Gondwana Research 26 (2014) 699–718

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Gondwana Research

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South China continental margin signature for sandstones and granites from Palawan, Philippines

Simon M. Suggate a,⁎, Michael A. Cottam a,b,RobertHalla, Inga Sevastjanova a,MargaretA.Forsterc, Lloyd T. White a, Richard A. Armstrong c, Andrew Carter d, Edwin Mojares e a SE Asia Research Group, Department of Earth Sciences, Royal Holloway University of London, Egham, Surrey TW20 0EX, United Kingdom b BP Exploration Operating Co. Ltd., Wellheads Avenue, Dyce, Aberdeen AB21 7PB, United Kingdom c Research School of Earth Sciences, The Australian National University, Canberra, ACT 0200, Australia d Department of Earth and Planetary Sciences, Birkbeck, University of London, Malet Street, London WC1E 7HX, United Kingdom e Geosciences Division, Mines and Geosciences Bureau, 1515L & S Bldg., Roxas Boulevard, Manila, Philippines article info abstract

Article history: We report results of heavy mineral analysis and U–Pb dating of detrital zircons from metasediments and Received 17 January 2013 Cenozoic sandstones, and U–Pb dating of zircons from Cenozoic granites of the North Palawan Continental Received in revised form 8 July 2013 Terrane (NPCT) and the South Palawan Terrane (SPT). The NPCT metasediments are derived mainly from granitic Accepted 21 July 2013 and metamorphic rocks of continental character. They contain zircons that indicate a maximum depositional age Available online 29 July 2013 of Late Cretaceous and other age populations indicating a South China origin. The sediments were deposited on Handling Editor: M. Santosh the South China margin before rifting of the continental margin during opening of the South China Sea. Miocene SPT sandstones contain similar heavy mineral assemblages suggesting sources that included NPCT Keywords: metasediments, metamorphic basement rocks at the contact between the SPT and the NPCT, South China Sea Palawan rift volcanic and/or minor intrusive rocks, and the Palawan ophiolite complex. The SPT sandstones are very North Borneo similar to Lower Miocene Kudat Formation sandstones of northern Borneo suggesting a short-lived episode of Mount Capoas granite sediment transport from Palawan to Borneo in the Early Miocene following arc-continent collision. U–Pb dating – Zircon U Pb geochronology of zircons shows that the Central Palawan granite is Eocene (42 ± 0.5 Ma). The Capoas granite was intruded Heavy minerals during a single pulse, or as two separate pulses, between 13.8 ± 0.2 Ma and 13.5 ± 0.2 Ma. Inherited zircon ages from the Capoas granite imply melting of continental crust derived from the South China margin with a contribution from Cenozoic rift-related and arc material. © 2013 International Association for Gondwana Research. Published by Elsevier B.V. All rights reserved.

1. Introduction As an area with proven hydrocarbon potential, Palawan has been the attention of a number of recent studies (e.g. Yumul et al., 2009; Knittel Palawan, the westernmost island of the Philippine archipelago, lies et al., 2010; Walia et al., 2012). Despite this, many aspects of the tectonic at the southern margin of the South China Sea, approximately 400 km evolution and geology of this region remain unclear. In particular, there to the northeast of Borneo (Fig. 1). Geologically, Palawan can be divided are still outstanding questions about the ages of igneous, metamorphic into two blocks, the North Palawan Continental Terrane (NPCT) and the and sedimentary rocks on Palawan. For example, metasedimentary South Palawan Terrane (SPT) (e.g. Hamilton, 1979; Taylor and Hayes, rocks that were previously considered Palaeozoic have yielded Creta- 1983; Faure et al., 1989; Yumul et al., 2009). The NPCT is interpreted ceous detrital zircons (e.g. Walia et al., 2012). The geology of Palawan as a continental fragment that was derived from the South China margin is also similar to that of North Borneo and both include Mesozoic (e.g. Holloway, 1982; Taylor and Hayes, 1983; Hall, 1996). This is ophiolitic rocks that are overlain by Mesozoic–Cenozoic sedimentary supported by previous provenance studies (Suzuki et al., 2000; Walia rocks and are intruded by granites. Both areas share a strong NE–SW et al., 2012) which suggested that Upper Cretaceous to Eocene sand- orientation (Fig. 1). In both cases (e.g. Hutchison, 2010) the onshore stones of Central Palawan (NPCT) were derived from the Kwangtung regions are flanked to the west by significant bathymetric troughs and Fukien regions of South China. The SPT includes a Lower (the NW Borneo and Palawan Troughs) that are in turn flanked by Cretaceous–Eocene ophiolitic complex (e.g. Yumul et al., 2009)and bathymetric highs (the Dangerous Grounds and Reed Bank). Perhaps Oligocene to Miocene sediments. Almost nothing is known about the most notably, both areas are intruded by young granite plutons: the provenance of these sediments from this terrane. Mt Kinabalu pluton in northern Borneo (Cottam et al., 2010), and the Mt Capoas intrusion in Palawan (Encarnación and Mukasa, 1997). ⁎ Corresponding author. Tel.: +44 1784 443592; fax: +44 1784 434716. K–Ar age determinations on the Kinabalu granite in northern Borneo E-mail address: [email protected] (S.M. Suggate). by a number of authors (Jacobson, 1970; Rangin et al., 1990; Bellon 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.2013.07.006 700 S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718

Rangin, 1991; Swauger et al., 1995; Hutchison et al., 2000) suggested of the proto-South China Sea beneath NW Borneo and the Cagayan that the granite may be as old as ~14 Ma. However, U–Pb dating of Arc and the opening of the South China Sea (Holloway, 1982; Taylor zircons by Cottam et al. (2010) showed that the Kinabalu granite is a and Hayes, 1983; Kudrass et al., 1986; Vogt and Flower, 1989; Rangin Late Miocene pluton emplaced and crystallised in less than et al., 1990; Hall, 1996; Hutchison, 1996; Schluter et al., 1996; 800,000 years between 7.85 ± 0.08 and 7.22 ± 0.07 Ma. Encarnación Encarnación and Mukasa, 1997; Hutchison et al., 2000; Hall, 2002; and Mukasa (1997) had reported Middle Miocene ages (~14 Ma) for Replumaz and Tapponnier, 2003; Cottam et al., 2010; Hutchison, the Capoas granite based on U–Pb dating of zircon and monazite but 2010; Franke et al., 2011; Hall, 2012). Subduction of the proto-South recognised that these were discordant and could be mixtures of older China Sea terminated in the Early Miocene after collision of the NPCT cores and younger magmatic rims. The new SHRIMP age data for the with the active continental margin of Sabah and the Cagayan Arc Kinabalu granite raised the question of whether the Capoas granite is (Holloway, 1982; Rangin et al., 1990; Tan and Lamy, 1990; Hinz et al., possibly of similar age and origin. 1991; Hall, 1996; Hall and Wilson, 2000; Hutchison et al, 2000). Oceanic Heavy minerals are sensitive provenance indicators, because of the spreading in the South China Sea ceased in the Early or Middle Miocene diversity of common assemblages, restricted parageneses of many com- (Taylor and Hayes, 1983; Briais et al., 1993; Barckhausen and Roeser, mon heavy mineral species and their ability to preserve geochemical 2004). characteristics of parental source rocks. Heavy mineral analysis has been successfully applied in provenance studies across the world 3. Geology and stratigraphy of Palawan Island (Morton et al., 1994; Mange et al., 2005; Garzanti and Ando, 2007), in- cluding SE Asia (e.g. van Hattum et al., 2006; Clements and Hall, 2011; The geology of Palawan Island (Fig. 2) has commonly been Suggate, 2011; Sevastjanova et al., 2012; Witts et al., 2012; van interpreted to comprise two discrete tectonic elements (e.g. Hamilton, Hattum et al., in press), in areas where there are sufficient differences 1979; Holloway, 1982; Taylor and Hayes, 1983; Mitchell et al., 1986; between sediment source areas. Several authors have suggested that Encarnación et al., 1995; Encarnación and Mukasa, 1997; Almasco initial heavy mineral assemblages undergo modifications during et al., 2000). The northern part of the island is made up of the sediment generation, transport and storage. The most significant of continental-derived metamorphic and sedimentary rocks of the NPCT. these include (a) hydraulic sorting (density fractionation), (b) dissolu- The southern part of the island comprises ophiolitic rocks and Cenozoic tion during deep burial (diagenetic dissolution) and (c) dissolution clastic sediments of the SPT. The NPCT and SPT are in contact along a during tropical weathering. It is recognised that these secondary pro- broadly north–south trending steep fault that cuts through Ulugan cesses change the initial abundances of the minerals (e.g. Garzanti Bay, in the centre of the island. et al., 2011; Andò et al., 2012) or possibly can selectively remove min- erals from the initial assemblage (e.g. Morton and Hallsworth, 2007). 3.1. North Palawan Continental Terrane metamorphic and sedimentary However, minerals that remain in the heavy mineral assemblage still rocks yield useful information about their source rocks. Recent provenance studies based on heavy minerals suggest that The NPCT includes a succession of low to medium grade metamor- during the Early Miocene Palawan shed granitic and metamorphic phic rocks and sedimentary rocks related to the pre-, syn- and post- detritus to northern Borneo (van Hattum, 2005; Suggate, 2011; van rift stages of the opening of the South China Sea (Sales et al., 1997; Hattum et al., in press). Provenance studies of NPCT metasediments Suzuki et al., 2000; Franke et al., 2011) and isolated granite bodies in (Suzuki et al., 2000; Walia et al., 2012) concentrated on light minerals central and northern Palawan. Reviewing the stratigraphy of the and U–Pb dating of detrital zircons. Detrital heavy minerals were briefly NPCT, Sales et al. (1997) classified it on the basis of three distinct tecton- described from thin section, but interpretations of provenance were ic environments: pre-rift and rift; drifting and South China Sea (SCS) based on limited data, insufficient for detailed characterisation of seafloor spreading; collision and post-collision. Based on the region's heavy mineral assemblages (e.g. Mange and Maurer, 1992). offshore seismostratigraphy, Franke et al. (2011) recognised four main In order to address these uncertainties, we carried out fieldwork phases: (1) Mesozoic pre-rift sedimentation associated with the margin in Palawan to collect igneous rocks, metasediments and Cenozoic of the Asian mainland; (2) Latest Cretaceous–Eocene sedimentation as- sandstones from the NPCT and SPT. We report here the results of sociated with rifting of the South China Sea basin; (3) Oligocene to Early heavy mineral analysis, U–Pb dating of detrital zircons and zircons Miocene sedimentation concurrent with the drifting episode of the from Cenozoic granites from Palawan. Palawan–Mindoro microcontinental block during South China Sea seafloor spreading; (4) Late Miocene to Recent sedimentation during 2. Geological background and after the collision between the microcontinental block and the Philippine Mobile Belt. There is general agreement that parts of northern Borneo and The oldest rocks reported from the NPCT (Fig. 3) are a series of Palawan (Fig. 1), along with areas such as the Dangerous Grounds and Upper Palaeozoic to Lower Mesozoic metasedimentary rocks (Sales Reed Bank in the South China Sea, are extended and attenuated et al., 1997). They include sandstones, tuffs, slates, phyllites and schists continental fragments rifted from the South China margin. The rifted (Sales et al., 1997; Yumul et al., 2009) that have undergone medium- material has been termed the Palawan Continental Terrane (PCT; grade regional metamorphism (e.g. Suzuki et al., 2000). Metamorphic e.g. Holloway, 1982; Taylor and Hayes, 1983), the North Palawan rocks from Mindoro in the north of the NPCT have variously been Block (NPB; e.g. Almasco et al., 2000), and the North Palawan Continen- dated as Late Palaeozoic (Knittel and Daniels, 1987), older than Late tal Terrane (NPCT; e.g. Encarnación et al., 1995; Encarnación and Cretaceous (Sarewitz and Karig, 1986), and Paleocene (Faure et al., Mukasa, 1997). The term North Palawan Continental Terrane (NPCT) 1989). Dating of igneous and detrital zircons from metamorphic rocks is used here. This continental crust was originally envisaged to be a sin- exposed in southern Mindoro suggests a Late Palaeozoic (Middle to gle large fragment rifted from the South China margin (Holloway, 1982; Late Permian) age for the metamorphic rocks of the NPCT (Knittel Taylor and Hayes, 1983), but recent studies (Yumul et al., 2009)have et al., 2010). These rocks were suggested to have formed in association suggested that there are several internal sutures and multiple with a Permian magmatic arc that extended along the south coast of fragments. Continental crust has been identified in northern Palawan, Asia (Knittel et al., 2010) prior to the opening of the SCS. In places, the parts of the islands of Mindoro and Panay, and Reed Bank (Holloway, metasediments are overlain by a sequence of cherts, clastic sediments 1982; Taylor and Hayes, 1983; Kudrass et al., 1986; Schluter et al., and carbonates, exposed mainly in the north of Palawan and on the 1996; Encarnación and Mukasa, 1997; Yumul et al., 2009; Franke Calamian Islands (e.g. Sales et al., 1997; Suzuki et al., 2000; Yumul et al., 2011; Knittel, 2011). The NPCT moved south during subduction et al., 2009). All of these rocks belong to the pre-rift succession, and S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718 701

117°0'0"E 118°0'0"E 119°0'0"E 120°0'0"E

SOUTH CHINA MARGIN NPCT

PHILIPPINES Capoas Granite 11°0'0"N BORNEO Palawan

South China Sea

125°0'0"E 10°0'0"N

Puerto Princesa 20°0'0"N 9°0'0"N

120°0'0"E

Luzon Sulu Sea SPT Philippines 15°0'0"N 8°0'0"N

115°0'0"E

South Capoas China Granite Sea Reed Bank Panay b Palawan

Palawan Trough 10°0'0"N

Dangerous Grounds Cagayan Ridge Sulu Mindanao Sea

North West Borneo Trough Mount Kinabalu granite

5°0'0"N Celebes Sea Borneo a

Fig. 1. The position of Palawan, Philippines and northern Borneo within SE Asia (a). SRTM digital elevation model and sea floor bathymetry of Palawan showing the North Palawan Continental Terrane (NPCT), the South Palawan Terrane (SPT), the location of the regional capital Puerto Princesa and the Capoas granites bodies (b). 702 S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718

118°0'0"E 119°0'0"E

Quaternary Alluvium

Middle Miocene Capoas and Bay Peak Granites Oligocene - Miocene Siliciclastics Middle Eocene Central Palawan Granite Bodies Eocene Siliciclastics Mt Beaufort Palawan Metamorphics 11°0'0"N Stavely Range SPT - Cretaceous - Eocene Gabbro Capoas Ophiolite Complex Granite Espina Basalt Bay Peak Granite Tumarbong Semi Schist Caramay NPCT - Cretaceous to Schist Eocene Meta-sediments Babuyan River Turbidites Ulugan Fault Mesozoic Mélange

10°0'0"N South China North Palawan Sea Continental Terrane (NPCT)

South Palawan Terrane (SPT) 9°0'0"N

Sulu Sea Kilometres 0 25 50 100

Fig. 2. Simplified geological map of Palawan Island, Philippines modified from Almasco et al. (2000) and Mines and Geoscience Bureau (2011). The Ulugan fault (red dashed line) is the boundary between the North Palawan Continental Terrane (NPCT) and the South Palawan Terrane (SPT). were deposited along the southern margin of Asia prior to the opening et al., 2000) which is variously called the Boayan Formation (Walia of the SCS (e.g. Sales et al., 1997; Suzuki et al., 2000; Yumul et al., et al., 2012), the Boayan Clastics (Hashimoto and Sato, 1973) and the 2009; Franke et al., 2011). Boayan–Caruray Clastics (Wolfart et al., 1986). These rocks are overlain by a sequence of Upper Cretaceous–Eocene sedimentary rocks in Central Palawan (Suzuki et al., 2000)thatare 3.2. North Palawan Continental Terrane granitic rocks thought to represent rift-related sedimentation (Sales et al., 1997; Franke et al., 2011). They are very low to low grade metamorphosed The Central Palawan granite (Fig. 4)isadifficult-to-access north- sedimentary rocks that are exposed mainly in Central Palawan and trending body with a mapped area of approximately 19 km2.Ithas include mudstone, pebbly mudstone, and interbedded sandstone and also been called Stripe Peak granite (Mitchell et al., 1985). Float samples mudstone (Suzuki et al., 2000). The succession is divided into three collected during this study were taken from riverbeds approximately units: the Caramay Schist, the Concepcion Pebbly Phyllite, which is 20 km away from the mapped area of the granite. It has been suggested also called the Tumarbong Semi Schist (Mines and Geoscience Bureau, to be no older than Late Eocene, as it intrudes sedimentary rocks of 2011), and the Babuyan River Turbidite (Mitchell et al., 1985; Suzuki probable Eocene age (Mitchell et al., 1985). Two K–Ar dates (36.6 ± S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718 703

South Palawan North Palawan separate plutons, or if they are linked at depth. Here we subdivide the Terrane Continental Terrane Capoas granite into the Mount Capoas granite, the Bay Peak granite and the Binga Point granite. PLEISTOCENE MA Only the Mount Capoas granite has been studied in detail Pliocene- Pliocene- (Encarnación and Mukasa, 1997). It is an equigranular to porphyritic L Recent clastics Recent clastics biotite granite (29% quartz; 23% K-feldspar; 33% plagioclase; 15% E biotite; abundant accessory zircon; subordinate monazite and PLIOCENE 5 apatite) with a textural continuum between K-feldspar phenocryst- rich and phenocryst-poor varieties (Encarnación and Mukasa, L 1997). The granite contains enclaves of biotite-rich fine-grained granite and K-feldspar phenocrysts that show magmatic flow align- 10 ment (Encarnación and Mukasa, 1997). Chemically the granite is classified as metaluminous and high-K calc-alkaline, and plots on the tectonic discrimination diagrams of Pearce et al. (1984) in the + + Capoas Granite fi M Miocene Sediments + syn-collisional and volcanic arc granite elds (Encarnación and Emplacement 15 inc. Isugod Formation Mukasa, 1997). Previous dating studies have suggested a late Middle Miocene age for crystallisation of the Capoas intrusion (Encarnación and Mukasa, 1997). Based on the age and regional tectonic models, Encarnación and Mukasa (1997) suggested that the Mount Capoas granite formed in a “post-rifting, non-collisional tectonic setting 20 E unrelated to any subduction zone”. They argued that the chemical M I O C E N affinities with syn-collisional and volcanic arc granites reflect source rock composition, rather than the tectonic setting of melting. The St Pauls Limestone meaning of the Late Middle Miocene age is open to question. The 25 age is based on a small number of zircon and monazite analyses – L from a single sample of the Mount Capoas granite. The U Pb analyses were carried out using isotope dilution methods that have been Oligocene superseded in many ways by newer techniques. The whole-scale Sediments 30 dissolution of grains that was used does not allow distinction between the ages of magmatic rims and those of any inherited E cores. Encarnación and Mukasa (1997) dated seven fractions of

OLIGOCENE zircons. Despite attempts to avoid zircons with obvious cores, all of 34 the analyses fall off the U–Pb concordia forming a mixing array L 37 + + Central Palawan towards an older component with an estimated Proterozoic age + Granite (Encarnación and Mukasa, 1997). All analyses reflect variable mixing M 41 Emplacement of magmatic and inherited ages. Based on the lower intercept of a South Palawan weighted regression line passing through all the data points 49 Ophiolite Encarnación and Mukasa (1997) derived a magmatic crystallisation EOCENE E Complex age of 15 +3/−4 Ma for the Mount Capoas granite. However, such 55 Rift Meta-sediments estimates are extremely sensitive to the slope of the regression (inc. Babuyan River Turbidites, Tumarbong Semi line; small changes in data and/or weightings can produce large Schist & Caramay Schist variations in intercept age. They also analysed four sub-samples of 207 206 206 238 PALEO- CENE monazite from the same sample. The Pb/ Pb and U/ Pb 65 ages are inversely discordant (Encarnación and Mukasa, 1997). K However, 207U/235Pb ages are concordant and range between 145 Pre-rift Sediments 13.5 ± 0.2 Ma to 12.7 ± 1.3 Ma, with an error weighted mean age (cherts, clastics and J carbonates) of 13.4 ± 0.4 Ma (Encarnación and Mukasa, 1997). 200 Direct dating methods such as SIMS (Secondary Ionisation Mass T Spectrometry), of which the SHRIMP (Sensitive High Resolution Ion 251 MicroProbe) is an example, have been used successfully to indepen- Metamorphic dently date cores and rims (e.g. Ireland and Williams, 2003; Ireland P Basement et al., 2008). Such studies can therefore provide information on both the magmatic (crystallisation) age of the rock, the age(s) of possible Fig. 3. Onshore stratigraphy of the North Palawan Continental Terrane (NPCT) and the South Palawan Terrane (SPT) based on data from Mitchell et al. (1985), Almasco et al. protoliths and subsequent phases of metamorphism. We report new (2000), Franke et al. (2011), Mines and Geoscience Bureau (2011) and this study. SHRIMP ages below.

1.8 Ma and 37.0 ± 1.9 Ma) from biotite in biotite–quartz monzonite 3.3. South Palawan Terrane (Mitchell et al., 1985) support a Late Eocene age for the intrusion. The Capoas granite comprises several small bodies that intrude the The SPT (Fig. 3) is dominated by ophiolitic rocks belonging to the basement rocks of the NPCT on the Capoas peninsula in north-central Palawan Ophiolitic Complex (Mitchell et al., 1986). The complex com- Palawan (Fig. 4). The largest body (~7 × 7 km) crops out in the prises a full ophiolitic sequence of basal harzburgites, gabbros, pillow flanks and summit of Mount Capoas. Further south, a second body basalts and chert (Encarnación et al., 1995). It is dated as Early (~4 × 7 km) is exposed in coastal outcrops and the flanks of Bay Peak. Cretaceous to Eocene based on radiolarians (Raschka et al., 1985), Some geological maps show a third, smaller (~3 × 3 km) exposure of nannoplankton (Müller, 1991), biostratigraphy (Faure et al., 1989), granite around Binga Point. It is unclear if these three bodies represent and K–Ar dating of basalt (Fuller et al., 1991). 704 S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718

KM m Cretaceous - Eocene Ei m a Ophiolite Complex 119°0'0"E Quaternary Mt Beaufort Esg Alluvium Metamorphics Esg Holocene Stavely Range Siliciclastics Gabbro Espina Miocene Eb u Siliciclastics Basalt 9°20'0"N 11°0'0"N Eocene Siliciclastics

Esg PLi Map B

Qa Mi Keb Keb Map C Ebu Esg Ulugan

Ma Mr KEb p Fault 53 & 55

Keb Esg Qa

9°10'0"N Esg Ma

Eb u KEb p Keb Puerto Princesa

Keb Keb Esg Palawan, Qa 118°10'0"E 118°0'0"E Keb Philippines d KEb p Map D

117°0'0"E Detrital South Middle Miocene Capoas and Bay Peak Granites U-Pb analysis China

Oligocene to Pliocene sediments 9°0'0"N Sea Middle Eocene Central Palawan Granitic Intrusion Detrital Upper Cretaceous to Eocene meta-sediments HM analysis Cretaceous-Eocene Ophiolite Complex Mesozoic mélange Kilometers Granite U-Pb 0 25 50 100 150 200 analysis

b 119°20'0"E 118°50'0"E 119°10'0"E 31 Quaternary Alluvium Holocene Iwahig 10°50'0"N Formation Oligo-Miocene St Paul’s Mount

10°30'0"N Limestone Capoas Middle Eocene Central granite Palawan Granite Eocene Mt Beaufort Binga Metamorphics 3337 Point 35 34 granite San Miguel

10°45'0"N Quaternary Alluvium

Middle Miocene Capoas Granite Bodies New Upper Cret to Eocene Canipo Tumarbong Semi Schist

8 & 11 Mesozoic Bay Mélange 10°10'0"N Cretaceous-Eocene 26 Peak granite Meta-sediments 27

10°40'0"N 30 Tumarbong 25 5 Semi Schist Caramay Schist 21 24 19 Babuyan River Turbidites 119°15'0"E c

Fig. 4. Simplified geological map of Palawan (a). Geological map of the Mount Capoas region showing granite sample locations (b). Geological map of central Palawan showing sample locations of metasediments and Central Palawan granite (c). Geological map of central southern Palawan showing sample locations of Neogene sandstones (d). S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718 705

Along the contact between the SPT and the NPCT through Ulugan siliciclastic samples (PAL-5, PAL-21, PAL-55) and two granite samples Bay in central Palawan amphibolites and schists form a sole of high- (PAL-5, PAL-11) from the Central Palawan granite were analysed by grade metamorphic rocks (Encarnación et al., 1995). The ophiolitic LA-ICPMS at University College London. Zircon separates from four sam- rocks are overlain by a sequence of Paleogene and Neogene clastic sed- ples from the Mount Capoas granite (PAL-33, PAL-34, PAL-35, PAL-37) imentary rocks (Almasco et al., 2000). The character of these sedimen- and four samples from the Bay Peak granite (PAL-25, PAL-26, PAL-27, tary rocks is largely unknown. However, the association of ophiolitic PAL-30) were analysed by sensitive high-resolution ion microprobe and continental rocks overlain by Paleogene and Neogene clastic sedi- (SHRIMP) on the SHRIMP II at the Australian National University. mentary rocks has led to comparisons with the stratigraphy of northern Borneo (e.g. Hamilton, 1979; Müller, 1991; Almasco et al., 2000). 5.1. U–Pb isotopic dating — LA–ICP–MS

4. Sampling The U–Th–Pb isotope analyses were performed using a New Wave 213 aperture-imaged frequency-quintupled laser ablation system Siliciclastic sedimentary rock and granite samples were collected (213 nm) coupled to an Agilent 7700 quadrupole-based ICP–MS. Grains from Palawan (Fig. 4)duringafield survey in 2011 conducted in collab- typically were ablated with 40 μm laser spot. Real-time data were oration with the Philippines Mines and Geoscience Bureau. processed using the GLITTER® software package (Griffinetal.,2008). Siliciclastic sedimentary rock samples were collected from the Plesovice zircon (TIMS reference age 337.13 ± 0.37 Ma; Sláma et al., Babuyan River Turbidites, Caramay Schist and the Tumarbong Semi 2008) and NIST SRM 612 silicate glass (Pearce et al., 1997)wereused Schist of the NPCT and from the Miocene Isugod Formation of the SPT. as external standards for correcting mass fractionation and instrumen- Float samples were collected from the Central Palawan granite. tal bias. A 10% cutoff was adopted to reject discordant data. 238U/206Pb Sampling was limited to float samples from riverbeds because of the ages are used for zircons b1000 Ma and the 207Pb/206Pb ages were inaccessibility of the main granite body. Sampling of the Capoas granite used for older zircons. was limited to two of its three bodies: the Bay Peak granite and the Mount Capoas granite. The Binga granite, the smallest of the three 5.2. U–Pb isotopic dating — SHRIMP granite bodies within the Capoas granite, was not sampled. Although sampling of the Capoas granite was limited to a small number of coastal High purity zircon separates were analysed alongside the outcrops, field observations suggest little lithological variation within 417 Ma Temora U–Pb dating standard (Black et al., 2003)andthe the pluton. In outcrop the granite has a consistent composition and tex- SL13 U and Th concentration standard (U = 238 ppm and Th = ture. There is a coarse-grained groundmass of quartz, mica, pink feld- 20 ppm; Claoué-Long et al., 1995). The grains were sectioned and spar and hornblende with large phenocrysts of feldspar (up to 3 cm) polished until exposed through their midsections and Au coated. that display a strong, but variable, preferred orientation. Occasional The internal zonation and structure of single grains were mapped even larger megacrysts display both simple twinning and concentric zo- using cathodoluminescence and reflected light images, allowing nation. It was not possible to sample the Capoas granite over a range of spot analyses to be targeted on grain areas free of cracks and inclu- elevations because of the inaccessibility of the mountain. However, sions. U–Pb analyses were performed following the analytical proce- minimal lithological variation was observed within float boulders on dures outlined by Williams (1998). Data reduction and all age the cobble beach around the base of Mt Capoas. Although not in situ, calculations were achieved using the SQUID 1.03 and Isoplot/Ex the abundance of similar cobbles, likely to be sourced from all elevations 2.29 programmes of Ludwig (2001a,b). Young ages are assumed to of the pluton, suggests little lithological variation. Field observations be concordant, and were determined solely using the 238U/206Pb suggest the Bay Peak granite is different from the Mt Capoas granite. It ratio; common Pb was estimated using the 207Pb. Precambrian crys- has a medium-grained groundmass of quartz, mica, feldspar and horn- tals and cores were corrected for common Pb using the 204Pb/206Pb blende. Feldspar phenocrysts are smaller (up to 1.5 cm) than those ratio, and the age was based on the 206Pb/207Pb ratio. 238U/206Pb seen in the Capoas granite, being only slightly larger than the ground- ages are used for zircons b1000 Ma and the 207Pb/206Pb ages were mass, subhedral and with no apparent preferred orientation. The Bay used for older zircons. Uncertainties in isotopic ratios and ages Peak granite was well exposed in coastal outcrops to the south of Bay (including data tables and error bars for plotted data) are reported Peak itself, as well as occurring as characteristic knolls of large at the 1σ level. Final, weighted mean ages are reported as 95% sub-rounded boulders both within and along the track that leads confidence limits, with the uncertainty in the standard calibrations north over the western flanks of Bay Peak. These sites allowed sampling included. of the Bay Peak granite over a small elevation range. 6. Results 5. Methods 6.1. Heavy minerals and detrital zircon geochronology Heavy minerals were separated from five metasedimentary samples from the NPCT and two sandstones from the SPT following the standard Heavy mineral assemblages were identified for seven samples (Fig. 5 procedure described by Mange and Maurer (1992). Point counting was and Table 1) from the NPCT and the SPT. Five samples were analysed performed on the heavy mineral assemblage using an automated from the NPCT. The Babuyan River Turbidite sample (PAL-5) contains stepping stage. The line point-counting method of Mange and Maurer predominantly colourless euhedral, subhedral and anhedral zircon (1992) was used in this study. At least 200 non-opaque and non- (98.5%), titanite (0.9%), apatite (0.3%), epidote (0.3%), rutile (tr.) and an- micaceous heavy minerals were identified and counted. Different atase (tr.). A few rounded zircons with frosted surfaces are also present. types of zircon, tourmaline and apatite were counted separately. The Tumarbong Semi Schist samples (PAL-19 and PAL-31) contain zir- Opaque, altered, carbonate, mica group and light minerals were con (94.4–100%), amphibole (0–1.6%), clinopyroxene (0–1.2%), epidote recorded, but not included into the total heavy mineral count. Selected (0–0.8%), tourmaline (0–0.8%), chlorite (0–0.4%), garnet (0–0.4%), rutile heavy mineral grains were analysed with a JEOL Scanning Electron (0–0.4%) and traces (1 grain on the slide) of orthopyroxene. Zircon is Microscope (SEM) with the attached energy dispersive system (EDS) predominantly colourless euhedral and subhedral. Some rutile and in order to confirm optical identifications. zircon is surrounded by micaceous matrix. Amphibole is fresh and Zircon separates were separated using standard heavy liquid and is pleochroic in shades of green and brown. The Caramay Schist samples Frantz isodynamic separation techniques. High-purity zircon separates (PAL-21 and PAL-24) contain colourless, euhedral, subhedral, anhedral were handpicked and mounted in epoxy resin. Zircons from three and subrounded zircon (93.7–99.0%), apatite (0–5.1%), chlorite 706 S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718

NPCT Meta-sediments Tumarbong Semi Schist PAL-31 1 Zr 100.0 % Tumarbong Semi tot Zr 41.4 % Schist PAL-19 2 colourless Zr1 34.3 % 12 euhedral

Zrtot 94.4 %

Zr1 27.5 % Zr2 49.4 % colourless subhedral

colourless Zr 9.6 % euhedral Oth

colourless Zr 4.5 % subroundedcolourless 5 subhedral Other 1.6 % Grt 0.4 % Zr 10.1 % Ep 0.8 % 3 Cpx 1.2 % Am 1.6 % ZrOth 7.6 %

Zr6 2 %

Zr5 4.4 %

Zr3 3.6 % Babuyan River Turbidites PAL-5 12

Zrtot 98.5 %

Zr1 25.5 % Zr2 57.9 % Caramay Schist PAL-24 colourless euhedral 1

colourless Other 0.9 % subhedral Ep 0.3 % Ap 0.3 % Zrtot 99.0 % Zr6 2.1 % ZrnOth 0.6 % Zr1 16.8 %

Zr5 9.1 % colourless colourless euhedral Zr 70.1 % subhedral 2 Other 1 % Zr3 2.7 % ZrOth 0.3 %

Zr6 1.7 %

Zr4 0.6 % Zr5 3.7 % Zr 6 % 3 Zr 0.3 % Miocene Sandstones 4 PAL-55 123 Caramay Schist PAL-21 Zrtot 97.4 % Zr 28.9 % 1 1 2

Zr2 44.8 % Zr 93.7 % Zr 27 % colourless tot 1 euhedral Zr 49.2 % colourless Other 1.3 % 2 colourless subhedral Sp 0.3 % euhedral Ep 0.3 % Zr 3.9 % Am 0.6 % colourless Other 0.3 % Oth subhedral Grt 0.3 % Zr 2.9 % Cpx 0.6 % 6 Ap 5.1 % Miocene Sandstones PAL-53 Zr5 12.3 % Zr 4.2 % Zr 1.2 % 3 13 Oth Zr5 10.8 % Zr6 1.2 %

Am 55.6 % Zr3 4.2 % Zrtot 1.7% Zrtot - total zircon Zr4 0.3 % Zr1- colourless, euhedral Zr2- colourless, subhedral Ap 1% amphibole Zr3- colourless, subrounded SPT Sandstones Zr 0.7% Oth Zr4- colourless, rounded Zr 0.3% 5 Zr5- colourless, anhedral Zr2 0.7% Zr6- colourless, elongate Other 2.6% Zr - zircon, other Heavy mineral groups Ky 1.6 % Oth Approx. amount in each sample Grt 1 % Ap - apatite Total = 100% Cpx 2 % Am- amphibole Opx 2.9 % Sp 14.7 % Cpx - clinopyroxene Opx - orthopyroxene granitic/ volcanic ultramafic metamorphic (ophiolitic) Ep 17 % Ep - epidote 1 23 Sp - Cr spinel 2 Grt - garnet St - staurolite Ky - kyanite

Fig. 5. Detrital heavy mineral compositions of sediments from the NPCT and SPT. Other zircons include purple, brown, yellow, zoned with visible overgrowths and surrounded by matrix. Other heavy minerals include titanite, tourmaline, monazite, rutile, clinozoisite and chlorite. Geological map key as for Fig. 4. S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718 707

Table 1 Sample locations and compositions of detrital heavy mineral assemblages analysed from Palawan.

North Palawan Continental Terrane meta-sediments South Palawan Terrane sandstones

Babuyan River Turbidites Tumarbong Semi Schist Caramay Schist Isugod Formation

PAL-5 PAL-19 PAL-31 PAL-21 PAL-24 PAL-53 PAL-55

E118.81523 N10.06044 E119.07534 N10.01709 E119.32183 N10.59063 E119.09926 N10.02111 E119.21148 N10.10088 E118.05455 N9.18894

Zrn 98.5 94.4 100 93.7 75.8 1.7 97.4 Tur 0.8 0.3 Rt tr. 0.4 0.3 Ttn 0.9 tr. Mnz 0.6 Grt 0.4 0.3 1 St Am 1.6 55.6 0.6 Ap 0.3 5.1 1 Cpx 1.2 0.6 2 Opx tr. 2.9 Sp 14.7 0.3 Ep 0.3 0.8 17 0.3 Czo 0.3 tr. An tr. tr. Chl 0.4 0.5 Frg 23.4 Fbr 0.3 tr. Ky 1.6 n 330 251 198 333 389 306 308 Provenance Granitic/metamorphic and volcanic Granitic/metamorphic, group: volcanic and ultramafic (ophiolitic)

Zrn — zircon, Tur — tourmaline, Rt — rutile, Ttn — titanite, Mnz — monazite, Grt — garnet, St — staurolite, Am — amphibole, Ap — apatite, Cpx — clinopyroxene, Opx — orthopyroxene, Sp — Cr spinel, Ep — epidote, Czo — clinozoizite, An — anatase, Chl — chlorite, Frg — polymineral fragments, Fbr — fibrolite (sillimanite, Ky — kyanite). N — total number of heavy minerals counted.

(0–0.7%), clinopyroxene (0–0.6%), garnet (0–0.3%), clinozoisite extensive granophyric intergrowth textures between quartz and feld- (0–0.3%) and possibly fibrolite (0–0.3%). Apatite is euhedral (fresh) spar, which often appear to radiate from a central rounded quartz grains and colourless. Some apatite grains show faint pleochroism from and indicate simultaneous crystallisation of quartz and feldspar. The colourless to light brown. PAL-11 sample shares a similar mineralogy (K-feldspar, plagioclase, Heavy mineral assemblages of the two Miocene sandstones from the quartz and biotite altered to chlorite), but was deformed after SPT (PAL-53 and PAL-55) are very different. PAL-55 is composed of crystallisation. Quartz exhibits undulose extinction, grain boundary mi- zircon (97.4%), amphibole (0.6%), epidote (0.3%) and Cr spinel (0.3%). gration and subgrain development, and the feldspar grains show exten- As in all samples analysed from NPCT, colourless euhedral and subhedral sive micro-fracturing. Plagioclase exhibits deformation twinning. The zircon dominate PAL-55 from the SPT. PAL-53 is composed of amphibole granophyric textures observed in the PAL-8 sample reflect simultaneous (55.6%), epidote (17%) and Cr spinel (14.7%), orthopyroxene (2.9%), crystallisation of quartz and feldspar. These textures were not observed clinopyroxene (2%), zircon (1.7%), kyanite (1.6%), garnet (1%) and apa- in the other sample of this granite (PAL-11), which might indicate that tite (1%). Amphibole is pleochroic in green-brown and blue-green these textures may have been destroyed due to the localized deforma- shades. SEM–EDS analyses show that SPT amphiboles are of actinolite tion observed in this sample. composition. Representative field photographs and heavy mineral The Capoas granite is a fine-grained granodiorite (Fig. 8a–b). The photomicrographs of sediments from the NPCT and SPT are presented samples are predominantly composed of plagioclase, orthoclase, quartz in Fig. 6a–j. and biotite. The feldspars commonly show sericitisation and oscillatory Detrital zircons from the Babuyan River Turbidites and the Caramay zoning. The sample PAL-37 has undergone some alteration and has Schist from the NPCT yield almost identical age populations (Fig. 7). smaller amounts of biotite compared to the other samples. The granodi- There are two Phanerozoic populations: Cretaceous to Jurassic (60 Ma orite underwent some localized post-crystallisation deformation, as to 200 Ma) and a smaller Middle Devonian to Middle Ordovician microfractures and deformation twinning were observed in plagioclase (380 Ma to 460 Ma). A Paleoproterozoic population is prominent in in PAL-37 and some of the biotite grains were kinked in PAL-30. All sam- both samples. Detrital zircons from the Neogene sandstones from the ples showed undulose extinction and subgrain development in quartz SPT contain Cenozoic, Cretaceous, Jurassic, Permo-Triassic, Palaeozoic grains indicating that regional post-crystallisation strain occurred. and Proterozoic zircons. The dominant age populations are Cretaceous The Bay Peak granite is a medium-grained granodiorite (Fig. 8c–d). to Jurassic (60 Ma to 200 Ma). There is a smaller Paleocene to Eocene The samples are composed predominantly of plagioclase, orthoclase, (60 Ma to 40 Ma) age population (Fig. 7). quartz and biotite. PAL-27 contains trace amounts of epidote. Plagio- clase and orthoclase show oscillatory zoning indicating local composi- 6.2. Granite petrography tional changes in the melt during crystallisation (Vernon, 2004). Exsolution lamellae intergrowths are seen in PAL-26 and suggest that Two samples (PAL-8, PAL-11) from the Central Palawan granite have there was some instability during crystallisation and unmixing of the a similar appearance and mineralogy. PAL-8 comprises feldspar, quartz solid solution into two minerals (Vernon, 2004). The granodiorite is and biotite (altered to chlorite), with some minor hornblende. It is effectively undeformed, but undulose extinction of the feldspars and impossible to differentiate between plagioclase and K-feldspar as all of quartz, subgrain development in quartz grains indicates that some the feldspar in this sample is sericitised. This sample also shows post-crystallisation strain occurred (Vernon, 2004). 708 S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718

Fig. 6. Selection of field photographs of outcrops, sediment samples and heavy mineral photomicrographs from the sediments on the NPCT and the SPT. Babuyan River Turbidites (a), titanite (b), Tumurbong Semi Schist (c), amphibole (d), Caramay Schist (e), apatite (f), PAL-53 — SPT Miocene sandstones (g), staurolite (h), PAL-55 — SPT Miocene sandstones (i), Cr spinel (j). Scale bars are 100 μm. S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718 709

Proterozoic naehcrA Cen K J T/P C/D O/S Neo- Meso- Paleo-

Magmatic age 30 rebmunsesylanA 27 n=50 1 3=n 24 Central Palawan 21 etinarg 81 15 12 9 NAWALAPC 6 3 LA-ICPMS 0 0

5

83=n 81=n rebmunsesylanArebmunsesylanArebmunsesylanA 10 4 CAPOAS 9 ehtmorfsnocrizdetirehnI 8 3 yaBdnasaopaCtnuoM 7 setinargkaeP 6 5 2 4 3 2 1 1 SHRIMP 0 0

20 18 49=n 2 6=n 16 TPSenecoiM 14 Sandstones 12 (PAL-55) 10 8 1 6 4 2 LA-ICPMS 0 0 50 45 522=n 2 52=n

40 OENROBNDNATPS 35 enotsdnaSuajaTenecoiMylraE 30 Member alusninePtaduK , 25 oenroBN 20 1 15 10 5 LA-ICPMS 0 0

27

rebmunsesylanArebmunsesylanA 24 10 89=n 12=n 21 9 8 tsihcSyamaraC 18 7 (PAL-21) 15 6 NPCT 12 5 9 4 3 6

2 NPCT 3 1 LA-ICPMS 0 0

20 18 79=n 10 12=n 16 9 setidibruTreviRnayubaB 14 8 (PAL-5) 12 7 NPCT 6 10 5 8 4 6 3 4 2 2 1 LA-ICPMS 0 0 0 100 200 300 400 500 500 1000 1500 2000 2500 3000 3500 4000 AaaM,eg M,egA

Fig. 7. Histograms and probability density curves for all zircons analysed from the NPCT metasediments, the Central Palawan granite, the SPT sandstones, Early Miocene sandstones from northern Borneo (Suggate, 2011) and inherited zircons from the Capoas granite bodies.

The Capoas and Bay Peak granites share a similar granodiorite compo- 6.3. Magmatic ages of granites sition of plagioclase, K-feldspar, quartz and biotite. The only major differ- ence between these is the grain-size, where the Capoas granite samples U–Pb (LA–ICPMS) dating of zircons from the Central Palawan granite are finer grained than the Bay Peak granite. These could therefore repre- (Table 2) yielded Middle Eocene ages (42 ± 0.5 Ma) that are sent one pulse of magmatism that crystallised differently, or two distinct interpreted to represent the magmatic age of the zircons and thus the pulses of similar chemistry with different grain-sizes. crystallisation age of the granite (Fig. 9). 710 S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718

Fig. 8. Representative field photographs of outcrops and thin section photomicrographs (ppl and xpl) of the Mount Capoas (a–b) and the Bay Peak (c–d) granites.

U–Pb SHRIMP dating of zircons from the Mount Capoas granite to common Pb (Fig. 10). These groups define a mean magmatic age of bodies reveal a group of tightly clustered Middle Miocene ages that 13.5 ± 0.2 Ma. One hundred and nineteen spot analyses were made are interpreted to represent zircon magmatic ages and thus the on four samples (PAL-25, PAL-26, PAL-27, PAL-30) from the Bay Peak crystallisation age of the pluton (Fig. 10 and Table 2). There is very little granite body. Ninety-two form a coherent group interpreted as variation between the ages from the Mount Capoas granite bodies, with reflecting the magmatic age (Fig. 11). There is a greater variation in the mean ages plotting within error of each other. Eighty-seven the ages from the Bay Peak granite, but the mean ages still plot within spot analyses were made on four samples (PAL-33, PAL-34, PAL-35, error of each other. There is no correlation between age and elevation. PAL-37) from the Capoas granite body. Fifty-eight form a coherent All of the magmatic ages plot close to the concordia, stretched along group interpreted as the magmatic age (Fig. 11). Fifty-seven of the themixinglinetocommonPb(Fig. 10). These groups define a magmatic ages plot close to concordia, stretched along the mixing line mean magmatic age of 13.8 ± 0.2 Ma. Representative CL images of

Table 2 Sample locations, descriptions and mean magmatic ages of granites from Palawan.

Sample number Longitude (decimal degrees) Latitude (decimal degrees Elevation (m) Lithology Spot analysesa Magmatic analysesb Age (Ma)c Error ± (Ma)d

Zircon SHRIMP ages Mount Capoas Intrusion PAL-33 E 119.301248 N 10.774655 4 Granodiorite 21 18 13.5 0.2 PAL-34 E 119.290950 N 10.769261 4 Granodiorite 25 20 13.5 0.2 PAL-35 E 119.291377 N 10.769329 9 Granodiorite 22 11 13.5 0.2 PAL-37 E 119.309682 N 10.772678 6 Granodiorite 19 9 13.3 0.4 87 58 Mean = 13.5 Mean = 0.25 Bay Peak Intrusion PAL-25 E 119.333292 N 10.652703 32 Granodiorite 41 29 13.8 0.3 PAL-26 E 119.336209 N 10.671705 192 Granodiorite 37 29 14.1 0.2 PAL-27 E 119.333001 N 10.664068 154 Granodiorite 19 17 13.6 0.2 PAL-30 E 119.329835 N 10.654861 1 Granodiorite 22 17 13.8 0.3 119 92 Mean = 13.8 Mean = 0.25

Zircon LA–ICPMS ages Central Palawan Granitic Intrusion PAL-8 E 118.874868 N 10.159678 34.0 Granite 25 14 42.1 1.2 PAL-11 E 118.874868 N 10.159678 34.0 Granite 28 15 42.0 1.3 53 29 Mean = 42.05 Mean = 1.25

a Total number of spot analyses made on sample. b Number of analyses giving magmatic ages. c Mean age of all accepted magmatic analyses. d Errors are 1σ for SHRIMP analyses and 2σ for LA-ICPMS analyses. S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718 711

51

49 Central Palawan Granite PAL-8, PAL-11 Age = 41.96 ± 0.5 Ma 47 (97.3% conf, from coherent group of 21)

45

43 Age

41

39

37

35

Fig. 9. Zircon age extractor diagram (Ludwig, 2001b) showing magmatic zircon LA–ICPMS U–Pb ages for samples from the Central Palawan granite. Green error boxes indicate analyses accepted for calculation of the median age. The blue error-boxes indicate analyses rejected for calculation of the median age. Box heights are 2σ error.

magmatic zircons from the Mount Capoas granite bodies are presented orthopyroxene (0–2.9%) clinopyroxene (0–2%), epidote (0–2.6%), Cr in Fig. 12. spinel (0–2.3%) and minor (b1%) titanite, kyanite, tourmaline, mona- zite, chlorite, garnet, rutile, staurolite, clinozoisite, and fibrolite. The 6.4. Inherited zircons diversity of zircon and apatite morphological types and the presence of different amphibole varieties suggest that these minerals are derived In addition there is a wide range of inherited zircon ages in all the from different sources that are discussed below. granites (Fig. 6). The Central Palawan granite contains a small number Zircon is ubiquitous in crustal igneous, volcanic and metamorphic of zircons with Cretaceous, Jurassic, Palaeozoic and Proterozoic ages. rocks. The abundance of euhedral and subhedral zircon suggests first- The Mount Capoas granite and Bay Peak granite contain inherited zir- cycle provenance from granitic, rhyolitic or metamorphic rocks. Apatite cons with several significant age populations. All are from analyses of is a common accessory mineral in almost all igneous rock types. It also cores. Fifty-six of the 206 spot analyses are ages that are inherited, crystallises in carbonatites, hydrothermal and metamorphic (regional with all except one being greater than twice the magmatic age. and thermal) rocks or may be of authigenic origin (e.g. Deer et al., There are two major peaks, one of Cretaceous and Jurassic ages 1966; Mange and Maurer, 1992). The fresh euhedral morphology and representing 53% of all inherited ages, and a second of Neoproterozoic presence of slightly pleochroic grains suggest that apatite was derived ages representing 18% of all inherited ages. The Bay Peak granite predominantly from volcanic rocks. This is consistent with the associa- (PAL-25) contains the oldest inherited ages. This sample includes tion of apatite and clinopyroxene (augite), which is a common accesso- two zircons with Archaean (2747 ± 26 Ma and 2505 ± 11 Ma) ry of intermediate volcanic rocks (e.g. Mange and Maurer, 1992). cores. One other Archaean (2586 ± 6 Ma) core is present in the Less common, subhedral and subrounded apatite that is present in Capoas granite sample PAL-35. Both granite bodies have yielded a zircon-dominated assemblages was most likely derived from the range of inherited Proterozoic zircon ages. There is a group of five granitic sources. Amphibole is common predominantly in igneous and Paleoproterozoic and Mesoproterozoic zircon ages from 1810 ± metamorphic rocks. The most common amphibole in the SPT is actino- 38 Ma to 1389 ± 28 Ma and a group of ten Neoproterozoic ages lite, which forms in contact and regionally metamorphosed rocks. from 955 ± 9 Ma to 662 ± 7 Ma. There is one Devonian age According to Deer et al. (1966), the tremolite–actinolite association is (396 ± 5 Ma), one Carboniferous age (310 ± 4 Ma) and two Triassic characteristic of low-grade regionally metamorphosed ultramafic ages (247 ± 4 Ma and 230 ± 3 Ma). The largest group is of 30 Juras- rocks, whereas actinolite–epidote–chlorite associations are produced sic and Cretaceous ages (191 ± 4 Ma to 74 ± 1 Ma). The youngest by low-temperature metamorphism of basaltic rocks (Deer et al., inherited ages are Paleocene (64 ± 0.9 Ma), Late Eocene (36 ± 1966). Actinolite from the SPT is found in association with epidote, chlo- 0.5 Ma), Early Oligocene (30 ± 0.4 Ma) and Early Miocene (18 ± rite and Cr spinel, which is an indicator of ultramafic/ophiolitic source 1.7 Ma). Representative CL images of inherited zircons from the rocks (e.g. Mange and Maurer, 1992). Such heavy mineral associations Mount Capoas granite bodies are presented in Fig. 12. suggest that the SPT actinolite was derived from metamorphosed ultra- mafic rocks. Rutile, kyanite, fibrolite (sillimanite), staurolite and 7. Discussion clinozoisite are metamorphic minerals (e.g. Mange and Maurer, 1992). Kyanite and fibrolite indicate a contribution from high-grade metamor- 7.1. Provenance of the NPCT and SPT sediments phic rocks. Garnet may be derived from a variety of source rocks (e.g. Suggate and Hall, 2013), but most commonly is of metamorphic or- The heavy mineral species present in the NPCT and SPT sediments igin. Titanite and monazite are derived either from acid igneous or are zircon (73.5–100%), amphibole (0–55.6%), apatite (0–12.3%), metamorphic rocks (e.g. Mange and Maurer, 1992). 712 S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718

Capoas Granite 0.12 0.12

To common Pb PAL-33 To common Pb PAL-34

0.10 0.10 Pb Pb

206 0.08 206 0.08

Pb/ Pb/ 206 238 206 238 Mean Pb/ U age Mean Pb/ U age: 13.50 ± 0.11 Ma 207 13.42 ± 0.12 Ma 207 MSWD = 1.2, N = 20 MSWD = 0.95, N = 18 0.06 0.06

Data plotted uncorrected for common Pb Data plotted uncorrected for common Pb 4.1

16 15 131 12 11 16 15 14 12 11 0.04 0.04 400 440 480 520 560 600 400 440 480 520 560 600 238Pb/206Pb 238Pb/206Pb

0.12 0.12

To common Pb PAL-35 To common Pb PAL-37

0.10 0.10

0.08 Pb Pb

206 238 206 Mean Pb/ U age: 206 0.08 13.29 ± 0.21 Ma

Pb/ MSWD = 0.58, N = 9 Pb/ Mean 206Pb/238U age: 0.06 207

207 13.52 ± 0.16 Ma MSWD = 1.3, N = 11 0.06 0.04 16 15 14 13 12 11 Data plotted uncorrected for common Pb

Data plotted uncorrected for common Pb 16 15 14 13 12 11 0.04 0.02 400 440 480 520 560 600 400 440 480 520 560 600 238Pb/206Pb 238Pb/206Pb

Bay Peak Granite 0.20 0.08 PAL-25 To common Pb PAL-26 10.1 To common Pb 0.07 0.16 Mean 206Pb/238U age: 13.80 ± 0.12 Ma MSWD = 0.72, N = 29 Mean 206Pb/238U age: 13.81 ± 0.12 Ma Pb Pb 0.06 MSWD = 1.00, N = 29 206 0.12 206 Pb/ Pb/ 0.05 207 207 16 15 13 12 0.08 Data plotted uncorrected for common Pb 0.04

21.1 20 18 12 0.04 0.03 300 340 380 420 460 500 540 400 420 440 460 480 500 520 540 238Pb/206Pb 238Pb/206Pb

0.068 PAL-30 PAL-27 To common Pb Mean 206Pb/238U age: 0.10 13.59 ± 0.13 Ma Data plotted uncorrected for common Pb 0.064 MSWD = 1.3, N = 17

To common Pb 0.060 0.08 Pb

Pb 0.056 Mean 206Pb/238U age: 206 13.82 ± 0.15 Ma 206 MSWD = 1.4, N = 17

0.052 Pb/ Pb/ 207

207 0.048 0.06

14.8 14.4 13.2 12.8 12.4 0.044

Data plotted uncorrected for common Pb 16 15.6 15.2 14.8 14.444 12.8 12.4 0.040 0.04 430 450 470 490 510 400 420 440 460 480 500 520 238Pb/206Pb 238Pb/206Pb

Fig. 10. Tera–Wasserburg concordia diagrams (Tera and Wasserburg, 1972) showing zircon SHRIMP U–Pb analyses for samples from the Mount Capoas (red) and Bay Peak (blue) granites. Data-point error ellipses are 68.3% confidence. Uncertainties are 1σ weighted mean ages and reported as 95% confidence limits. S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718 713

14.8 Mount Capoas Granite Age = 13.50 ± 0.2 Ma Pal 26 Pal 25 Pal 30 14.4

Pal 37 Pal 27 14.0 Pal 33 Pal 34 Pal 35

13.6 Age

13.2 Bay Peak Granite Age = 13.80 ± 0.3 Ma 12.8

12.4

Fig. 11. Zircon age extractor diagrams (Ludwig, 2001b) showing SHRIMP U–Pb ages for magmatic zircon samples from the Mount Capoas and Bay Peak granites. Box heights are 2σ error.

To aid provenance interpretations the dominant heavy mineral Eocene rift-related volcanic and/or minor intrusive rocks of the South assemblages have been have been assigned to different heavy miner- China Sea margin, and the Palawan Ophiolite Complex. The Middle al provenance groups: (1) granitic/metamorphic, (2) volcanic and Eocene (42 Ma) Central Palawan granite is an example of a South (3) ophiolitic/ultramafic. China Sea rift-related intrusion. The NPCT metasediments contain heavy mineral assemblages typical of granitic and metamorphic rocks with a continental crust char- 7.2. Palawan and north Borneo sediments acter, and a subordinate volcanic component. Cretaceous and Jurassic are the dominant zircon age populations. The most likely sources are Lower Miocene sandstones from the Tajau Sandstone Member of the Mesozoic rocks of the South China continental margin (Fig. 13)where Kudat Formation of Sabah have unusual heavy mineral assemblages there are abundant Jurassic and Lower Cretaceous granitic and volcanic compared to other sandstones, both older and younger, from northern rocks and small Triassic plutons (e.g. Zhou et al., 2008; Sun et al., 2012). Borneo (van Hattum, 2005; Suggate, 2011; van Hattum et al., in There are also Upper Cretaceous–Paleogene tholeiitic basalts, andesites press). They were derived predominantly from a granitic and metamor- and trachytes/rhyolites in the Sanshui, Heyuan and Lienping sedimenta- phic source, and contain continental derived accessory minerals that in- ry basins in South China (Chung et al., 1997). All these are potential clude unabraded zircon, tourmaline, rutile, monazite and apatite as well sources for the granitic/metamorphic and volcanic detritus in the as medium- to high-grade metamorphic minerals that include garnet, NPCT sediments which were deposited before the NPCT rifted away epidote, staurolite, sillimanite and kyanite. Heavy mineral assemblages from the South China margin during Oligocene opening of the South and compositions (Suggate, 2011; Suggate and Hall, 2013) indicate China Sea. This interpretation supports previous provenance interpreta- that they were not derived from the same sources as other Borneo sand- tions by Suzuki et al. (2000) and Walia et al. (2012) that the NPCT stones whereas they have many similarities to possible Palawan metasediments were derived from the South China margin, that the sources. Garnet and kyanite in the Tajau Sandstone Member are sug- three units (Caramay Schist, Concepcion Pebbly Phyllite/Tumarbong gested to be derived from high-grade metamorphic rocks exposed Semi Schist and Babuyan River Turbidite) are contemporaneous, and along the contact between the SPT and the NPCT in Ulugan Bay. This that they do not form part of the basement of north Palawan. The suggestion is supported by similar medium- to high-grade metamor- Caramay Schist was originally interpreted to be of Palaeozoic age phic minerals in the Neogene SPT sandstones and the Lower Miocene (Mitchell et al., 1985), and the Concepcion Pebbly Phyllite was sug- Tajau Sandstone Member. Both also contain Cr spinel and clinopyroxene gested to be of probable Palaeozoic but possible Early Cenozoic age derived from an ultrabasic source area, likely to be the Palawan (Mitchell et al., 1985). There were no age data to support these interpre- Ophiolite Complex. tations. The Babuyan River Turbidite was dated as Late Cretaceous based The zircon age populations of the Neogene SPT sandstones and the on the presence of the coccolith Prediscophaera cretacea (Wolfart et al., Lower Miocene Tajau Sandstone Member are also similar. Zircons of 1986). Suzuki et al. (2000) suggested all these units were Cretaceous to Eocene age (36 Ma to 49 Ma) are found in both. Cretaceous zircons Eocene in age. Walia et al. (2012) showed that all these units contain could have a Borneo source since zircons of this age derived from the Cretaceous zircons. The new U–Pb zircon ages from our study (Fig. 13) Schwaner Mountains (van Hattum et al., 2006; Hall et al., 2008; indicate that the maximum depositional age for the NPCT meta- Suggate, 2011; van Hattum et al., in press) dominate the Paleogene sediments is Late Cretaceous and confirms the conclusion of Walia and Neogene sediments. However, the presence of Jurassic zircons in et al. (2012). The zircon ages from the Caramay Schist and the Babuyan the SPT and Kudat Peninsula suggests a non-Borneo source. Jurassic zir- River Turbidite are almost identical and suggest that the two are derived cons are largely absent from Paleogene and Neogene sediments and from a protolith of similar age (Late Cretaceous or younger). Jurassic igneous rocks are not abundant in Borneo, except for one gran- The Miocene sandstones of the SPT have heavy mineral assemblages ite body in the south Schwaner Mountains of SW Kalimantan (Haile that indicate they were derived predominantly from a granitic and et al., 1977; L. Davies, pers. comm., 2012). A significant population of metamorphic source and an ultrabasic (ophiolitic) source, with a Permo-Triassic zircons would be expected in sediments derived from minor volcanic contribution. The zircons in the sandstones (PAL-55) of Borneo, where zircons of this age are abundant in Paleogene sedimenta- the SPT (Fig. 13) are predominantly Cretaceous and Jurassic but include ry rocks (van Hattum et al., 2006). The similarities of heavy mineral Eocene ages. Probable source areas for the Miocene SPT sandstones are assemblages and detrital zircon ages indicate a short-lived episode of the NPCT metasediments, metamorphic rocks at the SPT-NPCT contact, erosion and transport of sediment from Palawan to northern Borneo 714 S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718

Fig. 12. Representative CL images of magmatic and inherited zircons from the Mount Capoas and Bay Peak granites.

in the Early Miocene at about 20 Ma which we interpret to be the result The inherited zircons in the Mount Capoas granite indicate that dur- of collision of the NPCT with the Cagayan Arc. ing magma formation, transport and emplacement the granite sampled continental crust or sediments that had been reworked from older rocks 7.3. Age and crustal inheritance patterns of the Mount Capoas granite that were once part of the South China margin (Fig. 13). Cenozoic inherited zircon ages probably indicate magmatism associated with The new U–Pb ages presented here provide a precise age for rifting of the South China Sea or subduction of the proto-South China the Mount Capoas granite. These new ages broadly confirm earlier Sea. Other inherited zircons are predominantly Cretaceous, Jurassic 207Pb/235U mean ages of 13.4 ± 0.4 Ma on monazite from the Mount and Proterozoic, and the oldest grains are Archaean. The crustal inheri- Capoas granite body by Encarnación and Mukasa (1997) and show tance pattern suggests a number of different sources and gives an in- that the Capoas granite is significantly older (~6.6 myr) than the sight into the NPCT basement. The basement of the NPCT is thought to Mount Kinabalu granite in northern Borneo. The Bay Peak granite is be remnants of the Cathaysian block that rifted away from South slightly older (0.3 myr) than the Mount Capoas granite suggesting ei- China in the Cenozoic. A belt of granitic and metamorphic rocks of Pro- ther a single magmatic pulse between 13.8 Ma and 13.5 Ma, or two terozoic, Jurassic and Cretaceous age is known from SE China (Yui et al., pulses that lasted no more than 300 ka. 1996; Li et al., 2007; He et al., 2010; Zhu et al., 2010; Jiang et al., 2011). S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718 715

PHAN- PROTEROZOIC ARCHEAN EROZOIC NEO- MESO- PALEO- NEO- MESO- PALEO- EO-

24 CAPOAS Inherited zircons Capoas granite

n= 56

50

Neogene Sandstones SPT AND N BORNEO PAL 55

n= 100

140 Tajau Sandstone Mbr Kudat Formation

n= 250

70 Caramay Schist PAL−21 NPCT n= 119

70 Babuyan River Turbidites

Number of analyses PAL-5

n= 118

220 Plutonic Protolith

n= 608

24 SOUTH CHINA MARGIN

Volcanic Protolith

n= 109

130

Metamorphic Protolith

n= 820

190

Detrital Protolith

n= 1133

0 1000 2000 3000 4000 Age, Ma

Fig. 13. Schematic probability density curves that show zircon populations common in the Capoas granite bodies (inherited zircons), the SPT and northern Borneo, the NPCT and zircon ages that are expected to occur in rocks derived from the South China margin (probability density curves based on data from Duan et al. (2011), Gao et al. (2011), He et al. (2010), Jiang et al. (2011), Knittel (2011), Knittel et al. (2010), Li et al. (2005), Li et al. (2007), Li et al. (2009), Li et al. (2011), Liu et al. (2009), Shu et al. (2011), Wan et al. (2007), Wang et al. (2007), Wong et al. (2011), Xu et al. (2005), Yao et al. (2012), Ye et al. (2007), Yui et al. (1996), Yui et al. (2012), Zhang et al. (2006), Zheng et al. (2006),andZhu et al. (2010)). 716 S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718

The source of the small number of Archaean zircons is uncertain. There Appendix A. Supplementary data is no record of exposed Archaean basement rocks in South China but zir- con xenocrysts in Cenozoic and Mesozoic volcanic and plutonic rocks in Supplementary data to this article can be found online at http://dx. South China (Fletcher et al., 2004; Zheng et al., 2011)suggestthepres- doi.org/10.1016/j.gr.2013.07.006. ence of unexposed Archaean basement beneath the western Cathaysia Block, where the oldest exposed rocks are Neoproterozoic in age References (Fletcher et al., 2004; Zheng et al., 2011). This basement has yielded zircons with age populations of 2900–2500 Ma (Zheng et al., 2011). Al- Almasco, J.N., Rodolfo, K., Fuller, M., Frost, G., 2000. Paleomagnetism of Palawan, ternatively, the Archaean zircons could be reworked from a protolith Philippines. Journal of Asian Earth Sciences 18, 369–389. further to the north in the North China Craton (Jahn et al., 1987; Liu Andò, S., Garzanti, E., Padoan, M., Limonta, M., 2012. Corrosion of heavy minerals during weathering and diagenesis: a catalog for optical analysis. Sedimentary Geology 280, et al., 1992) where Archaean rocks are widespread. 165–178. Encarnación and Mukasa (1997) suggested that the Mount Capoas Barckhausen, U., Roeser, H.A., 2004. Seafloor spreading anomalies in the South China Sea – granite formed in a post-rifting, non-collisional tectonic setting revisited. In: Clift, P., Wang, P., Kuhnt, W., Hayes, D.E. (Eds.), Continent Ocean Interactions within the East Asian Marginal Seas. American Geophysical Union unrelated to any subduction zone. The age of the granite indicates that Geophysical Monograph, 149, pp. 121–125. it cannot be related to proto-South China Sea subduction which was ter- Bellon, H., Rangin, C., 1991. Geochemistry and isotopic dating of the Cenozoic volcanic arc minated by Early Miocene collision, and it post-dates collision by about sequences around the Celebes and Sulu seas. In: Silver, E.A., Rangin, C., von Breymann, M.T., et al. (Eds.), Proceedings of the Ocean Drilling Program Scientific 6 myr. An alternative is magmatism associated with the early stages of Results, 124, pp. 321–338. development of the Sulu Arc associated with northwestward subduc- Black, L.P., Kamo, S.L., Allen, C.M., Aleinikoff, J.N., Davis, D.W., Korsch, R.J., Foudoulis, C., tion of the Celebes Sea (Hall, in press). Collision in the Early Miocene 2003. TEMORA 1: a new zircon standard for Phanerozoic U–Pb geochronology. Chemical Geology 200, 155–170. caused folding and thrusting on Palawan (e.g. Holloway, 1982; Briais, A., Patriat, P., Tapponnier, P., 1993. Updated interpretation of magnetic anomalies Hutchison, 1996). This elevated much of the region around Palawan and sea floor spreading stages in the South China Sea: implications for the Tertiary above sea level and sediment from the orogenic belt was transported tectonics of Southeast Asia. Journal of Geophysical Research 98, 6299–6328. Chung, S.-L., Cheng, H., Jahn, B.-M., O'Reilly, S.Y., Zhu, B., 1997. Major and trace element, south to the Kudat Formation of northern Sabah. South of Palawan and Sr–Nd isotope constraints on the origin of Paleogene volcanism in South China and east of northern Sabah ODP drilling shows that the oldest rocks in prior to the South China Sea opening. Lithos 40, 203–220. the Sulu Sea were erupted in a backarc basin oceanic before 19 Ma, Claoué-Long, J.C., Compston, W., Roberts, J., Fanning, C.M., 1995. Two Carboniferous ages: 40 39 but are overlain by rocks of a volcanic arc that emerged rapidly above a comparison of SHRIMP zircon dating with conventional zircon ages and Ar/ Ar analysis. In: Geochronology Time Scales and Global Stratigraphic Correlation. SEPM sea level and then subsided below the CCD by about 15–14 Ma (Silver Special Publication, 54, pp. 3–21. and Rangin, 1991; Silver et al., 1991). This implies an interval of rapid Clements, B., Hall, R., 2011. A record of continental collision and regional sediment flux for migration of the active Sulu arc to the southeast (Hutchison, 1992), the Cretaceous and Palaeogene core of SE Asia: implications for early Cenozoic palaeogeography. Journal of the Geological Society 168, 1187–1200. collapse of the volcanic arc, and extension of the former orogenic belt Cottam, M.A., Hall, R., Sperber, C., Armstrong, R., 2010. Pulsed emplacement of the Mount of Palawan. Hall (in press) suggested that trench rollback at about Kinabalu granite, North Borneo. Journal of the Geological Society of London 167, 16 Ma drove Neogene extension in Palawan, and was accompanied by 49–60. Deer, W.A., Howie, R.A., Zussman, J., 1966. An Introduction to the Rock Forming Minerals. crustal melting. The syn-collisional and volcanic arc character of the Longmans, London. granite is interpreted to not reflect the tectonic setting of magmatism Duan, L., Meng, Q.-R., Zhang, C.-L., Liu, X.-M., 2011. Tracing the position of the South China but the compositions of the source rocks that were melted (Frost block in Gondwana: U–Pb ages and Hf isotopes of Devonian detrital zircons. Gondwana Research 19, 141–149. et al., 2001). Encarnación, J., Mukasa, S.B., 1997. Age and geochemistry of an “anorogenic” crustal melt and implications for I-type granite petrogenesis. Lithos 42, 1–13. Encarnación, J.P., Essene, E.J., Mukasa, S.B., Hall, C.H., 1995. High pressure and temperature 8. Conclusions subophiolitic kyanite–garnet amphibolites generated during initiation of mid tertiary subduction, Palawan, Philippines. Journal of Petrology 36, 1481–1503. NPCT metasediments are no older than Late Cretaceous, they were Faure, M., Marchadier, Y., Rangin, C., 1989. Pre-Eocene synmetamorphic structure in the Mindoro–Romblon–Palawan area, West Philippines, and implications for the history formed on the South China margin and were derived from granitic of Southeast Asia. Tectonics 8, 963–979. and metamorphic rocks, all of which rifted away during opening of Fletcher, C.J.N., Chan, L.S., Sewell, R.J., Campbell, S.D.G., Davis, D.W., Zhu, J., 2004. Basement the South China Sea. The Miocene SPT sandstones and Lower Miocene heterogeneity in the Cathaysia crustal block, southeast China. In: Malpas, J., Fletcher, C.J.N., Ali, J.R., Aitchison, J.C. (Eds.), Aspects of the Tectonic Evolution of China. Geological Tajau Sandstone Member of northern Borneo were derived from four Society, London, Special Publications, 226, pp. 145–155. different sources, which include the NPCT metasediments, metamor- Franke, D., Barckhausen, U., Baristeas, N., Engels, M., Ladage, S., Lutz, R., Montano, J., – phic basement rocks at the contact between the SPT and NPCT, South Pellejera, N., Ramos, E.G., Schnabel, M., 2011. The continent ocean transition at the southeastern margin of the South China Sea. Marine and Petroleum Geology 28, China Sea rift volcanic and/or minor intrusive rocks, of which the Middle 1187–1204. Eocene (42 ± 0.5 Ma) Central Palawan granite is an example, and the Frost, B.R., Barnes, C.G., Collins, W.J., Arculus, R.J., Ellis, D.J., Frost, C.D., 2001. A geochemical local ophiolite complex. classification for granitic rocks. Journal of Petrology 42, 2033–2048. Fuller, M., Haston, R., Jin-lu Lin, R.B., Schmidtke, E., Almasco, J., 1991. Tertiary paleomag- The Mount Capoas granite body was intruded during a single pulse netism of regions around the South China Sea. Journal of Southeast Asian Earth that endured for c.300 ka or as two separate pulses between 13.8 ± Sciences 6, 161–184. 0.2 Ma (Bay Peak granite) and 13.5 ± 0.2 Ma (Mount Capoas granite). Gao, S., Yang, J., Zhou, L., Li, M., Hu, Z., Guo, J., Yuan, H., Gong, H., Xiao, G., Wei, J., 2011. Age fi and growth of the Archean Kongling terrain, South China, with emphasis on 3.3 Ga It is signi cantly older than the Kinabalu granite of northern Borneo. granitoid gneisses. American Journal of Science 311, 153–182. However, like the Kinabalu granite, inherited zircon ages from the Garzanti, E., Ando, S., 2007. Plate tectonics and heavy mineral suites of modern sands. In: Mount Capoas granite imply melting of continental crust derived from Mange, M.A., Wright, D.T. (Eds.), Developments in Sedimentology 58. Elsevier, – the South China margin with a contribution from Cenozoic rift-related Amsterdam, pp. 741 763. Garzanti, E., Andó, S., France-Lanord, C., Censi, P., Vignola, P., Galy, V., Lupker, M., 2011. and arc material. Melting is suggested to have occurred in an extension- Mineralogical and chemical variability of fluvial sediments 2. Suspended-load al setting induced by subduction rollback. silt (Ganga–Brahmaputra, Bangladesh). Earth and Planetary Science Letters 302, 107–120. Griffin, W.L., Powell, W.J., Pearson, N.J., O'Reilly, S.Y., 2008. Glitter: data reduction software – Acknowledgements of laser ablation ICPMS MS. In: Sylvester, P. (Ed.), Mineralogical Association of Canada Short Course Series, 40, pp. 204–207. Haile, N.S., McElhinny, M.W., McDougall, I., 1977. Palaeomagnetic data and radiometric ages The project was funded by the SE Asia Research Group at Royal from the Cretaceous of West Kalimantan (Borneo), and their significance in interpreting Holloway University of London, supported by an oil company consor- regional structure. Journal of the Geological Society of London 133, 133–144. Hall, R., 1996. Reconstructing Cenozoic SE Asia. In: Hall, R., Blundell, D.J. (Eds.), Tectonic tium. We thank Roland de Jesus at the Mines and Geosciences Bureau evolution of SE Asia. Geological Society of London Special Publication, 106, pp. (MGB) for the permission to conduct fieldwork in Palawan. 153–184. S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718 717

Hall, R., 2002. Cenozoic geological and plate tectonic evolution of SE Asia and the SW Mange, M.A., Dewey, J.F., Floyd, J.D., 2005. The origin, evolution and provenance of the Pacific: computer-based reconstructions, model and animations. Journal of Asian Northern Belt (Ordovician) of the Southern Uplands Terrane, Scotland: a heavy Earth Sciences 20, 353–434. mineral perspective. Proceedings of the Geologists' Association 116, 251–280. Hall, R., 2012. Late Jurassic–Cenozoic reconstructions of the Indonesian region and the Mines and Geoscience Bureau, 2011. Geological Map of Northern Palawan. Indian Ocean. Tectonophysics 570–571, 1–41. Mitchell, A.H.G., Estacio, R., Flores, R., Lazo, E., Salvado, H., Santiago, A., 1985. Geology of Hall, R., 2013. Contraction and extension in Northern Borneo driven by subduction rollback. Central Palawan: United Nations-Bureau of Mines and Geosciences, Internal Techni- Journal of Asian Earth Sciences. http://dx.doi.org/10.1016/j.jseaes.2013.04.010 (in cal Report, p. 6 (45 pp.). press). Mitchell, A.H.G., Hernandez, F., dela Cruz, A.P., 1986. Cenozoic evolution of the Philippine Hall, R., Wilson, M.E.J., 2000. Neogene sutures in eastern Indonesia. Journal of Asian Earth archipelago. Journal of Southeast Asian Earth Sciences 1, 3–22. Sciences 18, 787–814. Morton, A.C., Hallsworth, C., 2007. Stability of detrital heavy minerals during burial Hall, R., van Hattum, M.W.A., Spakman, W., 2008. Impact of India–Asia collision on SE diagenesis. In: Mange, M.A., Wright, D.T. (Eds.), Developments in Sedimentology, Asia: the record in Borneo. Tectonophysics 451, 366–389. 58. Elsevier, Amsterdam, pp. 215–245. Hamilton, W., 1979. Tectonics of the Indonesian region. USGS Professional Paper, p. 1078 Morton, A.C., Humphreys, B., Dharmayanti, D.A., Sundoro, 1994. Palaeogeographic impli- (345 pp.). cations of the heavy mineral distribution in Miocene sandstones of the North Suma- Hashimoto, W., Sato, T., 1973. Geological structure of North Palawan, and its bearing on tra Basin. Journal of Southeast Asian Earth Sciences 10, 177–190. the Geological History of the Philippines. In: Kobayashi, T., Toriyama, R. (Eds.), Müller, C., 1991. Biostratigraphy and geological evolution of the Sulu Sea and surrounding Geology and Paleontology of SE Asia, pp. 145–161. area. In: Silver, E.A., Rangin, C., von Breymamr, M.T., et al. (Eds.), Proceedings of the He,Z.-Y.,Xu,X.-S.,Niu,Y.,2010.Petrogenesis and tectonic significance of a Mesozoic Ocean Drilling Program Scientific Results, College Station, TX (Ocean Drilling Pro- granite–syenite–gabbro association from inland South China. Lithos 119, gram) 124, pp. 121–131. 621–641. Pearce, J.A., Harris, N.B.W., Tindle, A.G., 1984. Trace element discrimination diagrams for Hinz, K., Block, M., Kudrass, H.R., Meyer, H., 1991. Structural elements of the Sulu Sea, the tectonic interpretation of granitic rocks. Journal of Petrology 25, 956–983. Philippines. Geologisches Jahrbuch, Reihe A 127, 483–506. Pearce, J.G.N., Perkins, T.W., Westgate, A.J., Gorton, P.M., Jackson, E.S., Neal, R.C., Chenery, Holloway, N.H., 1982. North Palawan block — its relation to Asian mainland and role in P.S., 1997. A compilation of new and published major and trace element data for NIST evolution of South China Sea. American Association of Petroleum Geologists Bulletin SRM 610 and NIST SRM 612 glass reference materials. Geostandards and 66, 1355–1383. Geoanalytical Research 21, 115–144. Hutchison, C.S., 1992. The Southeast Sulu Sea, a Neogene marginal basin with outcropping Rangin, C., Jolivet, L., Pubellier, M., 1990. A simple model for the tectonic evolution extensions in Sabah. Bulletin of the Geological Society of Malaysia 32, 89–108. of southeast Asia and Indonesia region for the past 43 m.y. Bulletin de la Société Hutchison, C.S., 1996. The ‘Rajang Accretionary Prism’ and ‘Lupar Line’ problem of Borneo. Géologique de France 8, 889–905. In: Hall, R., Blundell, D.J. (Eds.), Tectonic evolution of SE Asia. Geological Society of Raschka, H., Nacario, E., Rammelmair, D., Samonte, C., Steiner, L., 1985. Geology of the London Special Publication, pp. 247–261. ophiolite of central Palawan Island, Philippines. Ofioliti 10, 375–390. Hutchison, C.S., 2010. The North-West Borneo Trough. Marine Geology 271, 32–43. Replumaz, A., Tapponnier, P., 2003. Reconstruction of the deformed collision zone Hutchison, C.S., Bergman, S.C., Swauger, D.A., Graves, J.E., 2000. A Miocene collisional belt between India and Asia by backward motion of lithospheric blocks. Journal of in north Borneo: uplift mechanism and isostatic adjustment quantified by Geophysical Research 108, 2285. http://dx.doi.org/10.1029/2001JB000661. thermochronology. Journal of the Geological Society 157, 783–793. Sales, A.O., Jacobsen, E.C., Morado Jr., A.A., Benavidez, J.J., Navarro, F.A., Lim, A.E., 1997. The Ireland, T., Williams, I., 2003. Considerations in zircon geochronology by SIMS. Zircon. petroleum potential of deepwater northwest Palawan block GSEC 66. Journal of Asian Mineralogical Society of America, Washington, pp. 215–241. Earth Sciences 15, 217–240. Ireland, T.R., Clement, S., Compston, W., Foster, J.J., Holder, P., Jenkins, B., Lanc, P., Schram, Sarewitz, D.R., Karig, D.E., 1986. Geologic evolution of Western Mindoro Island and the N., Williams, I.S., 2008. Development of SHRIMP. Australian Journal of Earth Sciences Mindoro suture zone, Philippines. Journal of Southeast Asian Earth Sciences 1, 55, 937–954. 117–141. Jacobson, G., 1970. Gunung Kinabalu area, Sabah. Geological Survey of Malaysia, Report, p. Schluter, H.U., Hinz, K., Block, M., 1996. Tectono-stratigraphic terranes and detachment 8(111pp.). faulting of the South China Sea and Sulu Sea. Marine Geology 130, 39–78. Jahn, B.M., Auvray, B., Cornichet, J., Bai, Y.L., Shen, Q.H., Liu, D.Y., 1987. 3.5 Ga old amphib- Sevastjanova, I., Hall, R., Alderton, D., 2012. A detrital heavy mineral viewpoint on olites from eastern Hebei Province, China: field occurrence, petrography, Sm–Nd sediment provenance and tropical weathering in SE Asia. Sedimentary Geology isochron age and REE geochemistry. Precambrian Research 34, 311–346. 280, 179–194. Jiang, Y.-H., Zhao, P., Zhou, Q., Liao, S.-Y., Jin, G.-D., 2011. Petrogenesis and tectonic impli- Shu, L.-S., Faure, M., Yu, J.-H., Jahn, B.-M., 2011. Geochronological and geochemical fea- cations of Early Cretaceous S- and A-type granites in the northwest of the Gan-Hang tures of the Cathaysia block (South China): new evidence for the Neoproterozoic rift, SE China. Lithos 121, 55–73. breakup of Rodinia. Precambrian Research 187, 263–276. Knittel, U., 2011. 83 Ma rhyolite from Mindoro — evidence for Late Yanshanian Silver, E.A., Rangin, C., 1991. Leg 124 tectonic synthesis. In: Silver, E.A., Rangin, C., von magmatism in the Palawan Continental Terrane (Philippines). Island Arc 20, 138–146. Breymann, M.T., et al. (Eds.), Proceedings of the Ocean Drilling Program. Scientific Knittel, U., Daniels, U., 1987. Sr-isotopic composition of marbles from Puerto Galera area Results, 124, pp. 3–9. (Mindoro, Philippines): additional evidence for a Palaeozoic age of a metamorphic Silver, E.A., Rangin, C., von Breymann, M.T., et al., 1991. Proceedings of the Ocean Drilling complex in the Philippine island arc. Geology 15, 136–138. Program. ScientificResults124. Knittel, U., Hung, C.-H., Yang, T.F., Iizuka, Y., 2010. Permian arc magmatism in Mindoro, Sláma, J., Kosler, J., Condon, D.J., Crowley, J.L., Gerdes, A., Hanchar, J.M., Horstwood, M.S.A., the Philippines: an early Indosinian event in the Palawan Continental Terrane. Morris, G.A., Nasdala, L., Norberg, N., Schaltegger, U., Schoene, B., Tubrett, M.N., Tectonophysics 493, 113–117. Whitehouse, M.J., 2008. Plesovice zircon — a new natural reference material for Kudrass, H.R., Wiedicke, M., Cepek, P., Kreuzer, H., Müller, P., 1986. Mesozoic and U–Pb and Hf isotopic microanalysis. Chemical Geology 249, 1–35. Cainozoic rocks dredged from the South China Sea (Reed Bank area) and Sulu Sea Suggate, S., 2011. Provenance of Neogene Sandstones of Sabah, northern Borneo. (PhD and their significance for plate–tectonic reconstructions. Marine and Petroleum Geol- Thesis) Royal Holloway University of London (441 pp.). ogy 3, 19–30. Suggate, S., Hall, R., 2013. Using detrital garnet compositions to determine provenance: a Li,W.-X.,Li,X.-H.,Li,Z.-X.,2005.Neoproterozoic bimodal magmatism in the new compositional database and procedure. In: Scott, R., Smyth, H.S., Morton, A.S., Cathaysia Block of South China and its tectonic significance. Precambrian Re- Richardson, N. (Eds.), Sediment provenance studies in hydrocarbon exploration and search 136, 51–66. production. Geological Society of London Special Publication 386. http://dx.doi.org/ Li, X.-H., Li, Z.-X., Li, W.-X., Liu, Y., Yuan, C., Wei, G., Qi, C., 2007. U–Pb zircon, geochemical 10.1144/SP386.8. and Sr‚Nd‚ Hf isotopic constraints on age and origin of Jurassic I- and A-type granites Sun, W.-D., Yang, X.-Y., Fan, W.-M., Wu, F.-Y., 2012. Mesozoic large scale magmatism and from central Guangdong, SE China: a major igneous event in response to foundering mineralization in South China: preface. Lithos 150, 1–5. of a subducted flat-slab? Lithos 96, 186–204. Suzuki, S., Takemura, S., Yumul, G.P., David, S.D., Asiedu, D.K., 2000. Composition and prov- Li, X.-H., Li, W.-X., Li, Z.-X., Lo, C.-H., Wang, J., Ye, M.-F., Yang, Y.-H., 2009. Amalgamation enance of the Upper Cretaceous to Eocene sandstones in Central Palawan, Philippines: between the Yangtze and Cathaysia Blocks in South China: constraints from constraints on the tectonic development of Palawan. Island Arc 9, 611–626. SHRIMP U–Pb zircon ages, geochemistry and Nd–Hf isotopes of the Shuangxiwu Swauger, D.A., Bergman, S.C., Marillo, A.P., Pagado, E.S., Surat, T., 1995. Tertiary stratigra- volcanic rocks. Precambrian Research 174, 117–128. phy and tectonic framework of Sabah, Malaysia: a field and laboratory study. GEOSEA Li, L.-M., Sun, M., Wang, Y., Xing, G., Zhao, G., Lin, S., Xia, X., Chan, L., Zhang, F., Wong, J., 95: 8th Regional Conference on Geology, Minerals, and Energy Resources of SE Asia, 2011. U–Pb and Hf isotopic study of zircons from migmatised amphibolites in the Manila, pp. 35–36. Cathaysia Block: implications for the early Paleozoic peak tectonothermal event in Tan, D.N.K., Lamy, J.M., 1990. Tectonic evolution of the NW Sabah continental margin Southeastern China. Gondwana Research 19, 191–201. since the Late Eocene. Bulletin of the Geological Society of Malaysia 27, 241–260. Liu, D.Y., Nutman, A.P., Compston, W., Wu, J.S., Shen, Q.H., 1992. Remnants of N3800 Ma Taylor, B., Hayes, D.E., 1983. Origin and history of the South China Sea Basin. In: Hayes, crust in the Chinese part of the Sino-Korean craton. Geology 20, 339–342. D.E. (Ed.), The tectonic and geologic evolution of Southeast Asian seas and islands, Liu, R., Zhou, H., Zhang, L., Zhong, Z., Zeng, W., Xiang, H., Jin, S., Lu, X., Li, C., 2009. Part 2 27. American Geophysical Union, Geophysical Monographs Series, pp. 23–56. Paleoproterozoic reworking of ancient crust in the Cathaysia Block, South China: ev- Tera, F., Wasserburg, G.J., 1972. U-Th-Pb systematics in three Apollo 14 basalts and the idence from zircon trace elements, U–Pb and Lu–Hf isotopes. Chinese Science Bulletin problem of initial Pb in lunar rocks. Earth Planetary Science Letters 17, 281–304. 54, 1543–1554. van Hattum, M.W.A., 2005. Provenance of Cenozoic Sedimentary Rocks of Northern Ludwig, K.L., 2001a. Squid v1.02, a user manual. Berkeley Geochronological Center Borneo. (PhD Thesis) University of London (457 pp.). Special, Publication, 2. vanHattum,M.W.A.,Hall,R.,Pickard,A.L.,Nichols,G.J.,2006.SE Asian sediments not from Ludwig, K.L., 2001b. Using Isoplot/EX, v2.49, a geochronological toolkit for Microsoft Asia: provenance and geochronology of North Borneo sandstones. Geology 34, 589–592. Excel. Berkeley Geochronological Center Special Publication, 1a. van Hattum, M.W.A., Hall, R., Pickard, A.L., Nichols, G.J., 2013. Provenance and geochronol- Mange, M.A., Maurer, H.F.W., 1992. Heavy Minerals in Colour. Chapman & Hall, London ogy of Cenozoic sandstones of northern Borneo. Journal of Asian Earth Sciences. (147 pp.). http://dx.doi.org/10.1016/j.jseaes.2013.02.033 (in press). 718 S.M. Suggate et al. / Gondwana Research 26 (2014) 699–718

Vernon, Ron H., 2004. A Practical Guide to Rock Microstructure. Cambridge University Yao, J., Shu, L., Santosh, M., Li, J., 2012. Precambrian crustal evolution of the South China Press (594 pp.). Block and its relation to supercontinent history: constraints from U–Pb ages, Lu–Hf Vogt, E., Flower, M.J., 1989. Genesis of the Kinabalu (Sabah) granitoid at a subduction– isotopes and REE geochemistry of zircons from sandstones and granodiorite. Precam- collision junction. Contributions to Mineralogy and Petrology 103, 493–509. brian Research 208–211, 19–48. Walia, M., Knittel, U., Suzuki, S., Chung, S.-L., Pena, R.E., Yang, T.F., 2012. No Paleozoic Ye, M.-F., Li, X.-H., Li, W.-X., Liu, Y., Li, Z.-X., 2007. SHRIMP zircon U–Pb geochronological and metamorphics in Palawan (the Philippines)? Evidence from single grain U–Pb dating whole-rock geochemical evidence for an early Neoproterozoic Sibaoan magmatic arc of detrital zircons. Journal of Asian Earth Sciences 52, 134–145. along the southeastern margin of the Yangtze Block. Gondwana Research 12, 144–156. Wan, Y., Liu, D., Xu, M., Zhuang, J., Song, B., Shi, Y., Du, L., 2007. SHRIMP U–Pb zircon Yui, T.F., Heaman, L., Lan, C.Y., 1996. U–Pb and Sr isotopic studies on granitoids from geochronology and geochemistry of metavolcanic and metasedimentary rocks in Taiwan and Chinmen-Lieyu and tectonic implications. Tectonophysics 263, 61–76. Northwestern Fujian, Cathaysia block, China: tectonic implications and the need to Yui,T.F.,Maki,K.,Lan,C.Y.,Hirata,T.,Chu,H.T.,Kon,Y.,Yokoyama,T.D.,Jahn,B.M.,Ernst,W.G., redefine lithostratigraphic units. Gondwana Research 12, 166–183. 2012. Detrital zircons from the Tananao metamorphic complex of Taiwan: implications Wang, Y., Fan, W., Zhao, G., Ji, S., Peng, T., 2007. Zircon U–Pb geochronology of gneissic for sediment provenance and Mesozoic tectonics. Tectonophysics 541–543, 31–42. rocks in the Yunkai massif and its implications on the Caledonian event in the Yumul Jr., G.P., Dimalanta, C.B., Marquez, E.J., Queano, K.L., 2009. Onland signatures of the South China Block. Gondwana Research 12, 404–416. Palawan microcontinental block and the Philippine mobile belt collision and crustal Williams, I.S., 1998. U–Th–Pb geochronology by ion microprobe. In: McKibben, M.A., growth process: a review. Journal of Asian Earth Sciences 34, 610–623. Shanks, W.C.I., Ridley, W.I. (Eds.), Applications of microanalytical techniques to Zhang, S.-B., Zheng, Y.-F., Wu, Y.-B., Zhao, Z.-F., Gao, S., Wu, F.-Y., 2006. Zircon U–Pb age and understanding mineralizing processes. Reviews in Economic Geology, 7, pp. 1–35. Hf isotope evidence for 3.8 Ga crustal remnant and episodic reworking of Archean Witts, D., Hall, R., Nichols, G., Morley, R., 2012. A new depositional and provenance model crust in South China. Earth and Planetary Science Letters 252, 56–71. for the Tanjung Formation, Barito Basin, SE Kalimantan, Indonesia. Journal of Asian Zheng, J., Griffin, W.L., O'Reilly, S.Y., Zhang, M., Pearson, N., Pan, Y., 2006. Widespread Earth Sciences 56, 77–104. Archean basement beneath the Yangtze craton. Geology 34, 417–420. Wolfart, R., Cepek, P., Gramann, F., Kemper, E., Porth, H., 1986. Stratigraphy of Palawan Zheng, J.P., Griffin, W.L., Li, L.S., O'Reilly, S.Y., Pearson, N.J., Tang, H.Y., Liu, G.L., Zhao, J.H., Island, Philippines. Newsletters on Stratigraphy 16, 19–48. Yu, C.M., Su, Y.P., 2011. Highly evolved Archean basement beneath the western Wong,J.,Sun,M.,Xing,G.,Li,X.-h,Zhao,G.,Wong,K.,Wu,F.,2011.Zircon U–Pb and Cathaysia Block, South China. Geochimica et Cosmochimica Acta 75, 242–255. Hf isotopic study of Mesozoic felsic rocks from eastern Zhejiang, South China: Zhou, X., Sun, T., Shen, W., Shu, L., Niu, Y., 2008. Petrogenesis of Mesozoic granitoids and geochemical contrast between the Yangtze and Cathaysia blocks. Gondwana volcanic rocks in South China: a response to tectonic evolution. Episodes 29, 26–33. Research 19, 244–259. Zhu, W.-G., Zhong, H., Li, X.-H., He, D.-F., Song, X.-Y., Ren, T., Chen, Z.-Q., Sun, H.-S., Liao, Xu, X., O'Reilly, S.Y., Griffin, W.L., Deng, P., Pearson, N.J., 2005. Relict Proterozoic basement J.-Q., 2010. The early Jurassic mafic–ultramafic intrusion and A-type granite from in the Nanling Mountains (SE China) and its tectonothermal overprinting. Tectonics northeastern Guangdong, SE China: age, origin, and tectonic significance. Lithos 24. http://dx.doi.org/10.1029/2004TC001652. 119, 313–329.