Tertiary palaeogeography of Sulawesi and Borneo 133 Biogeographic implications of the Tertiary palaeogeographic evolution of Sulawesi and Borneo

Steve J Moss1 and Moyra E J Wilson SE Asia Research Group, Department of Geology, Royal Holloway University of London, Egham, Surrey, TW0 0EX, UK& Email moyra@gl&rhbnc&ac&uk 1Now at School of Applied Geology, Curtin University of Technology, Perth, 6845, W&A& Australia& Email steve@lithos&curtin&edu&au

Key words: Wallacea, Wallace's Line, plants, animals, land, sea, maps

Abstract divide, originally thought to delineate regions of Asiatic and Australian flora and fauna, runs be- Sulawesi and Borneo are located in a critical position for tween the islands of Bali and Lombok and north biogeography, bordering Wallace’s faunal divide and in the through the Makassar Straits, which separate the middle of the Indonesian archipelago, an extremely active islands of Borneo and Sulawesi (Fig 1; George, tectonic area throughout the Tertiary Wallace’s original line now marks the western boundary of Wallacea: a biogeo- 1981) This faunal divide is now taken as the graphic zone with a high degree of species endemism be- western boundary of Wallacea (Dickerson, tween areas with Asiatic and Australian flora and fauna 1928), a ‘transitional’ area between Asiatic and Tectonic controls have strongly influenced the distribution Australian biotas (Whitten et al&, 1987) Wallacea of depositional environments and hence the past and present distribution of terrestrial and shallow marine biota includes Sulawesi, the Moluccas and the Lesser Palaeogeographic maps presented, using plate tectonic Sunda islands as well as an extensive area of reconstructions as a base, illustrate the evolution of the area shallow sea, and its eastern margin is taken as and highlight important features for palaeobiogeography Lydekker’s line; the western boundary of the The Tertiary geological history of eastern Kalimantan and strictly Australian fauna (Fig 1) The transitional Sulawesi is inextricably linked to the progressive accretion of continental and oceanic material from the east, onto the nature of biota within Wallacea is sometimes eastern margin of Sundaland (Eurasian margin), and to the seen, for example, by the eastward increase in resultant development of volcanic arcs This westward drift Australian representatives in the reptile fauna of material throughout the Tertiary, particularly that of mi- between the western and eastern boundary crocontinental blocks, may have provided a potential path- lines (Ziegler, 1983) However, for most organ- way which allowed rafting or island hopping of Australian biota towards Asia and vice versa A land bridge existed isms Wallacea does not represent a region of between Borneo and mainland SE Asia for much of the Ter- homogeneous biota, or a region of gradual tiary, whereas the formation of the Makassar Straits in the change in species composition In reality, early Tertiary isolated small land areas in Sulawesi from Wallacea is best described as a biogeographic those in Borneo Both of these factors resulted in strong region, situated between areas with Asiatic and biogeographic differences between Borneo and Sulawesi and contributed to a high degree of endemism on Sulawesi Australian floras and faunas, where organisms Chains of volcanic island arcs, related to subduction along show a high degree of endemism (George, the eastern edge of Sundaland during the Tertiary, may 1981; Whitten et al&, 1987) have presented island hopping routes to and from the Phil- The sharp contrast in fauna between areas ippines, Borneo and Sulawesi, and possibly Java bordering Wallace’s original line is not reflected to the same extent by the flora (George, 1981; Introduction Balgooy, 1987) There are approximately 2,300 genera of flowering plants in total in the archi- The islands of Borneo and Sulawesi are of prime pelago and for most Wallace’s line is unimpor- importance to the biogeography and palaeobio- tant, although 297 genera, including some of the geography of SE Asia Wallace’s (1863) faunal palms, do reach their eastern limit there

Biogeography and Geological Evolution of SE Asia, pp 133-163 Edited by Robert Hall and Jeremy D Holloway © 1998 Backhuys Publishers, Leiden, The Netherlands 134 S& J& Moss and M& E& J& Wilson

100° 120° 140° Philippines The area between Wallace's Line and Lydekker's Mainland SE Asia Line is known as WALLACEA. This is a subregion or transition zone which includes a large number of endemic species. WALLACE'S LINE: separating Australian and Asia fauna (1863). Now taken as the East boundary of strictly Asian fauna WEBER'S LINE: Boundary of SUNDA faunal balance Asian: Australian CONTINENTAL animals 50:50 for mammals and SHELF molluscs LYDEKKER'S LINE: West boundary of strictly Australian fauna BORNEO 0 0° Sumatra

SULAWESI

New Guinea

N Java

SAHUL 0 500 1000 1500 2000 CONTINENTAL SHELF km

100° 120° 140°

Fig1 Map of SE Asia showing the location of Borneo and Sulawesi in the centre of the region The original faunal divide of Wallace (1863) is shown Areas of continental shelves are shown in grey

(Dransfield, 1981; George, 1981) This may be crustal, or plate, movements have occurred in because many plants are better at overseas dis- the region During the last twenty years several persal (Briggs, 1987), because their range is of- plate tectonic reconstructions have been postu- ten strongly related to suitable habitats and cli- lated for the area (Carey, 1975; Peltzer and mate (Steenis, 1979; Balgooy, 1987; Takhtajan, Tapponnier, 1988; Rangin et al&, 1990; Daly et 1987), or because certain floral elements were al&, 1991; Lee and Lawver, 1994, 1995; Hall, present on both sides of Wallace’s line before 1996) There is now a growing consensus over the formation of the Makassar Straits Multiple some of the main points of the plate tectonic migration pathways, via northern and austral evolution of the area, although details of the re- routes, have been suggested for some groups of constructions and the driving mechanisms are plants after breakup of Gondwana (Dransfield, still under dispute The reconstructions show 1981, 1987; Whitmore, 1981b; Audley-Charles, the movements of lithospheric plates, and it is 1987; Truswell et al&, 1987; Morley, 1998 this important to realise that these do not directly volume) For certain groups of animals the correspond to regions of land and sea Makassar Straits appear to have been a barrier to A number of workers have related biogeoge- dispersal, whereas organisms such as some ori- ography to the plate tectonic evolution of SE ental frogs, reptiles, birds and mammals occur Asia Audley-Charles et al& (1981) showed SE on both sides of Wallace’s line and in some Asia in its world-wide context and identified cases their range extends as far as Australia major plate tectonic events, evaluating their im- However, overall there is still a clear faunal portance for biogeographers These included change across the Makassar Straits (Cranbrook, the separation of India from Antarctica-Australia, 1981; Briggs, 1987; Musser, 1987) the separation of Australia-New Guinea from The SE Asian region has been an extremely Antarctica, the juxtaposition of India with Asia, active tectonic area throughout the Cenozoic, and most recently the convergence and subse- and geological and geophysical evidence indi- quent juxtaposition of Australia with SE Asia cates that considerable lateral and vertical The regional evolution of SE Asia and its biogeo- Tertiary palaeogeography of Sulawesi and Borneo 135 graphic implications, with particular reference other islands on the Sunda Shelf, particularly to Sulawesi, were reviewed by Audley-Charles Sumatra, from which Borneo is separated by (1981) The formation of the Makassar Straits, about 220 km (Fig 1) There are, however, dif- and possible temporary land links across this ferences and in particular Borneo has a higher seaway, and the juxtaposition of different tec- number of endemic plants and animals than ad- tonic fragments in Sulawesi, particularly those in jacent areas to the west In relation to its size the the east with Australian affinity, were identified fauna of Borneo is less diverse than its western as major influences on the biogeography across neighbour Sumatra, but more of its animals are Wallace’s line The evolution and dispersal of exclusive with thirty nine land animals and thirty the angiosperms were discussed in the light of birds being endemic to the island (Whitten and plate tectonic events by Audley-Charles (1987) Whitten, 1992; MacKinnon et al&, 1996) The Burrett et al& (1991) related rifting of fragments mammal population of Borneo, represented by away from Australia and their subsequent con- 222 species of land animals, is almost identical vergence and collision with mainland SE Asia to to that of mainland Asia at family level with pri- biogeography All authors note the importance mates, bears, cats, squirrels and rhinos all repre- of superimposing palaeoenvironmental data sented Borneo has the highest number of spe- onto plate tectonic reconstructions to provide cies of primates and tree shrews within the SE meaningful information to biogeographers, and Asian region (MacKinnon et al&, 1996) Borneo the actual difficulties of undertaking such a task has some 450 resident species of birds, the third Audley-Charles (1987) and Hall (1998 this vol- highest in the region after New Guinea and ume) attempted to identify areas of past land, Sumatra, which is a reflection of the size of the shallow and deep sea regions from the plate tec- island, the diversity of available habitats and tonic evolution of SE Asia proximity to mainland Asia Borneo is one of the This paper concentrates on the Tertiary evolu- richest islands on the Sunda Shelf for freshwater tion of Borneo and Sulawesi and synthesises fish (394 species of which 149 are endemic), palaeoenvironmental information obtained from amphibians (at least 100) and reptiles (at least the geological record with plate tectonic recon- 166 species of snake, MacKinnon et al&, 1996) structions Areas of land, marginal marine, shal- Most of the freshwater fish species of Borneo are low marine and deep marine areas are shown seen in Sumatra and elsewhere in SE Asia, al- on plate tectonic reconstructions of Borneo and though again Borneo has a higher number of Sulawesi for the Tertiary and provide a means to endemic species Of all the vertebrate groups examine possible migrations or dispersals in the the primary freshwater fish most clearly demar- areas bordering Wallace’s line cate Wallace’s original line and there is a total absence of primary division freshwater fish in Sulawesi, although a few occur in the Philip- Present-day distribution of organisms in pines (Kottelat et al&, 1993) Borneo and Sulawesi Borneo has the most diverse flora of the Sunda Islands, with some 10,000-15,000 species Borneo and Sulawesi include a variety of habi- of flowering plants of which one third are en- tats, such as high mountainous areas, lower roll- demic (Whitten and Whitten, 1992; MacKinnon ing topography and flat coastal plains A com- et al&, 1996) Invertebrate species are extremely plex interplay of factors, including physical dif- abundant on Borneo, although accurate figures ferences in environment (altitude, soil type and are not available for the less well known groups slope all influenced by local geology), local and Much of the flora and fauna endemic to Borneo regional variations in climate as well as regional is confined to the high mountainous areas, par- geological evolution may all influence the na- ticularly in Sabah and Sarawak, indicating a de- ture and diversity of organisms found on Borneo gree of niche partitioning related to local envi- and Sulawesi Today both Borneo and Sulawesi ronmental conditions and to the lateral separa- have tropical climates, although some areas of tion of similar habitats Sulawesi may experience long dry periods and a On Sulawesi there is an extremely high de- more monsoonal climate than areas in Borneo gree of endemism amongst the fauna, particu- The present-day environments of Borneo and larly of the mammals The biota of Sulawesi, Sulawesi are described in detail in MacKinnon et particularly at a generic and higher level, shows al& (1996) and Whitten et al& (1987) affinities with those of both Australia and Asia, The biota of Borneo at both generic and spe- although far fewer families are represented com- cies level is similar to mainland SE Asia and pared with Borneo or New Guinea (Whitten et 136 S& J& Moss and M& E& J& Wilson al&, 1987; Michaux, 1994; Holloway, 1997) Out Whitten et al&, 1987) Of the non-endemic plants of 127 species of indigenous mammals, 79 (62%) in Borneo, about 50% do not occur in Sulawesi are endemic to Sulawesi, and this rises to 98% if (Whitten et al&, 1987) the bats are excluded (Whitten et al&, 1987) The invertebrate fauna of Sulawesi in general Much of the characteristic Sundaic fauna, includ- has affinities with areas to the west, but in com- ing moles, flying lemurs, tree shrews, lorises, parison is depauperate and displays a higher gibbons, pangolins, porcupines, dogs, otters, degree of endemism (Gressitt, 1961; Whitten et weasels, cats, elephants, tapirs, rhinoceroses al&, 1987; Vane-Wright, 1991) An Australian, or and mouse-deer do not occur east of Wallace’s in some cases a Philippine, affinity has also been line (Musser, 1987; Whitten et al&, 1987), al- recognised within some of the invertebrates, in- though Plio-Pleistocene elephant fossils have cluding the Lepidoptera (de Jong, 1990; been found in Sulawesi (Cranbrook, 1981; Holloway, 1987, 1990, 1997) and the cicadas Whitten et al&, 1987; Aziz, 1994) Of the Sula- The cicadas are poor dispersers, show a high wesian mammals many of the placentals have degree of endemism (73 out of 77 species in Sundaic affinities, some of the endemics, such as Sulawesi are endemic), and a number of species the anoa, have no Sundaic relatives, whereas the are restricted to one of Sulawesi’s arms or to its marsupials are clearly an Australian element central part, perhaps reflecting the Tertiary geo- (Musser, 1987; Michaux, 1994) A high degree of logical evolution of Sulawesi (Duffels, 1990) endemism also occurs within the indigenous amphibian (19 out of 25 species) and reptile (13 out of 40 lizard species and 15 out of 64 species Data sources of snake are endemic with one monotypic ge- nus) populations and it is likely that more spe- The plate tectonic reconstructions of Hall (1996) cies of these groups have yet to be discovered are used as a template in this paper upon which (Whitten et al&, 1987) About a quarter of the to draw palaeogeographic maps Although these birds on Sulawesi (total 328) are endemic and reconstructions differ from many of the earlier although a dominant Sundaic influence is seen, plate tectonic reconstructions for SE Asia some Australian elements also occur (Mayr, (Rangin et al&, 1990; Daly et al&, 1991; Lee and 1944; Whitten et al&, 1987; Holmes and Phillipps, Lawver, 1994; 1995) in terms of their detail, par- 1996; Michaux, 1996) Unlike Borneo, Sulawesi ticularly in eastern SE Asia, the Borneo-Sulawesi has no records of strictly freshwater fish parts of the reconstructions do not differ signifi- (Cranbrook, 1981; Whitten et al&, 1987; Kottelat cantly for the purposes of plotting palaeogeo- et al&, 1993) However, of the fish that live pri- graphic data marily in freshwater and show a little saltwater The series of palaeogeographic maps pre- tolerance, and those with considerable marine sented here illustrates the evolution of Borneo tolerance, such as the diadromous fish, 68 spe- and Sulawesi during the Cenozoic The data cies occur in Sulawesi and of these 52 are en- used in constructing these maps were derived demic (78%, compared with 38% in Borneo) from fieldwork by the London University SE Asia Like Borneo there are 8 endemic genera Research Group, and an extensive literature re- (Kottelat et al&, 1993) view of the islands of Borneo and Sulawesi The distribution of flora in Sulawesi appears These maps have been based on available geo- to be strongly related to climatic and local physi- logical evidence, including facies data, strati- cal conditions, including altitude and soil types graphic information, biostratigraphy, igneous, (Whitten et al&, 1987) Analysis of over 4000 spe- metamorphic, structural and palaeomagnetic cies in 540 genera suggests that the Sulawesi data Significant gaps exist within the data set flora is most closely related to other relatively and particularly for some of the remoter areas dry islands in the region (Balgooy, 1987) there is limited information Previous attempts at Dransfield (1981), suggested that the paucity of palaeogeographic reconstruction have either palms on Sulawesi may be related to a drier been limited to small areas, such as hydrocarbon Pleistocene climate Balgooy et al& (1996), rec- exploration blocks (Wain and Berod, 1989) or ognised 933 indigenous plant species on very generalised palaeogeographies for very Sulawesi, and of these 112 were endemic to the long time periods (Umbgrove, 1938; Beddoes, island Montane floras are similar to those in 1980; Rose and Hartono, 1978; Weerd and Borneo, whereas the flora of the lowlands and Armin, 1992) As far as we know this is the first areas underlain by ultrabasic rocks have a strong attempt to synthesise palaeographic data with affinity with that of New Guinea (Balgooy, 1987; plate tectonic information for the whole area of Tertiary palaeogeography of Sulawesi and Borneo 137

Borneo and Sulawesi ume) At the beginning of the Tertiary, Borneo The most important environmental elements formed a promontory of the Sundaland craton: distinguished are land areas, including regions the stable eastern margin of the Eurasian plate of mountainous topography, low lying regions (Hall, 1996; Metcalfe, 1998 this volume) East of of fluvial deposition, major river systems and Borneo, separating it from Sulawesi, are the marginal marine/deltaic systems Areas of shal- deep Makassar basins (Fig 2), formed during the low water and deeper water, fine grained and Paleogene (Situmorang, 1982) Two NW-SE coarser redeposited clastic and carbonate de- trending fault zones, the Adang and the posits were also mapped Volcanic centres, with Sangkulirang, bound the North Makassar basin regions of inferred subaerial and submarine to the south and north (Fig 2) Major tracts of volcanism, are also shown on the reconstruc- eastern, central and northern Borneo are cov- tions Thus the key environments for terrestrial ered by Tertiary sediments (Fig 2) which were and marine faunas and floras are emphasised deposited in fluvial, marginal-marine or marine The outlines of the present coastlines are shown environments These depocentres were often on the reconstructions for reference laterally interconnected through intricate and narrow links (Fig 2; Pieters et al&, 1987; Pieters and Supriatna, 1990) Tertiary sedimentation in Geology and tectonics of Borneo and these regions occurred contemporaneously Sulawesi with, and subsequent to, a period of widespread Paleogene extension and subsidence, which Borneo and Sulawesi are situated in a tectoni- may have begun in the middle Eocene or earlier cally complex region between three major plates (Eurasia, Indo-Australia and Pacific/Phil- ippine Sea) The present day setting is mirrored Sulawesi by the complexity of the pre-Tertiary and Terti- ary geology of these two islands Large areas of Sulawesi is formed of distinct north-south eastern Kalimantan and western Sulawesi had trending tectonic provinces (Fig 3; Sukamto, been accreted onto southwestern Borneo, part 1975) which are thought to have been of the eastern margin of Sundaland, by the sequentially accreted onto Sundaland during the Cenozoic (Hall, 1996; Metcalfe, 1998 this vol- Cretaceous and Tertiary In part due to a lack of ume) Subduction of the Indian Ocean, Philip- information, and to different interpretations of pine Sea and Molucca Sea plates has been re- the available data, the evolution and juxtaposi- sponsible for the progressive collision and ac- tion of fragments within Sulawesi remain highly cretion of fragments of continental and oceanic contentious and an attempt has been made to crust along the eastern margin of Sundaland describe different hypotheses and to evaluate throughout the Cenozoic Within this overall how these might affect biogeographic studies compressional regime a number of sedimentary The north and south arms of Sulawesi are basins and deep marginal basins formed along composed of thick Tertiary sedimentary and vol- the eastern and southern margins of Sundaland canic sequences overlying pre-Tertiary tectoni- as a result of Tertiary extension and subsidence cally intercalated metamorphic, ultrabasic and marine sedimentary rocks (Fig 3; Sukamto, 1975; Leeuwen, 1981) Central Sulawesi and parts of Borneo the SE arm of Sulawesi are composed of sheared metamorphic rocks and in the east there is a Borneo is bounded by three marginal basins highly tectonised melange complex (Sukamto, (South China, Celebes and Sulu Seas), 1975; Hamilton, 1979) Similarities between the microcontinental fragments of south China ori- pre-Tertiary rocks and dating of metamorphic gin to the north, and mainland SE Asia rocks suggests that they were accreted onto the (Indochina and peninsular Malaysia) to the west eastern margin of Sundaland before the Tertiary (Figs 1 and 2) Borneo has been interpreted as (Sukamto, 1975; Hasan, 1991; Parkinson, 1991; the product of Mesozoic accretion of oceanic Wakita et al&, 1994) The Tertiary stratigraphy of crustal material (ophiolite), marginal basin fill, western Sulawesi is similar to that of east island arc material and microcontinental frag- Kalimantan and the East Java Sea because the ments onto the Palaeozoic continental core of whole area began to subside in the early middle the Schwaner Mountains in the SW of the island Eocene and a large basin formed (Weerd and (Fig 2; Hutchison, 1989; Metcalfe, 1998 this vol- Armin, 1992) 138 S& J& Moss and M& E& J& Wilson

8°N 110° 114° 118°

South China Sea Sulu Sea

Sabah-Palawan trough Luconia Shoals Baram Sabah delta Sabah Basin 4°N Sarawak Sarawak Celebes Sea Natuna basins Tarakan Basin

es Muara awesi Trench ng Sul Ra Basin th tan or Central Kaliman N Mangkalihat Peninsula Ketungau Basin Muller Mts. Semitau 0° Melawi Basin Kutai Basin Mahakam Schwaner delta Mountains Makassar Straits Sulawesi Karimata Barito Straits Kalimantan Basin Paternoster Platform 0 200 Meratus Laut 4°S km Mountain Island

Cenozoic rocks Pre-Cenozoic rocks Early Cretaceous Plio-Pleistocene Mesozoic/early Tertiary deep volcanic arc & Volcanics marine sediments, mafic ophiolite sequence igneous rocks and melange Ophiolite Oligocene-early basic/ultrabasic units Miocene deep Mostly Mesozoic igneous, marine sediments metamorphic and sedimentary Cretaceous granites Cenozoic sediments rocks with some late Palaeozoic north of the Schwaner (includes some and early Cenozoic rocks Mountains. volcanics) Cretaceous granites & Major lineament, fault or fold Eocene volcanics tonalites intruding Palaeozoic Area of Sintang metamorphic rocks Intrusives

Fig2 Simplified geological map of Borneo

The eastern side of south Sulawesi and much anic lithosphere and overlying marine of the eastern part of the east and southeast sediments accreted to Sulawesi Dates varying arms of Sulawesi are composed of tectonically between Cretaceous to Miocene have been ob- intercalated marine sedimentary rocks and mafic tained for the mafic and ultramafic rocks in east- and ultramafic igneous rocks (Sukamto, 1975; ern south Sulawesi (Yuwono et al&, 1987; Silver et al&, 1978; Simandjuntak, 1990; Bergman et al&, 1996), although it is not clear Parkinson, 1991; Bergman et al&, 1996) These which represent emplacement or deformation rocks are ophiolites inferred to represent oce- ages (Bergman et al&, 1996; Polvé et al&, 1997) Tertiary palaeogeography of Sulawesi and Borneo 139

120° E 122° E 124° E

2° N 2° N N North Sulawesi Trench

East Sangihe Thrust 0° Una Una 0° Palu-Koro Fault Batui Thrust

Balantak Thrust North Median Sorong Fault Line ? Sula Thrust

2° S Banggai-Sula 2° S Block

Matano Fault South Sorong Fault ? ?

Tolo Thrust Lawanopo Fault

4° S 4° S

0 100 200 km

?

Walanae Fault Kabaena

Tukang Besi- Buton Block ? 6° S 6° S

120° E 122° E 124° E

West Sulawesi Central Sulawesi East Sulawesi Banggai-Sula and Tukang Plutono-Volcanic Arc Metamorphic Belt Ophiolite Belt Besi Blocks

Quaternary sediments Ophiolitic mélange Neogene and Continental basement Quaternary sediments and cover Cenozoic volcanics and volcaniclastics Pompangeo schists Ultramafic and mafic Continental basement Tertiary carbonates rocks (undifferentiated) below sea level

Other Tertiary sediments

Mesozoic metamorphic Active volcano Major thrust (teeth on Major strike-slip fault and ultramafic basement upper plate) complex

Fig3 Simplified geological map of Sulawesi 140 S& J& Moss and M& E& J& Wilson

Central and part of southeast Sulawesi have In the NW tip of Borneo, Maastrichtian to early been attached to western Sulawesi in the recon- Eocene fluvial/marginal marine sands were de- structions The East Sulawesi ophiolite was em- posited within an intra-montane basin (Tate, placed after the mid Oligocene Debate on the 1991) These sediments may have been part of a location and origin of this oceanic crust larger fluvial system, fed by river systems from (Parkinson, 1991; Mubroto et al&, 1994; Monnier Indochina, supplying material to turbidites in et al&, 1995) need not concern biogeographers Sarawak, Sabah and parts of Kalimantan (Fig 4) since before accretion and uplift it was situated from late Cretaceous to lower Eocene times in a deep marine setting Palaeogene igneous (Moss, 1998) In the early to middle Eocene lithologies in the north arm of Sulawesi may also deep marine turbidites in Sarawak were uplifted represent part of an ophiolite sequence and deformed by the ‘Sarawak orogeny’ (Monnier et al&, 1995), although both shallow (Hutchison, 1996) Late middle Eocene shallow and deep marine origins for these rocks have and deep marine sediments unconformably been inferred (Carlile et al&, 1990) overlie older rocks By the early to middle On the islands of Buton-Tukang Besi and Eocene much of Borneo appears to have been Banggai-Sula metamorphic and igneous litholo- emergent Eocene (50-45 Ma) rhyolitic lavas and gies of continental origin are exposed or are ash occur in three localities in Kalimantan thought to underlie sediments of Palaeozoic and (Heryanto et al&, 1993; Pieters et al&, 1993a; Mesozoic ages respectively The Palaeozoic Suwarna et al&, 1993; Moss et al&, 1997) lithologies have Australian-New Guinea affini- On the reconstructions, west, central and ties, whereas deposition of shallow and deep parts of the SE arm of Sulawesi are regarded as a marine sediments during rifting and drifting of region of microcontinental material forming a the fragments is inferred for the Mesozoic contiguous land area during the early Paleo- (Audley-Charles, 1974; Hamilton, 1979; Pigram gene Much of mainland SE Asia, southern Bor- and Panggabean, 1984; Garrard et al&, 1988) neo and western Sulawesi appears to have been Buton is thought to have collided with eastern emergent during the Paleocene and the early Sulawesi during the early (Davidson, 1991) or Eocene, with a distinct lack of dated sediments middle Miocene (Smith and Silver, 1991), recorded from these periods Geochemistry and whereas latest Miocene to early Pliocene colli- dating of calc-alkaline rocks and interbedded sion with the east arm of Sulawesi is inferred for sediments in eastern South Sulawesi suggests Banggai-Sula (Garrard et al&, 1988; Davies, there was a volcanic arc in this area during the 1990) Fortuin et al& (1990) and Davidson (1991) Paleogene (Sukamto, 1975; Leeuwen, 1981; suggested that Tukang Besi was a separate mi- Sukamto and Supriatna, 1982) Paleogene basic crocontinental block which was accreted to volcanics and volcaniclastic lithologies are also Buton in the Plio-Pleistocene, although not all present in western central and northern authors recognise this as a separate microconti- Sulawesi, although both shallow and deep ma- nental fragment (Smith and Silver, 1991) rine origins have been suggested (Trail et al&, 1974; Carlile et al&, 1990; Polvé et al&, 1997) There was widespread basin formation in Palaeogeographic maps middle Eocene times around the margins of Sun- daland Much of eastern Borneo, western Eocene Sulawesi, the Makassar Straits and the east Java Sea was an area of Tertiary sedimentation, in During the Eocene (Figs 4 and 5) a land connec- which the depositional environments varied be- tion between southern Borneo and mainland SE tween fluvial, deltaic, shallow marine clastic and Asia is inferred (Pupilli, 1973) which may have carbonate shelves and areas of deeper water been present since the Jurassic (Lloyd, 1978) sedimentation Evidence for Eocene extension, Little geological information is available for the block-faulting and subsidence is seen on seismic Sunda Shelf, since few wells penetrate this area lines crossing the Makassar Straits (Burollet and A thin cover (<300 m) of Quaternary sediments Salle, 1981; Situmorang, 1982; Guntoro, 1995; is reported to overlie pre-Tertiary rocks in this Bergman et al&, 1996), and this was the time area (Ben-Avraham and Emery, 1973) Although when the land connection between Borneo and land is inferred for this area throughout much of Sulawesi was severed Sea floor spreading be- the Tertiary, it is possible that marine sediments gan in the marginal oceanic basin of the Celebes deposited during possible transgressions of this Sea in the mid-Eocene (Weissel, 1980; Rangin region may have been removed by later erosion and Silver, 1990) and may have influenced basin Tertiary palaeogeography of Sulawesi and Borneo 141

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? ? ? ? ? ? ? ? ?

? ? ? ? ?

?

? ? ? ? ? ?

Key to palaeoenvironments

Emergent mountainous (left) and low-lying (right) land areas

Fluvial & lacustrine facies showing inferred rivers and palaeoflow direction

Subaerially emergent (left) and submarine (right) volcanic & volcaniclastic lithologies

Shallow-marine carbonate shelf

Shallow-marine clastic shelf

Marginal marine clastics (includes delta & tidal deposits) with coals (black)

Coastline Major deltas Shelf edge Bathyal shales/marls interbedded with proximal (bottom) to distal (top) siliciclastic or carbonate redeposited lithologies

Bathyal shales and marls

Fig4 Palaeogeographic map for 50 Ma, early Eocene A key to the environments is shown Note that rivers are shown schematically for all time slices See pages 157-164 for colour plates of Figs 4 to 9 142 S& J& Moss and M& E& J& Wilson

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Fig5 Palaeogeographic map for 42 Ma, middle Eocene A key to the environments is shown in Fig 4 initiation in Borneo and Sulawesi (Hall, 1996; margin of the Mangkalihat peninsula (Sunaryo et Moss et al&, 1997) Rhyolitic volcanism, ash-falls al&, 1988) and in the Muller Mountains (Pieters et and lava flows were partially contemporaneous al&, 1993b) with initiation of formation of the Tarakan In west Borneo fluvial and lacustrine (Netherwood and Wight, 1992) and Kutai basins sediments were deposited throughout much of (Leeuwen et al&, 1990; Moss et al&, 1997) Similar the Eocene in elongate depocentres of the volcanism also occurred along the southern Melawi-Ketungau-Mandai area (Fig 2) It is in- Tertiary palaeogeography of Sulawesi and Borneo 143

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? ? ? ?Emergent or ? low energy shelf ? ? ? ? ? ?

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Fig6 Palaeogeographic map for 34 Ma early Oligocene A key to the environments is shown in Fig 4

ferred that sediment deposited in these areas late Eocene By middle to late Eocene times was supplied by rivers flowing from the south (Moss and Finch, 1998), large parts of the Kutai (Schwaner Mountains) or west (Indochina) depocentre and neighbouring western central since deep marine areas were present to the Sulawesi were areas of deep, open oceanic sedi- north and east Fluvial and marginal marine mentation and this is inferred to have been the sediments were also deposited in the Barito- case for much of the north and south Makassar Asem-Asem-Pasir area, although by late Eocene basins Around the margins of this deep basin in times shallow and deep marine clastic and car- the Kutai area, the northern part of the Tarakan bonate sedimentation prevailed Marginal ma- basin and western, central and northern rine lithologies with coals and intercalations of Sulawesi upper Eocene deltaic sands, coals and volcanic rocks occur with the Tarakan-Muara some shallow marine clastics were deposited depocentres, although shallow and deeper wa- (Kusuma and Darin, 1989; Coffield et al&, 1993; ter carbonate deposition was common by the Moss et al&, 1997; Weerd and Armin, 1992) In 144 S& J& Moss and M& E& J& Wilson western south Sulawesi marginal marine clastics The mainly fluviatile west Kalimantan basin and coals are conformably overlain by a thick (Melawi-Ketungau-Mandai area) had begun to shallow marine carbonate succession (Wilson diminish in size or had already been infilled by and Bosence, 1997) By late Eocene times, shal- the early Oligocene (Fig 6) Seismic data and fis- low marine carbonate sedimentation had been sion track dating of derived apatite grains sug- established over much of south Sulawesi gest that the Semitau ridge began to rise in the (Wilson, 1995) and southwestern central early Oligocene (Moss et al&, 1997) and this up- Sulawesi (Coffield et al&, 1993) although these lift would have favoured erosion rather than areas were separated by a deep marine basinal deposition in this area Deltaic and pro-delta area (Wilson and Bosence, 1996) environments appear in the western part of the Kutai basin toward the end of the Oligocene (Weerd and Armin, 1992; Tanean et al&, 1996; Oligocene Moss et al&, 1997, 1998) This is thought to be related to uplift and erosion of the central In the Oligocene (Fig 6) a land connection be- ranges of Borneo at the end of the Oligocene tween Borneo and Indochina is inferred (Pupilli, which supplied sediment towards the Makassar 1973; Lloyd, 1978) Turbidites were deposited in Straits Sabah in a deep marine basin These may have Tectonically disrupted ophiolitic rocks been fed from major river systems of Indochina (Simandjuntak, 1986) comprising much of the or Kalimantan They pass laterally into shallow east and SE arms of Sulawesi represent oceanic marine and deltaic sediments in Brunei (Tate, crust and overlying deep marine sediments 1994) and at the margins of the basin in Sabah Metamorphic ages of 28-32 Ma obtained from at and Sarawak There were several areas of shal- the base of the East Sulawesi ophiolite low marine carbonates in this region throughout (Parkinson, 1991) suggest the ophiolites were the Oligocene During the Oligocene the detached in an oceanic setting at this time and Sarawak basin was progressively infilled The emplaced later The progressive emplacement west Sarawak coastline had a north-south orien- of the ophiolitic sequence would have resulted tation for the early Oligocene to early Miocene in the development of more extensive land ar- (Doust, 1981; Agostinelli et al&, 1990) eas in Sulawesi Flat-lying reflectors seen on seismic sections The microcontinental blocks of Banggai-Sula, across much of the north and south Makassar Buton and Tukang Besi, although drifting west- basins suggest deep marine sedimentation oc- wards towards Sulawesi, had yet to be accreted curred in a uniformly subsiding basin during the onto Sulawesi These blocks rifted from the Aus- Oligocene (Situmorang, 1982; Guntoro, 1995) tralian-New Guinea continent during the late However, in other parts of the basin, particularly Mesozoic (Audley-Charles, 1974; Hamilton, along the eastern margin of the Paternoster plat- 1979; Pigram and Panggabean, 1984; Garrard et form, seismic and borehole data suggests active al&, 1988; Davidson, 1991) During the Ceno- faulting may have continued through the zoic, some were areas of shallow marine sedi- Oligocene and possibly into the Miocene mentation (Garrard et al&, 1988; Smith and Sil- (Situmorang, 1982; Guntoro, 1995; Wilson and ver, 1991; Davidson, 1991) and may have be- Bosence, 1996) Oligocene deep marine sedi- come emergent mentation also occurred in much of the Kutai basin (Moss et al&, 1997) and in some areas of western central Sulawesi An input of volcani- Miocene clastic material is also recorded in western cen- tral Sulawesi In the Tarakan-Muara area, the During the Miocene (Figs 7 and 8) a switch in Mangkalihat peninsula, Barito basin, offshore sedimentation style from extensive carbonate southern Barito and in South Sulawesi extensive shelves to deltaic deposition and progradation shallow water carbonate platforms developed or occurred on the eastern side of Borneo, particu- continued to accumulate sediment during the larly in the Tarakan-Muara and Barito basins Oligocene, while deeper water marls were de- (Achmad and Samuel, 1984; Netherwood and posited in adjacent areas (Fig 6; Bransden and Wight, 1992; Weerd and Armin, 1992; Siemers et Matthews, 1992; Bishop, 1980; Armin et al&, al&, 1992; Carter and Morley, 1996; Stuart et al&, 1987; Netherwood and Wight, 1992; Saller et al&, 1996) The predominance of deltaic sedimenta- 1992, 1993; Supriatna et al&, 1993; Weerd and tion around the northern and eastern parts of Armin, 1992; Weerd et al&, 1987; Wilson, 1995) Borneo, particularly the extremely deep Kutai Tertiary palaeogeography of Sulawesi and Borneo 145

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Fig7 Palaeogeographic map for 21 Ma, early Miocene A key to the environments is shown in Fig 4

basin, suggests that most of the major river sys- area increased in eastern Borneo due to the tems were draining into these areas Abundant progradation of deltas, the distance across this detritus was supplied from the uplift and denu- seaway was progressively reduced dation of the centre of the island and coeval vol- A large area of carbonate deposition devel- canism (Tanean et al&, 1996; Moss et al&, 1997, oped during the middle to late Miocene in the 1998) By the end of the Miocene the drainage Luconia Shoals area, which was distant from ar- system within Borneo was similar to the present- eas of coastal siliciclastic deposition in Sarawak day The Mahakam delta had prograded to near (Doust, 1981; Agostinelli et al&, 1990; Rice- its present-day position by the late Miocene Oxley, 1991) By the end of the Miocene the (Addison et al&, 1983; Land and Jones, 1987) and palaeo-Baram delta had begun to prograde to siliciclastic marginal marine and deltaic deposi- the NW, and the coastline had adopted an orien- tion predominated in this area The Makassar tation similar to its present-day NE-SW orienta- Straits remained a deep water basin separating tion (Doust, 1981; Agostinelli et al&, 1991) In Sulawesi from Kalimantan, although as the land Sabah, shallow marine to marginal marine 146 S& J& Moss and M& E& J& Wilson

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Fig8 Palaeogeographic map for 8 Ma late Miocene A key to the environments is shown in Fig 4

sediments were deposited (Tjia et al&, 1990; et al&, 1987; Bergman et al&, 1996) Clennell, 1992) Volcanic arc activity occurred in The microcontinental blocks of Banggai-Sula the Sulu and Cagayan arcs during the Miocene and Buton-Tukang Besi were accreted onto (Rangin et al&, 1990) and this probably resulted eastern Sulawesi during the Miocene or earliest in emergent chains of volcanic islands During Pliocene The inferred timing of collision of the the late Miocene to the Pleistocene, basalts and various fragments onto eastern Sulawesi varies trachy-andesites were extruded in central Bor- depending on the author On Buton, obduction neo (Moss et al&, 1997, 1998) of ophiolitic material and the reworking of pre- Shallow marine carbonate deposition contin- Miocene strata into clastic deposits has been re- ued on high blocks in southern and western lated to early to middle Miocene collision with central Sulawesi until the middle Miocene, sur- SE Sulawesi (Fortuin et al&, 1989; Smith and Sil- rounded by deep marine sedimentation ver, 1991; Davidson, 1991) Prior to collision, (Wilson, 1995) The East Sulawesi ophiolite had deep marine sediments were deposited on been accreted onto western Sulawesi, and it is Buton, although uplift and thrusting associated inferred that land areas were emergent in central with collision would have created emergent Sulawesi during at least part of the Miocene as a land areas in the middle Miocene Pliocene result of this collision In the north arm of block faulting on Buton, which created contem- Sulawesi island arc basalts were erupted during poraneous areas of deep and shallow marine the Oligocene and Miocene They are interbed- sedimentation, may have been related to colli- ded with shallow marine carbonate deposits, sion of Tukang Besi (Fortuin et al&, 1989; and volcanic islands are inferred to have been Davidson, 1991) Eocene to middle Miocene emergent Between the middle Miocene through limestones present on Banggai-Sula indicate to the earliest Pliocene a volcanic arc developed shallow water depositional environments, possi- along the length of western Sulawesi (Yuwono bly locally emergent, prior to collision in the lat- Tertiary palaeogeography of Sulawesi and Borneo 147

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Fig9 Palaeogeographic map for 4 Ma, early Pliocene A key to the environments is shown in Fig 4

est Miocene to early Pliocene (Garrard et al&, presence of a drowned Pleistocene river drain- 1988; Davies, 1990) More extensive land areas age system on the Sunda Shelf (Umbgrove, would have formed after collision 1938) The Pleistocene river drainage system recognised by Umbgrove (1938) across the Sunda Shelf is related to a sea level lowstand Pliocene-Recent during a glacial period The final juxtaposition of the fragments that By the Pliocene (Fig 9) the coastlines of both comprise Sulawesi occurred between the Borneo and Sulawesi were similar to the Pliocene and the present Although most au- present Major shallow water carbonate areas thors infer that internal rotation and juxtaposi- persisted on the east and west sides of the tion was achieved via a system of linked strike- Makassar Straits The coastline of Borneo was slip faults and thrusts, the linkage and dominated by deltaic and marginal marine displacements along faults is still contentious depositional environments The Mahakam river The Pliocene reconstruction shown is based on carries a large sediment volume which is depos- matching palaeoenvironments and assuming ited mainly in the delta and deltaic progradation reasonable strike-slip displacements along major occurred throughout the Pliocene and continues faults and some internal deformation of blocks at the present day At some point in the latest within Sulawesi Collisions and subduction east Miocene or Pliocene Borneo lost its land con- of Sulawesi caused transpression during the nection to mainland Indochina (Lloyd, 1978) Neogene and Quaternary which resulted in up- Possible events responsible include reorganisa- lift of extensive areas in Sulawesi and caused tion of plates, the end of a late Miocene glacia- rapid uplift of a number of high mountain areas, tion, and/or global sea level changes in the late particularly in central Sulawesi (Bergman et al&, Miocene The present-day Karimata Strait did 1996) The transpressive regime also resulted in not form until 7000 years ago, shown by the extension and subsidence in other areas Bone 148 S& J& Moss and M& E& J& Wilson

Bay separates the south and SE arms of Sulawesi The Paleogene formation of the Makassar is suggested to have developed as an Straits, at a period when other basins were form- extensional feature in the late Oligocene ing around the margins of the Sundaland craton, (Davies, 1992) Seismic data suggests that the was one of the most important geological events form of Bone Bay was then further modified to affect the biogeography of Borneo and during the Miocene/Pliocene by transpressive Sulawesi Western Sulawesi was accreted to and transtensional movements (Davies, 1992; eastern Borneo in the late Cretaceous, forming a Guntoro, 1995) The nature of Quaternary continuous land area probably during part of sediments and historic legends suggest that until the Paleocene and the early Eocene During this quite recently a seaway separated the south arm period, prior to the formation of the Makassar from the rest of Sulawesi (Bemmelen, 1949; Straits, the interchange of terrestrial biota be- Sartono, 1982) tween Borneo and western Sulawesi could have Igneous activity continued in western occurred unhindered across a continuous land Sulawesi until the Pliocene and Pleistocene and bridge However, the actual movement of or- is similar in nature to the late Miocene volcanics ganisms would have depended on habitat avail- in the same area (Yuwono et al&, 1987; Bergman ability and dispersal rates of organisms across a et al&, 1996) Along the north arm of Sulawesi, land bridge which may have existed for as little Miocene to Pliocene volcanism is related to as ten million years Palynological evidence south-dipping subduction of the Celebes Sea from the middle to upper Eocene Malawa For- oceanic crust under the north arm of Sulawesi mation in South Sulawesi suggests that diverse (Carlile et al&, 1990) A string of active Quater- angiosperms with Laurasian affinity were estab- nary to Recent volcanoes dominate the Sangihe lished in South Sulawesi prior to the rifting of Islands and the eastern part of the Minahasa re- the Makassar Straits (Morley, 1998 this volume) gion, and are related to west-dipping subduc- Distribution patterns and fossil evidence for tion under this area some groups of plants (Truswell et al&, 1987), such as some of the palms, the families of Magnoliaceae/Winteraceae and the genera Fagus/ Implications for palaeobiogeography and Nothofagus, have been used to infer various dis- biogeography persal pathways via northern and austral routes after the breakup of Gondwana, with an ancient Important elements of the palaeogeographic re- Gondwana origin being implicit (Dransfield, constructions for biogeographers are the extent 1981; Whitmore, 1981b) of land areas and island chains, the timing and Subsidence resulting in the formation of the nature of material accreted onto the margin of Makassar Straits and surrounding Tertiary the Sundaland craton and the distribution of dif- basinal areas would have progressively in- ferent environments through time and space creased the spatial separation of emergent land The reconstructions show that the spatial and areas in Borneo and western Sulawesi from the temporal distribution of land areas and habitats Eocene to the Oligocene Extensive shallow wa- differed considerably during the Tertiary from ter carbonate platforms developed in South those seen today in the Sulawesi-Borneo area Sulawesi, SE Kalimantan and the Mangkalihat Land migration of terrestrial organisms be- peninsula during the Tertiary Although it is pos- tween Borneo, mainland SE Asia and some of sible that small areas of these platforms were the Sunda Islands, such as Sumatra, would have emergent, subsidence rates in the region were been possible throughout much of the Tertiary, quite high and that any such islands would have since at least a transitory land connection is in- been limited in size and only emergent for short ferred to have existed between these areas until periods of time the Plio/Pleistocene The marked similarity be- Palaeogeographic information indicates that tween the flora and fauna of Borneo and main- there were only small land areas in western land SE Asia can be accounted for by the exist- Sulawesi between the middle Eocene and mid- ence of this land bridge during the Tertiary As dle Miocene, and that for the most part western noted earlier there is little information on the Sulawesi was isolated from major clastic input geology of the Sunda Shelf and evidence for However, a volcanic arc, part of which may marine incursions, perhaps associated with have been emergent, is inferred to have ex- Cenozoic global sea level changes (Haq et al&, tended down the east side of western Sulawesi 1987; 1988), may have been overlooked or re- into southern Java The formation of the moved by later erosion Makassar Straits and resultant isolation of local- Tertiary palaeogeography of Sulawesi and Borneo 149 ised, small land areas in western Sulawesi goes whether these animals were restricted to South some way towards explaining the affinities at Sulawesi (Musser, 1987) and only migrated into generic and higher level of Sulawesi’s terrestrial the area during the later part of the Neogene biota with those of Borneo and mainland SE during periods of low sea level and emergence Asia, and the high degree of endemism amongst of more extensive land areas bordering a narrow Sulawesi’s fauna and flora at species level seaway in the Makassar Straits Today South (Musser, 1987; Holloway, 1987) Musser (1987) Sulawesi has a dry climate compared with other noted that the non-volant mammals of Sulawesi areas in Sulawesi, and there are mostly lime- have ancient origins and that because the fauna stones or volcanic rocks in this area The climate is an unbalanced, depauperate one (40% of spe- and soil type, as well as palaeobiogeographic cies are bats) typical of oceanic islands, origin is separation of this area, would all have influ- believed to have been across sea enced the flora and therefore to some degree Rivers supplying clastic material derived from the fauna of this area (Balgooy, 1987) the erosion of the central part of Borneo begin- Volcanic arcs were important as potential ning in the Oligocene resulted in the land bridges and island hopping routes for or- progradation of large delta systems into north- ganisms during the Tertiary They are inferred to ern and eastern Borneo Sedimentation in the have existed along the north arm of Sulawesi Kutai basin and Makassar Straits progressively and the eastern side of west Sulawesi, perhaps reduced the distance between Borneo and extending down through Java from the Eocene Sulawesi to the present 200 km across the until the late Oligocene During the Neogene a Makassar Straits A compressive regime, which volcanic arc occurred along the north arm of developed in the area in the middle to late Sulawesi and possible island chain connections Miocene and continues to the present day, re- may have existed to the Philippines During the sulted in uplift or reduced subsidence rates in Miocene, the Sulu and Cagayan volcanic island the Makassar Straits region compared with the chain may have formed an island hopping route Paleogene Eustatic sea level changes, with for organisms between the northeast tip of Bor- magnitudes of tens of metres, related to fluctua- neo and parts of the Philippines tions in the size of the polar ice sheets have The nature and timing of material accreted been recorded during the Plio-Pleistocene This, onto western Sulawesi is of considerable impor- together with the compressive regime, suggests tance for potential migrations of terrestrial or- that part of the shallow water areas separating ganisms with Australian affinities The East Borneo and Sulawesi may have become emer- Sulawesi ophiolite, which now comprises much gent during the later part of the Neogene with of the east and southeast arms of Sulawesi, only a narrow seaway remaining where deep formed in a deep marine area and this area water channels now occur If such a situation would not have been subaerially emergent until developed, and assuming favourable conditions its accretion onto western Sulawesi Therefore occurred, migration of terrestrial organisms the East Sulawesi ophiolite could not have would have been facilitated, particularly during formed a potential ‘raft’ for the dispersal of ter- the Plio-Pleistocene, whereas the migration of restrial organisms marine organisms may have been hindered On In comparison, parts of the microcontinental the basis of palynological data Morley (1998 this fragments which make up the Banggai-Sula and volume) suggested that during the Neogene Buton-Tukang Besi islands, which were only a few plant taxa were able to disperse accreted onto eastern Sulawesi in the Miocene across the Makassar Straits, and it is likely that or Pliocene would have been islands or shallow those that did were well adapted to dispersal water areas during their drift towards Sulawesi A number of authors (Duffels, 1990; Musser, during the Tertiary These microcontinental 1987; Balgooy, 1987) have noted that the flora blocks were rifted from the margins of the Aus- and fauna of the south arm of Sulawesi is differ- tralian-New Guinea continent in the late ent from the rest of Sulawesi For much of the Mesozoic, and land bridges would have been Tertiary South Sulawesi was below sea level and severed at this time The stratigraphy of these it was probably only in the Pliocene when island microcontinental blocks indicates that the areas in South Sulawesi became connected with blocks subsided and became areas of deep ma- those in central Sulawesi Giant tortoise, el- rine sedimentation from the late Jurassic to Cre- ephant, stegodont and pig fossils have been taceous Therefore, although parts of these areas found in Pleistocene deposits in South Sulawesi, became emergent in the Tertiary, Australian af- but not in the rest of Sulawesi It is not clear finity fauna and flora could not have been 150 S& J& Moss and M& E& J& Wilson

‘rafted’ on these microcontinental blocks How- This would have favoured the migration of sa- ever, during the Tertiary, the Australian conti- vannah plants and animals across the area be- nent drifted steadily northwards and some mi- tween mainland SE Asia, Borneo and other is- crocontinental blocks between the Australian lands on the Sunda Shelf (Morley and Flenley, and Sundaland cratons became emergent as is- 1987) Cooler conditions during glacial periods lands These blocks, some of which were and lowered sea levels exposing more land ar- accreted onto Sulawesi in the Miocene or eas (Whitmore, 1981) in the late Tertiary and Pliocene, may then have rafted or acted as an Quaternary would have encouraged animals to island hopping routes for Australian organisms, move southwards over land bridges to Borneo such as some of the marsupials, to colonise Also during glacial maxima, montane vegetation Sulawesi Palms have a large fruit, suggesting zones would have been lower (Hope, 1996) long-distance dispersal might be limited and providing ‘stepping stones’ for the migration of Dransfield (1981, 1987) noted that the disjunc- montane and temperate taxa (Whitmore, 1981a; tion of Papuasian and Sundaland palms oc- Morley and Flenley, 1987) curred between Sulawesi and the Moluccas, Today the current directions and strengths consistent with relatively recent (Miocene) jux- around Borneo and Sulawesi vary depending on taposition Another possible island hopping the prevailing wind directions Surface currents route for Australian fauna to reach Sulawesi may in the East Java Sea flow predominantly east or have been via the Philippines and along the west at opposing times of year, whilst those in Sangihe volcanic arc Palaeomagnetic evidence the Makassar Straits are predominantly south di- suggests that India rifted away from the Gond- rected and around the rest of the Sulawesi coast- wanaland supercontinent at about 140 Ma, line more variable The deep water channels in whereas Australia-New Guinea separated from the Makassar Straits form a pathway for waters Antarctica between 110-90 Ma It may be possi- from the Celebes Sea, through the East Java Sea ble that organisms, particularly some of the to the Indian Ocean, principally through the flora, which had evolved prior to these two Lombok Straits During the Tertiary, the land ar- separation events, were present in both India eas of Borneo and Sulawesi would have been and Australia, and that after the interaction of smaller than today and currents would have these areas with the Sundaland craton that mi- been less constrained, but still controlled by pre- grations could have occurred from both east and vailing wind directions The dispersal of marine west into the Malay archipelago organisms, especially those with a planktonic The wind and current direction as well as the larval stage, such as corals or molluscs, would distribution of land masses and their local cli- have been unhindered throughout the Tertiary mates during the Tertiary would have affected and partly controlled by prevailing wind and the distribution and migration of both terrestrial current directions and the availability and spac- and marine biota Although, in general, Borneo ing of suitable habits Whitmore (1981a) noted has a wetter climate than Sulawesi, both have that sea level fluctuations would alter current tropical monsoonal climates and are affected by patterns in the region and thereby affect cli- winds from the east and west at opposing times mates, with periods of more seasonal climates of the year, depending on when low and high occurring during glacial periods when sea levels pressure zones develop over the adjacent conti- were lowered nental land masses of Australia and mainland SE Asia These strong monsoonal winds would help to distribute wind blown biota east-west Conclusions between some of the closer islands in the archi- pelago today Although it is difficult to infer past Borneo and Sulawesi, bordering Wallace’s origi- wind directions and strengths, it would seem nal line of faunal divide, are of prime impor- likely that during the Tertiary, since the Austral- tance to biogeographers, since these islands oc- ian land mass was further to the south, the ef- cur at the ‘mixing zone’ or area of overlap be- fects of one of the monsoons would have been tween Asian and Australian biota Borneo and less than today (Whitmore, 1981a) There is a Sulawesi are located in the midst of a conver- growing amount of evidence that Indonesia, and gent zone of three major plates, and the tectonic particularly Borneo (from the pollen record), evolution of the area, together with the climate was more strongly seasonal during the late and local factors, strongly influenced the past Tertiary and middle Pleistocene than today and present day distribution of fauna and flora (Whitmore, 1981a; Morley and Flenley, 1987) The main palaeogeographic changes in the Tertiary palaeogeography of Sulawesi and Borneo 151

Borneo-Sulawesi region and their implications Acknowledgements for biogeography are: 1 A continuous land connection between Bor- Discussions with Tony Barber, John Chambers, neo and mainland SE Asia may have existed Ian Cloke, Robert Hall, Neville Haile, Jon Noad throughout much of the Tertiary and would and Chris Parkinson are gratefully acknowl- have allowed fairly unhindered migration of ter- edged Robert Hall is particularly thanked for al- restrial biota lowing us to use the reconstructions The help- 2 Western Sulawesi had been accreted to east- ful comments of reviewers Tony Whitten and ern Borneo by the late Cretaceous, and by the Charles Hutchison were much appreciated early Eocene there were continuous land areas SJM’s and MEJW’s post-doctoral work with the in the Schwaner Mountains, NW Kalimantan, the University of London SE Asia Research Group Mangkalihat peninsula and parts of western are funded by a consortium of oil companies, Sulawesi The dispersal of certain flora and Arco, Lasmo, Mobil Oil, Exxon, Canadian Petro- fauna between Borneo and western Sulawesi leum, Union Texas and Unocal who are all could have occurred at this time gratefully acknowledged Additional funding for 3 Extension in the Makassar Straits region and fieldwork was provided by British Petroleum the formation of surrounding Tertiary basinal ar- and Maersk Oil and these companies are also eas in the Paleogene resulted in the progressive thanked Drs Irwan Bahar, Rab Sukamto and separation of locally emergent land or volcanic Kustomo Hasan of GRDC, Bandung are grate- areas in western Sulawesi and Borneo, and this fully acknowledged for their help and encour- isolation may have contributed to the high de- agement with our research projects Dharma gree of species endemism on Sulawesi Satria Nas, Alexander Limbong and the people 4 The East Sulawesi ophiolite was accreted onto of Sulawesi and Kalimantan are thanked for Sulawesi during or after the late Oligocene and their invaluable help and friendship in the field resulted in the formation of more extensive land areas in Sulawesi Since the ophiolite formed in a deep marine setting it would not have acted as References a potential raft for biota 5 Microcontinental fragments accreted onto Achmad, Z and Samuel, L 1984 Stratigraphy and depositional cycles in the N E Kalimantan Basin Indo- eastern Sulawesi in the Miocene to Pleistocene nesian Petroleum Association Proceedings 13th Annual may have been emergent as they drifted towards Convention 109-120 Sulawesi and allowed island hopping or rafting Addison, R , Harrison, R K , Land, D H and Young, B R for biota of Australian affinity 1983 Volcanogenic tonsteins from Tertiary coal meas- 6 Island hopping routes for the dispersal of or- ures, East Kalimantan, Indonesia International Journal of Coal Geology 3: 1-30 ganisms between Borneo-Sulawesi and the Phil- Agostinelli, E , Mohamad Raisuddin bin Ahmad Tajuddin, ippines may have existed along volcanic arcs, Antonielli, E and Mohamad bin Mohd Aris 1990 such as the long-lived North Sulawesi arc, the Miocene-Pliocene palaeogeographic evolution of a tract Sulu and Sangihe arcs, and the Cagayan arc of Sarawak offshore between Bintulu and Miri Bulletin 7 The uplift and subsequent erosion of Borneo of the Geological Society of Malaysia 27: 117-135 Armin, R A , Cutler, W G , Mahadi and Weerd, A van de since the late Oligocene and the emergence of 1987 Carbonate platform, slope and basinal deposits of more extensive land areas in Sulawesi led to the Upper Oligocene, Kalimantan, Indonesia (abstract) progressive reduction in width of the Makassar American Association of Petroleum Geologists Bulletin Straits This may have facilitated the interchange 71: 526 of biota during the later part of the Tertiary, par- Audley-Charles, M G 1974 Sulawesi In Mesozoic-Cenozoic Orogenic Belts pp 365-378 Edited by A M Spencer ticularly during periods of relative sea level lows Geological Society of London Special Publication 4 when large areas of shallow marine shelves may Audley-Charles, M G 1981 Geological history of the region have become emergent of Wallace’s line In Wallace’s line and plate tectonics 8 Although Borneo and western Sulawesi re- pp 24-35 Edited by T C Whitmore Clarendon Press, Oxford Monographs on Biogeography 1 mained in near tropical latitudes throughout the Audley-Charles, M G 1987 Dispersal of Gondwanaland: Tertiary, the wide variety of micro-environments relevance to evolution of the Angiosperms In Biogeo- shown by the palaeogeographic maps would graphical Evolution of the Malay archipelago pp 3-25 have led to niche partitioning This partially ex- Edited by T C Whitmore Clarendon Press, Oxford plains the higher number of endemic species in Monographs on Biogeography 4 Audley-Charles, M G , Hurley, A M and Smith, A G 1981 Borneo compared with Sumatra, which other- Continental movements in the Mesozoic and Cenozoic wise does show a marked similarity in fauna and In Wallace’s line and plate tectonics pp 9-23 Edited by flora with Borneo T C Whitmore Clarendon Press, Oxford Monographs 152 S& J& Moss and M& E& J& Wilson

on Biogeography 1 tional Symposium on Sequence Stratigraphy in SE Asia Aziz, F 1994 Vertebrate faunal evolution of Sulawesi Is- Edited by C A Caughey, D C Carter, J Clure, M J land, Indonesia, during the late Neogene In Pacific Gresko, P Lowry, R K Park and A Wonders Indone- Neogene events in time and space pp 79-85 Edited by sian Petroleum Association: 345-361 R Tsuchi IGCP 246 Clennell, M B 1992 The melanges of Sabah, Malaysia Balgooy, M M J 1987 A plant biogeographical analysis of Ph D Thesis, University of London Sulawesi In Biogeographical Evolution of the Malay ar- Cloke, I R , Moss, S J and Craig, J 1997 The influence of chipelago pp 94-102 Edited by T C Whitmore Claren- basement reactivation on the extensional and inversional don Press, Oxford Monographs on Biogeography 4 history of the Kutai Basin, Eastern Kalimantan Journal of Balgooy, M M J , Hovenkamp, P H and Welzen, P C van the Geological Society of London 154: 157-161 1996 Phytogeography of the Pacific — floristic and his- Coffield, D Q , Bergman, S C , Garrard, R A , Guritno, N , torical distribution patterns in plants In The origin and Robinson, N M and Talbot, J 1993 Tectonic and evolution of Pacific island biotas, New Guinea to eastern stratigraphic evolution of the Kalosi PSC area and associ- Polynesia: patterns and processes pp 191-213 Edited by ated development of a Tertiary petroleum system, south A Keast and S A Miller SPB Academic Publishing bv, Sulawesi, Indonesia Proceedings of the Indonesian Pe- Amsterdam troleum Association 22nd Annual Convention: 679-706 Beddoes, L R 1980 Hydrocarbon plays in Tertiary Basins Cranbrook, Earl of 1981 The vertebrate faunas In of southeast Asia Paper presented at the Offshore SE Wallace’s line and plate tectonics pp 57-69 Edited by T Asia Conference, Singapore SE Asia Petroleum Explora- C Whitmore Clarendon Press, Oxford Monographs on tion Society (SEAPEX): 18 Biogeography 1 Bemmelen, R W van 1949 The Geology of Indonesia Vol Daly, M C , Cooper, M A , Wilson, I , Smith, D G and 1a Government Printing Office, The Hague, Nether- Hooper, B G D 1991 Cenozoic plate tectonics and ba- lands 732 pp sin evolution in Indonesia Marine and Petroleum Geol- Ben-Avraham, Z and Emery, K O 1973 Structural frame- ogy 8: 2-21 work of the Sunda Shelf American Association of Petro- Davies, I C 1990 Geological and exploration review of the leum Geologists Bulletin 57: 2323-2366 Tomori PSC, Eastern Indonesia Proceedings of the Indone- Bergman, S C , Coffield, D Q , Talbot, J P and Garrard, R sian Petroleum Association 19th Annual Convention: 41-67 A 1996 Tertiary tectonic and magmatic evolution of Davies, I 1992 The Gulf of Bone: an opening for explora- western Sulawesi and the Makassar Strait: evidence for a tion? Eastern Indonesian Symposium (abstract): 2 Miocene continent-continent collision In Tectonic evo- Davidson, J W 1991 The geology and prospectivity of lution of SE Asia pp 391-429 Edited by R Hall and D J Buton island, S E Sulawesi, Indonesia Proceedings of Blundell Geological Society of London Special Publica- the Indonesian Petroleum Association 20th Annual Con- tion 106 vention: 209-233 Bishop, W P 1980 Structure, stratigraphy and hydrocar- de Jong, R 1990 Some aspects of the biogeography of the bons offshore southern Kalimantan, Indonesia American Hesperiidae (Lepidoptera, Rhopalocera) of Sulawesi In Association of Petroleum Geologists Bulletin, 64: 37-58 Insects and the rain forests of south East Asia (Wallacea) Bransden, P J E and Matthews, S J 1992 Structural and pp 35-43 Edited by W J Knight and J D Holloway stratigraphic evolution of the East Java Sea Indonesia Royal Entomological Society, London Indonesian Petroleum Association, Proceedings 21st An- Dickerson, R E 1928 Distribution of life in the Philippines nual Convention: 417-454 Bureau of Printing, Manila Briggs, J C 1987 Biogeography and Plate Tectonics Devel- Doust, H 1981 Geology and exploration history of offshore opments in Palaeontology and Stratigraphy 10 Elsevier, central Sarawak In Energy Resources of the Pacific Re- Amsterdam gion pp 117-132 Edited by M T Halbouty American Burollet, P F and Salle, C 1981 Seismic reflection profiles Association of Petroleum Geologists, Studies in Geology 12 in the Makassar Strait In The Geology and Tectonics of Dransfield, J 1981 Palms and Wallace’s line In Wallace’s Eastern Indonesia pp 273-276 Edited by A J Barber line and plate tectonics pp 43-56 Edited by T C and S Wiryosujono Geological Research and Develop- Whitmore Clarendon Press, Oxford Monographs on Bio- ment Centre, Bandung, Special Publication 2 geography 1 Burrett, C , Duhig, N , Berry, R and Varne, R 1991 Asian Dransfield, J 1987 Bicentric distribution in Malesia as ex- and south-western Pacific continental terranes derived emplified by palms In Biogeographical Evolution of the from Gondwana, and their biogeographic significance Malay archipelago pp 60-72 Edited by T C Whitmore In Austral Biogeography Edited by P Y Ladiges, C J Clarendon Press, Oxford Monographs on Biogeography 4 Humphries and L W Martinelli, Australian Systematic Duffels, J P 1990 Biogeography of Sulawesi cicadas Botany 4: 13-24 (Homoptera: Cicadoidea) In Insects and the rain forests Carey, S W 1975 Tectonic evolution of southeast Asia Pro- of south East Asia (Wallacea) pp 63-72 Edited by W J ceedings of the Indonesian Petroleum Association 4th Knight and J D Holloway Royal Entomological Society, Annual Convention: 17-48 London Carlile, J C , Digdowirogo, S and Darius, K 1990 Geologic Fortuin, A R , Smet, M E M de , Hadiwasastra, S , Marle, L setting, characteristics and regional exploration for gold J van, Troelstra, S R and Tjokrosapoetro, S 1990 Late in the volcanic arcs of North Sulawesi, Indonesia In Cenozoic sedimentary and tectonic history of south Epithermal gold mineralization of the Circum Pacific: Buton, Indonesia Journal of southeast Asian Earth Sci- Geology, Geochemistry, Origin and Exploration pp ences 4: 107-124 105-140 Edited by J W Hedenquist, N C White and G Garrard, R A , Supandjono, J B and Surono 1988 The Siddeley Journal of Geochemical Exploration 35 geology of the Banggai-Sula microcontinent, eastern In- Carter, I S and Morley, R J 1996 Ultilizing outcrop and donesia Proceedings of the Indonesian Petroleum Asso- palaeontological data to determine a detailed sequence ciation 17th Annual Convention: 23-52 stratigraphy of the early Miocene sediments of the Kutei George, W 1981 Geological history of the region of Basin, East Kalimantan In Proceedings of the Interna- Wallace’s line In Wallace’s line and plate tectonics pp Tertiary palaeogeography of Sulawesi and Borneo 153

3-8 Edited by T C Whitmore Clarendon Press, Oxford 235: 149-180 Monographs on Biogeography 1 Lee, T -Y and Lawver, L A 1995 Cenozoic plate recon- Gressitt, J L 1961 Problems in zoogeography of Pacific and struction of Southeast Asia Tectonophysics 251: 85-138 Antarctic insects Pacific Insects Monograph 2: 1-94 Leeuwen, T M van 1981 The geology of southwest Guntoro, A 1995 Tectonic evolution and crustal structure Sulawesi with special reference to the Biru area In The of the central Indonesian region from geology, gravity Geology and Tectonics of Eastern Indonesia pp 277- and other geophysical data Ph D Thesis University of 304 Edited by A J Barber and S Wiryosujono Geologi- London 335 pp cal Research and Development Centre, Bandung, Special Hall, R 1996 Reconstructing Cenozoic SE Asia In Tectonic Publication 2 evolution of SE Asia pp 153-184 Edited by R Hall and Leeuwen, T van, Leach, T , Hawke , A A , and Hawke, M D J Blundell Geological Society of London Special Pub- M 1990 The Kelian disseminated gold deposit, East lication 106 Kalimantan, Indonesia In Epithermal gold mineralization Hall, R 1998 The plate tectonics of Cenozoic SE Asia and of the Circum Pacific: Geology, Geochemistry, Origin the distribution of land and sea In Biogeography and and Exploration pp 1-62 Edited by J W Hedenquist, N Geological Evolution of SE Asia Edited by R Hall and J C White and G Siddeley Journal of Geochemical Explo- D Holloway (this volume) ration 35 Haq, B V , Hardenbol, J and Vail, P R 1987 Chronology of Lloyd, A R 1978 Geological evolution of the South China fluctuating sea levels since the Triassic Science 235: Sea SEAPEX Proceedings 4: 95-137 1156-1167 Ludmadyo, E , McCabe, R , Harder, S and Lee, T 1993 Bor- Haq, B V , Hardenbol, J and Vail, P R 1988 Mesozoic and neo: a stable portion of the Eurasian margin since the Cenozoic chronostratigraphy and cycles of sea level Eocene Journal of Southeast Asian Earth Sciences 8: 225-231 change In Sea-Level Changes — An Integrated Ap- Kottelat, M , Whitten, A J , Kartikasari, S N and proach pp 71-108 Edited by C K Wilgus et al , SEPM Wirjoatmodjo, S 1993 Freshwater Fishes of Western In- Special Publication, 42 donesia and Sulawesi Periplus Editions Hasan, K 1991 The Upper Cretaceous flysch succession of Kusuma, I and Darin, T 1989 The hydrocarbon potential the Balangbaru Formation, Southwest-Sulawesi Pro- of the Lower Tanjung Formation, Barito Basin, S E ceedings of the Indonesian Petroleum Association 20th Kalimantan Indonesian Petroleum Association Proceed- Annual Convention: 183-208 ings 18th Annual Convention 1: 107-138 Hamilton, W 1979 Tectonics of the Indonesian region MacKinnon, K , Hatta, G , Halim, H and Mangalik, A 1996 United States Geological Survey Professional Paper 1078: The Ecology of Kalimantan Periplus Editions 802 pp 345 pp Mayr, E 1944 Wallace’s line in the light of recent Heryanto, N , Williams, P R , Harahap, B H and Pieters, P zoogeographic studies Quarterly Review of Biology 19: E 1993 Geology of the Sintang sheet area Kalimantan 1-14 1:250,000 Geological Research and Development Cen- Metcalfe, I 1998 Palaeozoic and Mesozoic geological evo- tre, Bandung, Indonesia lution of the SE Asian region: multi-disciplinary con- Holloway, J D 1987 Lepidoptera patterns involving straints and implications for biogeography In Biogeogra- Sulawesi: what do they indicate of past geography? In phy and Geological Evolution of SE Asia Edited by R Biogeographical Evolution of the Malay archipelago pp Hall and J D Holloway (this volume) 103-118 Edited by T C Whitmore Clarendon Press, Michaux, B 1994 Land movements and animal distribu- Oxford Monographs on Biogeography 4 tions in east Wallacea (eastern Indonesia, Papua new Holloway, J D 1990 Patterns of moth speciation in the Guinea and Melanesia) Palaeogeography, Palaeoclima- Indo-Australian archipelago In The unity of evolutionary tology, Palaeoecology 112: 323-343 biology pp 340-370 Edited by E C Dudley Michaux, B 1996 The origin of southwest Sulawesi and Dioscorides Press, Portland, Oregon other Indonesian terranes: a biological view Palaeoge- Holloway, J D 1997 Sundaland, Sulawesi and eastwards: a ography, Palaeoclimatology, Palaeoecology 122: 167- zoogeographic perspective Malayan Nature Journal 50: 183 207-227 Monnier, C , Girardeau, J , Maury, R C and Cotten, J 1995 Holmes, D and Phillipps, K 1996 The birds of Sulawesi Back-arc basin for the East Sulawesi ophiolite (eastern Oxford University Press 86 pp Indonesia) Geology 23: 851-854 Hope, G 1996 Quaternary change and the historical Morley, R J 1998 Palynological evidence for Tertiary plant biogeography of Pacific islands In The origin and dispersals in the SE Asian region in relation to plate tec- evolution of Pacific island biotas, New Guinea to eastern tonics and climate In Biogeography and Geological Evo- Polynesia: patterns and processes pp 165-190 Edited by lution of SE Asia Edited by R Hall and J D Holloway A Keast and S A Miller SPB Academic Publishing bv, (this volume) Amsterdam Morley, R J and Flenley, J R 1987 Late Cainozoic Hutchison, C S 1989 Geological evolution of South-East vegetational and environmental changes in the Malay Asia Clarendon Press Oxford 368 pp archipelago In Biogeographical Evolution of the Malay Hutchison, C S 1996 The ‘Rajang Accretionary Prism’ and archipelago pp 50-59 Edited by T C Whitmore Claren- ‘Lupar Line’ problem of Borneo In Tectonic evolution of don Press, Oxford Monographs on Biogeography 4 SE Asia pp 247-261 Edited by R Hall and D J Blundell Moss, S J 1998 Late Cretaceous-Palaeogene turbidites in Geological Society of London Special Publication 106 Kalimantan/Sarawak: are they really part of an accretion- Land, D H and Jones, C M 1987 Coal geology and explo- ary complex? Journal of the Geological Society of Lon- ration of part of the Tertiary Kutai Basin in East don, in press Kalimantan, Indonesia In Coal and Coal-bearing Strata: Moss, S J and Finch, E M 1998 New nannofossil and Recent Advances pp 235-255 Edited by A C Scott foraminiferal determinations from East and West Geological Society Special Publication 32 Kalimantan and their implications Journal of Southeast Lee, T -Y and Lawver, L A 1994 Cenozoic plate recon- Asian Earth Sciences, in press structions of the South China Sea region Tectonophysics Moss, S J , Chambers, J , Cloke, I , Carter, A , Dharma Satria, 154 S& J& Moss and M& E& J& Wilson

Ali, J R , and Baker, S 1997 New observations on the Société géologique de France, 8 (VI), 889-905 sedimentary and tectonic evolution of the Tertiary Kutai Rice-Oxley, E D 1991 Palaeoenvironments of the Lower Basin, East Kalimantan In Petroleum Geology of South- Miocene to Pliocene sediments in offshore NW Sabah east Asia pp 395-416 Edited by A Fraser, S J Matthews area Bulletin of the Geological Society of Malaysia 28: and R W Murphy Geological Society of London Special 165-194 Publication 126 Rose, R and Hartono P 1978 Geological evolution of the Moss, S J , Carter, A , Hurford, A and Baker, S 1998 A Late Tertiary Kutei-Melawi Basin, Kalimantan, Indonesia In- Oligocene tectono-volcanic event in East Kalimantan donesian Petroleum Association Proceedings 7th Annual and the implications for tectonics and sedimentation in Convention 1: 225-252 Borneo Journal of the Geological Society of London 155: Saller, A , Armin, R , La Ode Ichram and Glenn-Sullivan, C 177-192 1992 Sequence stratigraphy of Upper Eocene and Mubroto, B , Briden, J C , McClelland, E and Hall, R 1994 Oligocene limestones, Teweh area, central Kalimantan Palaeomagnetism of the Balantak ophiolite, Sulawesi Indonesian Petroleum Association Proceedings 21st An- Earth and Planetary Science Letters 125: 193-209 nual Convention 1: 69-92 Musser, G G 1987 The mammals of Sulawesi In Biogeo- Saller, A , Armin, R , La Ode Ichram and Glenn-Sullivan, C graphical Evolution of the Malay archipelago pp 73-94 1993 Sequence stratigraphy of aggrading and Edited by T C Whitmore Clarendon Press, Oxford backstepping carbonate shelves, Oligocene, Central Monographs on Biogeography 4 Kalimantan, Indonesia In Carbonate Sequence Netherwood, R and Wight, A 1992 Structurally controlled, Stratigraphy: Recent Developments and Applications pp linear reefs in a Pliocene delta-front setting, Tarakan Ba- 267-290 Edited by R G Loucks and J F Sarg American sin, Northeast Kalimantan In Carbonate rocks and reser- Association of Petroleum Geologists Memoir 57 voirs of Indonesia pp 3 1 3-3 1 36 Edited by C T Sartono, S 1982 Genesa Danau Tempe, Sulawesi Selatan Siemers, M W Longman, R K Park and J G Kaldi A Pertumuan Arkeologi 2: 555-560 core workshop held in conjunction with 1992 Indone- Siemers, C T , Sutiyono, S and Wiman, S K 1992 Descrip- sian Petroleum Association Annual Convention 1 tion and reservoir characterization of a late Miocene, Parkinson, C D 1991 The petrology, structure and geo- delta-front coral-reef buildup, Serang Field, Offshore East logic history of the metamorphic rocks of central Kalimantan, Indonesia In Carbonate rocks and reservoirs Sulawesi, Indonesia Ph D Thesis, University of London, of Indonesia pp 5 1 5-5 1 27 Edited by C T Siemers, M 337 pp W Longman, R K Park and J G Kaldi A core workshop Peltzer, G and Tapponnier, P 1988 Formation and evolu- held in conjunction with 1992 Indonesian Petroleum As- tion of strike-slip faults, rifts, and basins during the India- sociation Annual Convention 1 Asia collision: an experimental approach Journal of Silver, E A , Joyodiwiryo, Y and McCaffrey, R 1978 Gravity Geophysical Research 93: 15085-15117 results and emplacement geometry of the Sulawesi Pieters, P E and Supriatna, S 1990 Geological Map of the ultramafic belt, Indonesia Geology 6: 537-531 West, Central and East Kalimantan Area 1:1,000,000 Simandjuntak, T O 1986 Sedimentology and Tectonics of Geological Research and Development Centre, the Collision Complex in the east arm of Sulawesi Ph D Bandung, Indonesia Thesis University of London 374 pp Pieters, P E , Abidin, H Z and Sudana, D 1993a Geology Simandjuntak, T O 1990 Sedimentology and tectonics of of the Long Pahangai sheet area, Kalimantan 1:250,000 the collision complex in the east arm of Sulawesi, Indo- Geological Research and Development Centre, nesia Geologi Indonesia Journal of the Indonesian As- Bandung, Indonesia sociation of Geologists 13: 1-35 Pieters, P E , Surono, and Noya, Y 1993b Geology of the Situmorang, B 1982 The formation and evolution of the Puttissibau sheet area, Kalimantan 1:250,000 Geological Makassar Basin as determined from subsidence curves Research and Development Centre, Bandung, Indonesia Indonesian Petroleum Association Proceedings 11th An- Pieters, P E , Trail, D S and Supriatna, S 1987 Correlation nual Convention 1: 83-107 of Early Tertiary rocks across Kalimantan Indonesian Smith, R B and Silver, E A 1991 Geology of a Miocene Petroleum Association Proceedings 16th Annual Conven- collision complex, Buton, eastern Indonesia Geological tion 1: 291-306 Society of America Bulletin 103: 660-678 Pigram, C J and Panggabean, H 1984 Rifting of the north- Steenis, C G G J van 1979 Plant geography of east ern margin of the Australian continent and the origin of Malesia Botanical Journal of the Linnean Society, 79: 97-178 some microcontinents in eastern Indonesia Stuart, C J , Schwing, H F , Armin, R A , Sidik, B , Tectonophysics 107: 331-353 Abdoerrias, R , Vijaya, S , Boer, W D de, Wiman, S K , Polvé, M , Maury, R C , Bellon, H , Rangin, C , Priadi, B, Heitman, H L , Yusuf, S K and Nurhono, A 1996 Se- Yuwono, S , Joron, J L and Soeria Atmadja, R 1997 quence stratigraphic studies in the lower Kutai Basin, Magmatic evolution of Sulawesi (Indonesia): constraints East Kalimantan, Indonesia In Proceedings of the Inter- on the Cenozoic geodynamic history of the Sundaland national Symposium on Sequence Stratigraphy in SE active margin Tectonophysics 272: 69-92 Asia pp 363-368 Edited by C A Caughey et al Indone- Pupilli, M 1973 Geological evolution of South China Sea sian Petroleum Association, Jakarta, Indonesia area tentative reconstruction from borderland geology Sukamto, R 1975 The structure of Sulawesi in the light of and well data Indonesian Petroleum Association Pro- plate tectonics Regional Conference on the Geology and ceedings 2nd Annual Convention 1: 223-241 mineral resources of SE Asia, Jakarta: 1-25 Rangin, C and Silver, E 1990 Geological setting of the Sukamto, R and Supriatna, S 1982 Geologi lembar Ujung Celebes and Sulu Seas In Initial Reports of the Ocean Pandang, Benteng dan Sinjai quadrangles, Sulawesi Drilling Program 124 pp 35-42 Edited by C Rangin, E Geological Research and Development Centre, A Silver and M T von Breymann Bandung, Indonesia Rangin, C , Jolivet, L and Pubellier, M 1990 A simple Sunaryo, R , Martodjojo, S and Wahab, A 1988 Detailed model for the tectonic evolution of southeast Asia and geological evaluation of the hydrocarbon prospects in Indonesia region for the past 43 m y Bulletin de la the Bungalun area, East Kalimantan Indonesian Petro- Tertiary palaeogeography of Sulawesi and Borneo 155

leum Association Proceedings 17th Annual Convention Annual Convention 1: 55-78 1: 423-446 Wakita, K , Munasri, Sopaheluwakan, J , Zulkarnain, I and Sunyata, and Wahyono 1991 VI Palaeomagnetism In Miyazaki, K 1994 Early Cretaceous tectonic events im- Studies in East Asian Tectonics and Resources (SEATAR): plied in the time-lag between the age of radiolarian chert Crustal transect VII Java-Kalimantan-Sarawak-South and its metamorphic basement in the Bantimala area, China Sea Edited by C S Hutchison CCOP 26: 66 pp South Sulawesi, Indonesia The Island Arc 3: 90-102 Supriatna, S , Santosa, S and Djamal, B 1993 Geologi Wallace, A R 1863 On the physical geography of the Malay Lembar Muaralesan, Kalimantan Timur Kolokium Hasil archipelago Journal Royal Geographical Society 33: 217-234 Pemetaan dan Penelitian Puslitbang Geologi, 1991/1992 Weerd, A A , van de and Armin, R A 1992 Origin and Geological Research and Development Centre Special evolution of the Tertiary hydrocarbon bearing basins in Publication 14: 20-30 Kalimantan (Borneo), Indonesia American Association Suwarna, N , Sutrisno, Keyser, F , de, Langford, R P and of Petroleum Geologists Bulletin 76: 1778-1803 Trail, D S 1993 Geology of the Singkawang sheet area, Weerd, A A , van de , Armin, R A , Mahadi, S and Ware, P Kalimantan, 1:250,000 Geological Research and Devel- L B 1987 Geologic setting of the Kerendan gas and opment Centre, Bandung, Indonesia condensate discovery, Tertiary sedimentary geology and Takhtajan, A 1987 Flowering plant origin and dispersal: paleogeography of the northwestern part of the Kutei The cradle of the angiosperms revisited In Biogeo- Basin, Kalimantan, Indonesia Indonesian Petroleum Asso- graphical Evolution of the Malay archipelago pp 26-31 ciation Proceedings 16th Annual Convention 1: 317-338 Edited by T C Whitmore Clarendon Press, Oxford Weissel, J K 1980 Evidence for Eocene oceanic crust in the Monographs on Biogeography 4 Celebes Basin In The Tectonic and Geologic Evolution of Tanean, H , Paterson, D W and Endharto, M 1996 Source Southeast Asian Seas and Islands pp 37-48 Edited by D provenance interpretation of Kutei basin Sandstones and E Hayes American Geophysical Monograph Series 23 implications for the tectono-stratigraphic evolution of Whitmore, T C 1981a Palaeoclimate and vegetation his- Kalimantan Indonesian Petroleum Association Proceed- tory In Wallace’s line and plate tectonics pp 36-42 Ed- ings 25th Annual Convention 1: 333-345 ited by T C Whitmore Clarendon Press, Oxford Mono- Tate, R B 1991 Cross-correlation of geological formations graphs on Biogeography 1 in Sarawak and Kalimantan Bulletin Geological Society Whitmore, T C 1981b Wallace’s line and some other of Malaysia 28: 63-95 plants In Wallace’s line and plate tectonics pp 70-80 Tate, R B 1994 The sedimentology and tectonics of the Edited by T C Whitmore Clarendon Press, Oxford Temburong Formation — deformation of early Cenozoic Monographs on Biogeography 1 deltaic sequences in NW Borneo Bulletin Geological Whitten, A and Whitten, J 1992 Wild Indonesia World Society of Malaysia 35: 97-112 Wildlife Fund for Nature New Holland, London, 208 pp Tjia, H D , Komoo, I , Lim, P S and Tungah Surat 1990 Whitten, A J , Mustafa, M and Henderson, G S 1987 The The Maliau basin, Sabah: geology and tectonic setting Ecology of Sulawesi, Gadjah Mada University Press 777 pp Bulletin of the Geological Society of Malaysia 27: 261- Wilson, M E J 1995 The Tonasa Limestone Formation, 292 Sulawesi, Indonesia: Development of a Tertiary Carbon- Trail, D S , John, T V , Bird, M C et al 1974 The general ate Platform Ph D Thesis, University of London, 520 pp geological survey of block II, Sulawesi Utara, Indonesia Wilson, M E J and Bosence, D W J 1996 The Tertiary PT Tropical Endeavour Indonesia evolution of South Sulawesi: a record in redeposited car- Truswell, E M , Kershaw, A P and Sluiter, I R 1987 The bonates of the Tonasa Limestone Formation In Tectonic Australian-South-east Asian connection: Evidence from evolution of SE Asia pp 365-389 Edited by R Hall and the palaeobotanical record In Biogeographical Evolu- D J Blundell Geological Society of London Special Pub- tion of the Malay archipelago pp 32-49 Edited by T C lication 106 Whitmore Clarendon Press, Oxford Monographs on Bio- Wilson, M E J and Bosence, D W J 1997 Platform top geography 4 and ramp deposits of the Tonasa carbonate platform, Umbgrove, J H F 1938 Geological history of the East Sulawesi, Indonesia In Petroleum Geology of SE Asia Indies American Association of Petroleum Geologists pp 247-279 Edited by A J Fraser, S J Matthews and R Bulletin 22: 1-70 W Murphy Geological Society of London Special Publi- Vane-Wright, R I 1991 Transcending the Wallace Line: do cation 126 the western edges of the Australian region and the Aus- Yuwono, Y S , Maury, R C , Soeria-Atmadja, P and Bellon, tralian plate coincide In Austral Biogeography Edited H 1987 Tertiary and Quaternary geodynamic evolution by P Y Ladiges, C J Humphries and L W Martinelli, of South Sulawesi: Constraints from the study of volcanic Australian Systematic Botany 4: 183-197 units Geologi Indonesia 13: 32-48 Wain, T and Berod, B 1989 The tectonic framework and Ziegler, B 1983 Introduction to Palaeobiology General paleogeographic evolution of the Upper Kutei Basin Palaeontology Ellis Horwood Series in Geology, Indonesian Petroleum Association Proceedings 18th Chichester, UK 156 S& J& Moss and M& E& J& Wilson Colour plates for:

Biogeographic implications of the Tertiary palaeogeographic evolution of Sulawesi and Borneo

Steve J Moss1 and Moyra E J Wilson SE Asia Research Group, Department of Geology, Royal Holloway University of London 1Now at School of Applied Geology, Curtin University of Technology, Perth, 6845, W)A) Australia

Captions

Fig4 Palaeogeographic map for 50 Ma, early Eocene A key to the environments is shown Note that rivers are shown schematically for all time slices Fig5 Palaeogeographic map for 42 Ma, middle Eocene Fig6 Palaeogeographic map for 34 Ma early Oligocene Fig7 Palaeogeographic map for 21 Ma, early Miocene Fig8 Palaeogeographic map for 8 Ma late Miocene Fig9 Palaeogeographic map for 4 Ma, early Pliocene ?

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Key to palaeoenvironments

Emergent mountainous (left) and low-lying (right) land areas

Fluvial & lacustrine facies showing inferred rivers and palaeoflow direction

Subaerially emergent (left) and submarine (right) volcanic & volcaniclastic lithologies

Shallow-marine carbonate shelf

Shallow-marine clastic shelf

Marginal marine clastics (includes delta & tidal deposits) with coals (black)

Major deltas

Bathyal shales/marls interbedded with proximal (top) to distal (bottom) siliciclastic or carbonate redeposited lithologies

Bathyal shales and marls 50 Ma - early Eocene ?

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Key to palaeoenvironments

Emergent mountainous (left) and low-lying (right) land areas

Fluvial & lacustrine facies showing inferred rivers and palaeoflow direction

Subaerially emergent (left) and submarine (right) volcanic & volcaniclastic lithologies

Shallow-marine carbonate shelf

Shallow-marine clastic shelf

Marginal marine clastics (includes delta & tidal deposits) with coals (black)

Major deltas

Bathyal shales/marls interbedded with proximal (top) 42 Ma - to distal (bottom) siliciclastic or carbonate redeposited lithologies middle Eocene Bathyal shales and marls ? ?

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? ? ? ?Emergent or ? low energy shelf ? ? ? ? ? ?

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Key to palaeoenvironments Emergent mountainous (left) and low-lying (right) land areas

Fluvial & lacustrine facies showing inferred rivers and palaeoflow direction

Subaerially emergent (left) and submarine (right) 34 Ma - volcanic & volcaniclastic lithologies early Oligocene Shallow-marine carbonate shelf Shallow-marine clastic shelf

Marginal marine clastics (includes delta & tidal deposits) with coals (black)

Major deltas

Bathyal shales/marls interbedded with proximal (top) to distal (bottom) siliciclastic or carbonate redeposited lithologies

Bathyal shales and marls ?

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? ?

? ? ? ?

Key to palaeoenvironments

Emergent mountainous (left) and low-lying (right) land areas

Fluvial & lacustrine facies showing inferred rivers and palaeoflow direction

Subaerially emergent (left) and submarine (right) volcanic & volcaniclastic lithologies

21 Ma - Shallow-marine carbonate shelf early Miocene Shallow-marine clastic shelf

Marginal marine clastics (includes delta & tidal deposits) with coals (black)

Major deltas

Bathyal shales/marls interbedded with proximal (top) to distal (bottom) siliciclastic or carbonate redeposited lithologies

Bathyal shales and marls ?

?

? ?

? ? ? ?

?

?

? ? ?

? ? ? ? ? ? ?

Key to palaeoenvironments

Emergent mountainous (left) and low-lying (right) land areas

Fluvial & lacustrine facies showing inferred rivers and palaeoflow direction

Subaerially emergent (left) and submarine (right) volcanic & volcaniclastic lithologies

Shallow-marine carbonate shelf

8 Ma - late Miocene Shallow-marine clastic shelf

Marginal marine clastics (includes delta & tidal deposits) with coals (black)

Major deltas

Bathyal shales/marls interbedded with proximal (top) to distal (bottom) siliciclastic or carbonate redeposited lithologies

Bathyal shales and marls ?

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Key to palaeoenvironments

Emergent mountainous (left) and low-lying (right) land areas

Fluvial & lacustrine facies showing inferred rivers and palaeoflow direction

Subaerially emergent (left) and submarine (right) volcanic & volcaniclastic lithologies 4 Ma - early Pliocene Shallow-marine carbonate shelf Shallow-marine clastic shelf

Marginal marine clastics (includes delta & tidal deposits) with coals (black)

Major deltas

Bathyal shales/marls interbedded with proximal (top) to distal (bottom) siliciclastic or carbonate redeposited lithologies

Bathyal shales and marls