirs of the British Geological Survey 10. 691–712. Collins, A.S., Pisarevsky, S.A., 2005. Amalgamating eastern Gondwana: the evolution of Metcalfe, I., 2006. Palaeozoic and Mesozoic tectonic evolution and palaeogeography of the Circum-Indian Orogens. Earth-Science Reviews 71, 229–270. East Asian crustal fragments: the Korean Peninsula in context. Gondwana Research Duan, L., Meng, Q.-R., Zhang, C.-L., Liu, X.-M., 2011. Tracing the position of the South 9, 24–46. China block in Gondwana: U–Pb ages and Hf isotopes of Devonian detrital zircons. Metcalfe, I., 2011. Tectonic framework and Phanerozoic evolution of Sundaland. Gondwana Gondwana Research 19, 141–149. Research 19, 3–21. Dunning, G.R., Macdonald, A.S., Barr, S.M., 1995. Zircon and monazite U–Pb dating of the Miller, C., Thöni, M., Frank, W., Grasemann, B., Klötzli, U., Guntli, P., Draganits, E., 2001. Doi inthanon core complex, northern Thailand: implications for extension within the The early Palaeozoic magmatic event in the Northwest Himalaya, India: source, Indosinian Orogen. Tectonophysics 251, 197–213. tectonic setting and age of emplacement. Geological Magazine 138, 237–251. Y.-L. Lin et al. / Gondwana Research 24 (2013) 1031–1037 1037

Mitchell, A.H.G., 1981. Phanerozoic plate boundaries in mainland SE Asia, the Sinclair, G., 1997. A study of the Praniburi Formation and Khao Tao Formation. The In- Himalayas and Tibet. Journal of the Geological Society 138, 109–122. ternational Conference on Stratigraphy and Tectonic Evolution of Southeast Asia Nantasin, P., Hauzenberger, C., Liu, X., Krenn, K., Dong, Y., Thöni, M., Wathanakul, P., and the South Paciﬁc in Bangkok, Thailand, pp. 337–345. 2012. Occurrence of the high grade Thabsila metamorphic complex within the Sone, M., Metcalfe, I., 2008. Parallel Tethyan sutures in mainland Southeast Asia: new low grade Three Pagodas shear zone, Kanchanaburi Province, western Thailand: insights for Palaeo-Tethys closure and implications for the Indosinian orogeny. petrology and geochronology. Journal of Asian Earth Sciences 60, 68–87. Comptes Rendus Geosciences 340, 166–179. Pongsapich, W., Vedchakanchana, S., Pongprayoon, P., 1980. Petrology of the Pranburi- Song, S., Ji, J., Wei, C., Su, L., Zheng, Y., Song, B., Zhang, L., 2007. Early Paleozoic granite in Hua Hin Metamorphic complex and geochemistry of gneisses in it. Bulletin. Geolog- Nujiang River of northwest Yunnan in southwestern China and its tectonic impli- ical Society of Malaysia 12, 55–74. cations. Chinese Science Bulletin 52, 2402–2406. Putthapiban, P., Suensilpong, S., 1978. The igneous geology of the granitic rocks of the Ueno, K., 2003. The Permian fusulinoidean faunas of the Sibumasu and Baoshan blocks: Hub Kapong-Hua Hin area. Journal of the Geological Society of Thailand 3, 1–22. their implications for the paleogeographic and paleoclimatologic reconstruction of Ramezani, J., Tucker, R.D., 2003. The Saghand Region, Central Iran: U–Pb geochronology, the Cimmerian Continent. Palaeogeography, Palaeoclimatology, Palaeoecology 193, petrogenesis and implications for Gondwana Tectonics. American Journal of Science 1–24. 303, 622–665. Ueno, K., Hisada, K.-i., 2001. The Nan-Uttaradit-Sa Kaeo Suture as a Main Paleo-Tethyan Ridd, M.F., 2009. The Phuket terrane: a Late Palaeozoic rift at the margin of Sibumasu. Suture in Thailand: is it real? Gondwana Research 4, 804–806. Journal of Asian Earth Sciences 36 (2–3), 238–251. Ustaömer, P.A., Ustaömer, T., Collins, A.S., Robertson, A.H.F., 2009. Cadomian (Ediacaran– Ridd, M.F., 2012. The role of strike-slip faults in the displacement of the Palaeotethys Cambrian) arc magmatism in the Bitlis Massif, SE Turkey: magmatism along the de- suture zone in Southeast Thailand. Journal of Asian Earth Sciences 51, 63–84. veloping northern margin of Gondwana. Tectonophysics 473, 99–112. Rino, S., Kon, Y., Sato, W., Maruyama, S., Santosh, M., Zhao, D., 2008. The Grenvillian and Wang, X.-d, Lin, W., Shen, S.-z, Chaodumrong, P., Shi, G.R., Wang, X.-j, Wang, Q.-l, 2013. Pan-African orogens: world's largest orogenies through geologic time, and their Early Permian rugose coral Cyathaxonia faunas from the Sibumasu terrane (Southeast implications on the origin of superplume. Gondwana Research 14, 51–72. Asia) and the southern Sydney Basin (Southeast Australia): paleontology and Saki, A., 2010. Proto-Tethyan remnants in northwest Iran: geochemistry of the gneisses paleobiogeography. Gondwana Research 24, 185–191. and metapelitic rocks. Gondwana Research 17, 704–714. Wilde, S.A., Wu, F., Zhang, X., 2003. Late Pan-African magmatism in northeastern Schaltegger, U., Fanning, C.M., Günther, D., Maurin, J.C., Schulmann, K., Gebauer, D., China: SHRIMP U–Pb zircon evidence from granitoids in the Jiamusi Massif. 1999. Growth, annealing and recrystallization of zircon and preservation of mona- Precambrian Research 122, 311–327. zite in high-grade metamorphism: conventional and in-situ U–Pb isotope, Wu, F.-Y., Yang, Y.-H., Xie, L.-W., Yang, J.-H., Xu, P., 2006. Hf isotopic compositions of cathodoluminescence and microchemical evidence. Contributions to Mineralogy the standard zircons and baddeleyites used in U–Pb geochronology. Chemical and Petrology 134, 186–201. Geology 234, 105–126. Scherer, E.E., Whitehouse, M.J., Münker, C., 2007. Zircon as a monitor of crustal growth. Zhang, Z., Dong, X., Santosh, M., Liu, F., Wang, W., Yiu, F., He, Z., Shen, K., 2012. Petrol- Elements 3, 19–24. ogy and geochronology of the Namche Barwa Complex in the eastern Himalayan Searle, M.P., Whitehouse, M.J., Robb, L.J., Ghani, A.A., Hutchison, C.S., Sone, M., Ng, S.W.-P., syntaxis, Tibet: constraints on the origin and evolution of the north-eastern margin Roselee, M.H., Chung, S.-L., Oliver, G.J.H., 2012. Tectonic evolution of the Sibumasu– of the Indian Craton. Gondwana Research 21, 123–137. Indochina terrane collision zone in Thailand and Malaysia: constraints from new Zhou, J.-B., Wilde, S.A., Zhang, X.-Z., Zhao, G.-C., Liu, F.-L., Qiao, D.-W., Ren, S.-M., Liu, J.-H., U–Pb zircon chronology of SE Asian tin granitoids. Journal of the Geological Society 2011. A >1300 km late Pan-African metamorphic belt in NE China: new evidence 169, 489–500. from the Xing'an block and its tectonic implications. Tectonophysics 509, 280–292. Sevastjanova, I., Clements, B., Hall, R., Belousova, E.A., Grifﬁn, W.L., Pearson, N., 2011. Zhu, D.-C., Zhao, Z.-D., Niu, Y., Dilek, Y., Wang, Q., Ji, W.-H., Dong, G.-C., Sui, Q.-L., Liu, Y.-S., Granitic magmatism, basement ages, and provenance indicators in the Malay Yuan, H.-L., Mo, X.-X., 2012. Cambrian bimodal volcanism in the Lhasa terrane, Peninsula: insights from detrital zircon U–Pb and Hf-isotope data. Gondwana Research southern Tibet: record of an early Paleozoic Andean-type magmatic arc in the 19, 1024–1039. Australian proto-Tethyan margin. Chemical Geology 328, 290–308.