©2005 Society of Economic Geologists, Inc. Economic Geology 100th Anniversary Volume pp. 891–930

Supplement to

Tectonic Setting, Geology, and Gold and Copper Mineralization in Cenozoic Magmatic Arcs of Southeast Asia and the West Pacific

STEVE GARWIN, ROBERT HALL, AND YASUSHI WATANABE (Note: Figure and table numbers correspond to those cited in the printed part of the paper)

APPENDIX 1 Descriptions of the Geologic Settings and Mineral Deposit Styles for Major Cenozoic Magmatic Arcs of Southeast Asia and the West Pacific

Southwestern Kuril intrusions and domes of the Miocene bimodal assemblage. The host rocks of these deposits are Cretaceous to Paleogene Geologic setting: The Miocene to Recent Kuril magmatic sedimentary rocks and Miocene sedimentary and volcanic arc extends approximately 2,200 km from the northeastern rocks. These deposits occur mainly as gold-bearing quartz- Kamchatka peninsula to southwestern Hokkaido, where it adularia veins in the east-northeasterly strike-slip faults, connects to the Aleutian and northeastern Japan arcs, respec- whereas some of them are disseminated in the host rocks tively (Fig. 11; Table 1). The southwestern portion of the (Watanabe, 1995). The timing of the epithermal gold miner- Kuril arc is associated with the Kuril backarc basin, which alization ranges from 14 to 4 Ma, with a hiatus from 12 to 8 formed before the middle Miocene, due to northeast-south- Ma, which corresponds to the period of the backarc basin vol- west rifting (Baranov et al., 2002). The basement rocks of the canism. A few 3 to 1.5 Ma low-sulfidation gold deposits are southwestern Kuril arc consist of a Mesozoic accretionary also located near the present andesitic volcanic front (Yahata complex with a cover of Cretaceous and Paleogene sedimen- et al., 1999). Representative deposits in northeast Hokkaido tary rocks. Eocene to middle Miocene ilmenite-series grani- are Konomai (73.2 t Au, 1,243 t Ag), Sanru (6.7 t Au, 46.4 t toids intrude the basement rocks (Ishihara et al., 1998). The Ag), and Itomuka (3,086 t Hg). volcanism of the southwestern Kuril arc has changed from Small volcanic islands in the middle and northeastern parts middle Miocene andesitic activity to middle to late Miocene of the Kuril arc have not been well explored. The middle and bimodal basalt and rhyolite, including a period from 12 to 8 northeastern parts contain polymetallic base metal vein-type Ma with basalt-only volcanism. The andesitic and bimodal prospects of middle and late Miocene age, which are associ- volcanic activity migrated trenchward during the middle ated with intrusive rocks (Ishihara, 1994). Miocene (Watanabe, 1995). The middle to late Miocene bi- modal and basalt-only volcanism occurred mainly in a north- Japan (northeastern and southwestern) south–trending graben perpendicular to the arc trend Geologic setting: The Japan arc extends approximately (Watanabe, 1995). The basalts of the Miocene bimodal as- 1,800 km from southwest Hokkaido to north Kyushu, where semblage changed from island-arc type at 13 to 11 Ma to it connects to the Kuril and Ryukyu arcs, respectively (Fig. backarc basin basalt at 9 to 7 Ma and again changed into is- 11; Table 1). The arc has a concave configuration toward the land-arc type at 5 to 4 Ma (Ikeda et al., 2000). Since the Pacific Ocean, consisting of a north-trending northeast seg- Pliocene, bimodal volcanism in the backarc has disappeared ment and east-trending southwest segment. Presently these and andesitic volcanic activity at the volcanic front has be- segments are bounded by a major fault zone (Itoigawa- come dominant. This Plio-Pleistocene activity was associated Shizuoka tectonic line), which also marks the boundary be- with formation of calderas several to ten kilometers in diam- tween the North American and Eurasian plates (Uyeda, eter, which erupted large amounts of felsic ignimbrite (Ikeda, 1991). The Izu-Bonin arc is connected with the Japan arc 1991). near the joint between the northeast and southwest segments, East-northeasterly trending right-lateral strike-slip faults and the Pacific and Philippine Sea plates subduct beneath the were active during the late middle Miocene nearby the vol- northeast and southwest segments, respectively. canic front of the southwestern Kuril arc due to oblique sub- The basement rocks of the Japan arc consist of continental duction of the Pacific plate (Watanabe, 1995). This fault blocks of Permian-Triassic gneiss (the Hida belt, central movement led to the westward migration and collision of the Japan) and high pressure-temperature schist, and a Jurassic Kuril forearc sliver with the northeastern Japan arc at south- accretionary complex (Isozaki, 1997a, b). Mesozoic and ern Hokkaido, forming the present concave joint between the Paleogene I-type granitoids related to oceanic plate subduc- Kuril and northeastern Japan arcs (Kimura et al., 1983). tion intruded into these basement rocks (Ishihara and Sasaki, Mineral deposit styles: More than 40 low-sulfidation ep- 1991). The Japan arc was a part of the Eurasian continent ithermal gold and mercury deposits and prospects are distrib- until latest Oligocene but was separated from the continent uted in northeast Hokkaido at the southwestern Kuril arc due to backarc spreading mainly along the Japan and Yamato (Fig. 11, App. 2). They are associated mainly with rhyolitic basins during the early Miocene, with about 60º clockwise

1 2 and counterclockwise rotation of the southwest and northeast Some Kuroko-type gypsum deposits are distributed in the segments, respectively (Otofuji et al., 1985; Hoshi and Taka- backarc in the southwest segment of the Japan arc (Sato, hashi, 1999). 1974). An Re-Os age of the Wanibuchi deposit in the south- Since the early Miocene, arc volcanism has been active in west segment, 18.4 ± 0.6 Ma (Terakado, 2001), is older than both segments. This volcanism is divided into rift-related ac- the range of ages (15.4–12.4 Ma; Sawai and Itaya, 1993) for tivity including bimodal volcanism of basalt and rhyolite in Kuroko mineralization in the northeast segment, suggesting the backarc during the early-middle Miocene and subduc- that Kuroko-style settings occurred slightly earlier in the tion-related andesite-dacite activity during the late Miocene, southwest segment than in the northeast segment of the Pliocene, and Quaternary (Tsuchiya, 1990, Nakajima et al., Japan arc. 1995; Kimura et al., 2003). Rift-related basaltic activity Some middle (or early) Miocene epithermal Au-Ag de- occurred during the Plio-Pleistocene in northern Kyushu, at posits occur in the northeast segment of the Japan arc and are the western end of the southwest segment of the Japan arc. related to felsic volcanism (Watanabe, 2002). These include This rifting is related to the backarc spreading along the Oki- the Sado deposit (72.7 t Au, 2,278 t Ag), which has character- nawa trough (Kamata and Kodama, 1999). istics of an intermediate-sulfidation type. Because different The tectonic regime of the northeast segment of the arc sets of mineralization ages, 24.4 to 22.1 Ma (Ministry of In- since the Miocene has changed from early to middle Miocene ternational Trade and Industry, 1987a) and 14.5 to 13.4 Ma extension, characterized by arc-parallel normal faulting with (Shikazono and Tsunakawa, 1982), are reported for the de- rifted basins, to late Pliocene to Quaternary shortening with posit, the relationship between the Kuroko and epithermal arc-parallel thrusting and folding, through a late Miocene to mineralization is not clear. early Pliocene transitional regime without significant tectonic Late Miocene to Pleistocene Cu-Pb-Zn-Ag epithermal and deformation (Sato, 1994). The middle Miocene rifting and re- Au-Ag epithermal deposits are mainly distributed in the lated bimodal volcanism is best developed in the middle part northeast segments of the Japan arc, associated with calc-al- of the northeast segment. Bimodal volcanism is not clear or kaline andesite-dacite volcanism in a terrestrial environment. mixed with andesite-dacite volcanism in the northern and These deposits are mostly of vein type and hosted by southern margins of the northeast segment, where the Okhotsk transtensional faults. Although there are numerous mineral continental block and the Izu-Bonin arc have collided with prospects of late Miocene age, economic deposits were the Japan arc during the middle Miocene, respectively (Kimura mainly formed during the Pliocene or Pleistocene in an arc et al., 1983; Amano, 1991. East-northeasterly trending right- setting (Watanabe, 2002). Epithermal deposits during this pe- lateral strike-slip faulting occurred during the Pliocene in the riod are classified into intermediate- or high-sulfidation types, northern part of the northeast segment due to the westward but the high-sulfidation deposits are small (Watanabe, 2002). migration of the frontal Kuril arc (Watanabe, 1990). Representative deposits are the Chitose intermediate-sulfida- Significant faulting and folding have not been recognized in tion (18 t Au, 83 t Ag), Teine high- and intermediate-sulfida- the southwest segment of the Japan arc during the Miocene tion (9 t Au, 130 t Ag), Toyoha polymetallic epithermal (1.8 and Pliocene. Since the latest Pliocene, east-trending right- Mt Zn, 0.5 Mt Pb, 3,000 t Ag, 10 t Au), Takatama intermedi- lateral strike-slip faulting has occurred along the Median tec- ate-sulfidation (28.7 t Au, 280 t Ag), and Ashio xenothermal tonic line and other tectonic zones, as well as thrusting along (0.6 Mt Cu) deposits. the north-northwest–trending Itoigawa-Shizuoka tectonic An epithermal gold province occurs in northern Kyushu, ine. These tectonic movements are ascribed to the oblique where backarc rifting along the Okinawa trough has extended subduction of the Philippine Sea plate beneath the southwest into the arc. The province contains about 20 low-sulfidation segment of the Japan arc (Itoh et al., 2002) and convergence deposits of Plio-Pleistocene age, associated with intermediate between the North American and Eurasian plates (Uyeda, to felsic volcanism in and around the Beppu-Shimabara 1991), respectively. graben (Sawai and Nagao, 2003). These include the Taio de- Mineral deposit styles: Metallic mineral deposits of the Japan posit (36.0 t Au, 137 t Ag). arc include middle Miocene Cu-Pb-Zn (-Ag-Au) Kuroko de- posits and late Miocene to Pleistocene Cu-Pb-Zn and Au-Ag Izu-Bonin epithermal deposits (Fig 10; Watanabe, 2002). About 70 Geologic setting: The north-trending Izu-Bonin arc extends Kuroko deposits, including massive gypsum and barite de- approximately 1,200 km from the Izu peninsula of Honshu Is- posits, have been discovered in the 800-km-long northeast seg- land to the Iwo-jima Islands at 25º N and 142º E in the Pacific ment of the Japan arc (Sato, 1974). These deposits are associ- Ocean (Fig. 11; Table 1). This magmatic arc is situated along the ated with monogenetic rhyolite volcanism of the middle eastern margin of the Philippine Sea plate due to northwest- Miocene backarc bimodal assemblage in a submarine environ- ward subduction of the Pacific plate. It connects to the Japan ment. In spite of the wide distribution of the Kuroko deposits arc in the north and the Mariana arc in the south. Rift grabens in the northeast segment, economic deposits are limited to the exist in the backarc of the central portion of the Izu-Bonin, and middle part of the segment. In particular, productive Kuroko the Ogasawara plateau on the Pacific plate is being subducted deposits cluster in submarine calderas in the Hokuroku district. beneath the southern margin of the arc (Tamaki, 1985). Representative deposits in the Hokuroku district are Hanaoka This arc was located farther southwest relative to Japan (0.96 Mt Cu, 1.3 Mt Zn, 0.3 Mt Pb), Shakanai (0.1 Mt Cu, 0.3 when Cenozoic arc magmatism commenced in the middle Mt Zn, 0.1 Mt Pb), Kosaka (0.6 Mt Cu, 1.7 Mt Zn, 0.4 Mt Pb; Eocene, and then the arc moved northeast in response to Ohmoto et al., 1983), and the gold-rich Nurukawa deposit (6.8 clockwise rotation and backarc spreading of the Philippine t Au, 123 t Ag + Zn + Pb + Cu). Sea plate (Seno and Maruyama, 1984; Hall et al., 1995). The

0361-0128/98/000/000-00 $6.00 2 3 arc probably reached its present position by the middle (Figs. 2, 10; Table 1). The arc consists of the Ryukyu trench, Miocene and has collided and accreted to the Japan arc at its forearc islands, an active volcanic belt, and the Okinawa northern end in the Izu peninsula (Amano, 1991; Takahashi trough in the backarc. The Ryukyu arc is related to westward and Saito, 1997). However, some workers (e.g., Hall, 2002) subduction of the Philippine Sea plate beneath the Eurasian suggest this collision took place as late as the Pliocene. This plate at a velocity of 6 to 7 cm/yr (Shinjo, 1999). accretion is inferred to have increased the coupling force be- The basement rocks consist of Permian to Cretaceous tween the arc and subducting Pacific plate (Okino et al., sedimentary or serpentinite mélange, including blocks of 1999). Two stages of arc rifting are recognized, including mid- limestone and metamorphic rocks, and Cretaceous to Paleo- dle Miocene and latest Pliocene to Quaternary. The middle gene sedimentary rocks. These basement rocks are overlain Miocene rifting occurred in the northern part of the backarc by late Cenozoic sedimentary rocks. Middle to late Miocene with north-northwest–trending rift axes, which were trun- ilmenite-series and magnetite-series granitoids intruded the cated by northeast transform faults (Yamazaki and Yuasa, forearc and backarc sides of the northern part of the arc, re- 1998). The latest Pliocene to Quaternary rifting is manifested spectively. This intrusive activity was followed by Pliocene in the central part of the arc by several grabens with north- and Quaternary calc-alkaline andesite volcanism, which is as- trending axes located behind the volcanic front (Taylor, 1992). sociated with rhyolite and dacite in the backarc (Karakida et The oldest island-arc rocks in the Izu-Bonin arc are middle al., 1992). Paleomagnetic data (Kodama et al., 1995) and lo- Eocene (49–48 Ma) island-arc tholeiite and boninite series cations determined from Global Positioning System (GPS) basalt to rhyolite. This volcanism continued for more than 10 data (Nishimura et al., 1999) for the northern part of the arc m.y. and was followed by tholeiitic and calc-alkaline volcanism, indicate that the forearc has rotated counterclockwise with which occurred along the arc until 27 Ma. Arc volcanism be- respect to the backarc part since 2 Ma, resulting in east- came inactive during 23 to 20 Ma, when backarc spreading in trending extension along the Kagoshima graben in south the Shikoku basin was active. Middle Miocene to Holocene Kyushu. In the central and southern part of the arc, middle Izu-Bonin frontal arc volcanism is bimodal (basalt and rhyolite- and late Miocene high Mg andesite and basalt occur with dacite; Taylor, 1992), whereas calc-alkaline andesite and dacite calc-alkaline andesite (Shinjo, 1999). Since the latest characterized the backarc from 12.5 to 2.9 Ma (Ishizuka et al., Pliocene, backarc spreading began in the Okinawa trough 1998). Post-2.8 Ma backarc volcanism consists of clinopyrox- (Sibuet et al., 1998), which is characterized by bimodal vol- ene-olivine basalt associated with rifting (Ishizuka et al., 1998). canism of basalt and rhyolite (Shinjo and Kato, 2000), sea- The tectonic regime of the Izu-Bonin arc has been exten- floor hydrothermal activity and Kuroko-style mineralization sional, characterized by several stages of normal faulting at (Marumo and Hattori, 1999). least since the Oligocene, except along its northern margin, Near Taiwan, the arc is characterized by Eocene pyroclas- where the arc has collided with the Japan arc. Accretion of tic rocks and andesite flows, Miocene marine siliciclastic several microcontinental blocks since the middle Miocene rocks and an active submarine volcano (Hutchison, 1989). has rotated the central part of the Japan arc. This accretion Northern Taiwan lies at the junction between the Ryukyu and also formed an accretionary prism and thrusts in the Japan Luzon arcs, where these two arcs started colliding at 10 Ma forearc (Mazzotti et al., 2002). The Izu block, accreted to the (Teng, 1996). In this region, Plio-Pleistocene centers of mag- Japan arc at about 1 Ma (Amano, 1991), contains northwest- matism (2.8–0.2 Ma; Chung et al., 1995) have migrated west- trending right-lateral and north-northeast–trending left-lat- ward, in part, initiated by the westerly encroachment of the eral strike-slip faults that localize epithermal gold deposits. Ryukyu trench and the southwestward opening of the Oki- Mineral deposit styles: Metallic mineral deposits along the nawa trough (Teng et al., 1992). Backarc extension in the Izu-Bonin arc include Kuroko and epithermal deposits (Fig. Pleistocene led to the emplacement of andesitic to dacitic hy- 11). Kuroko-style submarine hydrothermal mineralization is pabyssal plugs and flows, dated in the Chinkuashih region at presently recognized at Myojin Knoll, Myojinsho, and in the 1.3 to 0.9 Ma (Tan, 1991; Wang et al., 1999). The volcanic Sumisu rift of the Izu-Bonin arc (Glasby, 2000). The gold-rich rocks overlie a Miocene marine sedimentary rock sequence, Cu-Zn-Pb Sunrise deposit at Myojin Knoll is estimated to have similar to that exposed in the Ryukyu arc to the northeast. 9 million tons (Mt) of mineralized material (Iizasa et al., 1999). Mineral deposit styles: The southern Kyushu epithermal Epithermal Au-Ag deposits are located in the Izu peninsula gold province in the northern Ryukyu arc contains Plio-Pleis- at the northern end of the Izu-Bonin arc. These include tocene low-sulfidation deposits, represented by Hishikari Seigoshi (16.0 Au, 511 Ag), Toi (12.1 t Au; 94 t Ag), Mochikoshi (260 t Au, 208 t Ag), Yamagano, (28.4 t Au, 28.3 t Ag), and (4.9 t Au, 104 t Ag), and others. These deposits consist of Okuchi (22.2 t Au, 17.0 t Ag) with a few high-sulfidation de- northwest- or north-northeast–trending, gold-bearing adu- posits, such as Akeshi (8.9 t Au, 4.7 t Ag), Kasuga (8.8 t Au, laria-quartz veins oriented subparallel to regional strike-slip 5.0 t Ag), and Iwato (8.1 t Au, 13.7 t Ag), and the Kushikino faults. These veins have characteristics of an intermediate- or intermediate-sulfidation deposit (55.9 t Au, 477 t Ag; Fig. 11; low-sulfidation type. Mineralization ages vary from 2.5 to 1.4 Izawa and Watanabe, 2001). These deposits cluster on the Ma, which corresponds to a period of bimodal volcanism of western side of the Kagoshima graben (Izawa and Urashima, basalt and rhyolite-dacite, as well as andesitic volcanism 1987). Epithermal gold mineralization in the province started (Ministry of International Trade and Industry, 1987b). with Pliocene high- and intermediate-sulfidation deposits in the west of the province (Kushikino, 3.7–3.4 Ma; Kasuga. Ryukyu 5.5–5.3 Ma; Iwato, 4.7–4.2 Ma, and Akeshi, 3.7 Ma) and has Geologic setting: The Ryukyu arc extends approximately extended eastward with time to form Pleistocene low-sulfida- 1,200 km from southern Kyushu Island in Japan to Taiwan tion deposits (Okuchi, 1.6–1.2 Ma; Hishikari, 1.1–0.7 Ma;

0361-0128/98/000/000-00 $6.00 3 4

Sudo et al., 2003). This eastward expansion of the metallo- The Neogene component of the arc includes andesitic flows, genic province followed an eastward shift of the Ryukyu vol- tuffs, and volcaniclastic rocks. The Mount Pinatubo stratovol- canic front and is probably related to the counterclockwise ro- cano forms part of the Quaternary portion of the western tation of Kyushu Island (Izawa and Watanabe, 2001). The Luzon arc. Kushikino intermediate-sulfidation deposit is associated with Older portions of the arc occur in the Luzon Central an andesitic polygenetic volcano (Izawa and Zeng, 2001), Cordillera and include Eocene (?) to Miocene basaltic to an- whereas low-sulfidation deposits are associated with rhyolitic desitic volcanic breccias, volcaniclastic rocks, limestones, or dacitic monogenetic volcanic activity in the backarc shales, and conglomerates (United Nations Development (Miyashita, 1975). Magmatic activity related to the high-sulfi- Program, 1987a; Metal Mining Agency of Japan, 1979). In the dation deposits has not been clarified, although these deposits Central Cordillera, several phases of diorite to tonalite intru- are hosted by late Miocene to early Pliocene andesitic vol- sions and their hypabyssal equivalents were emplaced from canic rocks (Hedenquist et al., 1994). The low-sulfidation de- the early Miocene through the Pliocene (Metal Mining posits in the metallogenic province are composed mostly of Agency of Japan, 1979, 1983; United Nations Development adularia-quartz veins with alteration halos of sericite-chlorite Program, 1987a; Garcia, 1991). The Kias Creek dike complex at depth and quartz-smectite ± kaolinite near the surface in in Baguio (Mitchell and Leach, 1991) includes pyroxene- widespread chlorite or smectite-zeolite alteration zones hornblende-phyric diabases, lamprophyres, and appinites (Izawa and Urashima, 1987). High-sulfidation deposits are that contain amphibolite xenoliths of inferred arc basement characterized by replacement ores hosted by residual quartz origin (Paddy Waters, writ. commun., 2004). Three of these and quartz-alunite-dickite (or kaolinite) alteration zones dikes indicate Ar-Ar ages that range from 4.6 to 4.0 Ma (Hedenquist et al., 1994). (Paddy Waters, writ. commun., 2004). Mineralized diatreme The Chinkuashih high-sulfidation Au-Cu district in north- breccias are associated with the emplacement of the Balatoc eastern Taiwan has produced more than 92 t Au (Fig. 2, App. plug in the Baguio district. This magmatism is dated at 1.0 Ma 2; Tan, 1991). Orebodies consist of enargite-gold vein sys- (Metal Mining Agency of Japan, 1983; Cooke et al., 1996). tems, hydrothermal breccia pipes, and replacement bodies, The pre- and postmineralization Plio-Pleistocene quartz dior- which are spatially and temporally associated with Pleistocene ite and dacite intrusions and diatreme-related pyroclastic dacitic hypabyssal intrusions. Host rocks include the dacitic rocks in the Mankayan district span the periods 2.2 to 1.8 and intrusions and Miocene calcareous and carbonaceous sand- 1.2 to 0.9 Ma, respectively (Arribas et al., 1995; Hedenquist stones and shales. Bonanza grades have been reported from et al, 1998). Plio-Pleistocene ages are reported for mineral- many of these orebodies, but in more recent years mine ized diorite intrusions at Sto. Thomas II (Sillitoe, 1989; grades averaged approximately 3 g/t Au. The majority of the Baluda and Galapan, 1993) and Black Mountain (Waters, past production was from the 2-km-long Penshan-Hsumei 2004) near Baguio, and at Tawi-Tawi (Wolfe, 1981) in the vein system in the central portion of the district. The Chi- southeastern portion of the Central Cordillera. ufen-Wutanshan intermediate-sulfidation vein system occurs Mineral deposit styles: Porphyry copper-gold deposits and about 1 km west of the high-sulfidation deposits and pro- related high- and intermediate-sulfidation epithermal sys- duced 29 t Au (Tan, 1991). The Tatun district, located 30 km tems are abundant in the Luzon Central Cordillera and west- west of Chinkuashih, is characterized by one high-sulfidation ern Luzon arcs (Fig. 13, App. 3). These deposits are predom- system, which was prospected for gold and copper in the past inantly centered about Neogene to Pleistocene quartz (Yen, 1971). diorite-diorite intrusions hosted by coeval volcanic suites. The Central Cordillera hosts the intermediate-sulfidation gold Luzon lode systems of Acupan, Antamok, and Itogon, and the Sto. Geologic setting: The Luzon arc, as defined in this paper, Thomas II porphyry in the Baguio district, where an esti- represents a composite arc system that extends 1,200 km mated 800 t Au have been produced (Mitchell and Balce, southward from the Coastal Range of southeastern Taiwan 1990). In Acupan, several major gold-bearing quartz vein sys- through the volcanic islands north of Luzon, the Luzon Cen- tems, 0.65 Ma in age (Cooke et al., 1996), occur adjacent to tral Cordillera, and the Western Luzon arc, terminating in the and within the Pleistocene Balatoc diatreme and comprise vicinity of southern Marinduque Island (Fig. 12; Table 1; sheeted veins, stockworks, and the high-grade “GW” breccia Cardwell et al, 1980; Bureau of Mines and Geo-Sciences, bodies (Cooke and Bloom, 1990). The Itogon intermediate- 1982; Mitchell and Leach, 1991). The arc has been active sulfidation gold-bearing quartz vein deposit occurs along the from the Oligocene to the present and is presently underlain eastern periphery of the Balatoc diatreme and is the eastward by an east-dipping Benioff zone related to the Manila trench extension of the Acupan system. The total length of the com- (Divis, 1980). The subduction of the Scarborough Seamounts bined deposits approximates 4 km. In Antamok, major quartz beneath northern Luzon during the Plio-Pleistocene proba- vein systems and associated stockworks are hosted by an- bly led to extinction of volcanism in the Central Cordillera desitic agglomerate and intercalated lava flows. Emplace- and the volcanic islands north of Luzon from ~4 to 2 Ma and ment of the Antamok and Acupan-Itogon vein systems was eastward migration of magmatism from ~2 Ma to the controlled by tensional fractures developed along regional Holocene (Fig. 7; Yang et al., 1996). east-northeast– and northwest-trending conjugate strike-slip Cretaceous ophiolitic basement is exposed in the Zambales faults (Fernandez and Damasco, 1979). The average global region of the western Luzon arc. The United Nations (United grades of these three deposits are inferred to range from 4 to Nations Development Program, 1987b) infers a similar se- 6 g/t Au, which includes past production from high-grade quence to form the foundation for the Central Cordillera. (>10 g/t Au) lodes.

0361-0128/98/000/000-00 $6.00 4 5

The Lepanto high-sulfidation enargite-gold deposit, the Mineral deposit styles: This K alkaline province includes Victoria and Teresa intermediate-sulfidation vein systems, the Didipio district on the southeastern margin of the Palali and the Far South East and Guinaoang porphyry deposits intrusion and the Isabella district within the Cordon syenite occur in the nearby Mankayan district, which contains a min- complex (Fig. 13). Significant resources occur in the Dinkidi imum of 700 t Au in combined past production and current copper-gold porphyry deposit (120 t Au, 0.5 Mt Cu) in Didi- resources. There is a clear genetic association between por- pio and the Marian intermediate-sulfidation epithermal gold phyry and epithermal styles of mineralization in Mankayan. mine and nearby porphyry copper-gold system in Isabella. The Far South East porphyry formed below and coeval to Dinkidi is hosted by a composite monzonite stock that has Lepanto at 1.4 to 1.3 Ma, both deposits associated with the been intruded by a highly mineralized syenite pegmatite dike, emplacement of quartz diorite porphyry; the Victoria vein which forms a gold-rich (5–15 g/t Au) core (Wolfe et al., system formed at ~1.15 Ma, as the hydrothermal system 1999). The spatial extent of quartz stockwork veins and flank- waned (Hedenquist et al, 1998, 2001). At Lepanto, residual ing feldspar-destructive sericitic and argillic alteration zones quartz alteration of dacitic wall rocks host east-trending enar- for the deposit is more restricted than recorded in the calc-al- gite-gold branch veins and stratiform lodes localized around kaline porphyry systems elsewhere in Luzon. The Runruno the intersection of the steeply dipping northwest-striking intermediate-sulfidation gold deposit and the Pao high-sulfi- Lepanto fault and the gently dipping unconformable base of dation enargite-gold occurrence (Kavalieris and Gonzalez, a Pliocene dacitic pyroclastic sequence. The dacitic rocks 1990) are also located in the Cordon arc. form part of the Mankayan diatreme-dome complex (Garcia, 1991; Baker, 1992). The Victoria gold-base metal-quartz vein Philippine system is located <1 km southwest of Far South East, at a Geologic setting: The Philippine arc (Cardwell et al., 1980) similar level to Lepanto. The veins average 7.3 g/t Au and or the Pacific Cordillera extends more than 1,000 km from form an east-trending tensional array localized by right-lateral Camarines in southern Luzon to the Pujada peninsula in movement on mine-scale strike-slip faults (Claveria et al., southeastern Mindanao (Fig. 12; Table 1). The arc occurs 1999). The Teresa intermediate-sulfidation gold deposit, dis- close to the sinistral Philippine fault. Geologic basement to covered in 2002, lies to the southwest of Victoria and extends the arc consists of Cretaceous ultramafic rocks and Paleogene south to the Nayak vein system. It contains an estimated re- andesitic volcanic, volcaniclastic, marine siliciclastic, and car- source of 7.3 Mt at ~5.3 g/t Au (Waters, 2004). Both the bonate rocks (Bureau of Mines and Geo-Sciences, 1982). Mankayan and Baguio districts occur in zones of structural The arc includes segments that have been active at differ- complexity near major north-northwest–trending fault splays ent times between the Oligocene and Quaternary (Divis, of the sinistral strike-slip Philippine fault (Fig. 13). 1980; United Nations Development Program, 1987b). The gold-rich Dizon copper porphyry deposit in the Zam- Oligocene-Miocene basaltic breccias and turbidites are over- bales region and the Tayson copper-gold porphyry deposit in lain by Neogene andesitic to dacitic volcaniclastic rocks, lavas, the Batangas area occur in the western Luzon arc. Both por- and calcareous siliciclastic rock units in northeastern Min- phyry deposits are located in Miocene to Pliocene windows in danao (United Nations Development Program, 1987b). A fo- Quaternary volcanic cover. liated to massive trondjhemite dome (Paracale granodiorite of The Chimei copper-gold porphyry system in the Coastal Frost, 1959), Miocene diorite and andesite porphyry, and Range in eastern Taiwan is inferred to lie in the northern ex- Pliocene dacite porphyry occur in Camarines (United Nations tension of the Luzon arc. Early Miocene ages (22 and 19 Ma) Development Program, 1987c). The diorite and andesite por- are indicated for andesite from the Chimei porphyry deposit phyry intrusions in the Leyte, Surigao, Co-O, and Masara (Chen, 1975, in Hutchison, 1989). areas of east Mindanao are Miocene in age (Mitchell and Leach, 1991). Miocene andesitic volcanic rocks, volcaniclastic Cordon rocks, and intrusions also characterize the Leyte sector of the Geologic setting: Surface exposures of alkaline igneous arc. In eastern Mindanao, late Pliocene to Quaternary an- rocks in north-central Luzon define two discrete regions, the desitic volcanoes, associated eruptive products and por- Cordon syenite complex and the Palali intrusion, which lie at phyritic stocks occur near Surigao and Lake Leonard in the the southern end of the Cagayan rift basin. The basement to Masara region (Mitchell and Leach, 1991; Sajona et al., the Cagayan basin consists of Cretaceous to Paleogene calc- 1997). Pleistocene to Recent (active) volcanoes characterize alkaline plutonic, volcanic, and volcaniclastic rocks (Table 1). arc portions in Camarines, southeastern Luzon, and Leyte K alkaline magmatism occurred in the late Oligocene and (Divis, 1980). early Miocene, as indicated by K-Ar ages of ~25 Ma for the The Philippine arc presently lies above a west-dipping Cordon Syenite Complex (Knittel, 1983) and 25 to 17 Ma for Benioff zone related to the Philippine trench. However, the Palali intrusion (Metal Mining Agency of Japan, 1977). pre-Pliocene arc magmatism is not related to subduction at The emplacement of these intrusive complexes may be re- this trench, as the trench is a young feature (Hamilton, lated to intraplate magmatism initiated by subduction be- 1979) and the subducting slab only reaches depths of 150 to neath Luzon, as expressed by Divis (1983) and Knittel and 250 km (Gudmundsson and Sambridge, 1998). The source Cundari (1990), but there is no agreement as to the polarity. of this pre-Pliocene magmatism is probably related to east- Other possible sources of the alkaline magmatism include de- directed subduction on the west side of the Philippines. layed partial melting of a relict subduction slab, as postulated However, the subduction history in the Philippines is com- for southeastern Papua New Guinea by Johnson et al. (1978) plex and most likely involved the formation of small intra- and Smith and Milsom (1984) or intra-arc extension. Philippines ocean basins within an overall strike-slip zone.

0361-0128/98/000/000-00 $6.00 5 6

The present Philippine fault is mechanically linked to Masbate-Negros Pliocene to Recent subduction along the Philippine trench, Geologic setting: This arc assemblage consists of two over- but the Philippine fault predates this subduction, which im- lapping arcs of different ages. The combined arc system ex- plies a complex plate boundary during the Neogene. The ge- tends 400 km and includes eastern Panay (Fig. 12; Table 1). ology of the islands indicates a long history of strike-slip The arc system is terminated against the Philippine fault in faulting (Rutland, 1968; Karig et al., 1986). the north and abuts the Sulu-Zamboanga arc to the south. Mineral deposit styles: The gold districts of Paracale, Sta Cretaceous basement includes marine sedimentary rocks and Elena-Tabas, and Nalesbitan in the Camarines Norte, and pillow basalts, exposed in southeast Negros (Hamilton, 1979) Surigao, Masara, and the Diwalwal-Compestela areas in east- and serpentinized ultramafic rocks in northeastern Masbate ern Mindanao are characteristic of the gold districts in the (Mitchell and Leach, 1991). Philippine arc (Fig. 13). Several historic intermediate-sulfida- In the older western arc, Eocene to Oligocene andesitic to tion lodes in the Paracale area (e.g., Longos mine) occur dacitic volcanic and clastic rocks host a Miocene dacitic dia- along the contact between the Paracale trondjhemite and ser- treme complex at Bulawan in southwest Negros and middle pentinized ultramafics (Frost, 1959). Gold in the Paracale and Miocene dioritic intrusions in northeast Masbate (Mitchell Sta Elena-Tabas areas are associated with intermediate-sulfi- and Leach, 1991). In the younger eastern arc, middle dation lodes (United Nations Development Program, 1987c), Miocene to Pliocene andesite flow breccias, volcaniclastic which contain tellurides at Exciban (James and Fuchs, 1990), rocks and conglomerates are overlain by late Pliocene an- and the Larap (Mantanlang) porphyry Cu-Mo-Au deposit desitic volcanic rocks and Quaternary andesite to basalt stra- (Sillitoe and Gappe, 1984). Nalesbitan is a small high-sulfida- tovolcanoes (Bureau of Mines and Geo-Sciences, 1982; tion gold deposit hosted by andesitic volcanic rocks (Sillitoe et United Nations Development Program, 1987d). al., 1990). In central Samar, Kuroko-type massive sulfide de- The two arcs are the product of subduction beneath Negros posits at the Bagacay mine and Sulat deposit contain signifi- but the polarity of the older arc is not clear; it has been inter- cant gold in addition to copper and silver (Bureau of Mines preted to be situated above a west- (Sajona et al., 1997) or and Geo-Sciences, 1986). east-dipping (Holloway, 1982; Hall, 2002) subduction zone. Gold deposits and prospects in eastern Mindanao consist The younger arc is probably the product of east-dipping sub- of intermediate-sulfidation lode and stockwork styles duction at the Negros trench, which currently appears to be (Placer, Co-O, Diwalwal-Compestela, and Masara), dissem- inactive or almost so (Cardwell et al., 1980) and associated inated sedimentary rock-hosted and replacement styles with a slab that extends to a depth of about 100 km (Gud- (Siana and Hijo), and porphyry Cu-Au deposits (Boyongan, mundsson and Sambridge, 1998). Kingking, Amacan, and Mapula). Descriptions of the major- Mineral deposit styles: The western Masbate-Negros arc ity of these deposits are included in Mitchell and Leach contains the Masbate intermediate-sulfidation stockwork gold (1991), with the exception of Boyongan and Bayugo, which mine (62 t Au, Aroroy district) in northeastern Masbate, and were recently discovered near Surigao. The Boyungan de- the Bulawan intermediate-sulfidation gold deposit and gold- posit is hosted by a K silicate altered, calc-alkaline diorite- poor Sipalay and Hinobaan porphyry Cu ± Mo deposits in porphyry composite stock emplaced within a sequence of southwest Negros (Fig. 13; Sillitoe and Gappe, 1984). Approx- Neogene(?) andesite, pyroclastic rocks, and basaltic flows imately 40 t Au were exploited from underground lode mines (Josef, 2002). The deposit is concealed beneath a more than in the Aroroy district prior to World War II (Mitchell and 50-m-thick, postmineralization cover sequence of Quater- Leach, 1991). Open-pit reserves established in 1980 averaged nary andesitic flows, laharic breccia, tuff, mudstone, and 2.3g/t Au. Gold mineralization is associated with Miocene an- conglomerate. The Boyungan and Bayugo porphyry systems desite to dacite clastic rocks at Masbate and a similar-aged formed at ~2.6 to 2.3 Ma, approximately coeval to the de- dacitic diatreme complex at Bulawan (Mitchell and Leach, velopment of the Siana sedimentary rock-hosted deposit 1991; Philex, 1995). In contrast, the gold-poor porphyry sys- (Waters, 2004). Boyongan is inferred to have been uplifted tems are considered to be Eocene to Oligocene in age (Bureau during the late Pliocene-Pleistocene and to have formed a of Mines and Geo-Sciences, 1986; Singer et al., 2002). prominent topographic high, on the basis of an unusually The eastern Masbate-Negros arc includes geothermal areas deep supergene oxidation profile that extends 300 to 500 m and several andesite-hosted silica bodies, which are inferred beneath the base of the Quaternary cover rock sequence to represent the upper levels of high-sulfidation epithermal (Josef, 2002; Waters, 2004). This relationship indicates that systems (United Nations Development Program, 1987d). shortly after Boyongan formed, it was uplifted by at least 1 There may be potential for concealed porphyry-style miner- km in the Plio-Pleistocene to partly expose the K silicate-al- alization at depth. Pliocene(?) conglomerates with pyritic- tered core of the system and then downdropped as much as quartz and acid-sulfate–altered clasts indicate a minimum age 500 m in a pull-apart basin, developed by movement along for the high-sulfidation systems in southeast Negros (Mitchell strands of the sinistral Philippine fault system, prior to Qua- and Balce, 1990). ternary volcanism, which concealed and preserved the de- posit. In northeastern Mindanao, the westward-younging and progressive compositional changes of intrusive centers Sulu-Zamboanga from ~4.5 Ma to Recent (Sajona et al., 1997), and the for- Geologic setting: This arc extends approximately 400 km mations of porphyry deposits at ~2.5 Ma, could be related to westward from the Semporna peninsula in eastern Sabah west-directed subduction, if initated at 6 to 5.5 Ma (Paddy through the Sulu archipelago to the Zamboanga peninsula, Waters, writ. commun., 2004). where it is truncated by the western Cotobato and the

0361-0128/98/000/000-00 $6.00 6 7

Masbate-Negros arc systems (Fig. 12; Table 1). The Zam- massive sulfide deposits (e.g., Canatuan and Malusok). Host boanga peninsula can be subdivided into two segments by the rocks include intermediate volcanic and volcaniclastic rocks Sindangan-Cotobato-Daguma lineament (Cotabato fault and coeval intrusions for the porphyry and epithermal styles zone of Pubellier et al., 1991, and Rohrlach et al., 1999), of deposits and siliciclastic sedimentary rocks and schists for which has been interpreted as the accretionary boundary be- the massive sulfide deposits. The Sibutad epithermal vein sys- tween the Cotabato island arc to the northeast and a conti- tem is the largest gold resource discovered to date (23 t Au) nental fragment to the southwest (Jimenez et al., 2002). The and contains hydrothermal breccia bodies, silica sinter de- juxtaposition of these two terranes commenced in the middle posits, and alteration types indicative of shallow- to near-sur- Miocene, with collision still active today, according to Rangin face development during the Pleistocene (Jimenez et al., et al. (1999). The source of the interpreted continental frag- 2002). ment is not clear nor is its existence documented conclusively. In the Semporna peninsula, a high-sulfidation system at Pre-Tertiary granitoids and metasedimentary rocks form the Nagos and intermediate-sulfidation quartz-gold lodes at Bt. basement in the southwestern part, and Cretaceous serpen- Mantri are hosted by andesite to dacite volcanic and volcani- tinized ultramafic rocks and metasedimentary rocks comprise clastic rocks and hypabyssal plugs of inferred Pliocene age the basement in the northeastern part, of the Zamboanga (Kirk, 1968; Yan, 1990). Mineralization styles in both Nagos peninsula (Hamilton, 1979; Jimenez et al., 2002). and Bt. Mantri are interpreted by Yan (1990) to have devel- The Sulu and Zamboanga sectors of the arc are composed oped in the upper levels of epithermal systems. generally of Neogene to Quaternary andesitic volcanics and sedimentary rocks. Plio-Pleistocene subaerially erupted an- Cotabato-Central Mindanao desitic volcanic rocks and hypabyssal intrusions occur in the Geologic setting: This section describes two arcs, the Cota- northeastern part of Zamboanga, with Miocene marine silici- bato arc to the southwest and the Central Mindanao arc to the clastic and carbonate rocks covering much of southwestern northeast (Fig. 12; Table 1). In southern Mindanao, the Zamboanga; the suture between the two terranes is marked boundary between these two arcs is marked by the Cotabato by a Neogene mélange complex (Jimenez et al., 2002). In the fault zone. The Cotabato arc includes the Daguma and Semporna and Dent peninsulas of Sabah there are Neogene Sarangani regions and is inferred to be the northern extension calc-alkaline and K-rich calc-alkaline basalts, andesites, and of the Sangihe arc. The Cotabato fault zone has been inter- dacites above a Cretaceous to Paleogene basement of chert, preted as the onshore extension of the Molucca Sea collision basalts and ultramafic rocks (Kirk, 1968; Hutchison, 1989; zone (Pubellier et al., 1991), but there is no evidence in Min- Yan, 1990; Chiang, 2002). Arc activity terminated in the late danao for the northward continuation of the Halmahera arc, Pliocene and intraplate basalts were erupted in the Pleis- and the Molucca Sea collision zone may terminate at the Cota- tocene at a number of small centers. Chiang (2002) suggests bato fault, which acted as a strike-slip fault during the Neo- that geochemical variation in the Mio-Pliocene volcanic rocks gene (Hall, 1996, 2002). Toward the northwest, this fault zone indicates northwest-directed subduction. The change to in- is obscured by a sequence of Quaternary flood basalts, basalt traplate basic magmatism during the Pleistocene indicates to dacite stratovolcanoes, and the Cotabato sedimentary basin. sampling of a new and different mantle source. The Central Mindanao arc is poorly defined, however, the arc The polarity of subduction is not clear because there is no is bound by the Cotabato fault and the Cotabato basin to the significant seismicity beneath the Sulu arc. Older northwest- southwest and the Agusan-Davao trough to the east. The com- dipping subduction of the Celebes Sea is suggested to have bined arc assemblage extends more than 350 km in a northerly reversed to southeast-dipping subduction of the Sulu Sea on direction across southwest and central Mindanao. the north side of the Sulu arc, which remained active until the In the Cotabato arc, Paleogene metavolcanic and metased- late Pleistocene (Hamilton, 1979; Hutchison, 1989) due to imentary rocks are overlain by Miocene marine clastic and collision of the Cagayan volcanic arc and Palawan (Rangin et carbonate rocks and intruded by an early to middle Miocene al., 1990). However, in Sabah, where the Sulu arc can be diorite batholith and andesite to dacite hypabyssal stocks (Bu- traced onshore into the Dent-Semporna arc, there is no evi- reau of Mines and Geo-Sciences, 1982). Plio-Pleistocene an- dence for southeast-directed subduction on the north side of desitic flows, pyroclastic rocks and intrusions, and limited the arc. Hall and Wilson (2000) and Hall (2002) suggested Quaternary dacite-andesite volcanic rocks characterize the that after the Cagayan arc collision, the Celebes Sea began northwestern and southeastern portions of the onshore part subducting in a northwest direction beneath the south side of of the arc. the Sulu arc and this interpretation is favored by geochemical The Central Mindanao arc contains a sequence of Oligocene evidence from Sabah (Chiang, 2002). to middle Miocene basalts, volcaniclastic and carbonate Mineral deposit styles: Gold systems are localized in the rocks, and late Miocene andesite to basalt volcanic and ma- Zamboanga and Semporna segments of the arc (Figs. 12–13), rine clastic rocks locally intruded by Neogene diorites (Bu- but no large deposits have been found. Gold occurrences in- reau of Mines and Geo-Sciences, 1982; Sajona et al., 1997). clude alluvial deposits, small-scale mining centers, and sev- Active Quaternary basaltic and lesser andesitic volcanoes and eral prospects. In Zamboanga, more than 12 precious and their eruptive products cover much of the region. The central base metal deposits and prospects of Neogene to Pleistocene portion of Central Mindanao is underlain by fault-bound sliv- age occur proximal to the Cotabato fault zone (Jimenez et al., ers of Cretaceous (?) ultramafic rocks (Sajona et al., 1997). 2002). These mineralized systems include intermediate-sulfi- The Cotobato trench is characterized by a shallow, north- dation veins and stockworks (e.g., Sibutad), porphyry copper east-dipping Benioff zone, which is inferred to have developed prospects (e.g., Labangan), and gold-rich volcanic-associated in recent times (Cardwell et al., 1980; Hutchison, 1989) and is

0361-0128/98/000/000-00 $6.00 7 8 not related to pre-Quaternary arc development. The east-dip- the northern portion of the Sangihe arc through the northern ping Molucca slab, which extends to about 600 km beneath arm of Sulawesi and into the neck of Sulawesi, where it ends in Mindanao, is inferred to have played a major role in Neogene the sinistral Palu fault (Fig. 14; Table 1; Hamilton, 1979). The magmatism in both the Cotobato and Central Mindanao arcs. western portion of the arc overlies Sundaland continental crust The Cotobato arc may continue to the north as the Masbate- and Cretaceous to Eocene metamorphic rocks, which are in- Negros arc, however, reconstruction of a continuous volcano- truded by late Miocene to Pliocene granitoids (Kavalieris et al., plutonic arc across the Sulu-Zamboanga arc is uncertain. 1992). These rocks are overlain unconformably by Eocene to Mineral deposit styles: The southern portion of the Coto- Oligocene marine basalt to andesite and sedimentary rocks that bato arc includes porphyry Cu-Au, skarn and epithermal gold form part of an oceanic arc to the east of the Marisa region occurrences and prospects associated with Neogene dioritic (Carlile et al., 1990; Kavalieris et al., 1992). Geochemical and stocks to hypabyssal dacite porphyry bodies and diatremes lo- isotopic data from northwestern Sulawesi support the inferred cally (Fig. 13; Sillitoe and Gappe, 1984). The Tampakan high- transition from continental- to oceanic-arc settings from west sulfidation epithermal and/or porphyry Cu-Au deposit (270 t to east and indicate the presence of an underthrust fragment of Au, 6.8 Mt Cu) occurs within the eroded flanks of a Pliocene the Australian continent that extends from the western edge of (?) andesitic stratovolcano that lies unconformably on a North Sulawesi through the northern and central parts of west northerly trending ramp anticline in the hanging wall to a re- Sulawesi (Elburg et al., 2003). The early to middle Miocene gional east-directed thrust fault (Rohrlach et al., 1999). A syn- portion of the arc consists of andesitic to dacitic volcanic and mineralization diorite porphyry dike is dated at 3.2 Ma (U/Pb volcaniclastic rocks and sedimentary rocks intruded by diorite, by laser ablation ICP-MS; R. Loucks, pers. commun., 2002). quartz diorite, granodiorite, and their subvolcanic porphyritic Enargite-bearing, high-sulfidation mineralization and ad- equivalents in the Gorontalo, Kotamobagu, and south Sangihe vanced argillic alteration overprints the porphyry system from areas (Carlile et al., 1990; Kavalieris et al., 1992). A Pliocene surface to depths of about 500 m, with relict K silicate alter- rhyodacitic pyroclastic sequence and flow dome complex char- ation zones present at 600 m below surface (Rohrlach et al., acterizes the Gunung Pani area in Marisa (Kavalieris et al., 1999). Small-scale mining centers are located at T’boli in 1990; Pearson and Caira, 1999). Quaternary andesitic strato- South Cotobato, Tampakan in the Sarangani Range, and else- volcanoes define the arc from north of the Kotamobagu area where in southern Mindanao. Gold is recovered from inter- through Sangihe Island. mediate-sulfidation quartz veins hosted by Miocene volcanic Major northwesterly trending faults influence the distribu- and volcaniclastic sequences. tion of volcanic and sedimentary rock successions in north Su- Mitchell and Leach (1991) cited widespread epithermal lawesi. The movement along these faults is oblique-slip, with mineralization in the Sarangani Range, which lies in the arc-parallel extension indicated by the progressive down-to- southeastern part of the Cotobato arc. Small-scale mining the north movement of the fault blocks located north of Ko- near Bukidnon is associated with narrow quartz veins hosted tamabagu (Carlile et al., 1990). in phyllites and ultramafic rocks (Mitchell and Leach, 1991). Mineral deposit styles: Gold and copper deposits in the The relationship of these veins to the Central Mindanao arc, north Sulawesi-Sangihe arc commonly lie <10 to 20 km from if any, is unclear. major northwesterly trending arc-transverse oblique-slip faults (Figs. 8, 14). Many of these deposits are hosted by early Other Philippine arcs to middle Miocene andesitic volcanic rocks intruded by hy- Additional Cenozoic magmatic arcs of the Philippines in- pabyssal intrusions. West of Marisa, the western sector of the clude the Oligocene arcs of the Sierra Madre in central Luzon arc has a continental affinity and is characterized by alluvial and the northeast Luzon-Polillo-Catanduanes in eastern gold derived from small orogenic lodes hosted by metamor- Luzon (Fig. 12; Mitchell and Leach, 1991). Epithermal veins, phic basement (Kavalieris et al., 1992). The Gunung Pani porphyry copper, skarn, and gold-bearing massive sulfide disseminated and stockwork intermediate-sulfidation gold prospects and alluvial gold workings occur in the East Rizal deposit (41 t Au) is controlled by north-northeast– and north- region of the Sierra Madre arc. Gold-bearing, Besshi-type east-oriented faults in a rhyodacitic dome complex built upon massive sulfide prospects exist in eastern Bicol and small ep- continental basement along the margin of Sundaland (Kava- ithermal veins characterize prospects in Catanduanes Island. lieris et al., 1990). The deposit is 3.3 to 3.1 m.y. old (Ar-Ar; In central Cebu, quartz-diorite porphyry intrusions, vol- Pearson and Caira, 1999) with gold contained in siliceous canic and volcaniclastic rocks of probable Cretaceous age host limonitic and quartz-adularia lined fractures and mosaic the gold-bearing Atlas porphyry Cu-Mo deposits (Sillitoe and quartz breccias (Carlile et al., 1990; Kavalieris et al., 1990). Gappe, 1984). Cretaceous quartz diorite bodies also occur in The Gorontalo region hosts porphyry copper-gold deposits Bohol, but these intrusions lack significant mineralization in the Tombulilato district, the Bolangitang intermediate-sul- (Bureau of Mines and Geo-Sciences, 1982). Miocene an- fidation epithermal prospect, and the Motombato high-sulfi- desitic volcanics occur on both islands and may be linked via dation epithermal system and contains >140 t gold and sub- a paleoarc system. Alternatively, the Bohol arc may extend stantial copper resources (App. 4). These Pliocene systems north beneath northwestern Leyte, as proposed by Mitchell (2.9–2.4 Ma; Perello, 1994) are hosted by Miocene volcanic and Leach (1991). rocks and overlying dacite to rhyolite, which are intruded by quartz diorite stocks (Lowder and Dow, 1978). The North Sulawesi-Sangihe Tombulilato district lies ~10 to 20 km from a major north- Geologic setting: The Miocene to Recent North Sulawesi- westerly oriented, arc-transverse dextral-fault zone (Pearson Sangihe magmatic arc extends approximately 1,200 km from and Caira, 1999).

0361-0128/98/000/000-00 $6.00 8 9

In the Kotamobagu region, intermediate-sulfidation Neogene diorite to granodiorite bodies intrude the volcanic stockwork veins in andesitic volcanic and volcaniclastic rocks rock sequences and are associated with porphyry Cu-Au- at Lanut, Mintu, and Doup, and silicified middle Miocene (Mo) prospects on Bacan Island and gold prospects in the limestone at Lobongan in the Ratatotok district, support small- northern part of the western arm of Halmahera Island. Vol- scale mining activities. The north- to northeast-trending canic activity has ceased at the southern end of the arc, and intermediate-sulfidation vein systems at Lanut and nearby the active volcanic arc moved west during the Pliocene (Hall high-sulfidation lodes lie within a northwesterly corridor of et al., 1988b) and is now built on the western margin of the mineral prospects that extends more than 30 km across the Neogene arc. hinge portion of north Sulawesi. The Toka Tindung interme- Mineral deposit styles: A porphyry Cu-Au prospect occurs diate-sulfidation vein system (2.4 Ma; Moyle et al., 1997) in at Kaputusan on Bacan Island, where it is associated with northeastern Sulawesi is overlain by a Quaternary ash cover. anomalous molybdenum and bismuth (Fig. 14; van Leeuwen, Host rocks consist of Neogene andesitic volcanic and volcani- 1994). This small resource is centered in a Neogene quartz clastic rocks that overlie siliciclastic sedimentary rocks. The diorite intrusion in pre-Miocene volcanic host rocks (Carlile main Toka Tindung and satellite deposits (35 t Au) form a se- and Mitchell, 1994; Malaihollo and Hall, 1996). ries of en echelon, north-trending lodes that lie in a north- The Gosowong intermediate-sulfidation bonanza vein sys- west-oriented structural corridor (Wake et al., 1996). tem in the northwestern arm of Halmahera Island contains The sedimentary rock-hosted Mesel gold deposit in the nearly 27 t of gold at an average grade of 27 g/t (Olberg et al., Ratatotok district (62 t Au) has many similarities to Carlin- 1999). The steeply east dipping vein lies adjacent to a north- type gold deposits in Nevada (Turner et al., 1994; Garwin et west-trending fault (Research Information Unit, 1997) that al., 1995). In Mesel, most of the ore is controlled by steeply forms part of a major northwest-oriented topographic linea- dipping faults and is hosted in a decalcified, dolomitized, and ment that extends through the western arm of Halmahera. silicified middle Miocene carbonate sequence adjacent to, The deposit is hosted by a Neogene sequence of andesitic to and beneath, a premineralization, porphyritic andesite laccol- dacitic volcanic rocks and subordinate volcaniclastic rocks. ithic intrusion. The Taware porphyry Cu-Au prospect and the The age of mineralization is constrained to lie between 2.9 to Bawone-Binebase high-sulfidation system on south Sangihe 2.4 Ma (Olberg et al., 1999). The recently discovered Ken- Island are inferred to be of Miocene age (Carlile et al., 1990). cana and Toguraci intermediate-sulfidation vein systems lie 1 km south and 2 km southwest of Gosowong, respectively. Halmahera Kencana, the larger of the two deposits, contains 70 t of gold Geologic setting: This Neogene to Recent arc sweeps across at an average grade of 41 g/t in a quartz vein breccia (indi- the western arm of the Halmahera Islands and includes cated plus inferred categories; Mining News, 2004). Kencana Bacan and Obi Islands (Fig. 14; Table 1). The modern arc ex- is hosted by a northwest-trending, 35° to 55° northeast-dip- tends 400 km from near the Philippine trench to the western ping, fault within a sequence of andesitic volcanic and vol- extension of the Sorong fault. The basement to the arc con- caniclastic rocks (IAGI, 2004). Other mineralization in the sists primarily of Cretaceous-Paleocene ophiolite in Halma- area includes intermediate-sulfidation epithermal and por- hera, Bacan, and Obi (Hall et al., 1991), although there are phyry styles (Olberg et al., 1999). Small intermediate-sulfida- Mesozoic and probable Precambrian gneiss and schist ex- tion veins occur on Obi Island, hosted in part by andesitic posed on Bacan (Hamilton, 1979; Malaihollo and Hall, 1996). peperites (N. White, writ. commun., 2004). The Halmahera region has a long history of arc activity. The ophiolitic basement was formed in an intra-oceanic arc (Bal- Medial New Guinea lantyne, 1992) and is overlain in Halmahera and Obi by prod- Geologic setting: New Guinea can be divided into four ucts of a Late Cretaceous arc and in Halmahera, Bacan, and major structural-stratigraphic belts, from south to north: (1) Obi by an Eocene to Oligocene arc (Hall et al., 1988a, b, the stable northern margin of the Australian craton (Fly plat- 1995; Ali and Hall, 1995; Malaihollo and Hall, 1996). These form), (2) Papuan fold belt, (3) New Guinea mobile belt, and arcs formed as the result of subduction at the margin of the (4) allochthonous Paleogene volcanic island arcs accreted in Philippine Sea plate in an intra-oceanic setting, and arc activ- the Miocene (Fig. 15; Dow, 1977; Hamilton, 1979; Pigram ity was terminated between the late Oligocene and early and Davies, 1987; Rogerson and McKee, 1990; Hall, 2002). Miocene by collision with the north Australian margin (Hall, The suture zones between the accreted island arcs and mo- 1996). During the middle Miocene, there was little or no arc bile belts are typically marked by craton-directed overthrusts activity and platform carbonates were deposited over a large of Paleogene ophiolite and mélange (Dow, 1977; Hamilton, area and arc activity resumed in the late middle Miocene. All 1979). The late Miocene to Pleistocene medial Irian Jaya these rocks form the basement to the Neogene Halmahera magmatic arc of Carlile and Mitchell (1994) lies within the arc, which was active from about 11 Ma between Obi in the Papuan fold belt, where south-directed compressional tec- south and Morotai at the north end of the island chain (Baker tonics have led to localized deformation, crustal thickening, and Malaihollo, 1996). The active arc shows geochemical ev- and block uplift during the Plio-Pleistocene to Recent idence of a continental crustal contribution to magmas on (Hamilton, 1979; Weiland and Cloos, 1996; Hill and Raza, Bacan (Morris et al., 1983) and a similar contribution can be 1999). The medial New Guinea magmatic belt, as defined in identified in the Neogene lavas on Bacan (Forde, 1997), this paper, extends more than 1,500 km along the central which indicates movement of Australian continental frag- crest of New Guinea, includes the Quaternary stratovolca- ments along strands of the Sorong fault, as first suggested by noes near Bosavi, and continues to the southeast through the Hamilton (1979). Owen Stanley thrust belt to the Papuan peninsula and nearby

0361-0128/98/000/000-00 $6.00 9 10

D’Entrecasteaux Islands (Dow, 1977; Rogerson and McKee, Arnold, 1994). The main Grasberg intrusion cooled extremely 1990; McDowell et al., 1996). The basement consists of a rapidly, as indicated by nearly identical ages determined by thick sequence of Paleozoic sedimentary rocks in Irian Jaya Re-Os (2.9 ± 0.3 Ma on sulfide), Ar-Ar (3.33 ± 0.12–3.01 ± and Paleozoic metamorphic rocks and Permo-Triassic granite 0.06 Ma on biotite), and (U-Th)/He (3.1–2.9 ± 0.1 Ma on ap- overlain by Mesozoic siliciclastic rocks in Papua New Guinea atite), which supports the interpretation that the intrusive (Hamilton, 1979; Dow and Sukamto, 1984; Pigram and complex was emplaced within ~1 km of the paleosurface Davies, 1987; Hill and Raza, 1999). (Weiland and Cloos, 1996; McInnes et al., 2004). The Gras- The late Miocene to Pleistocene high K calc-alkaline to K berg complex occurs about the intersection of northeast- alkaline intrusions (e.g., intrusive complexes at Porgera, Gras- trending, sinistral strike-slip fault systems with steeply north- berg, and Ok Tedi; McDowell et al., 1996) in the Central east dipping reverse faults (MacDonald and Arnold, 1994) in Ranges of New Guinea do not overlie a well-defined Benioff the hanging wall to a major frontal thrust (Hill et al, 2002). zone and lack coeval subaerial volcanic rocks. However, this The vertical ore distribution exceeds 1,500 m. paucity of volcanic rocks may in part reflect the extensive up- The Pleistocene (1.2 Ma) Ok Tedi porphyry Cu-Au system lift and erosion of the region (e.g., average exhumation rates (441 t Au, 4.5 Mt Cu; App. 5) is centered on monzonite por- of ~0.7–1.7 mm/yr since the mid-Pliocene; Weiland and phyry stocks and breccia dikes, emplaced in Middle to Late Cloos, 1996). The distribution of these intrusions coincides Cretaceous siltstone and sandstone (Rush and Seegers, 1990). with the margins of uplifted basement blocks adjacent to Lenses of copper-gold-magnetite and sulfide skarn locally north-northeast– to northeast-trending lineaments defined by occur within this rock sequence. The vertical distribution of faults, volcanoes, and drainage patterns (e.g., Grasberg, Ok ore exceeds 600 m, including an oxidized gold-rich cap that Tedi, Porgera, Bosavi, Murray, and Bulolo lineaments; Fig. formed an annulus to the quartz stockwork core of the de- 15; Davies, 1991; Corbett, 1994; Fischer and Warburton, posit in the leached cap, prior to mining (Rush and Seegers, 1996; Hill et al., 2002; Pubellier and Ego, 2002). These linea- 1990). Ok Tedi occurs in the core of a west-trending doubly ments parallel the structural trend of basement rocks, as in- plunging anticline in the hanging wall to a major frontal thrust ferred from aeromagnetic data (The Australian Petroleum that lies along a major northeast-trending basement fault in- Company Proprietary, 1961) and locally define boundaries to ferred from the distribution of regional-scale folds and Plio- domains of differing structural styles in the Papuan fold belt Pleistocene intrusions (Mason, 1996; Mason and Ord, 1999). (e.g., Ok Tedi; Mason, 1994, 1996). These relationships have Ok Tedi is the largest porphyry-skarn complex of several sys- led Hill et al. (2002) and others to infer the localization of in- tems that formed in the Star Mountains contemporaneous to trusions at high crustal levels along dilatent segments of reac- Plio-Pleistocene thrust faulting (Arnold and Griffin, 1978). tivated, orogen-parallel extensional Mesozoic basement faults The Ertsberg skarn complex, 2 km southeast of the Gras- near intersections with south-directed frontal thrusts. In con- berg porphyry deposit, includes the Ertsberg, Ertsberg East, trast, there is no clear relationship between thrust faults and Intermediate, and Deep ore zones, DOM, and Big Gossan the Pliocene (3.2–2.8 Ma) calc-alkaline intrusions that occur copper-gold skarn deposits. Combined past production and south of the Sorong fault system in the Bird’s Head at Aisas- present reserves in the Ertsberg skarn deposits exceed 140 t jur, Papua (Paddy Waters, writ. commun., 2004). of gold and 3.8 Mt of copper (Mertig et al., 1994; van The southward migration of K-rich magmatism and related Leeuwen, 1994). The majority of the gold and copper re- mineralization follows the southward progression of fold and sources are hosted in the Erstberg East (Intermediate and thrust belt deformation (Davies, 1991), with intrusion-related Deep ore zones) orebody (189 t Au, 2.4 Mt Cu) in one of the mineral deposits forming in zones of major uplift at the inter- largest Cu-bearing magnesian skarns in the world (Mertig et section between frontal thrusts and orogen-transverse strike- al., 1994; Coutts et al., 1999). The skarns are hosted within or slip (transfer) fault zones (Hill et al, 2002). The source of the adjacent to the Pliocene Ertsberg intrusion (3.1–2.6 Ma; K-rich magmas is ambiguous. Favored possibilities include de- Mertig et al., 1994; Meinert et al., 1997). The subsurface, layed partial melting of the mantle modified by previous (?Cre- Kucing Liar magnetite-copper-gold skarn, about 500 m taceous) subduction beneath the continental margin, prior to southwest of the Grasberg intrusive complex, contains more the accretion of allochthonous arc terranes in the mid-Miocene than 450 t Au (Widodo et al., 1999). The protolith lithologies (Johnson et al., 1978) and asthenospheric upwelling due to the for the Ertsberg skarns consist of a basal dolomitic unit and docking of arc terranes transported from the east (McDowell an upper limestone sequence of early Tertiary age (New et al., 1996). The results of mantle tomographic imaging sup- Guinea Group Limestone; Mertig et al., 1994). port the existence of ancient subduction slabs within the man- The Wabu Ridge gold skarn in the Hitalipa district, 35 km tle beneath New Guinea (Hall and Spakman, 2002). north of Grasberg-Erstberg, contains a geologic resource of Mineral deposit styles: This belt contains the Carstenz dis- more than 250 t Au and occurs along the margin of a late trict, which includes the Grasberg porphyry Cu-Au deposit, Miocene to early Pliocene K alkaline intrusive-extrusive com- the Ertsberg Cu-Au skarn complex, and a gold-rich skarn at plex (6.6–5.2 Ma; O’Connor et al., 1999). The deposit is Wabu. Grasberg contains a resource of 4,000 Mt at 0.64 g/t hosted by an Oligocene sequence of limestone and calcareous Au (2,560 t) and 0.6 percent Cu (24 Mt; Figs. 14–15, App. 4; siltstone in a south-vergent anticline-thrust fault complex, van Leeuwen, 1994). The proven and probable reserve of the close to the intersection of a northeast-trending sinistral combined open-pit and underground deposits totals 1950 t of strike-slip fault (O’Connor et al., 1999). gold (year-end 1998; Widodo et al., 1999). The deposit is The Porgera mine in the New Guinea Highlands contains hosted by Pliocene diorite to monzonite stocks (3.3–2.7 Ma) two major stages of gold mineralization, early intermediate- and an andesite-diorite diatreme complex (MacDonald and sulfidation type within the open-pit (premine reserve: 54 Mt

0361-0128/98/000/000-00 $6.00 10 11

5.8 g/t Au) and late high-grade ?low-sulfidation type in zone The Pliocene Tolukuma intermediate-sulfidation quartz- VII, which lies along the Roamane fault at a depth of 200 to adularia-carbonate vein system, 100 km north of Port 500 m beneath surface (premine reserve: 5.9 Mt at 27 g/t Au; Moresby, is high grade (1.5 Mt at 13.8 g/t Au). The deposit is Handley and Bradshaw, 1986; Handley and Henry, 1990; associated with phreatomagmatic breccias in the hanging wall Richards and Kerrich, 1993; Sillitoe and Hedenquist, 2003). of a normal fault that juxtaposes andesitic volcanic rocks Both stages of mineralization are related to the 6.0 ± 0.3 Ma against footwall Owen Stanley Metamorphics (Semple et al., emplacement of the mafic (diorite-gabbro) sodic-alkalic 1998). Porgera Intrusive Complex within Jurassic carbonaceous silt- stones and Cretaceous calcareous shales (Handley and Henry, Maramuni 1990; Richards, 1990; Richards and McDougall, 1990). The Geologic setting: The Maramuni arc forms a belt of early stage consists of disseminated pyrite and quartz-carbon- Miocene calc-alkaline, intermediate to mafic volcanic and in- ate-base metal sulfide veins and associated sericite-carbonate trusive rocks that extends ~1,000 km across the southwestern alteration; the later stage consists of quartz-roscoelite (V- margin of the New Guinea mobile belt from near the Irian bearing sericite)-adularia veins and breccias with native gold Jaya border to 100 km southeast of Port Moresby (Fig. 15; and minor pyrite and Au-Ag telluride minerals (Handley and Table 1; Page, 1976; Dow, 1977; Rogerson and McKee, 1990; Bradshaw, 1986; Ronacher et al., 1999). The presence of McDowell et al., 1996; Hill and Raza, 1999). Arc magmatism magnetite-chalcopyrite-pyrrhotite and biotite-actinolite-an- is inferred to be related to the subduction of the Solomon Sea hydrite in the early-stage assemblage at more than 1,000 m beneath the Papuan Peninsula and eastern New Guinea, fol- below zone VII (Ronacher et al., 1999) provides a potential lowing the early to mid-Miocene collision of the Ontong Java link to porphyry-style mineralization at depth. The duration plateau with the Melanesian arc and the southwestward jump of the hydrothermal system, including both early and late in subduction zones, from the Melanesian to the Marumuni stages of mineralization, is ~100,000 yrs, as constrained by the trench (Cullen and Pigott, 1989; Hill and Raza, 1999; Hall, 40Ar/39Ar laser dating method (Ronacher et al., 2002). 2002). The basement to the arc includes pre-Triassic metavol- Intermediate-sulfidation gold systems occur at Hidden Val- canic rocks and granite in the Papuan fold belt (Papuan ley, Kerimenge, Hamata, and Wau in the Wau-Bulolo graben province) and variably metamorphosed, latest Cretaceous to (Carswell, 1990; Hutton et al., 1990; Nelson et al., 1990; Paleogene mélange and ophiolite in the New Guinea and Denwer and Mowat, 1998). This graben is an intra-arc rift Owen Stanley thrust belts (Solomon province; Hamilton, basin formed in the Pliocene as a result of movement along 1979; Pigram and Davies, 1987; Rogerson and McKee, 1990). inferred northeast-trending strike-slip faults in a basement of The arc has been exhumed at least 3 to 4 km mainly from 8 Cretaceous to Paleogene schist and phyllite (Owen Stanley to 5 Ma, due to the late Miocene collision of the Finisterre- Metamorphics) that was intruded by the mid-Miocene Mo- Adelbert (Melanesian) arc, which caused regional uplift of robe Granodiorite (Lowenstein, 1982; Dekker et al., 1990; northern Papua New Guinea (Crowhurst et al., 1996). This Corbett, 1994). The deposits are typically associated with exhumation exposed mid-Miocene batholiths east of the faults and late-stage breccia bodies and diatremes related to Bosavi lineament, including the Bismark (17–13 Ma), Mara- mid-Pliocene dacite to andesite porphyry intrusions (e.g., muni Diorite (15–10 Ma), Akuna (17–15 Ma) and Morobe Edie Porphyry; Carswell, 1990). The common ore type con- Granodiorite (14–12 Ma) intrusive complexes (Page and Mc- sists of quartz-carbonate-base metal sulfide veins and related Dougall, 1972; Page, 1976; Lowenstein, 1982; Hall et al., sericite-quartz-pyrite alteration. These systems contain more 1990). The margins of these batholiths serve as the locus for than 190 t Au at grades that range from 1.0 to 3.7 g/t Au. the emplacement of late Miocene porphyries and related The ore mineralogy and paragenetic sequence of events at copper-gold mineralization (e.g., Yandera porphyry; Watmuff, the Pliocene Umuna lode, Misima Island (77 t Au) is similar 1978). to those described for the deposits of the Bulolo graben Mineral deposit styles: Middle to late Miocene Cu-Au por- (Lewis and Wilson, 1990; Appleby et al., 1996). At Umuna, phyry and skarn mineralization styles are associated with dior- pyritic quartz and quartz-carbonate veins fill a steeply dipping ite to granodiorite porphyritic intrusions in the Marumuni arc fault zone in greenschist facies metamorphic rocks (Lewis (Fig. 15). The subeconomic Frieda River porphyry system de- and Wilson, 1990). The Plio-Pleistocene Gameta and Wapola veloped between 13.6 and 11.5 Ma and has a mean K/Ar age intermediate-sulfidation gold deposits (4.2 t Au) on Fergus- of 11.9 Ma (Whalen et al., 1982). The major orebodies, son Island share characteristics with the style of mineraliza- Horse-Ivaal and Koki, are centered on small, elongate calc-al- tion at Misima (Appleby et al., 1996). Gameta and Wapola are kaline microdiorite stocks (<1.5 km in length), cut by late- localized along gently to moderately dipping detachment stage andesite porphyry and postmineralization trachyan- faults related to metamorphic core complexes that place Cre- desite dikes (Hall et al, 1990). The estimated depth of taceous or older ultramafic rocks of the Solomon Sea plate on emplacement of the porphyry complex is 1.5 to 2 km beneath pre-Cretaceous gneiss and amphibolite of the Australian cra- paleosurface (Hall et al., 1990). The Nena high-sulfidation ton (McNeil, 1990; Chapple and Ibil, 1998). Pliocene gran- Cu-Au deposit, 7 km northwest of Frieda, formed contempo- odioritic plutons form the core to the domal uplifts. The core raneously with the Frieda porphyry deposits (Hall et al., complexes are inferred to have formed from late Pliocene to 1990). The deposit is hosted by a middle Miocene sequence Recent time in response to isostatic uplift of subducted sialic of andesitic lapilli tuff, directly beneath an andesitic lava unit continental crust through overlying, obducted oceanic crust (Bainbridge et al., 1998). Hypogene covellite, stibnoluzonite, and rifting due to the westerly propagation of the Woodlark and luzonite-enargite are the primary ore minerals hosted by basin spreading center (Chapple and Ibil, 1998). residual quartz alteration. The deposit formed at a similar

0361-0128/98/000/000-00 $6.00 11 12 structural-stratigraphic level to the porphyry deposits with The origin of the shoshonitic K alkaline Tabar-Feni Island ore distributed over a vertical extent of ~300 m (Bainbridge chain, which lies approximately 400 km above the New Britain et al., 1998). The Frieda and Nena deposits lie along the subduction slab, is less evident. However, Pliocene to Recent northeast-trending zone of faults and intrusions that extend magmatism in this arc could originate from subduction southwest through Ok Tedi, which Bainbridge et al. (1998) modified mantle and be related to north-trending rifting of suggested represents a basement fault that has localized the the outer Melanesian arc during the opening of the Bismarck southwestward migration of magmatism from mid-Miocene Sea, which commenced at ~3.5 Ma (Johnson, 1979; Wallace at Frieda to Pleistocene at Ok Tedi. et al., 1983; McInnes and Cameron, 1994). A subarc mantle The middle Miocene Wafi porphyry and coeval high-sulfi- source to Lihir Island magmatism is supported by the simi- dation system contains in excess of 107 t Au and 1.3 Mt Cu larity between 187Os/188Os values from samples of gold ore (Tau-Loi and Andrew, 1998). The Wafi deposits are hosted by and related intrusions from the Ladolam deposit and the pre- siliciclastic rocks of the Owen Stanley Metamorphics, in- sent-day mantle (187Os/188Os value of 0.1217), as sampled truded by diorite to dacite porphyry stocks, adjacent to two from xenoliths collected from a nearby sea-floor volcano major northeast-trending faults (Ercig et al., 1991; Tau-Loi (McInnes et al., 1999). and Andrew, 1998). The porphyry system is centered on a The geologic basement to the Melanesian arc is not ex- diorite stock, less than 300 m in diameter, concealed beneath posed but is inferred to be pre-Eocene oceanic crust (Hall, a leached cap of residual quartz and is extensively overprinted 2002) The oldest rocks exposed include Eocene calc-alkaline by advanced argillic alteration that extends to ~450 m be- pillow lavas, volcaniclastic rocks, minor limestone, and rare neath surface; the relict potassic zone is preserved at ~600-m gabbroic intrusions (Dow, 1977; Rogerson and McKee, 1990). depth. The depth of porphyry-style mineralization exceeds The northwest-trending faults that extend across eastern New 900 m. Several enargite-bearing residual quartz-hosted gold Britain, New Hanover, and southern New Ireland Islands are zones occur near fault intersections with the margin of the 1.0 inferred to link to offshore transform faults that separate by 0.6 km Wafi diatreme (Ercig et al., 1991; Tau-Loi and An- northeast-oriented spreading ridges in the Bismarck Sea drew, 1998). Secondary K-feldspar in the potassic zone of the (Falvey and Pritchard, 1982; Rogerson and McKee, 1990). porphyry deposit indicates a K/Ar date of 14 Ma, whereas, North-trending horst blocks form the foundation for the Is- alunite from the advanced argillic zone returns a K/Ar date of lands of the Tabar-Feni chain and localize Pliocene to recent 13 Ma (Tau-Loi and Andrew, 1998). volcanism on Lihir Island (Moyle et al., 1990). On A subeconomic porphyry Cu-Au system is associated with Bougainville Island, northwest-trending faults and lineaments mid- to late Miocene dacitic to dioritic stocks at Yandera (9–7 localize the distribution of Pleistocene to Recent volcanoes, Ma; Watmuff, 1978) and a small gold skarn occurs adjacent to where more than 1,200 m of uplift has occurred since the the Elandora andesite to granodiorite porphyry (late early Miocene (Clark, 1990). Miocene?) at Mount Victor in Kainantu (Abiari et al., 1990). Mineral deposit styles: The Melanesian arc hosts early At Mount Victor, the causal Elandora porphyries are localized Miocene (25–22 Ma) Cu-Au porphyry (±skarn) prospects, along the margins of the mid-Miocene Akuna batholith and such as Esis, Plesyumi, and Kulu (Hine and Mason, 1978; Cretaceous Mount Victor Granodiorite (Abiari et al., 1990). Hine et al., 1978; Titley, 1978) and the Wild Dog high-sulfida- tion deposit (Lindley, 1990) on New Britain, and the Legusu- Melanesian (inner and outer) lum porphyry prospect on New Ireland (Fig. 15; Rogerson and Geologic setting: The calc-alkaline Melanesian arc, as de- McKee, 1990; Singer et al., 2002). The Arie and Mount Kren scribed in this paper, from west to southeast, includes the ac- porphyry systems on Manus Island are middle Miocene creted portions of the Finisterre-Adelbert arcs in northeast- (15–13 Ma; Singer et al., 2002). The Arie deposit is the largest ern New Guinea and New Britain Island (inner Melanesian of all the Miocene systems (165 Mt at 0.32% Cu) and is related arc) and the Manus, New Ireland, and Bougainville Islands to diorite porphyry and breccia bodies hosted by basaltic to an- (outer Melanesian arc; Fig. 15; Table 1), which corresponds desitic volcanic and volcaniclastic rocks (Singer et al., 2002). to the Finisterre province of Rogerson and McKee (1990). The Pliocene (3.4 Ma) Panguna copper-gold porphyry de- The Melanesian arc represents the northerly continuation of posit (768 t Au, 6.4 Mt Cu) on Bougainville Island is centered the Solomon arc, which began development in the Eocene to on a series of diorite, quartz diorite, and granodiorite stocks early Oligocene in response to southwest-directed subduc- localized along the margin of a premineralization (~5–4 Ma) tion of the Pacific plate (Falvey and Pritchard, 1982; Hall, quartz diorite pluton (Clark, 1990). The following description 2002). The collision of the Ontong Java plateau in the early is based on that of Clark (1990). Intrusive breccia pipes in the Miocene jammed the Melanesian trench with a general hia- surrounding andesitic volcanic sequence and along intrusive tus in arc magmatism from the mid- to late Miocene until contacts host high-grade ore (>1.0 g/t Au and 1.0% Cu). northeast-directed subduction was established beneath the Mapped faults and regional lineaments defined from side- New Britain trench in the earliest Pliocene (~6 Ma; Hall, looking airborne radar indicate two populations: west-north- 2002). Magmatism continues through to the present. The west trends, which correspond to the elongate dimensions configuration of the arc system is largely due to the modifica- of synmineralization diorite stock and related dikes, and tion of the mid-Oligocene arc by westerly transport of the northeast trends, which parallel late-stage pebble dikes and inner Melanesian arc toward New Guinea, which led to postmineralization (1.6 Ma) andesite dikes. The deposit ex- accretion of the Finisterre-Adelbert terranes in the late tends from surface to a depth of ~650 m. Miocene (Pigram and Davies, 1987; Crowhurst et al., 1996; The Pleistocene (~0.3 Ma) Ladolam gold deposit (1,378 t Au) Hall, 2002). on Lihir Island lies in the floor of the K alkaline Quaternary

0361-0128/98/000/000-00 $6.00 12 13

Luise caldera, in the hanging wall of a north-northeast–trend- about 4 to 3 Ma as a result of collision between the arc and ing normal fault (Moyle et al., 1990; Carman, 1995, 2003). the Australian margin in Timor (Carter et al., 1976). Clastic Three major styles of hydrothermal alteration are evident. and carbonate sedimentary rocks are intercalated with the Early porphyry-style potassic (biotite-orthoclase-albite-anhy- volcanic sequences of both generations of arc. The Neogene drite) and propylitic (calcite-chlorite-K-feldspar-albite-K- arc is characterized by calc-alkaline andesitic to dacitic vol- mica) alteration types are overprinted by transitional epither- canic rocks and their intrusive equivalents in Sumatra, and mal adularia and late epithermal silicic, argillic, and advanced basaltic to andesitic volcanic rocks and intrusions of calc-alka- argillic alteration styles (Carman, 2003). The superposition of line and tholeiitic affinities in the Java–Flores and east Banda these types of alteration and a range of K/Ar dates obtained sectors (Hamilton, 1979; Hutchison, 1989; Soerja-Atmadja et from hydrothermal minerals (1.0–0.2 Ma for biotite, K- al., 1994). Dacitic to rhyolitic suites occur locally and are par- feldspar, and illite, and 0.15 Ma for alunite) led Moyle et al. ticularly abundant in the Alor, Wetar, and Romang sectors. (1990) and Carman (1995) to call upon catastrophic sector Quaternary basaltic to dacitic, and locally rhyolitic, volcanic collapse of the Luise stratovolcano (present rim elevation of products cover older volcanic rocks throughout much of the ~700 m) and the telescoping of the hydrothermal system arc. from porphyry to epithermal conditions at ~0.3 Ma. The gold Mineral deposit styles: The arc is characterized by interme- in the deposit is mostly contained in epithermal, pyrite-marc- diate-sulfidation vein systems at Mangani, Salida, Lebong asite-arsenopyrite breccia and quartz-calcite vein ore types Tandai/Donok, and Lampung in Sumatra and also in West that typically extend from near sea level to 200 m below Java (Fig. 14, App. 4). The geologic basement to Sumatra and (Moyle et al., 1990; Carman, 2003). Sillitoe and Hedenquist western Java consists of Sundaland continental crust, where (2003) interpret the epithermal event at Ladolam to be low no direct link between the intermediate-sulfidation deposits sulfidation, on the basis of the extensional back-arc setting and coeval intrusions is apparent. Nearly 80 t Au was pro- and alkaline host rocks. duced from high-grade lodes (~15 g/t Au) in Lebong Tandai and Lebong Donok in the Bengkulu district by the Dutch Sunda-Banda prior to 1941 (Kavalieris, 1988; van Leeuwen, 1994). Lebong Geologic setting: This Eocene to Recent arc extends nearly Tandai is hosted by Miocene andesitic volcanic rocks and 4,000 km from northwestern Sumatra through Java and ter- Lebong Donok occurs in Miocene carbonaceous shale associ- minates in the Banda Island group of eastern Indonesia (Fig. ated with the brecciated margins of a competent dacite intru- 14; Table 1). The basement to the arc varies from Mesozoic to sion (Kavalieris, 1988). The Tandai lode is localized along a late Paleozoic platform sedimentary rocks deposited on con- steeply dipping east-west fault system, which is offset by tinental crust that are intruded by two mica granites in Suma- northeast- and northwest-oriented strike-slip faults (Jobson et tra, through Cretaceous to Tertiary melange and ophiolite in al., 1994). Tandai, Donok, and Rawas, to the east, occur central and eastern Java, to oceanic crust in the Banda arc within 20 to 30 km of the Sumatra fault near major east- and (Hamilton, 1979). northeast-trending arc-transverse faults. An Eocene to early Miocene calc-alkaline arc, the “Old An- At Miwah in Aceh, northern Sumatra, a high-sulfidation desites” of van Bemmelen (1949), extends through Sumatra system is hosted by north-trending, tensional fracture zones and Java and continues eastward toward the Banda arc. The in andesitic to dacitic volcanic rocks, intruded by a Pliocene dextral Sumatra fault follows the arc and is inferred by Hamil- rhyodacite within 25 km of the Sumatra fault (Williamson and ton (1979) to have been active since the late Oligocene; more Fleming, 1995). The Tangse porphyry Cu-(Mo) prospect oc- recent work indicates the fault became active during the curs 40 km to the northwest of Miwah and is hosted by a mid- Miocene (McCarthy and Elders, 1997). Although the term dle to late Miocene plutonic complex (van Leeuwen et al., “Old Andesites” has given the impression that the arc is an- 1987). At Martabe, east of Sibolga and south of Lake Toba, desitic, and such rocks are the most obvious arc products, recently discovered disseminated high-sulfidation deposits dacitic rocks are widespread, as minor intrusions, lavas, and are hosted by multistage phreatomagmatic breccias and pyroclastic and ash deposits. The dacitic rocks have been dacitic flow dome complexes localized by extensional faults overlooked because they have commonly been reworked into adjacent to a strand of the Sumatra fault (Levet et al., 2003; sedimentary sequences (Smyth et al., 2003) but show that arc Sutopo et al., 2003). Early, texture-destructive, residual activity began in the Eocene in Java. Arc activity ceased, or quartz alteration zones are tabular and partly controlled by significantly declined, in the early Miocene and there was the moderate dips of local breccia units and underlying por- widespread deposition of sedimentary rocks, especially car- phyritic andesite adjacent to steeply dipping dilational faults. bonates, between Java and Sumba. This style of advanced argillic alteration serves as preparation Arc activity resumed in the late middle Miocene, and a for subsequent gold depositional events. Gold is associated middle Miocene to Recent magmatic arc is built on older sed- with late-stage fracture- and breccia-controlled enargite-lu- imentary and volcanic rocks in most of the Sunda-Banda arc, zonite mineralization and, to a lesser extent, earlier, interme- and in Java lies to the north of the axis of the older arc. The diate-sulfidation chalcedony veins (Levet et al., 2003). More volcanic arc has propagated east into the Banda region since than five deposits occur over a 7-km strike length, the largest about 12 Ma; the volcanic rocks east of Sumbawa are less than of which, Purnama, has a resource of 116 t Au. 9 Ma old and the volcanoes become progressively younger Gunung Pongkor (103 t Au at 17.1 g/t Au) in western Java eastward (Abbott and Chamalaun, 1981; Honthaas et al., is a low sulfide intermediate-sulfidation bonanza vein system 1998). Volcanism continues to the present day, although hosted by Miocene andesitic tuffs and breccias and a subvol- Banda arc volcanic activity ceased in the Wetar region at canic andesite intrusion (Basuki et al., 1994). The Pongkor

0361-0128/98/000/000-00 $6.00 13 14 vein system consists of four main northwesterly trending veins hosted in argillically altered felsic volcanic breccias of that define a northeast-oriented corridor. This corridor extends Miocene age. Most of the copper is contained in enargite, through the Bayah dome to the southwest, where it controls which is atypical of volcanic-associated massive sulfide sys- the distribution of several vein systems in the historic Cikotok tems. The age of mineralization is believed to lie between 5 mining district. The host rocks in the Bayah dome consist of and 4 Ma (van Leeuwen, 1994; Sewell and Wheatley, 1994). Pliocene volcanic and clastic sequences, which locally are in- The Wetar deposits were formed in north elongate exten- truded by premineralization porphyritic dacite stocks. Individ- sional basins developed by the interaction of steeply dipping, ual lodes are hosted by steeply dipping north-northeast- and north-northwest and north-northeast trending conjugate north-northwest–trending faults. The northerly orientation and strike-slip faults inferred from the description of the geologic dilational character of these lodes are consistent with their de- setting of the deposits in Sewell and Wheatley (1994). velopment as a response to north-directed subduction in this sector of the arc. The age of intermediate-sulfidation vein min- Central Kalimantan eralization obtained from adularia is 8.5 Ma, which differs from Geologic setting: The Paleogene to Miocene Central Kali- the 2.1 to 1.5 Ma ages determined for other epithermal lode mantan arc of Carlile and Mitchell (1994) extends approxi- systems in the region (Marcoux and Milesi, 1994). mately 1,200 km from western Sarawak, through northwest The style of mineralization changes to the east. In the and central Kalimantan into northeastern Kalimantan (Fig. Lombok–Sumbawa portion of the arc, which is underlain by 14; Table 1). The trace of the arc disappears to the northeast, oceanic crust, high-sulfidation epithermal and porphyry Cu- beneath the western onshore extension of the Neogene Sulu- Au deposits and prospects are present. The Batu Hijau por- Zamboanga arc in the Semporna peninsula of Sabah. The phyry copper-gold deposit in southwest Sumbawa contains basement to the arc is continental in western Kalimantan, more than 366 t Au and 4.8 Mt Cu (Clode et al., 1999) and where the oldest rocks exposed consist of late Paleozoic mica occurs in an uplifted crustal block, which has been exhumed schists intruded by Triassic to Carboniferous and Cretaceous about 2 km since the mid-Pliocene (Garwin, 2002a). Mineral- (Schwaner Massif) granites (Hamilton, 1979; Hutchison, ization is genetically related to three stages of Neogene 1989). In contrast, Late Cretaceous to Paleogene ophiolite, tonalite porphyry intrusions emplaced in quartz diorite and arc volcanic and sedimentary rocks comprise the basement to andesitic volcaniclastic wall rocks. The tonalite porphyry com- the arc in eastern Kalimantan and Sabah. In the Bau area of plex was emplaced over a span of ~100,000 yrs at ~3.7 Ma west Sarawak, Triassic andesitic arc volcanic rocks are over- (Fletcher et al., 2000; Garwin, 2002a; McInnes et al., 2004). lain by Jurassic and Cretaceous marine carbonate and silici- A late mineralization diatreme occurs about 2 km northwest clastic rock sequences interpreted by Hutchison (1989) to of Batu Hijau. The deposit occurs in the central portion of a have been deposited along the marginal shelf of Sundaland. district characterized by several porphyry centers, peripheral The arc is defined by the discontinuous distribution of ero- intermediate-sulfidation vein systems, and distal, sedimentary sional remnants of calc-alkaline andesitic, trachyandesitic, and rock-hosted replacement-style mineralization (Meldrum et local dacitic volcanic-plutonic centers, inferred to be associated al., 1994; Irianto and Clark, 1995; Garwin, 2002a). Local con- with tonalite, granodiorite, and granite intrusions in western trols include the intersections of northeast- and northwest- (Sintang intrusive suite) and northeastern (Long Lai intrusive trending fault zones with the margins of premineralization suite) Kalimantan (Carlile and Mitchell, 1994). Arc activity is quartz diorite plutons. still poorly dated and may extend from the Eocene. Arc con- Enargite-gold veins at Elang, 60 km east of Batu Hijau, struction is related to south-directed subduction beneath the occur close to a porphyry copper-gold system, which formed Rajang accretionary complex of northwest Borneo in the at ~2.7 Ma (Maula and Levet, 1996; Garwin, 2000). Batu Oligocene to Miocene by Carlile and Mitchell (1994). Arc ac- Hijau and Elang occur within 20 to 30 km of a major left-lat- tivity diminished after early Miocene collision between the eral oblique-slip fault zone that controls the distribution of continental crust of the South China Sea margin and the active Miocene volcano-sedimentary units, Pliocene intrusions, and margin of northern Borneo (Hutchison et al., 2000; Hall and the present coastline of Sumbawa. Wilson, 2000). About ~1.3 km of exhumation from 25 to 23 Ma Base metal-rich, intermediate-sulfidation epithermal barite and the eastward shift of the Kutai basin sedimentation mark and quartz vein prospects are hosted in andesitic to dacitic this tectono-magmatic event (Moss et al., 1998). The distribu- volcanic rocks and intercalated sedimentary rocks in the tion of igneous rocks and middle to late Tertiary sedimentary West Flores, East Lomblen-Pantar, Wetar, and Romang re- basins indicates that northwest-trending arc-transverse faults gions of the Banda arc. In Romang, vein-style mineralization played a role in arc tectonics and magmatism (Fig. 8). is localized in a dilational zone along a west-northwest–trend- The sedimentary rocks of the Tertiary Kutei basin are lo- ing dextral strike-slip fault corridor (Garwin and Herryansjah, cally intercalated with arc-related pyroclastic rocks in eastern 1992). Local jasperoid replacing reefal limestone character- Kalimantan. Hamilton (1979) inferred that the development izes several prospects in the Flores-Romang sector of the arc of the Kutai basin is related to the rifting of the eastern mar- (e.g., localities in Rinca Island, West Flores, and south Ro- gin of Sundaland and the drifting of western Sulawesi away mang). At Wetar, Au-Ag barite deposits (23 t Au) represent a from Kalimantan in the middle Tertiary. Chambers and Daley submarine exhalative system in a sea-floor caldera setting (1997) indicated initial rift-basin formation in the Eocene and similar to the Kuroko deposits in Japan (Sewell and Wheatley, subsequent basin development by load subsidence to Recent 1994). Gold-silver mineralization occurs in stratiform barite time. It is now clear that the separation of western Sulawesi sand units (exhalite), which are underlain by copper-rich mas- and Kalimantan by rifting began in the Eocene, although it is sive pyrite-marcasite zones and quartz-pyrite stockworks still uncertain if there was ocean crust formation in the

0361-0128/98/000/000-00 $6.00 14 15

Makassar Strait (Cloke et al., 1999). Plio-Pleistocene tholei- and intermediate-sulfidation vein systems that have under- itic plateau flood-basalts form platforms in northwestern, gone supergene enrichment during weathering. A colloidal north-central, and northeastern Kalimantan. origin for the gold recovered from the Ampalit alluvial mine Mineral deposit styles: A well-defined northeasterly trend- in Central Kalimantan has been inferred by Seeley and ing belt of gold deposits and prospects extends approximately Senden (1994), on the basis of gold grain morphology and its 500 km along the southeastern margin of the Oligocene to fineness of 998. The delicate nature of the grain boundaries Miocene arc (Fig. 14). This central Kalimantan gold belt co- and the high fineness preclude mechanical transport from incides with the margins of the Kutei and Barito basins along nearby epithermal veins, which commonly contain electrum the eastern flanks of the Schwanner massif and the rifted (purity of <900 fine). margin of Sundaland. Andesitic volcanic rock-hosted, inter- mediate-sulfidation vein and stockwork mineral deposits Other Indonesian, Borneo, and Papua New Guinean arcs occur along this belt. The styles of mineralization in these sys- Several other late Cenozoic magmatic arcs are described by tems are discussed by Simmons and Browne (1990) for Mt. Carlile and Mitchell (1994), including the Miocene Northwest Muro, by Wake (1991) for Muyup, by Thompson et al. (1994) Borneo (Sarawak), the Neogene West Sulawesi, and Miocene for Masupa Ria, and van Leeuwen (1994) for Mirah and the Moon-Utawa arcs (Fig. 14). Although there is igneous activity others. The Mt. Muro vein complex is the largest of these de- in these regions, there are reasons to doubt that these arcs posits (51 t Au). The complex lies close to the northwest- formed in subduction-related settings. The Miocene igneous trending Trans Borneo shear of Hutchison (1989) and con- rocks of Sarawak are too poorly known and dated to be confi- sists of more than 15 vein systems, most of which strike dent of their origins. Recent work (Prouteau et al., 2001) sug- northwesterly and dip steeply. At Masupa Ria, intermediate- gests there are two suites: early Miocene arc volcanic rocks are sulfidation veins are superimposed on an early-stage high-sul- the product of south-directed subduction north of Borneo and fidation alteration system (Thompson et al., 1994). could be the equivalent of Paleogene rocks in Sabah (Hall and The Kelian intermediate-sulfidation deposit (179 t Au, van Wilson, 2000; Hutchison et al., 2001), whereas middle and late Leeuwen et al., 1990) is localized in a maar-diatreme com- Miocene magmatic rocks are postcollisional and have some plex, which contains multiple diatreme breccia pipes and late- adakitic features (Prouteau et al., 2001). stage endogenous quartz-porphyry domes (Davies et al., Neogene volcanic activity in western Sulawesi began at 1999). The diatreme complex postdates subvolcanic andesite about 11 Ma and was probably not related to active subduc- intrusions and a north-northeast–trending Eocene to Oligocene tion but rather to extension (Yuwono et al., 1988; Priadi et al., rhyolitic volcano-sedimentary sequence. The ore is hosted by 1994; Polvé et al., 1997). Elburg and Foden (1998) described a variety of breccia styles, which have undergone extensive the rocks as syncollisional and isotopically enriched and rela- hydrothermal alteration. Styles of mineralization include net- tively K rich, which they attribute to a contribution of sub- work veins and breccia and fracture filling by complex car- ducted sediments. Neogene magmatic rocks are commonly bonate-quartz-pyrite-sphalerite-galena-gold/electrum. Limited high K and include shoshonites and leucitites. The trace ele- K/Ar radiometric dating at Kelian indicates an early Miocene ment patterns in the lavas suggest subduction zone recycling, age for andesite intrusion (23 Ma) and sericite alteration (20 but they are most similar to rocks of postsubduction exten- Ma; van Leeuwen et al., 1990). The deposit lies adjacent to sional environments, such as those of the southwetern United the Kutei basin and along the rifted margin of Sundaland. States (Macpherson and Hall, 2002). Disseminated sedimentary rock-hosted gold deposits occur There was little volcanism in western New Guinea during in the Bau district of western Sarawak (~40 t Au in past pro- the Neogene and no evidence of significant subduction. Seis- duction, Wilford, 1955; Wolfenden, 1965). Gold is associated mically, there is a poorly defined slab beneath western New with carbonate and siliciclastic members of the Jurassic Bau Guinea, which suggests a south-dipping subducted slab of lit- Limestone in fault contact with the overlying Cretaceous tle more than 100 km at the New Guinea trench. Tomo- Pedawan Shale. Pervasive silicification and extensive collapse graphic images show no slab beneath western New Guinea breccias have developed close to the shale and/or limestone (Spakman and Bijwaard, 1998; Hall and Spakman, 2002). As contact along the Tai Parit fault and adjacent to argillic-al- noted by Carlile and Mitchell (1994), Neogene volcanic rocks tered dacite porphyry dikes. Tai Parit marks the general in- from Irian Jaya have been little explored and the mid- tersection between a north-northeast–oriented belt of middle Miocene Moon-Utawa rocks have not been well studied. Miocene (13–10 Ma; Metal Mining Agency of Japan, 1985) Other Miocene volcanic rocks in Irian Jaya have an unusual dacite to granodiorite intrusions with the northeast-trending chemical character that is postcollisional and quite different Bau anticline. Disseminated gold mineralization is associated from Neogene magmatic rocks in eastern New Guinea with arsenopyrite in silicified shale at Jugan, approximately 10 (Housh and McMahon 2000). km along trend, to the northeast. These sedimentary rock- Carlile and Mitchell (1994) postulated the existence of the hosted deposits form part of a >300 km2 district, which also Neogene Aceh arc in northernmost Sumatra, on the basis of includes weak porphyry copper-style mineralization and pre- the distribution of volcanic rocks of similar age and the cita- viously mined Cu-Au skarns, auriferous mesothermal and ep- tion of an offshore trench in Stephenson et al. (1982). How- ithermal polymetallic sulfide-veins, and disseminated mer- ever, this arc, if it exists at all, lacks a Benioff zone and a pro- cury deposits (Schuh, 1993) nounced bathymetric trench, as indicated by satellite gravity Historic and recent alluvial gold mines are common in data. It is more likely that the Aceh arc represents a young western and central Kalimantan. The placer gold is probably portion of the Sunda arc with magmatic activity localized sourced from orogenic quartz lodes in crystalline basement along a west-northwest–trending arc-transverse fault zone.

0361-0128/98/000/000-00 $6.00 15 16

Miocene to Pliocene calc-alkaline and alkaline volcanic ore assemblages at the Busi and Boniavat vein systems, which rocks and granodiorite to monzonite intrusions (Dondo Suite) are more quartz rich and typically contain only minor base in the western arm and neck of Sulawesi do not host signifi- metal sulfides (Russell, 1990). The age of mineralization at cant gold mineralization. However, significant gold deposits Busai is dated as 12.3 Ma (Russell and Finlayson, 1987). do occur at Awak Mas (26 t Au) and Palu (G. Hartshorn, pers. commun., 1999). Both deposits are located close to sinistral Burman strike-slip faults of the Palu fault system. In Awak Mas, epi- to Geologic setting: The Neogene to Quaternary Burman mesothermal quartz veins and stockworks are localized along magmatic arc includes an onshore portion in Myanmar, which shear zones in Cretaceous metasedimentary basement and extends ~1,200 km from the Jade mines in the north through near fault contacts with basalt (van Leeuwen, 1994). Gold oc- Mount Popa and Pegu Yoma in the south, and an offshore curs in pyritic quartz-albite-carbonate breccias, veins, and chain of islands and seamounts in the Narcandam and Barren stockworks. The Ag/Au ratio of the deposit is less than one. Island region of the Andaman Sea (Fig. 2; Table 1). The arc The genetic relationship between mineralization and the lies to the west of the dextral strike-slip Sagaing fault, which Neogene magmatic arc, if any, is not clear. marks the boundary between the Burma continental block to No significant gold prospects are known in the Northwest the west and the Shan-Thai core of the Eurasian plate to the Borneo arc of Hutchison (1989). However, gold occurs in east (Hutchison, 1989). The onshore portion of the arc is calc- placers and minor quartz veins near dacitic pyroclastic rocks alkaline to high K calc-alkaline, while the offshore sector is and flows of the Hose Mountains and the Usun Apau plateau tholeiitic (Hutchison, 1989). A belt of alkaline to shoshonitic (Kirk, 1968; Geological Survey of Malaysia, 1976). rocks, about 100 km to the east of the calc-alkaline arc, ex- The Miocene andesitic volcanic rocks and dioritic intru- tends along the eastern side of the Sagaing fault and contin- sions in the “Bird’s Head” portion of the Moon arc in Irian ues southward along the eastern shore of the Andaman Sea. Jaya are characterized by gold and base metal mineralization The eastward increase in alkalinity is attributed to the waning associated with quartz veins and stockworks (Carlile and stages of eastward subduction of the Indian plate beneath the Mitchell, 1994). No significant gold or copper prospects are Burma block during the transition to strike-slip movement as- documented for the Oligocene to Miocene volcanic arc rocks sociated with spreading in the Andaman Sea that began by on Yapen Island, east of the Moon arc. ~10 Ma (Curray et al., 1979; Stephenson and Marshall, 1984). The Mount Kinabalu pluton, satellite intrusions, and coeval The Burman magmatic arc is associated with a poorly defined andesitic-dacitic volcanic rocks in northwestern Sabah do not Benioff zone that extends to a depth of 200 km. lie along a well-defined magmatic arc. The ages of the causal The basement to the arc in the Banmauk region consists of high K calc-alkaline adamellite pluton and apophyses range Mesozoic phyllite, schist, gneiss, and amphibolite. Marine from 12.2 to 1.3 Ma (Kirk, 1968; Hutchison, 1989). However, basalt, andesite, volcaniclastic rocks, and mudstone overlie the most probable age ranges from 7.0 to 6.4 Ma (App. 4; Bel- the basement rocks and both sequences are intruded by the lon and Rangin, 1991; Imai, 2000). The pluton intrudes Pale- Cretaceous Kanzachaung granodiorite batholith (United Na- ogene sedimentary rocks of the Rajang accretionary prism to tions Development Program, 1978a). Eocene andesite sills the inactive Northwest Borneo trench (Hutchison, 1989). A and early Oligocene diorite to granodiorite stocks (e.g., series of northwest-trending faults pass through Mount Kina- Shangalon granodiorite), trachyte flows and dikes are overlain balu, forming a fault zone that extends through central Sabah by Oligocene to Miocene mudstones and sandstones (United to the Semporna peninsula (Kinabalu fault of Tokuyama and Nations Development Program, 1978a, b; Mitchell et al., Yoshida, 1974). Basement rocks consist of greenschist- and 1999). This succession covers much of the western forearc amhibolite-facies schist and gneiss of Mesozoic (?) age. and eastern backarc basins to the Burman arc. Late Miocene The Mamut Cu-Au deposit is centered on an apophysis to to Quaternary basalt and andesite are characteristic of the the Kinabalu pluton along the eastern flank of Mount Kina- Mount Popa, Taungthonlon, and Monywa areas. balu. Porphyry-style mineralization occurs in and adjacent to Mineral deposit styles: Alluvial gold occurs at Mansi, to the an adamellite porphyry stock (7.0 Ma; Imai, 2000) cut by west of the northern portion of the arc, and in the Jade Mines postmineralization granodiorite dikes in a sequence of weakly region to the north (Goosens, 1978; United Nations Develop- hornfelzed sandstone, mudstone, spillitc tuffs, and serpen- ment Program, 1978c). In the Banmauk region lode gold was tinized peridotite. The host-rock sequence is inferred to have recovered from pyritic quartz lodes hosted by Tertiary an- been tectonically emplaced in the early to middle Miocene desitic tuffs and breccias at Kyaukpazat (Goosens, 1978) and (Kosaka and Wakita, 1978). in granodiorite at Sadwin (United Nations Development Pro- Woodlark Island in Papua New Guinea is a remnant of a gram, 1978c). The Shangalon porphyry Cu-Au prospect is Miocene island arc built upon Cretaceous (?)-Eocene tholei- hosted by quartz diorite along the margin of the Cretaceous itic, Solomon Sea floor basalt, which is inferred to have been granodiorite batholith, 80 km southwest of Banmauk. obducted onto the Australian craton (Fig. 15; Russell and Fin- The Monywa high-sulfidation deposit occurs in an uplifted layson, 1987; Russell, 1990). Intermediate-sulfidation gold de- portion of the arc about 50 km north of Mount Popa. More posits, Kulumadau, Boniavat, and Busai, are related to a por- than 4.5 Mt of copper occurs in hypogene chalcocite-bearing phyritic microdioritic pluton and monzonite dikes emplaced in breccia bodies associated with hypabyssal dacitic intrusions, high K calc-alkaline andesitic volcanic and volcaniclastic rocks which indicate radiometric ages of 19 Ma at Letpadaung and of early to middle Miocene age (Russell, 1990). The ore as- 13 Ma at Kyisintaung (App. 6; Kyaw Win and Kirwin, 1998). semblage at Kulumadau contains calcite ± quartz-pyrite-base The gold content of the copper ore is minor. The intermedi- metal sulfides in phreatic explosion breccias, in contrast to the ate-sulfidation quartz veins that occur within 5 km of the

0361-0128/98/000/000-00 $6.00 16 17 chalcocite orebodies contain low levels of gold and silver APPENDICES 2 to 6 (Kyaw Win and Kirwin, 1998). In the Indawgyi region of the backarc basin, immediately Grade-Tonnage and Age Characteristics for Major Gold west of the Sagaing fault, Miocene (?) sedimentary rock- and Copper ± Gold Deposits in the Cenozoic Magmatic hosted gold mineralization at Kyaukpahto is localized in a de- Arcs of Southeast Asia and the West Pacific calcified and silicified calcareous arkosic sandstone sequence In these appendices, the total size and contained gold and (Male Formation) of probable Eocene age (Ye Myint Swe, copper contents (metric tonnes), grades (g/t Au and % Cu) 1990; Mitchell et al., 1999). Hydrothermal alteration includes and age of formation (Ma) are reported for all major and decalcification, silicification, and sericitic and argillic styles. some minor deposits. These contents include conservative re- Gold is associated with fine-grained pyrite and arsenopyrite in source figures for the deposits and combined reserves and/or quartz veinlets and as disseminated framboidal grains in sili- resources and past production for the mines, except where in- cified and brecciated sandstone. The region hosts numerous dicated otherwise. The grade-tonnage characteristics and age primary and alluvial gold occurrences that are spatially re- relationships are illustrated in Figures 17 and 18 in the lated to a 100-km-long segment of the Sagaing fault. printed part of the paper.

0361-0128/98/000/000-00 $6.00 17 18 sunakawa (1982) T try (1987a), Shikazono (1982) and Tsunakawa and (2001) and Internatinal Trade Industry (1987b) (1987b) 14.5-13.4 (K/Ar) and Indus- tional Trade 1.2 (K/Ar) Shimizu et al. (1998) atanabe (2002) Saito et al. (1967) Saito et al. (1967) Saito et al. (1967) (unpub. data)Saito et al. (1967) Miocene Association (1978)Association (1978) Shikazono (1986) 7.7 (K/Ar) Sawai and Itaya (1996) Seki (1993) W Mining Co. Ltd. (1981) Association (1978) Association (1978)Association (1978)Association (1978) (2002); Ministry of and Industry Trade Appendix 2 Cu Au Contained Contained Reference for Age (Ma) Metric tonnes Grade-Tonnage and Age Charactersitics of Significant Gold Copper Deposits in Cenozoic Magmatic Arcs Japan Taiwan Grade-Tonnage Izu-Bonin Izu 1.3 9.3 12 Japan Mining Industry Plio-Pleistocene Magmatic Region/district S iL oyoha EP-XE-PM NE Japan Southwest Hokkaidoeine 20 HS-IS NE Japanakatama SW Hokkaido IS 0.35 1.4 NE Japanodoroki Tohoku IS 7 NE Japan 7.5 Southwest Hokkaido 2.9 Kanbara and Kumita (1990) 2.9-0.5 (K/Ar) Sawai et al. (1989) aio 11 10 LS Shikazono (1986); SW Japan North Kyushu 29 4.4-4.0 (K/Ar) Sawai et al. (1992; 5.7 6 Japan Mining Industry Shikazono (1986) 6.3 3.1-2.1 (K/Ar) Sawai et al. (1992) 36 Japan Mining Industry 3.6-2.9 (K/Ar) et al. (1993) Yuan oichi VMS NE Japan Southwest Hokkaido 9 Past production only; 12.3 (K/Ar) Sawai and Itaya (1996) Deposit Style KonomaiSanru LSKitano-o arc LS LSHokuryu Kuril LSOhgane Kuril Kuril ISJapanTohokuT Northeast HokkaidoOsarizawa Kuril EP-PM NE 11.4 Northeast Hokkaido Northeast HokkaidoHosokura NE Japan EP-PM 0.5 0.9 Northeast HokkaidoT Southwest Hokkaido NE Japan 0.3Sado 0.4 Tohoku 28.5 (million t) 6.4 (%) IS (g/t)T 5.9 7.4 1.05 Cu (000s t) 0.15Chitose 8.2 Au (t) 5 NE Japan 300 ISShizukari Tohoku 73 IS Grade-tonnage dataT Koryu 4 3 7Nurukawa NE Japan VMS (1995)Hanaoka Watanabe IS Southwest Hokkaido NE Japan 2 (method)Osarizawa Kosaka VMS Southwest Hokkaido 2 15Shakanai 1.6 Mineland Y NE Japan (1995) VMS Shikazono (1986); Watanabe VMS 1.1 Tohoku NE Japan NE Japan Reference for age Shikazono (1986); Ashio 12.9-12.2 (K/Ar) Tohoku Southwest Hokkaido NE Japan Shikazono (1986); NE Japan et al. (1999) Yahata Bajo Tohoku XE-PM 7.7-7.4 (K/Ar) TohokuOhmori 12.4 (K/Ar)T 14.5 5.1 NE Japan IS 13.7 (K/Ar) IS Maeda (1996) 3 7 1.0 TohokuHoshino 11.4 (K/Ar) Sugaki and Isobe (1985) 41.8 LS et al. (1999) Yahata Seigoshi SW Japan 27.9 SW Japan Hirai et al. (2000) 8.7 IS Shikazono (1986) Chugoku North Kyushu 23 2.3 77 SW JapanRendaiji 24.9 6.8 0.1-0.2 North Kyushu 960 8 IS Izu-Bonin Japan Mining Industry To Izu 5.8 (K/Ar) Sakai and Oba (1970) 0.4-0.7 600 2.5 0.3-2.0 100 0.12 Izu-Bonin Saito et al. (1967); 3.5-3.3 (K/Ar) Shikazono and 24.1-22.1 (K/Ar) Izu 615 7 Ministry of Interna- Sawai et al. (1992) Ohmoto et al. (1983) 2.4 (K/Ar) 3 1.3 et al. (1988) Yamada Ohmoto et al. (1983) Ohmoto et al. (1983) (1991) Watanabe Middle Miocene 0.6 Ohmoto et al. (1983) Shikazono (1986); Furukawa Middle Miocene Miocene Middle Miocene et al. (1988) Yamada Middle Miocene 10.8 Ohmoto et al. (1983) Ohmoto et al. (1983) 13 1 3 4.0 (2001) Izawa and Watanabe 4.6-3.9 (K/Ar) 14 Shikazono (1986) (2001) Izawa and Watanabe Sawai et al. (2002) 2.8-2.5 (K/Ar) Japan Mining Industry 3 Sawai et al. (1998) 1.1 (K/Ar) 1.8-0.7 (K/Ar) Japan Mining Industry Sakota et al. (2000) Hamasaki and Bunno 1.5 (K/Ar) Ministry of Internatinal

0361-0128/98/000/000-00 $6.00 18 19 of International ogashi and Shibata Ministry of Internati0nal (1987b) and tional Trade Industry (1985) T (1984) and tional Trade Industry (2000) Industry (2000) (1987b) (K/Ar) Ministry Industry Pio-Pleistocene Industry 2.5 mal, IS = intermediate-sulfidation epithermal, LS low-sulfidation ang et al. (1999) Association (1978)W Nakamura et al. (1994) and Industry Trade Association (1978) Feebrey (2001)Association (1978) Feebrey (2001) and tional Trade Association (1978) and Industry Trade (Cont.) Appendix 2 Cu Au Contained Contained Reference for Age (Ma) Metric tonnes Magmatic Region/district HS Ryukyu Taiwan 20 0.6 4.6 119 92 (1991); Tan K/Ar) 1.0 (Ar/Ar, et al. (1999) Wang Notes: Grade-tonnage data includes combined resources and past production; mineralization styles: HS = high-sulfidation epither ugashima LS Izu-Bonin Izu 0.2Mining 12.2 2 Japan amagano LS Ryukyu South Kyushu 1.6 17.4 28 Murakami and 2.0-1.9 (K/Ar) Murakami and Deposit Style Mochikoshi LS arcY Izu-Bonin IzuChinkuashih (Taiwan) Kasuga HSAkeshiIwato HS 0.8 Ryukyu HS (million t)Kushikino South Kyushu IS Ryukyu (%)Fuke (g/t) South Kyushu Ryukyu 3 Cu (000s t) 6.4 ISHishikari Ryukyu Au (t) South KyushuY LS South Kyushu 0.9Okuchi Grade-tonnage data Ryukyu LS Ryukyu South Kyushu 8.3 3.1 5 South Kyushu (method)epithermal, PM = polymetallic, VMS Kuroko-type massive sulfide, XE xenothermal Ryukyu 9.8 South Kyushu Japan Mining Reference for age 5.5 6.7 9 1.6 9 47.3 Hayashi (2001) 56 Hayashi (2001); 8 13.6 4.5 (K/Ar) Japan Mining Industry 260 Hayashi (2001) 3 3.7 (K/Ar) 3.7-3.4 (K/Ar) Ministry of Interna- Izawa et al. (2001) 22 Izawa and Zeng (2001) Izawa et al. (1984) (2001) Izawa and Watanabe 4.7-4.2 (K/Ar) 2.2-1.4 (K/Ar) Japan Mining Industry 1.1-0.7 (K/Ar) Izawa et al. (1984); Ministry of Interna- Sekine et al. (2002) 1.6-1.2 (K/Ar) Ministry of Interna-

0361-0128/98/000/000-00 $6.00 19 20 et al. (2001) (14 Oct. 1994)Unit (2002) of Japan (1977) Angeles (1985) (1984) Leach (1991) commun., 1996); Benquet Corp., (1994) (estimate) Incorporated (1993, 1994) (estimate) Geo-Sciences (1986); Benquet Corp. (1995) (estimate) Cooke et al. (1996) Au (t) grade-tonnage data Age (Ma) Reference for age Cu (000s t) Appendix 3 Cu Au Containedfor Contained Reference Metric tonnes Grade-Tonnage and Age Charactersitics of Significant Gold Copper Deposits in Cenozoic Magmatic Arcs the Philippines Grade-Tonnage arcCordilerra Cordillera Region/districtCordillera (million t)Cordillera (%)Cordillera (g/t) Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Cordillera Magmatic 3 Style IS Luzon Central Mankayan 7.3 5.3 39 (2004) Waters 1.15 (?) Inferred: Hedenquist 1 2 esa ctoria* IS Luzon Central Mankayan 11 7.3 80 Claveria et al. (1999) 1.15 (K/Ar) Hedenquist et al. (2001) awi-Tawi PO CGD Luzon Central Bobok 159 0.39 0.16 620 25 Metal Mining Agency 4.6(K/Ar) Singer et al. (2002) ayson PO CGD Luzon Western Batangas 336 0.31 0.35 1042 118 Singer et al. (2002) 20.5 Singer et al. (2002) Deposit Far South East PO CGDSto Thomas II* Luzon Central PO CGD MankayanGuinaoang Luzon Central BaguioSan Fabian PO CGD 650Santo Nino* Luzon Central PO CGD Mankayan PO CGD Luzon Central Lobo* 449 San Fabian Luzon Central 0.65Batong Buhay* Baguio PO CGD 1.33 326T PO CGD Luzon Central 4225 314 0.38 Northwest Luzon Luzon Central Black 0.7 107 BaguioMountain* 0.37 286Kenon South 1616 865 0.37 0.27 PO CGDGambang 0.21 1206 PO CGD 0.6 Luzon Central 848 314 Luzon Central Claveria et al. (1999)Suluakan 0.35 210 Baguio 0.25 PO CGD Baguio(Worldwide) 0.2 121Botilao 642 1.4-1.3 (K/Ar) Luzon Central Cordillera PO CGD 1001 Singer et al. (2002) Mankayan Hedenquist et al. (2001) 66Ullman* 0.28 Luzon Central Baguio 0.25 62 Mining Journal PO CGDDilong/Hale 27 62 1.5 (K/Ar) 57 588 PO CGD Luzon Central 55.6 PO CGD Cordillera Thanksgiving* Research Information Northwest Luzon Luzon Central SK Sillitoe (1989) Luzon Central 20.6 82 3.5 (K/Ar)Lepanto* Baguio 0.38 TVI Pacific Inc. (1995) Northwest Luzon 123 0.38 Singer et al. (2002) 53 0.33 0.35 35Antamok* 0.33 7 Sillitoe and 0.32 236 HS Luzon Central 236 195 Baguio 1.5 (K/Ar) 0.52 IS Singer et al. (2002) Itogon* 0.35 38 Sillitoe and Gappe(1984) 0.19 0.13 0.5 Luzon Central Singer et al. (2002) 20 426 431 20Acupan* Mankayan 0.35 Singer et al. (2002) 18 IS Luzon Central 175 1.1 0.34 Baguio 0.33 IS 16 Singer et al. (2002) 16Vi Sillitoe and Gappe 40.7 129 (1980) Yumul Luzon Central 12Ter Baguio 7 3.1-2.9 (Ar/Ar) Luzon Central Sillitoe and Gappe (1984) Batong Buhay* (2004) 2.78 Waters Sillitoe and Gappe (1984) Baguio IS 11.6 13 3.29Dizon* Sillitoe and Gappe (1984) 1131T 31.1San Antonio Singer et al. (2002) Luzon Central Sillitoe and Gappe (1984) PO CGD PO CGD Northwest Luzon 134 Luzon Luzon Western Western 1 13 Zambales Marinduque 3.92 Claveria et al. (1999) 195 Mitchell and 1.4-1.3 (K/Ar) 187 Hedenquist et al. (2001) 13.0 0.57 315 0.36 0.1 122 5.5 (K/Ar) 0.93 1112 706 Sillitoe (1989) B. Andam (pers. Itogon-Suyoc Mining 13 20 97 Pleistocene(?) 182 Inferred from TVI Pacific Inc.(1995) Sillitoe and Gappe (1984) Bureau of Mines and Singer et al. (2002) 0.65 (K/Ar) 2.7 (K/Ar) Cooke et al. (1996) Sillitoe (1989)

0361-0128/98/000/000-00 $6.00 20 21 (2002) 2.6-2.3 (Ar/Ar) (2004) Waters on epithermal, LS = low-sulfidation PO CGD por- Unit (2002) opment Program (1992) oration (1993, 1994); Mitchell and Leach (1991) (estimate) opment Program (1992) (1991); White et al. (1995) Geo-Sciences (1986); Mitchell and Leach (1991) (estimate) Geo-Sciences (1986) (1991) (estimate) Group (1994) Unit (2002) Au (t) grade-tonnage data Age (Ma) Reference for age (Cont.) Cu (000s t) Appendix 3 Cu Au Containedfor Contained Reference Metric tonnes Mindanao 0.9 7.3 7 opment Program (1992) Magmatic arc Region/district (million t) (%) (g/t) 3 Style 1 Present or historic mines are indicated by * gold reserve figure is not included in the endowment estimates quoted text or figures. The Teresa Mineralization styles: DS = disseminated sedimentary rock-hosted, HS high-sulfidation epithermal, IS intermediate-sulfidati Notes: Grade-tonnage data includes combined resources and past production 1 2 3 apian* PO CGD Sierra Madre Marinduque 177 0.52 0.12 920 21 Sillitoe and Gappe (1984) 15 (K/Ar) et al. (1981) Walther ampakan PO CGD Cotabato Cotabato 900 0.75 0.3 6750 270 Rohrlach et al. (1999) 3.2 (U/Pb) R. Loucks, pers. commun. phyry copper-gold, PO CGM = porphyry copper-gold-molybdenum, SK = skarn, VMS volcanic-associated massive sulfide PO CGM = porphyry copper-gold-molybdenum, phyry copper-gold, Deposit PisumpanT Dinkidi PO CGDMarianRunruno Luzon Western Zambales PO CGDKingking PO CGDBoyongun IS CordonBayugo CordonAmacan * PO CGD PO CGD 20Mapula PhilippinesLarap Philippines Isabela-Didipio Cordon PO CGD PO CGD(Matanlang) Isabela-DidipioNalesbitan * Philippines Camarines Norte 124 Philippines PO CGD PO CGM Surigao 0.41 55 HS 400Placer* Philippines Philippines Isabela-Didipio 0.6 Surigao Masara 0.4 82 27 Masara Camarines Norte IS PhilippinesLongos Point* 0.35 250 0.43 1.0 65 IS 0.6 0.24Masara* 484 116 Camarines Norte 237 1447 12 7.6 Philippines 78 0.6Co-o * 0.35 IS Philippines 0.6 1.04 0.4 120 0.37 SurigaoSiana* 167 13 Sillitoe and Gappe (1984) 0.40 1500 Camarines Norte 2.1 (K/Ar) 228 0.4 IS 429 3.2 Philippines Singer et al. (2002) 0.36 Singer et al. (2002)Sulat Singer et al. (2002) DS/IS 1.23 Singer et al. (2002) 150 39.9 312 Masara 26Rapu-Rapu 28 Philippines 23.2 (K/Ar) 46Basay* Pliocene Philippines 25 (K/Ar)Hinobaan VMS Feebrey (2003) VMS et al. (1999) Wolfe Sipalay* Central East 28 Surigao 12.0 Sillitoe and Gappe (1984)Masbate* Sillitoe (1989) 20.5 Mitchell and Leach (1991) Research Information 3.9 POCGD Sillitoe and Gappe (1984) PO CGD 9 Late Miocene Philippines 1.63Bulawan* Philippines POCGD Masbate-Negros Masbate-Negros Mitchell and Leach (1991) IS 2.6-2.3 (Ar/Ar) Negros Negros Sillitoe and Gappe (1984)Sibutad (2004) Waters Rapu-Rapu Late Miocene Masbate-Negros Central Samar 4.8 ISCanatuan Negros Mitchell and Leach (1991) Singer et al. (2002) T United Nations Devel- 38 32.5 Masbate-Negros IS Pliocene 7.1 VMST'Boli Masbate 8.65 262 440 65 Masbate-Negros NegrosLutopan* 807Biga * 0.61 Sillitoe et al. (1990) Sulu-Zamboanga United Nations Devel- ZamboangaCarmen* Sulu-Zamboanga 5.42 IS 1.23 0.62 Zamboanga 14.5 0.44 0.41 PO CGM Manila Mining Corp- 2.54 198 0.29 0.14 Cebu 0.47 87 PO CGM 14 34 PO CGM 2.3 1153 1804 Pliocene 0.05 21 Cebu Cotabato Cebu 3793 20 Sillitoe (1989) 76 62 26 Cebu Mitchell and Leach 4.25 18 1.85 Cotabato 2.23 40 Cebu Cebu 4.3 (K/Ar) Bureau of Mines and 43 2.9 Singer et al. (2002) Singer et al. (2002) Bureau of Mines and 1.12 TVI-Pacific (2003b) Miocene United Nations Devel- 2.4 Sillitoe (1989) Singer et al. (2002) 533 2.6-2.3 (Ar/Ar) (2004) Waters ?30 (K/Ar) 62 17.5 5 390 395 Mitchell and Leach (1991) ?30 (K/Ar) Divis (1983) 0.5 41 24 Divis (1983) Mitchell and Leach 0.31 0.43 Singer et al. (2002) 0.43 TVI-Pacific (2003a) 5.5 2665 0.24 0.25 Late Miocene 1677 1699 Metals Economics Mitchell and Leach (1991) Jimenez et al. (2002) 165 Pleistocene 14.4 (K/Ar) 94 99 13 Jimenez et al. (2002) Sillitoe (1989) Sillitoe and Gappe (1984) 108 (K/Ar) Sillitoe and Gappe (1984) Sillitoe and Gappe (1984) et al. (1981) Walther Research Institute

0361-0128/98/000/000-00 $6.00 21 22 (1994) (1994); McDowell et al. (1996) McDowell et al. (1996) McDowell et al. (1996) McDowell et al. (1996) McDowell et al. (1996) Pliocene (approximate) Edition (April 1999) Unit (2002) (1994) (estimate only) Carlile and Mitchell (1994) (open pit and underground) (1994); McDowell et al. (1996) Sutopo et al. (2003)van Leeuwen (1994) commun. (2003) Au (t) grade-tonnage data Age (Ma) Reference for age Cu (000s t) Appendix 4 Cu Au Containedfor Contained Reference Metric tonnes Grade-Tonnage and Age Charactersitics of Significant Gold Copper Deposits in Cenozoic Magmatic Arcs Indonesia Borneo Grade-Tonnage Magmatic arc Region/district (million t) (%) (g/t) New Guinea New Guinea New Guinea New Guinea New Guinea Halmahera Gosowong 1.7 41 70 Mining News, 2004 Pliocene Olberg et al. (1999) 3 S Style *I 2 1 abu SK Medial Carstenz 117 2.16 253 O'Connor et al. (1999) 6.6-5.2 (K/Ar) O'Conner et al. (1999) apadaa PO CGD North Sulawesioka Tindung Gorontalo IS 43 North Sulawesi Kotamobagu 0.54 12.3 0.08 232 3 2.85 van Leeuwen (1994) 35 3.75 (K/Ar) Singer et al. (2002) Gold Gazette Asian 2.4 (K/Ar) Moyle et al (1997) angse PO CMD Sunda Tangse 600 0.15 900 van Leeuwen (1994) 13-9 van Leeuwen (1994) oguraci* IS Halmahera Gosowong 0.41 27 11 Intierra (2003) Pliocene Olberg et al. (1999) Deposit Bawone (Binebase) Cabang Kiri East PO CGDSungai Mak North Sulawesi HSKayubulan Ridge Gorontalo PO CGDBulagidun North Sulawesi PO CGDT North Sulawesi Gorontalo SangiheMotomboto Gorontalo PO CGD 136Gn. Pani North Sulawesi HS Marissa 75 SangiheT 84 0.43 IS North SulawesiDoup 0.58 GorontaloLanut* 0.76 14.4 585 4.5 0.76Bolangitang 0.33 North Sulawesi 0.39 Marissa 570 2 ISMesel Deposits* IS 638 IS 0.61 DS 79 0.68Kaputusan 88 North Sulawesi 25 North SulawesiGosowong* North Sulawesi 30 North Sulawesi 1.37 Kotamobagu 33 2.0 KotamobaguKencana Kotamobagu PO CGD Gorontalo van Leeuwen (1994) Halmahera 1.5 IS 12 van Leeuwen (1994) 2.9 (K/Ar) 10 5.5 9.7 40 Bacan van Leeuwen (1994) -- 2.4 (K/Ar) Perello (1994) Halmahera Late Pliocene 6 1.35 van Leeuwen (1994) Perello (1994) 3 Perello (1994) Gosowong 70 8.8 (K/Ar) 1.6 2.80 6.45 van Leeuwen (1994) 0.99 Lubis et al. (1994) van Leeuwen (1994) 41 Miocene 0.3 1.9 (K/Ar) 0.21 Carlile et al. (1990) 210 15 63 19 Perello (1994) van Leeuwen (1994); 27 3.3-3.1 (Ar/Ar) 11 Pearson and Caira (1999) 15 Research Information Newmont Mining (1994) van Leeuwen (1994) Late Miocene- Neogene Garwin et al. (1995) Neogene Carlile and Mitchell van Leeuwen (1994) Carlile et al. (1990) 27 White et al. (1995) Neogene Olberg et al. (1999) Carlile and Mitchell 2.9-2.4 (Ar/Ar) Olberg et al. (1999) Grasberg* (reserve) PO CGDKucing Liar Medial W SKErtsberg East Carstenz(IOZ/DOZ)* SK Medial Big Gossan New Guinea Ertsberg* SK Medial 1877 CarstenzDOM SK New Guinea T Medial 1.04 CarstenzMartabe 1.04 320 Medial SKGn. Pongkor* 19521 Carstenz HS ISLebong Tandai* 210 ISLebong Donok* Medial 1.41 1952 Carstenz IS 1.41 Sunda 37 Sunda 4512 1.14 Sunda et al. (1999) Widodo Carstenz 0.9 Sunda 32.6 3.3-2.7 (K/Ar) 2394 451 Sibolga Java West 2.69 MacDonald and Arnold Bengkulu 1.02 31 2.3 Bengkulu 995 189 et al. (1999) Widodo 0.8 6.0 66.7 2.8 750 ~3 1.67 2.9 38 Coutts et al. (1999) 0.42 518 26 3.1-2.6 (K/Ar) et al. (1999) Widodo Mertig et al. (1994); et al. (1999) Widodo 17.1 1.74 15.5 13 ~3 14.3 Mertig et al. (1994) 3.1-2.6 (K/Ar) et al. (1999) Widodo Mertig et al. (1994); 103 116 Mertig et al. (1994); 43 3.1-2.6 (K/Ar) 41 Mertig et al. (1994); Basuki et al. (1994); Levet et al. (2003); van Leeuwen (1994) van Leeuwen (1994) 8.5 (K/Ar) Pliocene(?) Miocene B. K. Levet, pers. Marcoux and Milesi (1994) Jobson et al. (1994) T Grasberg* (resource) PO CGD Medial Carstenz New Guinea 4000 0.6 0.64 24000 2560 van Leeuwen (1994) 3.3-2.7 (K/Ar) MacDonald and Arnold

0361-0128/98/000/000-00 $6.00 22 23 Fletcher et al. (2000); Garwin (2000, 2002a) Garwin (2000) (1994); van Leeuwen (1994) (1994) 4 4 Pleistocene(?) 6.8-6.4 (K/Ar) Rangin (1991) g Liar deposits, which include reserves as of December 1998 on epithermal, LS = low-sulfidation PO CGD por- Unit (1997) Unit (2002) Unit (2002) Parit and includes Tai Jugan)Unit (2002) Japan (1985) (on felsic intrusions) Au (t) grade-tonnage data Age (Ma) Reference for age (Cont.) Cu (000s t) Appendix 4 Cu Au Containedfor Contained Reference Metric tonnes Magmatic arc Region/district (million t) (%) (g/t) KalimantanKalimantan Kalimantan KalimantanKalimantanKalimantan Kalimantan Kalimantan Sumatra Unit (1997) Unit (2002) Miocene(?) (1990); Thompson et al. 3 Style U ages of zircons using a sensitive high-mass resolution ion microprobe (SHRIMP II) 238 1 Pb/ Present or historic mines are indicated by * The Kencana resource figure is not included in the endowment estimates quoted text or figures Mineralization styles: DS = disseminated sedimentary rock-hosted, HS high-sulfidation epithermal, IS intermediate-sulfidati ak Mas IS unrelated? Arc Central Sulawesi 22 1.9 42 Research Information Notes: Grade-tonnage data includes combined resources and past production, except for Grasberg, IOZ/DOZ, DOM, Big Gossan, Kucin 1 2 3 4 206 ay Linggo ISetar Deposits* Sunda VMS-HS Banda Lampung Wetar 0.41 5.4 9.1 4.2 4 23 Research Information van Leeuwen (1994) 5-4; 4.7 Sewell and Wheatley phyry copper-gold = PO CMD = porphyry copper-molybdenum, SK = skarn, VMS volcanic-associated massive sulfide or exhalative = PO CMD porphyry copper-molybdenum, phyry copper-gold Deposit Rawas*CibaliungCikondang IS ISMangani*W IS Sunda SundaBatu Hijau* IS SundaElang PO CGDSoripesa Bengkulu East Sunda SundaW Java West Java Sumbawa West West PO CGD ISKelian* 7.8 East Sunda 1640 Mangani 1.3Mount Muro* 0.7 Sumbawa West Banda IS IS 0.44Mirah 600 0.35 0.9Masupa Ria 7216 3.1 Central Central East Sumbawa 10.4Bau Deposits 0.35 IS IS 10.9(Sarawak)* 0.4 574 DS Central Central Mamut (Sabah)* 2100 6.5 PO CGD Central Central Kinabalu Pluton Central Aw Clode et al. (1999) 6.0 24 Mamut-Nungok 14 16.5 240Sungai Keruh 97 196 8 Central Kalimantan 3.7 (U/Pb) Bau IS Research Information Research Information Maula and Levet (1996) 6 0.48 2.7 (U/Pb) 1.96 van Leeuwen (1994) 0.5 Meratus- 0.3 3.1 941 1.85 Plio- 7.3 van Leeuwen (1994) Meratus 1 98 12 Marcoux and Milesi (1994) 12.8Information 51 4.3 179 4.3 Carlile and Mitchell (1994) Singer et al. (2002) Research Research Information van Leeuwen (1994) 7.0 (K/Ar); Early 4 20 (K/Ar) 1.8 Imai (2000); Bellon and 31 van Leeuwen et al. (1990) Simmons and Browne van Leeuwen (1994) Cox (1992) (estimate 25 (K/Ar) 8 13-10 (K/Ar) Thompson et al. (1994) Metal Mining Agency of van Leeuwen (1994)

0361-0128/98/000/000-00 $6.00 23 24 (1978) Page and McDougall (1972) and McDougall (1972) McDougall (1972) McLeod (1990) and Finlayson (1987) 25-24 (K/Ar) (1978) Titley 25 (K/Ar)22 (K/Ar) Hine et al. (1978) Hine and Mason (1978) Leaman (1998)Henry (1990) (1998) Mowat (1998)Andrew (1998)Andrew (1998) (1998); Page and (1998) Research Information Unit (2002) (1998) (K/Ar) Davies and Ballantyne (1987) mal, PO CGD = porphyry copper-gold = SK, skarn mal, PO CGD = porphyry copper-gold Appendix 5 Cu Au Contained Contained Reference for Age (Ma) Metric tonnes Grade-Tonnage and Age Charactersitics of Significant Gold Copper Deposits in Cenozoic Magmatic Arcs Papua New Guinea Grade-Tonnage arc or beltNew Guinea Region/districtNew Guinea (million t)New Guinea (%) (g/t)New Guinea Cu (000s t)New Guinea Au (t) grade-tonnage data New Guinea (method) Reference for age New Guinea New Guinea New Guinea New Guinea arc) (Tabar-Feni arc) (Tabar-Feni arc remnant Magmatic 2 Style 1 Present or historic mines are indicated by * Mineralization styles: HS = high-sulfidation epithermal, IS intermediate-sulfidation LS low-sulfidation epither Notes: Grade-tonnage data includes combined resources and past production 1 2 ild Dog HS Inner Melanesian New Britain Island 0.96 5.83 6 Lindley (1990) 23-22 Lindley (1990) au (Edie apolu* IS IS Medial Medial Morobe Provinceafi River 7.5 PO CGD Fergusson Islandafi River 5.3 Maramuni HS 3.7 Morobe Province 100 Maramuni 1.9 1.3 Morobe Province 0.6 28 18 1300oodlark* 10 Carswell (1990) IS 60 McNeil (1990) 2.6 3.8-2.4 (K/Ar) Carswell (1990); Page and Tau-Loi Neogene island Island Woodlark Pliocene 2.6 McNeil (1990) 14 (K/Ar) 47 and Andrew Tau-Loi and Tau-Loi 3.7 14 (K/Ar) and Andrew Tau-Loi 10 Russell (1990) 12.3 (K/Ar) Russell (1990); olukuma* IS Medial Central Province 1.5 13.8 21 Semple et al. (1998) Pliocene Langmead and andera PO CGD Maramuni 338 0.42 0.1 1420 34 (1978) Watmuff 7 Singer et al. (2002) Deposit Ok Tedi*Star Mt.(Futik) PO CGD PO CGD, SK Medial Mt. Bini Medial Porgera* PO CGD, ISHidden Valley Province Medial Western IS ?IS, LS 700 Province Western Umuna / 65Misima*Kerimenge Medial IS Central Province 0.64 Medial IS 0.63 85W 0.54 4480Creek)* 0.1 Enga ProvinceW Medial 351 Morobe Province 0.4Gameta 84 Medial 441 37 New Guinea 0.6Hamata 7 340 IS Misima Island Singer et al. (2002) Morobe ProvinceT IS 56 55 New Guinea Freida River 1.2-1.1 (K/Ar) 5.8 51 Page (1976) Singer et al. (2002)W 2.1 Medial PO CGDY Medial 1.6 (K/Ar)Nena Maramuni Dugmore and W Arnold and Griffin Fergusson Island 1.38 1.0Arie 2.3 487 Sepik West Morobe ProvincePlesyumi HS 78Esis 9.2 4.4KuluW PO CGD 1060 Handley and PO CGD(Mt. Sinivit) Nelson et al. (1990)Panguna* 77 Maramuni Inner Melanesian 55 Dugmore and Leaman PO CGDLadolam* Inner Melanesian New Britain Island 2.3 PO CGD 0.52 Manus Island 4.2 (K/Ar) PO CGD 0.31 3.1 Inner Melanesian 5.9 (Ar-Ar) Sepik West ?LS Inner MelanesianKabang (1990) Lewis and Wilson New Britain Island Nelson et al. (1990) 5512 Hutton et al. (1990) 165 New Britain Island Ronacher et al. (2002) 3.5 (K/Ar) Outer MelanesianW Bougainville Island 1397 Appleby et al. (1996) 69 3.8-2.4 (K/Ar) LS, PO CGD 329 Hutton et al. (1990); Outer Melanesian Outer Melanesian Lihir Island 5 0.32 Ambitle island 0.46 29 0.55 4.0 Hall et al. (1990) 1.63 420 6426 0.81 528 Chapple and Ibil (1998) 1125 Pleistocene Denwer and 12 (K/Ar) Chapple and Ibil (1998) 768 Whalen et al. (1982) 56 1.4 3.28 3.8-2.4 (K/Ar) Clark (1990) Denwer and Mowat Bainbridge et al. (1998) Singer et al. (2002) 12 (K/Ar) 15 Hall et al. (1990) 3.4 (K/Ar) 6 1378 Clark (1990) Lihir Gold (2003); Singer et al. (2002) Christopher (2002) 0.35-0.10 <0.5 (K/Ar) Moyle et al. (1990); Sillitoe (1989)

0361-0128/98/000/000-00 $6.00 24 25

REFERENCES Abbott, M.J., and Chamalaun, F.H., 1981, Geochronology of some Banda arc volcanics: Bandung, Geological Research and Development Centre Special Publication 2, p. 253–268. Abiari, T.B., Samuel, K., and Sie, A., 1990, Mount Victor gold deposit, Kainantu: Parkville, Victoria, Australasian Institute of Mining and Metal- lurgy Monograph Series 14, v. 2, p. 1725–1729. Ali, J.R., and Hall, R., 1995, Evolution of the boundary between the Philip-

Kirwin (1998) Kirwin (1998) pine Sea plate and Australia: Palaeomagnetic evidence from eastern In- donesia: Tectonophysics, v. 251, p. 251–275. Amano, K., 1991, Multiple collision tectonics of the south Fossa Magna in central Japan: Modern Geology, v. 15, p. 315–329. The Australian Petroleum Company Proprietary, 1961, Geological results of petroleum exploration in western Papua 1937–61: Journal of the Geologi- cal Society of Australia, v. 8, p. 1–133. Appleby, K., Circosta, G., Fanning, M., and Logan, K., 1996, New model for controls on gold-silver mineralization on Misima Island: Mining Engineer- ing, v. 48, p. 33–36. Arnold, G.O., and Griffin, T.J., 1978, Intrusions and porphyry copper prospects of the Star Mountains, Papua New Guinea, in Gustafson, L.B., and Titley, S.R., eds., Porphyry copper deposits of the southwestern Pacific islands and Australia: ECONOMIC GEOLOGY, v. 73, p. 785–795. Arribas, A., Jr., Hedenquist, J.W., Itaya, T., Okada, T., Concepcion, R.A., and Garcia, J.S., Jr., 1995, Contemporaneous formation of adjacent porphyry on epithermal and epithermal Cu-Au deposits over 300 ka in northern Luzon, Philippines: Geology, v. 23, p. 337–340. Bainbridge, A.L., Hitchman, S.P., and DeRoss, G.J., 1998, Nena copper-gold deposit, in Berkman, D.A., and Mackenzie, D.H., eds., Geology of Aus- tralian and Paua New Guinean mineral deposits: Melbourne, Victoria, Aus- tralasian Institute of Mining and Metallurgy Monograph Series 22, p. 855–861. Baker, E.M., 1992, The Mankayan diatreme complex and its relationship to copper-gold mineralization, northern Luzon, Philippines: Randol at Min- expo 1992, Las Vegas, Nevada, 17–18 October 1992, Proceedings from five workshops, plus a guidebook to mines in northern Sonora, Mexico, p. 69–74. Baker, S., and Malaihollo, J., 1996, Dating of Neogene igneous rocks in the Halmahera region: Arc initiation and development: Geological Society of London Special Publication, v. 106, p. 499–509. Appendix 6 Ballantyne, P.D., 1992, Petrology and geochemistry of the plutonic rocks of Cu Au Containedfor Contained Reference the Halmahera ophiolite, eastern Indonesia, an analogue of modern oceanic forearcs: Geological Society of London Special Publication, v. 60, p. 179–202. Baluda, B., and Galapan, J., 1993. Ore reserve, production history and geo- logic characteristics of the Sto. Tomas II copper-gold mine: Geology and

Metric tonnes Mineral Resources Symposium, Baguio district, December 1993, Proceed- ings, 10 p. Baranov, B., Wong, H.K., Dozorova, K., Karp, B., Lüdmann, T., and Kar- naukh, V., 2002, Opening geometry of the Kurile basin (Okhotsk Sea) as in- ferred from structural data: Island Arc, v. 11, p. 206–219. Basuki, A., Aditya, S.D., and Sinambela, D., 1994, The Gunung Pongkor gold-silver deposit, West Java, Indonesia: Journal of Geochemical Explo- ration, v. 50, p. 371–391. Indawgyi Bellon, H., and Rangin, C., 1991, Geochemistry and isotopic dating of Ceno- zoic volcanic arc sequences around the Celebes and Sulu seas: Proceedings of the Ocean Drilling Program, Scientific Results, v. 124, p. 321–338. Benquet Corporation, 1994, Benquet Corporation-1994 Annual Report: Manila, Philippines. ——1995, Benquet gold operations—information brochure: Manila, Philip- pines. Grade-Tonnage and Age Charactersitics of Significant Gold Copper Deposits Associated with the Burman Arc Myanamar Grade-Tonnage arc Region/district (million t) (%) (g/t) Cu (000s t) Au (t) grade-tonnage data Age (Ma) Reference for age Magmatic Bureau of Mines and Geo-Sciences, 1982, Geology and mineral resources of the Philippines, vol. 1 (Geology): Manila, Bureau of Mines and Geo-Sci- ences Ministry of Natural Resources,406 p. Bureau of Mines and Geo-Sciences, 1986, Geology and mineral resources of

2 the Philippines, vol. 2 (Mineral resources): Manila, Bureau of Mines and Geo-Sciences Ministry of Natural Resources,446 p.

Style Cardwell, R.K., Isacks, B.L., and Karig, D.E., 1980, The spatial distribution of earthquakes, focal mechanism solutions and subducted lithosphere in the Philippines and northeast Indonesian islands: Geophysical Monograph Series 23, p. 1–35. 1 Carlile, J.C., and Mitchell, A.H.G., 1994, Magmatic arcs and associated gold

Present or historic mines are indicated by * Mineralization styles: DS = disseminated sedimentary rock-hosted, HS high-sulfidation epithermal, IS intermediate-sulfidati and copper mineralization in Indonesia: Journal of Geochemical Explo- Notes: Grade-tonnage data includes combined resources and past production 1 2 ration v. 50, p. 91–142. Deposit Monywa* (Letpadaung) Monywa* HS(Kyisintaung) Kyaukpahto * HS DS/IS Burman arc Burman backarc Burman arc Kyaukpahto- Monywa Monywa 4 905 226 0.40 3.81 0.40 3620 905 15 Minproc (1985) Ivanhoe Mines (2003) 19 (K/Ar) Ivanhoe Mines (2003) and Kyaw Win Miocene(?) 13 (K/Ar) Mitchell et al. (1999) and Kyaw Win

0361-0128/98/000/000-00 $6.00 25 26

Carlile, J.C., Digdowirogo, S., and Darius, K., 1990, Geological setting, char- Burmma: American Association of Petroleum Geologists Memoir 29, p. acteristics and regional exploration for gold in the volcanic arcs of North 189–198. Sulawesi, Indonesia: Journal of Geochemical Exploration, v. 35, p. Davies, A.G.S., Cooke, D.R., and Gemmell, J.B., 1999, Characteristics, tim- 105–140. ing and formation of diatreme breccias at the Kelian gold deposit, East Carman, G.D., 1995, The Lihir Island gold deposit, Papua New Guinea: The Kalimantan, Indonesia: Parkville, Victoria, Australasian Institute of Mining dynamic role of magmatic-hydrothermal processes in its formation: Giant and Metallurgy Publication Series 4/99, p. 81–90. Ore Deposits II, Kingston, Ontario, April 25–27, 1995, Proceedings, p. Davies, H.L., 1991, Regional geologic setting of some mineral deposits of the 732–753. New Guinea region, in Proceedings of the Papua New Guinea Geology, Ex- ——2003, Geology, mineralization and hydrothermal evolution of the ploration and Mining Conference, Rabaul: Melbourne, Australasian Insti- Ladolam gold deposit, Lihir Island, Papua New Guinea: Society of Eco- tute of Mining and Metallurgy, p. 49–57. nomic Geologists Special Publication 10, p.247–284. Davies, R.M., and Ballantyne, G.H., 1987, Geology of the Ladolam gold de- Carswell, J.T., 1990, Wau gold deposits: Melbourne, Victoria, Australasian posit; Lihir Island, Papua New Guinea, in Pacific Rim Congress 87: an in- Institute of Mining and Metallurgy Monograph Series 14, v. 2, p. 1763– ternational congress on the geology, structure, mineralisation, and eco- 1767. nomics of the Pacific Rim, 26-29 August 1987, Gold Coast, Queensland, Carter, D.J., Audley-Charles, M.G., and Barber, A.J., 1976, Stratigraphical Australia, Proceedings: Parkville, Victoria, Australasian Institute of Mining analysis of island arc-continental margin collision in eastern Indonesia: and Metallurgy, p. 943–949. Journal of the Geological Society of London, v. 132, p. 179–189. Dekker, F., Balkwill, H., Slater, A., Herner, R., and Kampschuur, W., 1990, A Chambers, J.L.C., and Daley, T.E., 1997, A tectonic model for the onshore structural interpretation of the onshore eastern Papuan fold belt, based on Kutai Basin, East Kalimantan: Geological Society Special Publications, v. remote sensing and fieldwork: Chamber of Mines and Petroleum, Papua 126, p. 375–393. New Guinea, Petroleum Convention, Port Moresby, Papua New Guinea, Chapple, K.G., and Ibil, S., 1998, Gameta gold deposit: Melbourne, Victoria, Proceedings, v. 1, p. 319–336. Australasian Institute of Mining and Metallurgy Monograph Series 22, p. Denwer, K.P., and Mowat, B.A., 1998, Hamata gold deposit: Melbourne, Vic- 849–854. toria, Australasian Institute of Mining and Metallurgy Monograph Series Chen, J.C., 1975, Geochemistry of andesites from the Coastal Range, eastern 22, p. 833–836. Taiwan: Geological Society of China Proceedings 18, p. 73–88. Divis, A.F., 1980, The petrology and tectonics of Recent volcanism in the Chiang, K.K. 2002, Geochemistry of the Cenozoic igneous rocks of Borneo central Philippine Islands: Geophysical Monograph 23, p. 127–144. and tectonic implications: Unpublished Ph.D. thesis, University of London, ——1983, The geology and geochemistry of Philippine porphyry copper de- 364 p. posits: Geophysical Monograph 27, pt. 2, p. 173–216. Chung, S.L., Yang, T.F., Lee, C.Y., and Chen, C.H., 1995, The igneous Dow, D.B., 1977, A geological synthesis of Papua New Guinea: Australian provinciality in Taiwan: Consequence of continental rifting superimposed Bureau of Mineral Resources Bulletin 201, Geology and Geophysics, 41 p. by Luzon and Ryukyu subduction systems: Journal of Southeast Asian Dow, D.B., and Sukamto, R., 1984, Western Irian Jaya: The end-product of Earth Sciences, v. 11, p. 73–80. oblique plate convergence in the late Tertiary: Tectonophysics, v. 106, p. Clark, G.H., 1990, Panguna copper-gold deposit: Melbourne, Victoria, Aus- 109–139. tralasian Institute of Mining and Metallurgy Monograph Series 14, v. 2, p. Dugmore, M.A., and Leaman, P.W., 1998, Mount Bini copper-gold deposit: 1807–1816. Australasian Institute of Mining and Metallurgy Monograph Series 22, p. Claveria, R.J.R., Cuison, A.G., and Andam, B.V., 1999, The Victoria gold de- 843–848. posit in the Mankayan mineral district, Luzon, Philippines: Parkville, Vic- Elburg, M., and Foden, J., 1998, Temporal changes in arc magma geochem- toria, Australasian Institute of Mining and Metallurgy Publication Series istry, northern Sulawesi, Indonesia: Earth and Planetary Science Letters, v. 4/99, p. 73–80. 163, p. 381–398. Clode, C., Proffett, J., Mitchell, P., and Munajat, I., 1999, Relationships of in- Elburg, M., van, L.T., Foden, J., and Muhardjo, 2003, Spatial and temporal trusion, wall-rock alteration and mineralisation in the Batu Hijau copper- isotopic domains of contrasting igneous suites in western and northern Su- gold porphyry deposit: Parkville, Victoria, Australia, Australasian Institute lawesi, Indonesia: Chemical Geology, v. 199, p. 243–276. of Mining and Metallurgy Publication Series 4/99, p. 485–498. Ercig, M.M., Craighead, G.A., Halfpenny, R., and Lewis, P.J., 1991, The ex- Cloke, I.R., Milsom, J., and Blundell, D.J.B., 1999, Implications of gravity ploration history, geology and metallurgy of a high-sulphidation epithermal data from east Kalimantan and the Makassar Straits: A solution to the ori- gold deposit at Wafi River, Papua New Guinea, in Rogerson, R., ed., Pro- gin of the Makassar Straits?: Journal of Asian Earth Sciences, v. 17, p. ceeedings of the Papua New Guinea Geology, Exploration and Mining 61–78. Conference, Rabaul: Melbourne, Australasian Institute of Mining and Met- Cooke, D.R., and Bloom, M.S., 1990, Epithermal and subjacent porphyry allurgy, p. 58–65. mineralization, Acupan, Baguio District, Philippines; a fluid-inclusion and Falvey, D.A., and Pritchard, T., 1982, Preliminary paleomagnetic results from paragenetic study: Journal of Geochemical Exploration, v. 35, p. 297–340. northern Papua New Guinea: Evidence for large microplate rotations: Cir- Cooke, D.R., McPhail, D.C., and Bloom, M.S., 1996, Epithermal gold min- cum-Pacific Energy and Mineral Resources International Conference, 3rd, eralization, Acupan, Baguio district, Philippines: Geology, mineralization, Transactions, p. 593–599. alteration, and the thermochemical environment of ore deposition: ECO- Feebrey, C.A., 2003, Exploration reviews—Asia: of the Society of Economic NOMIC GEOLOGY, v. 91, p. 243–272. Geologists Newsletter 55, October, p. 30–31. Corbett, G.J., 1994, Regional structural control of selected Cu/Au occur- Fernandez, H.E., and Damasco, F.V., 1979, Gold depositon in the Baguio rences in Papua New Guinea, in Papua New Guinea Geology, Mining and gold district and its relationship to regional geology: ECONOMIC GEOLOGY, Exploration Conference, Lae, Papua New Guinea, Proceedings: Mel- v. 74, p. 1852–1868. bourne, Australasian Institute of Mining and Metallurgy, p. 57–70. Fischer, M.W., and Warburton, J., 1996, The importance of pre-Tertiary Coutts, B.P., Susanto, H., Belluz, N., Flint, D., and Edwards, A.C., 1999, Ge- basin architecture for hydrocarbon accumulation in the Papuan fold and ology of the Deep ore zone, Ertsberg east skarn system, Irian Jaya: thrust belt; models, analogues and implications: Chamber of Mines and Pe- Parkville, Victoria, Australasian Institute of Mining and Metallurgy Publi- troleum Papua New Guinea Petroleum Convention, 3rd, Port Moresby, cation Series 4/99, p. 539–547. Papua New Guinea, Proceedings, p. 111–131. Cox, R., 1992, Consultant economic geologist’s final technical evaluation re- Fletcher, I.R., Garwin, S.L., and McNaughton, N.J., 2000, SHRIMP U-Pb port: United Nations Department of Economic and Social Development dating of Pliocene zircons [abs.]: Beyond 2000: New Frontiers in Isotope Project MAL/88/012, unpublished report, 50 p. Geoscience, Lorne, 2000, Abstracts and Proceedings, p. 73–74. Crowhurst, P.V., Hill, K.C., Foster, D.A., and Bennett, A.P., 1996, Ther- Forde, E.J., 1997, The geochemistry of the Neogene Halmahera arc, eastern mochronological and geochemical constraints on the tectonic evolution of Indonesia: Unpublished Ph.D. thesis, University of London, 268 p. northern Papua New Guinea: Geological Society Special Publications, v. Frost, J.E., 1959, Notes on the genesis of the ore-bearing structures of the 106, p. 525–537. Paracale district, Camarines Norte, Philippines: Philippine Geologist, v. 13, Cullen, A.B., and Pigott, J.D., 1989, Post Jurassic tectonic evolution of Papua p. 31–43. New Guinea: Tectonophysics, v. 162, p. 291–302. Furukawa Mining Co. Ltd., 1981, Exploration activiry after the World War II Curray, J.R., Moore, D.G., Lawver, L.A., Emmel, F.J., Raitt, E.W., Henry, at the Ashio mine: Mineral exploration in Japan: Tokyo, Mining Geology, E.M., and Kielkhefer, R., 1979, Tectonics of the Andaman Sea and no. 1, p. 295–309 (in Japanese).

0361-0128/98/000/000-00 $6.00 26 27

Garcia, J.S., Jr., 1991, Geology and mineralization characteristics of the Hedenquist, J.W., Matsuhisa, Y., Izawa, E., White, N.C., Giggenbach, W.F., Mankayan mineral district, Benguet, Philippines, in Matsuhisa, Y., Aoki, and Aoki, M., 1994, Geology, geochemistry, and origin of high sulfidation M., and Hedenquist Jeffrey, W., eds., High-temperature acid fluids and as- Cu-Au mineralization in the Nansatsu district, Japan: ECONOMIC GEOLOGY, sociated alteration and mineralization: Chishitsu Chosajo Hokoku: v. 89, p. 1–30. Kawasaki, Japan, Geological Survey of Japan, p. 21–30. Hedenquist, J.W., Arribas, A., Jr., and Reynolds, T.J., 1998, Evolution of an Garwin, S.L., 2000, The setting, geometry and timing of intrusion-related hy- intrusion-centered hydrothermal system: Far Southeast-Lepanto porphyry drothermal systems in the vicinity of the Batu Hijau porphyry copper-gold and epithermal Cu-Au deposits, Philippines: ECONOMIC GEOLOGY, v. 93, p. deposit, Sumbawa, Indonesia: Unpublished Ph.D. thesis, Nedlands, West- 373–404. ern Australia, Australia, University of Western Australia, 320 p. Hedenquist, J.W., Claveria, R.J.R., and Villafuerte, G.P., 2001, Types of sul- ——2002, The geologic setting of intrusion-related hydrothermal systems fide-rich epithermal deposits and their affiliation to porphyry systems: Lep- near the Batu Hijau porphyry copper-gold deposit, Sumbawa, Indonesia: anto-Victoria-Far Southeast deposits, Philippines, as examples: ProExplo Society of Economic Geologists Special Publication 9, p. 333–366. Congresso, Lima, Peru, 29 p. (CD-ROM). Garwin, S.L., and Herryansyah, 1992, Geological setting, style and explo- Hill, K.C., and Raza, A., 1999, Arc-continent collision in Papua Guinea: Con- ration of gold-silver mineralisation on Romang Island, Moluccas province, straints from fission track thermochronology: Tectonics, v. 18, p. 950–966. East Indonesia, in Simatupang, M., and Wahju Beni, N., eds., Indonesian Hill, K.C., Kendrick, R.D., Crowhurst, P.V., and Gow, P.A., 2002, Copper- mineral development 1992: Indonesian Mining Association, p. 258–274. gold mineralisation in New Guinea: Tectonics, lineaments, thermochronol- Garwin, S.L., Hendri, D., and Lauricella, P.F., 1995, The geology of the ogy and structure, in Korsch, R.J., ed., Geodynamics of Australia and its Mesel sediment-hosted gold deposit, North Sulawesi, Indonesia: Parkville, mineral systems: Technologies, syntheses and regional studies: Melbourne, Victoria, Australasian Institute of Mining and Metallurgy Publication Series Australia, Blackwell Scientific Publications for the Geological Society of 9/95, p. 221–226. Australia, p 737–752. Gold Gazette Asian Edition, April 1999, More resources on the cards at Toka Hine, R., and Mason, D.R., 1978, Intrusive rocks associated with porphyry Tindung: p. 36–39. copper mineralization, New Britain, Papua New Guinea: ECONOMIC GE- Goossens, P.J., 1978, The metallogenic provinces of Burma, their definitions, OLOGY, v. 73, p. 749–760. geologic relationships and extensions into China, India and Thailand, in Hine, R., Bye, S.M., Cook, F.W., Leckie, J.F., and Torr, G.L., 1978, The Esis Nutalaya, P., ed., Proceedings of the third regional conference on geology porphyry copper deposit, East New Britain, Papua New Guinea: ECO- and mineral resources of Southeast Asia: Bangkok, Asian Institute of Tech- NOMIC GEOLOGY, v. 73, p. 761–767. nology, p. 493–536. Hirai, K., Ono, S., and Matsueda, H., 2000, Epithermal gold mineralization Geological Survey of Malaysia, 1976, Mineral resources Map of Sarawak, in the Kuromatsunai county, southwestern Hokkaido [abs.]: Annual Meet- Malaysia, 1:1,000,000 scale. ing of the Society of Resource Geology, 50th, Abstracts with Programs, P-01 Gudmundsson, O., and Sambridge, M., 1998, A regionalized upper mantle (in Japanese). (RUM) seismic model: Journal of Geophysical Research, v. 103, sec. B, p. Holloway, N.H., 1982, North Palawan block—its relation to Asian mainland 7121–7136. and role in evolution of South China Sea: American Association of Petro- Hall, R., 1996, Reconstructing Cenozoic SE Asia, in Hall, R., and Blundell, leum Geologists Bulletin, v. 66, p. 1355–1383. D.J., eds., Tectonic Evolution of SE Asia: Geological Society of London Honthaas, C., Rehault, J.P., Maury, R.C., Bellon, H., Hemond, C., Malod, Special Publication 106, p. 153–184. J.A., Cornee, J.J., Villeneuve, M., Cotten, J., Burhanuddin, S., Guillou, H., ——2002, Cenozoic geological and plate tectonic evolution of SE Asia and and Arnaud, N., 1998, A Neogene back-arc origin for the Banda Sea basins: the SW Pacific: Computer-based reconstructions, model and animations: Geochemical and geochronological constraints from the Banda ridges (East Journal of Asian Earth Sciences, v. 20, p. 353–434. Indonesia): Tectonophysics, v. 298, p. 297–317. Hall, R., and Spakman, W., 2002, Subducted slabs beneath the eastern In- Hoshi, H., and Takahashi, M., 1999, Miocene counterclockwise rotation of donesia-Tonga region: insights from tomography: Earth and Planetary Sci- Northeast Japan: A review and new model: Bulletin of the Geological Sur- ence Letters, v. 201, p. 321–336. vey of Japan, v. 50, p. 3–16. Hall, R., and Wilson, M.E.J., 2000, Neogene sutures in eastern Indonesia: Housh, T., and McMahon, T.P., 2000, Ancient isotopic characteristics of Neo- Journal of Asian Earth Sciences, v. 18, p. 787–814. gene potassic magmatism in western New Guinea (Irian Jaya, Indonesia): Hall, R., Audley-Charles, M.G., Banner, F.T., Hidayat, S., and Tobing, S.L., Lithos, v. 50, p. 217–239. 1988a, Basement rocks of the Halmahera region, eastern Indonesia: A Late Hutchison, C.S., 1989, Geological evolution of Southeast Asia: Oxford Mono- Cretaceous-early Tertiary arc and fore-arc: Journal of the Geological Soci- graphs on Geology and Geophysics, no. 13, 368 p. ety of London, v. 145, p. 65–84. Hutchison, C.S., Bergman, S.C., Swauger, D.A., and Graves, J.E., 2000, A Hall, R., Audley-Charles, M.G., Banner, F.T., Hidayat, S., and Tobing, S.L., Miocene collisional belt in north Borneo: Uplift mechanism and isostatic 1988b, Late Paleogene-Quaternary geology of Halmahera, eastern Indone- adjustment quantified by thermochronology: Journal of the Geological So- sia: Initiation of a volcanic island arc: Journal of the Geological Society of ciety of London, v. 157, p. 783–793. London, v. 145, p. 577–590. Hutton, M.J., Akiro, A.K., Cannard, C.J., and Syka, M.C., 1990, Kerimenge Hall, R.J., Britten, R.M., and Henry, D.D., 1990, Frieda River copper-gold gold prospect: Melbourne, Victoria, Australasian Institute of Mining and deposits: Melbourne, Victoria, Australasian Institute of Mining and Metal- Metallurgy Monograph Series 24, v. 2, p. 1769–1772. lurgy Monograph Series 14, v. 2, p. 1709–1715. Iizasa, K.; Fiske, R.S., Ishizuka, O., Yuasa, M., Hashimoto, J., Ishibashi, J., Hall, R., Nichols, G., Ballantyne, P., Charlton, T., and Ali, J., 1991, The char- Naka, J., Horii, Y., Fujiwara, Y., Imai, A., Koyama, S, 1999, A kuroko-type acter and significance of basement rocks of the southern Molucca Sea re- polymetallic sulfide deposit in a submarine silicic caldera: Science, v. 283, gion: Journal of Southeast Asian Earth Sciences, v. 6, p. 249–258. no. 5404, p. 975–977. Hall, R., Ali, J.R., Anderson, C.D., and Baker, S.J., 1995, Origin and motion Ikeda, Y., 1991, Geochemistry and magmatic evolution of Pliocene-early history of the Philippine Sea plate: Tectonophysics, v. 251, p. 229–250. Pleistocene pyroclastic flow deposits in central Hokkaido, Japan: Journal of Hamasaki, S., and Bunno, M., 2002: K-Ar ages of acid alteration and Seigoshi the Geological Society of Japan, v. 97, p. 645–666. vein-type deposit related to Quaternary volcanic activity at western side of Ikeda, Y., Stern, R.J., Kagami, H., and Sun, C-H., 2000, Pb, Nd, and Sr iso- Izu peninsula [abs.]: Society of Resource Geology, June 19–21, 2002, topic constraints on the origin of Miocene basaltic frocks from northeast Tokyo, Japan, Abstracts with Programs, O-39 (in Japanese). Hokkaido, Japan: Implications for opening of the Kurile back-arc basin: Is- Hamilton, W., 1979, Tectonics of the Indonesian region: U.S. Geological Sur- land Arc, v. 9, p. 161–172. vey Professional Paper, v. 1078, p. 345 p. Imai, A., 2000, Genesis of the Mamut porphyry copper deposit, Sabah, east Handley, G.A., and Bradshaw, P.M.D., 1986, The Porgera gold deposit, Malaysia: Resource Geology, v. 50, p. 1–23. Papua New Guinea, in Macdonald, A.J., ed., Gold ‘86: Toronto, ON, Irianto, B., and Clark, G.H., 1995, The Batu Hijau porphyry copper-gold de- Canada, Konsult International, p. 416–424. posit, Sumbawa Island, Indonesia: Parkville, Victoria, Australasian Institute Handley, G.A., and Henry, D.D., 1990, Porgera gold deposit: Melbourne, of Mining and Metallurgy Publication Series 9-95, p. 299–304. Victoria, Australasian Institute of Mining and Metallurgy Monograph Se- Ishihara, S., 1994, Mineralization in the Kuril Islands: Chishitsu News, no. ries 14, v. 2, p. 1717–1724. 480, p. 54–59 (in Japanese). Hayashi, T., 2001, Field stops: Kasuga, Iwato, and Akeshi mines: Society of Ishihara, S., and Sasaki, A., 1991, Ore deposits related to granitic magmatism Economic Geologists Guidebook Series v. 34, p. 133–138. in Japan: A magmatic viewpoint: Episodes, v. 14, p. 286–292.

0361-0128/98/000/000-00 $6.00 27 28

Ishihara, S., Matsuhisa, Y., Tanaka, R., Ihara, H., Nagasaka, A., Koike, T., and Kavalieris, I., and Gonzalez, J.M., 1990, Geology and mineralization of the Shibata, K., 1998, The timing and geneses of ilmenite-series and mag- Pao Prospect; a high sulphidation epithermal gold system hosted in alkaline netite-series granitic magmatism in the north-central Hokkaido, Japan: volcanics, North Luzon, Philippines, in Foots, J., and Brennan, T., eds., Bulletin of the Geological Survey of Japan, v. 49, p. 605–620. Proceedings of the Pacific Rim Congress 1990: Parkville, Victoria, Aus- Ishizuka, O., Uto, K., Yuasa, M., and Hochstaedter, A.G., 1998, K-Ar ages tralasian Institute of Mining and Metallurgy, v. 2, p. 413–418. from seamount chains in the back-arc region of the Izu-Ogasawara arc: Is- Kavalieris, I., Walshe, J.L., Halley, S., and Harrold, B.P., 1990, Dome-related land Arc, v. 7, p. 408–421. gold mineralization in the Pani volcanic complex, North Sulawesi, Indone- Isozaki, Y., 1997a, Contrasting two types of orogen in Permo-Triassic Japan: sia: A study of geologic relations, fluid inclusions, and chlorite composi- Accretionary versus collisional: Island Arc, v. 6, p. 2–24. tions: ECONOMIC GEOLOGY, v. 85, p. 1208–1225. ——1997b, Jurassic accretion tectonics of Japan: Island Arc, v. 6, p. Kavalieris, I., van Leeuwen, T.M., and Wilson, M., 1992, Geological setting 25–51. and styles of mineralization, north arm of Sulawesi, Indonesia: Journal of Itogon-Suyoc Mining Incorporated, 1993, Annual report: Manila, Philippines. Southeast Asian Earth Sciences, v. 7, p. 113–129. Itogon-Suyoc Mining Incorporated, 1994, Annual report: Manila, Philippines. Kimura, G., Miyasaka, S., and Miyashita, S., 1983, Collision tectonics in Itoh, Y., Tsutsumi, H., Yamamoto, H., and Arato, H., 2002, Active right-lat- Hokkaido and Sakhalin, in Hashimoto, M., and Uyeda, S., eds., Accretion eral strike-slip fault zone along the southern margin of the Japan Sea: tectonics in the Circum-Pacific regions: Tokyo, TERRAPUB., p. 123–134. Tectonophysics, v. 351, p. 301–314. Kimura, J-I., Kunikiyo, T., Osaka, I., Nagao, T., Yamauchi, S., Kakubuchi, S., Izawa, E., and Urashima, Y., 1987, Quaternary gold mineralization and its ge- Okada, S., Fujibayashi, N., Okada, R., Murakami, H., Kusano, T., Umeda, K., ologic environments in Kyushu, Japan: Tokyo, Society of Mining Geology Hayashi, S., Ishimaru, T., Ninomiya, A., and Tanase, A., 2003, Late Cenozoic Guidebook 2, p. 1–12. volcanic activity in the Chugoku area, southwest Japan arc during back-arc Izawa, E., and Watanabe, K., 2001, Quaternary gold mineralization and its basin opening and reinitiation of subduction: Island Arc, v. 12, p. 22–45. geologic environments in Kyushu, Japan: Society of Economic Geologists Kirk, H.J.C., 1968, The igneous rocks of Sarawak and Sabah: Geological Sur- Guidebook Series, v. 34, p. 11–15. vey of Borneo Region Malaysia Bulletin 5, 210 p. Izawa, E., and Zeng, N., 2001, Kushikino gold mineralization in a Pliocene Knittel, U., 1983, Age of the Cordon syenite complex and its implication on volcanic region, Kyushu, Japan: Society of Economic Geologists Guidebook the Mid-Tertiary history of North Luzon: Philippine Geology, v. 37, p. Series, v. 34, p. 53–60. 22–31. Izawa, E., Urashima, Y., and Okubo, Y., 1984, Age of mineralization of the Knittel, U., and Cundari, A., 1990, Mineralogical evidence for the derivation Nansatsu type gold deposits, Kagoshima, Japan: K-Ar dating of alunite from of metaluminous, potassic rocks from peralkaline precursors: The Cordon Kasuga, Iwato and Akeshi: Mining Geology, v. 34, p. 341–351 (in Japanese syenite complex (Philippines): Mineralogy and Petrology, v. 41, p. 163–183. with English abs.). Kodama, K., Tashiro, H., and Takeuchi, T., 1995, Quaternary counterclock- Izawa, E., Etho, J., Honda, M., Motomura, Y., and Sekine, R., 2001, wise rotation of south Kyushu, southwest Japan: Geology, v. 23, p. 823–826. Hishikari gold mineralization: A case study of the Hosen no. 1 vein hosted Kosaka, H., and Wakita, K., 1978, Some geologic features of the Mamut por- by basement Shimanto sedimentary rocks, southern Kyushu, Japan: Society phyry copper deposit, Sabah, Malaysia: ECONOMIC GEOLOGY, v. 73, p. of Economic Geologists Guidebook Series, v. 34, p. 21–30. 618–627. James, L.P., and Fuchs, W.A., 1990, Exploration of the Exciban gold-copper- Kyaw Win, U., and Kirwin, D., 1998, Exploration, geology and mineralisation tellurium vein system, Camarines Norte, Philippines: Journal of Geochem- of the Monywa copper deposits, central Myanmar, in Porter, T. M., ed., ical Exploration, v. 35, p. 363–385. Porphyry and hydrothermal copper and gold deposits: A global perspective. Japan Mining Industry Association, 1978, Gold and silver ores in Japan, Conference proceedings: Glenside, South Australia, Australia, Australian Tokyo: Tokyo Print, 154 p. (in Japanese). Mineral Foundation, p. 61–69. Jimenez, F.A., Jr., Yumul, G.P., Jr., Maglambayan, V.B., and Tamayo, R.A., Jr., Langmead, R.P., and McLeod, R.L., 1990, Tolukuma gold deposit: Mel- 2002, Shallow to near-surface, vein-type epithermal gold mineralization at bourne, Victoria, Australasian Institute of Mining and Metallurgy Mono- Lalab in the Sibutad gold deposit, Zamboanga del Norte, Mindanao, Philip- graph Series 14, v. 2, p. 1777–1781. pines: Journal of Asian Earth Sciences, v. 21, p. 119–133. Lewis, R.W., and Wilson, G.I., 1990, Misima gold deposit: Melbourne, Vic- Jobson, D.H., Boulter, C.A., and Foster, R.P., 1994, Structural controls and toria, Australasian Institute of Mining and Metallurgy Monograph Series genesis of epithermal gold-bearing breccias at the Lebong Tandai mine, 14, v. 2, p. 1741–1745. western Sumatra, Indonesia: Journal of Geochemical Exploration, v. 50, p. Lindley, I. D., 1990, Wild Dog gold deposit: Melbourne, Victoria, Aus- 409–428. tralasian Institute of Mining and Metallurgy Monograph Series 14, v. 2, p. Johnson, R.W., 1979, Geotectonics and volcanism in Papua New Guinea: A 1789–1792. review of the late Cainozoic: BMR Journal of Australian Geology and Geo- Lowder, G.G., and Dow, J.A.S., 1978, Geology and exploration of porphyry physics, v. 4, p. 181–207. copper deposits in North Sulawesi, Indonesia: ECONOMIC GEOLOGY, v. 73, Johnson, R.W., Mackenzie, D.E., and Smith, I.E., 1978, Delayed partial p. 628–644. melting of subduction-modified mantle in Papua New Guinea: Tectono- Lowenstein, P.L., 1982, Economic geology of the Morobe goldfield, Papua physics, v. 46, p. 197–216. New Guinea: Geological Survey of Papua New Guinea Memoir, 9, p. 244. Josef, L., 2002, The Boyongan porphyry Cu-Au deposit, Surigao del Norte, Lubis, H., Prihatmoko, S., and James, L.P., 1994, Bulagidun prospect: A cop- Philippines [abs.]: Annual Cordilleran Exploration Roundup, Gateway to per, gold and tourmaline bearing porphyry and breccia system in northern Discoveries, 19th, Vancouver, British Columbia, January 21–25, 2002, Ab- Sulawesi, Indonesia: Journal of Geochemical Exploration, v. 50, p. stracts, p. 37. 257–278. Kamata, H., and Kodama, K., 1999, Volcanic history and tectonics of the MacDonald, G.D., and Arnold, L.C., 1994, Geological and geochemical zon- southwest Japan arc: Island Arc, v. 8, p. 393–403. ing of the Grasberg igneous complex, Irian Jaya, Indonesia: Journal of Geo- Kanbara, H., and Kumita, K., 1990, Mode of occurrence and chemical com- chemical Exploration, v. 50, p. 143–178. position of electrum from the Toyoha polymetallic vein-type deposits, Macpherson, C.G., and Hall, R., 2002, Timing and tectonic controls in the Hokkaido, Japan, in Organization of Professor Y. Urashima Retirement evolving orogen of SE Asia and the western Pacific and some implications Ceremony, ed., Professor Yukitoshi Urashima Commemoration Volume on for ore generation: Geological Society of London Special Publication 204, the occasion of his retirement: Kagoshima, Kibunndo, p. 201–210 (in p. 49–68. Japanese with English abs.). Maeda, H., 1996, Relationship between volcanic activity and epithermal Karakida, Y., Hayasaka, S., and Hase, Y., eds., 1992, Regional geology of gold-silver mineralization: Example from Kitano-oh mine area and vicinity Japan. Part 9. Kyushu: Tokyo, Kyoritsu Shuppan, 371 p. (in Japanese). in Kitami metallogenic province, Hokkaido, Japan: Resource Geology, v. Karig, D.E., Sarewitz, D.R., and Haeck, G.D., 1986, Role of strike-slip fault- 46, p. 279–285. ing in the evolution of allochthonous terranes in the Philippines: Geology, Malaihollo, J.F.A., and Hall, R., 1996, The geology and tectonic evolution of v. 14, p. 852–855. the Bacan region, East Indonesia: Geological Society of London Special Kavalieris, I., 1988, The characteristics of epithermal mineral occurrences in Publication, v. 106, p. 483–497. the Bengkulu province, Sumatra [ext. abs.]: Geological Society of Australia, Marcoux, E., and Milesi, J.P., 1994, Epithermal gold deposits in West Java, Bicentennial Gold ‘88: Extended Abstracts, Poster Programme, v. 23, 1–02, Indonesia; geology, age and crustal source: Journal of Geochemical Explo- p. 316. ration, p. 393–408.

0361-0128/98/000/000-00 $6.00 28 29

Marumo, K., and Hattori, K., 1999, Seafloor hydrothermal clay alteration at Mitchell, A.H.G., and Leach, T.M., 1991, Epithermal gold in the Philippines: Jade in the back-arc Okinawa trough: Mineralogy, geochemistry and iso- Island arc metallogenesis, geothermal systems and geology: London, tope characteristics: Geochimica et Cosmochimica Acta, v. 63, p. United Kingdom, Academic Press, 457 p. 2785–2804. Mitchell, A.H.G., Htay, N., Ausa, C., Deiparine, L., Khine, A., and Po, S., Mason, R.A., 1994, Structural evolution of the western Papuan fold belt, 1999, Geological settings of gold districts in Myanmar: Parkville, Victoria, Papua New Guinea: Unpublished Ph.D. thesis, University of London, 331 Australasian Institute of Mining and Metallurgy Publication Series 4/99, p. p. 303–309. ——1996, Structure of the western Papuan fold belt: Petroleum Exploration, Miyashita, M., 1975, Gold and silver deposits in southern Kyushu, in Japan Development and Production in Papua New Guinea, Papua New Guinea Mining Industry Association, ed., Gold and silver ores in Japan, v. 1: Tokyo, Petroleum Convention, 3rd, Port Moresby, Papua New Guinea Chamber of Tokyo Print, p. 43–80 (in Japanese). Mines, Proceedings, p. 161–173. Metal Mining Agency of Japan, 1977, Report on geological survey of north- Mason, R.A., and Ord, A., 1999, Modelling the effects of crustal structure eastern Luzon. Phase III: Tokyo, Metal Mining Agency of Japan and Japan during convergence: Examples from New Guinea and the Andes, in International Cooperation Agency, unpublished consolidated report, 280 p. Anonymous, ed., Research review: CSIRO exploration and mining: Aus- Metal Mining Agency of Japan, 1979, Report on the geological survey of tralia, CSIRO Exploration and Mining, p. 111–112. northwestern Luzon. Phase I: Tokyo, Japan International Cooperation Maula, S., and Levet, B.K., 1996, Porphyry copper-gold signatures and the Agency, unpublished consolidated report. discovery of the Batu Hijau deposit, Sumbawa, Indonesia: Australian Min- Metal Mining Agency of Japan, 1983, Report on Acupan-Itogon geothermal eral Foundation, Conference on Porphyry Related Copper and Gold De- development. First phase survey: Tokyo, Japan International Cooperation posits of the Asia Pacific Region, Cairns, Australia, Proceedings, p. Agency, unpublihed consolidated report, 94 p. 8.1–8.13. Metal Mining Agency of Japan, 1985, Report on the collaborative mineral ex- Mazzotti, S., Lallemant, S.J., Henry, P., Le Pichon, X., Tokuyama, H., and ploration of the Bau district, West Sarawak: Tokyo, Japan International Co- Takahashi, N., 2002, Intraplate shortening and underthrusting of a large operation Agency, Metal Mining Agency of Japan, unpublished consoli- basement ridge in the eastern Nankai subduction zone: Marine Geology, v. dated report. 187, p. 63–88. Manila Mining Corporation, 1993, Manila Mining Corporation-1993 annual McCarthy, A.J., and Elders, C.F., 1997, Cenozoic deformation in Sumatra: report: Manila, Philippines. Oblique subduction and the development of the Sumatran fault system: Manila Mining Corporation, 1994, Manila Mining Corporation-1994 annual Geological Society of London Special Publication, v. 126, p. 355–363. report: Manila, Philippines. McDowell, F.W., McMahon, T.P., Warren, P.Q., and Cloos, M., 1996, Morris, J.D., Jezek, P.A., Hart, S.R., and Gill, J.B., 1983, The Halmahera is- Pliocene Cu-Au-bearing igneous intrusions of the Gunung Bijih (Ertsberg) land arc, Molucca Sea collision zone, Indonesia: A geochemical survey: district, Irian Jaya, Indonesia: K-Ar geochronology: Journal of Geology, v. Geophysical Monograph 27, pt. 2, p. 373–387. 104, p. 327–340. Moss, S.J., Carter, A., Baker, S., and Hurford, A., J., 1998, A late Oligocene McInnes, B.I.A., Evans, N.J., Sukarna, D., Permanadewi, S., Garwin, S., Be- tectono-volcanic event in East Kalimantan and the implications for tecton- lousova, E., Griffen, W.L. and Fu, F., 2004, Thermal histories of Indone- ics and sedimenatation in Borneo: Journal of the Geological Society of Lon- sian porphyry copper-gold deposits determined by U-Th-He, U-Pb, Re-Os, don, v. 155, p. 177–192. K-Ar and Ar-Ar methods: Nedlands, University of Western Australia Pub- Moyle, A.J., Wake, B.A., Tuckey, S.H., and Ariti, J., 1997, The Toka Tindung lication 33, p. 343–346. gold project, northern Sulawesi, Indonesia: Parkville, Victoria, Australasian McInnes, B.I.A., and Cameron, E.M., 1994, Carbonated, alkaline hybridiz- Institute of Mining and Metallurgy Publication Series 2/97, p. 27–34. ing melts from a sub-arc environment: mantle wedge samples from the Moyle, A.L., Doyle, B.J., Hoogvliet, H., and Ware, A.R., 1990, Ladolam gold Tabar-Lihir-Tanga-Feni arc, Papua New Guinea: Earth and Planetary Sci- deposit, Lihir Island: Melbourne, Victoria, Australasian Institute of Mining ence Letters, v. 122, p. 125–141. and Metallurgy Monograph Series 14, v. 2, p. 1793–1805. McInnes, B.I.A., McBride, J.S., Evans, N.J., Lambert, D.D., and Andrew, Murakami, H., and Feebrey, C.A., 2001, Geology and geophysical expression A.S., 1999, Osmium isotope constraints on ore metal recycling in subduc- of the Yamagano low-sulfidation epithermal Au-Ag deposit, southwest tion zones: Science, v. 286, p. 512–516. Kyushu, Japan: Society of Economic Geologists Guidebook Series, v. 34, p. McNeil, P.A., 1990, Wapolu gold deposit, Fergusson Island: Melbourne, Vic- 31–37. toria, Australia, Australasian Institute of Mining and Metallurgy Mono- Nakajima, S., Shuto, K., Kagami, H., Ohki, J., and Itaya, T., 1995, Across-arc graph Series 14, v. 2, p. 1783–1788. chemical and isotopic variation of late Miocene to Pliocene volcanic rocks Meinert, L.D., Hefton, K.K., Mayes, D., and Tasiran, I., 1997, Geology, zona- from the Northeast Japan arc: Geological Society of Japan Memoir 44, p. tion, and fluid evolution of the Big Gossan Cu-Au skarn deposit, Ertsberg 197–226 (in Japanese with English abs.). district, Irian Jaya: ECONOMIC GEOLOGY, v. 92, p. 509–534. Nakamura, K., Yamanaka, K., and Yamasaki, T., 1994, Gold mineralization of Meldrum, S.J., Aquino, R.S., Gonzales, R.I., Burke, R.J., Suyadi, A., Irianto, the Akeshi mine, Kagoshima Prefecture: Resource Geology, v. 44, p. B., and Clarke, D.S., 1994, The Batu Hijau porphyry copper-gold deposit, 155–171 (in Japanese with English abs.). Sumbawa Island, Indonesia: Journal of Geochemical Exploration, v. 50, p. Nelson, R.W., Bartram, J.A., and Christie, M.H., 1990, Hidden Valley gold- 203–220. silver deposit: Melbourne, Victoria, Australasian Institute of Mining and Mertig, H.J., Rubin, J.N., and Kyle, J.R., 1994, Skarn Cu-Au orebodies of the Metallurgy Monograph Series 14, v. 2, p. 1773–1776. Gunung Bijih (Ertsberg) district, Irian Jaya, Indonesia: Journal of Geo- Newmont Mining, 1994, Annual Report-1994: Denver, Colorado, Newmont chemical Exploration, v. 50, p. 179–202. Mining Corporation. Metals Economics Group, 1994, Gold acquisition service: Worldwide gold Nishimura, S., Masataka, A., and Miyazaki, S., 1999, Inter-plate coupling projects and mines database: Halifax, Nova Scotia, Metals Economics along the Nankai trough and southwastward motion along southern part of Group. Kyushu: Jishin, v. 51, p. 457–458 (in Japanese with English abs.). Mining Journal, 14 Oct. 1994, Mining week: Funds for Guinaoang deposit, p. O’Connor, G.V., Sunyoto, W., and Soebari, L., 1999, The discovery of the 272. Wabu Ridge gold skarn, Irian Jaya, Indonesia: Parkville, Victoria, Aus- Ministry of International Trade and Industry, 1987a, Report of regional geo- tralasian Institute of Mining and Metallurgy Publication Series 4/99, p. logical structure survey in the Sado area during the fiscal year Showa 61: 549–560. Tokyo, Ministry of International Trade and Industry, 193 p. (in Japanese). Ohmoto, H, Tanimura, S., Date, J., and Takahashi, T., 1983, Geologic setting Ministry of International Trade and Industry, 1987b, Report of regional geo- of the Kuroko deposits, Japan: ECONOMIC GEOLOGY MONOGRAPH 5, p. logical structure survey in the Izu area during the fiscal year Showa 61: 9–54. Tokyo, Ministry of International Trade and Industry, 195 p. (in Japanese). Okino, K., Ohara, Y., Kasuga, S., and Kato, Y., 1999, The Philippine Sea: New Minproc, 1985, The Kyaukpahto project—Burma. Definitive engineering survey results reveal the structure and the history of the marginal basins: study prepared for the Australasian Mineral Development Laboratories, v. Geophysical Research Letters, v. 26, p. 2287–2290. 1: Mining and Process Engineering Services Pty. Ltd., unpublished report. Olberg, D.J., Rayner, J., Langmead, R.P., and Coote, J.A.R., 1999, Geology Mitchell, A.H.G., and Balce, G.R., 1990, Geological features of some ep- of the Gosowong epithermal gold deposit, Halmahera, Indonesia: Parkville, ithermal gold systems, Philippines: Journal of Geochemical Exploration, v. Victoria, Australasian Institute of Mining and Metallurgy Publication Series 35, p. 241–296. 4/99, p. 179–185.

0361-0128/98/000/000-00 $6.00 29 30

Otofuji, Y., Matsuda, T., and Nohda, S., 1985, Opening mode of the Japan Ronacher, E., Richards, J.P., Villeneuve, M.E., and Johnston, M.D., 2002, Sea inferred from the palaeomagnetism of the Japan arc: Nature, v. 317, p. Short life-span of the ore-forming system at the Porgera gold deposit, 603–604. Papua New Guinea: Laser 40Ar/39Ar dates for roscoelite, biotite, and horn- Page, R.W., 1976, Geochronology of igneous rocks and metamorphic rocks in blende: Mineralium Deposita, v. 37, p. 75–86. the New Guinea Highlands: Australian Bureau of Mineral Resources Bul- Rush, P.M., and Seegers, H.J., 1990, Ok Tedi copper-gold deposits: Mel- letin 162, p. 117. bourne, Victoria, Australasian Institute of Mining and Metallurgy Mono- Page, R.W., and McDougall, I., 1972, Ages of mineralization of gold and por- graph Series 14, p. 1747–1754. phyry copper deposits in the New Guinea Highlands, An Issue on Australia Russell, P.J., 1990, Woodlark Island gold deposits: Melbourne, Victoria, Aus- and Adjacent Islands: ECONOMIC GEOLOGY, v. 67, p. 1034–1048. tralasian Institute of Mining and Metallurgy Monograph Series 14, v. 2, p. Pearson, D.F., and Caira, N.M., 1999, The geology and metallogeny of cen- 1735–1739. tral North Sulawesi: Parkville, Victoria, Australasian Institute of Mining Russell, P.J., and Finlayson, E.J., 1987, Volcanic-hosted epithermal mineral- and Metallurgy Publication Series 4/99, p. 311–326. ization on Woodlark Island, Papua New Guinea, in Pacific Rim Congress Perello, J.A., 1994, Geology, porphyry Cu-Au, and epithermal Cu-Au-Ag 87: an international congress on the geology, structure, mineralisation, and mineralization of the Tombulilato district, North Sulawesi, Indonesia: Jour- economics of the Pacific Rim, 26-29 August 1987, Gold Coast, Queensland, nal of Geochemical Exploration, v. 50, p. 221–256. Australia, Proceedings: Parkville, Victoria, Australasian Institute of Mining Philex, 1995, Bulawan deposit: Geology, Mineral and Hydrocarbon Re- and Metallurgy, p. 381–385. sources of Southeast Asia, GEOSEA Conference, 7th, Manila, Philippines, Rutland, R.W.R., 1968, A tectonic study of part of the Philippine fault zone: 14–18 February, 1995, poster presentation. Quarterly Journal of the Geological Society of London, v. 123, p. 293–325. Pigram, C.J., and Davies, H.L., 1987, Terranes and the accretion history of Saito, M., Bamba, T., Sawa, T., Narita, E., Igarashi, T., Yamada, K., and Sato, the New Guinea orogen: BMR Journal of Australian Geology and Geo- H., 1967, Metallic and non-metallic mineral deposits of Hokkaido: physics, v. 10, p. 193–211. Tsukuba, Geological Survey of Japan, 575 p. (in Japanese). Polvé, M., Maury, R.C., Bellon, H., Rangin, C., Priadi, B., Yuwono, S., Joron, Sajona, F.G., Bellon, H., Maury, R.C., Pubellier, M., Quebral, R.D., Cotten, J.L., and Soeria-Atmadja, R., 1997, Magmatic evolution of Sulawesi (In- J., Bayon, F.E., Pagado, E., and Pamatian, P., 1997, Tertiary and Quater- donesia): Constraints on the Cenozoic geodynamic history of the Sunda- nary magmatism in Mindanao and Leyte (Philippines): Geochronology, land active margin: Tectonophysics, v. 272, p. 69–92. geochemistry and tectonic setting: Journal of Asian Earth Sciences, v. 15, p. Priadi, B., Polve, M., Maury, R.C., Bellon, H., Soeria-Atmadja, R., Joron, 121–154. J.L., and Cotten, J., 1994, Tertiary and Quaternary magmatism in Central Sakai, Y., and Oba, M., 1970, Geology and ore deposits of the Sado Mine: Sulawesi: Chronological and petrological constraints: Journal of Southeast Mining Geology, v.20, p. 149–165 (in Japanese with English abs.). Asian Earth Sciences, v. 9, p. 81–93. Sato, H., 1994, The relationship between late Cenozoic tectonic events and Prouteau, G., Maury, R.C., Sajona, F.G., Pubellier, M., Cotten, J., and Bel- stress field and basin development in northeast Japan: Journal of Geophys- lon, H., 2001, Le magmatisme post-collisionnel du Nord-Ouest de Bornéo, ical Research, v. 99, p. 22261–22274. produit de la fusion d’un fragment de croûte océanique ancré dans le man- Sato, T., 1974, Distribution and geological setting of the Kuroko deposits: teau supérieur: Bulletin de la Société Géologique de France, v. 172, p. Mining Geology Special Issue 6, p. 1–9. 319–332. Sawai, O., and Itaya, T., 1993, K-Ar ages of kuroko-type deposits in the Pubellier, M., and Ego, F., 2002, Anatomy of an escape tectonic zone, west- Shakotan-Toya district, southwest Hokkaido, Japan: Resource Geology, v. ern Irian Jaya (Indonesia): Tectonics, v. 21, p. 1–16. 43, p. 165–172 (in Japanese with English abs.). Pubellier, M., Quebral, R., Rangin, C., Deffontaines, B., Muller, C., Butter- ——1996, K-Ar ages of several hydrothermal ore deposits in the Shakotan lin, J., and Manzano, J., 1991, The Mindanao collision zone: A soft collision peninsula, southwest Hokkaido, Japan: Resource Geology, v. 46, p. 327–336 event within a continuous Neogene strike-slip setting: Journal of Southeast (in Japanese with English abs.). Asian Earth Sciences, v. 6, p. 239–248. Sawai, O., and Nagao, T., 2003, Geochemical characteristics of volcanic rocks Rangin, C., Jolivet, L., and Pubellier, M., 1990, A simple model for the tec- in the gold deposit area, northern and central Kyushu [abs.]: Society of tonic evolution of Southeast Asia and Indonesia region for the past 43 m.y.: Resource Geology, June 18–20, 2003, Tokyo, Japan, Abstracts with Pro- Bulletin de la Société géologique de France, v. 8, p. 889–905. grams, P-16 (in Japanese). Rangin, C., Le, P.X., Mazzotti, S., Pubellier, M., Chamot, R.N., Aurelio, M., Sawai, O., Okada, T., and Itaya, T., 1989, K-Ar ages of sericite in hydrother- Walpersdorf, A., and Quebral, R., 1999, Plate convergence measured by mally altered rocks around the Toyoha deposits, Hokkaido, Japan: Mining GPS across the Sundaland/ Philippine Sea plate deformed boundary: The Geology, v. 39, p. 191–204. Philippines and eastern Indonesia: Geophysical Journal International, v. Sawai, O., Yoneda, T., and Itaya, T., 1992, K-Ar ages of Chitose, Todoroki and 139, p. 296–316. Teine Au-Ag vein-type deposits, southwest Hokkaido, Japan: Mining Geol- Richards, J.P., 1990, Petrology and geochemistry of alkalic intrusives at the ogy, v. 42, 323–330 (in Japanese with English abs.). Porgera gold deposit, Papua New Guinea: Journal of Geochemical Explo- Sawai, O., Matsumura, N., and Itaya, T., 1998, K-Ar ages of volcanic rocks ration, v. 35, p. 141–199. and gold deposits in the Hoshino gold area, northern-central Kyushu, Richards, J.P., and Kerrich, R., 1993, The Porgera gold mine, Papua New Japan: Journal of the Geological Society of Japan, v. 104, p. 377–386 (in Guinea: magmatic hydrothermal to epithermal evolution of an alkalic-type Japanese). precious metal deposit: ECONOMIC GEOLOGY, v. 88, p. 1017–1052. Sawai, O., Kageyama, S., Okada, T., and Itaya, T., 2001, K-Ar ages of some Richards, J.P., and McDougall, I., 1990, Geochronology of the Porgera gold epithermal gold deposits outside of the Beppu-Shimabara graben, deposit, Papua New Guinea: resolving the effects of excess argon on K-Ar Kyushu, Japan: Shigen Chishitsu, v. 51, p. 19–27 (in Japanese with Eng- and 40Ar/39Ar age estimates for magmatism and mineralization: Geochimica lish abs.). et Cosmochimica Acta, v. 54, p. 1397–1415. Sawai, O., Kawamura, H., Okada, T., and Itaya, T., 2002, K-Ar ages of vol- Research Information Unit, 1997, Register of Indonesian gold: Bassendean, canic rocks and gold deposits in the Bajo gold area, central Kyushu, Japan: Western Australia, Research Information Unit, Advance Press, 160 p. Shigen Chishitsu, v. 52, p. 121–133 (in Japanese with English abs.). Research Information Unit, 2002, Register of Indo-Pacific mining: Subiaco, Schuh, W.D., 1993, Geology, geochemistry and ore deposits of the Bau gold Western Australia, Research Information Unit, 260 p. mining district, Sarawak, Malaysia: Unpublished Ph.D. thesis, Tucson, Ari- Rogerson, R., and McKee, C., 1990, Geology, volcanism and mineral deposits zona, University of Arizona, 315 p. of Papua New Guinea: Melbourne, Victoria, Australasian Institute of Min- Seeley, J.B., and Senden, T.J., 1994, Alluvial gold in Kalimantan, Indonesia: ing and Metallurgy Monograph Series 14, v. 2, p. 1689. A colloidal origin?: Journal of Geochemical Exploration, v. 50, p. 457–478. Rohrlach, B., Madera, A., and Watt, R., 1999, Geology, alteration and min- Sekine, R., Izawa, E., and Watanabe, K., 2002, Timing of fracture formation eralisation of the Tampakan copper deposit: Parkville, Victoria, Aus- and duration of mineralization at the Hishikari deposit, southern Kyushu, tralasian Institute of Mining and Metallurgy Publication Series 4/99, p. Japan: Resource Geology, v. 52, p. 395–404. 517–525. Semple, D.G., Corbett, G.J., and Leach, T.M., 1998, Tolukuma gold-silver Ronacher, E., Richards, J.P., and Johnston, M.D., 1999, New mineralisation deposit: Melbourne, Victoria, Australasian Institute of Mining and Metal- and alteration styles at the Porgera gold deposit, Papua New Guinea: lurgy Monograph Series 22, p. 837–842. Parkville, Victoria, Australasian Institute of Mining and Metallurgy Publi- Seno, T., and Maruyama, S., 1984, Paleogeographic reconstruction and ori- cation Series 4/99, p. 91–94. gin of the Philippine Sea: Tectonophysics, v. 102, 53–84.

0361-0128/98/000/000-00 $6.00 30 31

Sewell, D.M., and Wheatley, C.J.V., 1994, The Lerokis and Kali Kuning sub- Tau-Loi, D., and Andrew, R.L., 1998, Wafi copper-gold deposit: Melbourne, marine exhalative gold-silver-barite deposits, Wetar Island, Maluku, In- Victoria, Australasian Institute of Mining and Metallurgy Monograph Se- donesia: Journal of Geochemical Exploration, v. 50, p. 351–370. ries 22, p. 827–831. Shikazono, N., 1986, Ag/Au total production ratio and Au-Ag minerals form Taylor, B., 1992, Rifting and the volcanic-tectonic evolution of the Izu-Bonin- vein-type and disseminated-type deposits in Japan: Mining Geology, v. 36, Mariana arc: Proceedings of the Oceanic Drilling Program, Scientific Re- p. 411–424. sults, v. 126, p. 627–651. Shikazono, N., and Tsunakawa, H., 1982, K-Ar ages of Hosokura Pb-Zn and Teng, L.S., 1996, Extensional collapse of the northern Taiwan mountain belt: Sado Au-Ag vein-type deposits, northeastern part of Japan: Mining Geol- Geology, v. 24, p. 949–952. ogy, v. 32, p. 479–482 (in Japanese with English abs.). Teng, L.S., Chen, C.H., Wang, W.S., Liu, T.K., Juang, W.S., and Chen, J.C., Shimizu, T., Matsueda, H., Ishiyama, D., and Matsubaya, O., 1998, Genesis 1992, Plate kinematic model for late Cenozoic arc magmatism in northern of epithermal Au-Ag mineralization of the Koryu mine, Hokkaido, Japan: Taiwan: Journal of the Geological Society of China, v. 35, p. 1–18. ECONOMIC GEOLOGY, v. 93, p. 303–325. Terakado, Y., 2001, Re-Os dating of the Kuroko ores from the Wanibuchi Shinjo, R., 1999, Geochemistry of high Mg andesites and the tectonic evolu- mine, Shimane Prefecture, southwestern Japan: Geochemical Journal, v. tion of the Okinawa trough-Ryukyu arc system: Chemical Geology, v. 157, 35, p. 169–174. p. 69–88. Thompson, J.F.H., Abidin, H.Z., Both, R.A., Martosuroyo, S., Rafferty, W.J., Sibuet, J.C., Deffontaines, B., Hsu, S.-K., Thareau, N., Le Formal, J.-P., and and Thompson, A.J.B., 1994, Alteration and epithermal mineralization in Liu, C.-S., 1998, Okinawa trough backarc basin: Early tectonic and mag- the Masupa Ria volcanic center, central Kalimantan, Indonesia: Journal of matic evolution: Journal of Geophysical Research, v. 103, p. 30245–30267. Geochemical Exploration, v. 50, p. 429–455. Sillitoe, R.H., 1989, Gold deposits in western Pacific island arcs; the mag- Titley, S.R., 1978, Geologic history, hypogene features, and processes of sec- matic connection: ECONOMIC GEOLOGY MONOGRAPH 6, p. 274–291. ondary sulfide enrichment at the Plesyumi copper prospect, New Britain, Sillitoe, R.H., and Gappe, I.M., Jr., 1984, Philippine porphyry copper de- Papua New Guinea: ECONOMIC GEOLOGY, v. 73, p. 768–784. posits: Geologic setting and characteristics: United Nations Development Togashi, Y., and Shibata, K., 1984, K-Ar age for alunite-bearing rock from the Program Technical Support for Regional Offshore Prospecting in East Asia; Iwato gold deposit, Kagoshima Prefecture, southern Japan: Mining Geol- United Nations, Economic and Social Commission for Asia and the Pacific, ogy, v. 34, p. 281-285 (in Japanese with English abs.). 89 p. Tokuyama, A. and Yoshida, S, 1994, Kinabalu fault, a large strike-slip fault in Sillitoe, R.H., and Hedenquist J.W., 2003, Linkages between volcanotectonic Sabah, east Malaysia: Geology and Palaeontology of Southeast Asia, v.14, settings, ore-fluid compositions, and epithermal precious-metal deposits: p.171–188. Society of Economic Geologists Special Publication 10, p. 315–343. Tsuchiya, N., 1990, Middle Miocene back-arc rift magmatism of basalt in the Sillitoe, R.H., Angeles, C.A., Jr., Comia, G.M., Antioquia, E.C., and Abeya, NE Japan arc, Bulletin of the Geological Survey of Japan, v. 41, p. 473–505. R.B., 1990, An acid-sulphate-type lode gold deposit at Nalesbitan, Luzon, Turner, S.J., Flindell, P.A., Hendri, D., Hardjana, I., Lauricella, P.F., Lindsay, Philippines: Journal of Geochemical Exploration, v. 35, p. 387–411. R.P., Marpaung, B., and White, G.P., 1994, Sediment-hosted gold mineral- Simmons, S.F., and Browne, P.R.L., 1990, Mineralogic, alteration and fluid- isation in the Ratatotok District, North Sulawesi, Indonesia: Journal of inclusion studies of epithermal gold-bearing veins at the Mt. Muro Geochemical Exploration, v. 50, p. 317–336. Prospect, central Kalimantan (Borneo), Indonesia: Journal of Geochemical TVI-Pacific Inc., 1995, Information memorandum: Calgary, Canada, TVI- Exploration, v. 35, p. 63–103. Pacific. Singer, D.A., Berger, V.I., and Moring, B.C., 2002, Porphyry copper deposits United Nations Development Program, 1978a, Geology and exploration geo- of the world: Database, maps and preliminary analysis: U.S. Geological chemistry of the Pinlebu-Banmauk area, Sagaing Division, Northern Burma: Survey Open-File Report 02-268, 20 p. New York, United Nations Development Program Technical Report 2, 78 p. Smith, I.E., and Milsom, J.S., 1984, Late Cenozoic volcanism and extension ——1978b, Geological survey and exploration, Burma: Project findings and in Eastern Papua: Geological Society Special Publications, v. 16, p. recommendations: New York, United Nations Development Program, 163–171. Technical Report PD/UN/BUR-72-002/9, 24 p. Smyth, H., Hall, R., Hamilton, J., and Kinny, P., 2003, Volcanic origin of ——1978c, Mineral exploration in selected areas: New York, United Nations quartz-rich sediments in East Java: Indonesian Petroleum Association, An- Development Program Technical Report 6, 86 p. nual Convention, 29th, Jakarta, 2003, Proceedings, p. 541–559. ——1987a, Geology and gold mineralization of Surigao del Norte: New York, Soerja-Atmadja, R., Maury, R.C., Bellon, H., Pringgoprawiro, H., Polve, M., United Nations Development Program, Technical Report 4, DP/UN/PHI- and Priadi, B., 1994, Tertiary magmatic belts in Java: Journal of Southeast 85-001/4, 60 p. Asian Earth Sciences, v. 9, p. 13–17. ——1987b, Geology and mineralization in the Panganiban-Tabas and Bulala Spakman, W., and Bijwaard, H., 1998, Mantle structure and large-scale dy- areas, Camarines Norte: New York, United Nations Development Program namics of South-East Asia, in Wilson, P., and Michel, G.W., eds., The geo- Technical Report No. 1, DP/UN/PHI-85-001/1, 43 p. dynamics of S and SE Asia (GEODYSSEA) project: Potsdam, Germany, ——1987c, Geology and hydrothermal alteration in the Amlan-Okoy River, GeoForschingsZentrum, p. 313–339. Pamplona and Ayungon areas, eastern Negros: New York, United Nations Stephenson, B., Ghazali, S.A. and Widjaja, H., 1982, Regional geochemical Development Program Technical Report No. 2, DP/UN/PHI-85-001/2, 54 atlas series of Indonesia/northern Sumatra: Bandung, Institute of Geologi- p. cal Sciences and Direktorat Sumber Daya Mineral. ——1992, The Philippines: A prospectus for the International Mining In- Stephenson, D., and Marshall, T.R., 1984, The petrology and mineralogy of dustry: New York, United Nations Development Program, 226 p. Mt. Popa volcano and the nature of the late-Cenozoic Burma volcanic arc: Uyeda, S., 1991, The Japanese island arc and the subduction process: Journal of the Geological Society of London, v. 141, p. 747–762. Episodes, v.14, p. 190–198. Sudo, S., Watanabe, Y., and Komura, K., 2003, 1:500,000 mineral resources van Bemmelen, R.S., 1949, The geology of Indonesia, v. II. Economic Geol- map of Kyushu: Tsukuba, Geological Survey of Japan. ogy: The Hague, Government Printing Office, 265 p. Sugaki, A., and Isobe, K., 1985, K-Ar ages of the Sanru and Koryu mines in van Leeuwen, T.M., 1994, 25 years of mineral exploration and discovery in Hokkaido, Japan: Journal of the Japanese Association of Mineralogy, Indonesia, in van Leeuwen, T.M., Hedenquist, J.W., James, L.P., and Dow, Petrology and Economic Geology, v. 80, p. 537–540 (in Japanese with Eng- J.A.S., eds., Mineral Deposits of Indonesia; Discoveries of the Past 25 lish abs.). Years: Journal of Geochemical Exploration 50, p. 13–90. Sutopo, B., Jones, M.L., and Levet, B.K., 2003, The Martabe gold discovery: van Leeuwen, T.M., Taylor, R.P., and Hutagalung, J., 1987, The geology of A high-sulphidation epithermal gold-silver deposit, north Sumatra, In- the Tangse porphyry copper-molybdenum propsect, Aceh, Indonesia: ECO- donesia: NewGenGold 2003 Conference, Case Histories of Discovery, NOMIC GEOLOGY, v. 82, p. 27–42. Perth, Western Australia, Gold Mining Journal, Proceedings, p. 147–158. van Leeuwen, T.M., Hawke, A., Leach, T. And Hawke, M., 1990, The Kelian Takahashi, M., and Saito, M., 1997, Miocene intra-arc bending at an arc-arc disseminated gold deposit, East Kalimantan, Indonesia: Journal of Geo- collision zone, central Japan: Island Arc, v. 6, p. 168–182. chemical Exploration, v. 35, p. 1–62. Tamaki, K., 1985, Two modes of back-arc spreading: Geology, v. 13, p. Wake, B.A., 1991, Gold mineralization at the Muyup prospect, East Kali- 475–478. mantan, Indonesia, in World Gold ‘91, Gold Forum on Technology and Tan, L.P., 1991, The Chinkuashih gold-copper deposits, Taiwan: Society of Practice, Proceedings: Parkville, Australasian Institute of Mining and Met- Economic Geologists Newsletter 7, p. 1, 21–24. allurgy, p. 271–278.

0361-0128/98/000/000-00 $6.00 31 32

Wake, B.A., Silvio, N.M., Lattore, A.Q., Iswahyudi, A.S. and Purwanto, A., Wolfenden, E.B., 1965, Bau mining district, west Sarawak, Malaysia. Part I: 1996, Geology of the Toka Tindung epithermal gold deposit, North Su- Bau: Geological Survey, Borneo Region, Malaysia, Bulletin 7, 147 p. lawesi, Indonesia, in Australian Mineral Foundation, eds., Porphyry Re- Yahata, M., Kubota, Y., Kurosawa, K., and Yamamoto, K., 1999, Evolution lated Copper and Gold Deposits of the Asia-Pacific Region Conference, in space and time of epithermal mineralization in northeastern Cairns, 12–13 August, 1996, Proceedings, p. 9.2–9.8. Hokkaido, Japan: Shigen-Chishitsu, v. 49, p. 191–202 (in Japanese with Wallace, D.A., Johnson, R.W., Chappell, B.W., Arculus, R.J., Perfit, M.R., English abs.). and Crick, I.H., 1983, Cainozoic volcanism of the Tabar, Lihir, Tanga and Yamada, R., Nishitani, Y., Tanimura, S., and Konishi, N., 1988, Recent de- Feni Islands, Papua New Guinea: Geology, whole-rock analyses and rock- velopment and geologic characteristics of the Nurukawa kuroko deposit: forming mineral compositions: Australian Bureau of Mineral Resources, Mining Geology, v. 38, p. 309–322 (in Japanese with English abs.). Geology and Geophysics Report 243, 2 fiche. Yamazaki, T., and Yuasa, M., 1998, Possible Miocene rifting of the Izu-Oga- Walther, H.W., Foerster, H., Harre, W., Kreuzer, H., Lenz, H., Mueller, P., sawara (Bonin) arc deduced from magnetic anomalies: Island Arc, v. 7, p. and Raschka, H., 1981, Early Cretaceous porphyry copper mineralization 374–382. on Cebu Island, Philippines, dated with K-Ar and Rb-Sr methods: Geolo- Yan, A., 1990, Features of volcanic-hosted epithermal gold mineralization in gisches Jahrbuch. Reihe D, Mineralogie, Petrographie, Geochemie, Lager- the Nagos and Mantri areas, Semporna peninsula, Eastern Sabah: Jabatan staettenkunde, v. 48, p. 21–35. Kajibumi Malaysia Report SB 91/1, 19 p. Wang, K.L., Chung, S.L., Chen, C.H., Shinjo, R., and Yang, T.F., 1999, Post- Yang, T.F., Lee, T., Chen, C.H., Cheng, S.N., Knittel, U., Punongbayan, R.S., collisional magmatism around northern Taiwan and its relation with open- and Rasdas, A.R., 1996, A double island arc between Taiwan and Luzon: ing of the Okinawa trough: Tectonophysics, v. 308, p. 363–376. Consequence of ridge subduction: Tectonophysics, v. 258, p. 85–101. Wang, Y., Sasaki, M., Sasada, M., and Chen, C.H., 1999, Fluid inclusion stud- Ye Myint Swe, 1990, Geology and gold mineralization at Kyaukpahto mine ies of the Chinkuashih high-sulfidation gold-cupper deposits in Taiwan: area, Kawlin township: Unpublished M.Sc thesis, Yangon, Yangon University. Chemical Geology, v. 154, p. 155–167. Yen, T.P., 1971, The Pleistocene tectonics, volcanism and ore deposits in Tai- Watanabe, Y., 1990, Pull-apart vein system of the Toyoha deposit, the most wan: Society Mining Geology Japan Special Issue 3, p. 60–64. productive Ag-Pb-Zn vein-type deposit in Japan: Mining Geology, v. 40, p. Yumul, G.P., 1980, Casenana project description, in Cordillera Central Re- 269–278. gion: Its geology and mineral resources—province of Benquet: Bureau of ——1991, Mineralization ages of Ofukeshi, Shizukari, Yakumo and Jokoku Mines and Geosciences, Ministry of Natural Resources, 62 p. deposits and structural movements related to vein-type mineralization in Yuwono, Y.S., Bellon, H., Maury, R.C., and Soeria-Atmadja, R., 1988, Ter- southwest Hokkaido: Mining Geology, v. 41, p. 141–146. tiary and Quaternary geodynamic evolution of S Sulawesi: Constraints from ——1995, A tectonic model for epithermal Au mineralization in NE the study of volcanic units: Geologi Indonesia, v. 13, p. 32–48. Hokkaido, Japan: Resource Geology Special Issue 18, p. 257–269. ——2002, Late Cenozoic metallogeny of southwest Hokkaido, Japan: Re- INTERNET REFERENCES CITED source Geology, v. 52, p. 191–210. Waters, P.J., 2004, Exploration models for giant copper-gold deposits at the Christopher, P.A., 2002, Technical report on the Feni property, Papua New district scale: examples from the SW Pacific [ext. abs.]: Centre for Global Guinea, prepared for New Guinea Gold Corporation, Vancouver, British Metallogeny, University of Western Australia, Publication 33, p. 51–56. Columbia, Canada, October 1, 2002. . tral portion of the Yandera porphyry copper prospect, Papua New Guinea: IAGI, 2004, Nusa Halmahera discovered 1.1 M Oz Au at Kencana deposit, ECONOMIC GEOLOGY, v. 73, p. 829–856. February 11, 2004 mail archive of the Indonesian Association of Geologists Weiland, R.J., and Cloos, M., 1996, Pliocene-Pleistocene asymmetric un- (IAGI), Jakarta, Indonesia.. thermochronology: Geological Society of America Bulletin, v. 108, p. Intierra, 2003, Deposit data sheet for Gosowong, Indonesia: Intierra Re- 1438–1449. source Intelligence, West Perth, Western Australia, 32 p. . geochemistry of the Frieda River prospect area, Papua New Guinea: ECO- Ivanhoe Mines, 2003, Monywa copper project mineral resources: Other pro- NOMIC GEOLOGY, v. 77, p. 592–616. jects in Asia Pacific: Toronto, Canada, Ivanhoe Mines . ithermal gold deposits of the Southwest Pacific: Journal of Geochemical Levet, B.K., Jones, M.L., and Sutopo, B., 2003, The Purnama gold deposit Exploration, v. 54, p. 87–136. in the Martabe district of North Sumatra, Indonesia: Asian Update on Widodo, S., Manning, P., Wiwoho, N., Johnson, L., Belluz, N., Kusnanto, B., Mineral Exploration and Development, SMEDG-AIG Symposium 2003, Macdonald, G., and Edwards, A.C., 1999, Progress in understanding and North Sydney, October 10, 2003. . toria, Australasian Institute of Mining and Metallurgy Publication Series Lihir Gold, 2003, Lihir announces a significant increase in resource and re- 4/99, p. 499–507. serves: News Release, January 28, Papua New Guinea, Lihir Gold Limited, Wilford, G.E., 1955. The geology and mineral resources of the Kuching- 5 p. . Au-Cu mineralisation, northern Sumatra, Indonesia: Parkville, Victoria, Newcrest Mining, 2004, Toguraci operations overview: Melbourne, Australia, Australasian Institute of Mining and Metallurgy Publication Series 9/95, p. Newcrest Mining Limited. . 637–642. TVI-Pacific, 2003a, The Canatuan project: Calgary, Canada, TVI-Pacific In- Wolfe, J.A., 1981, Philippine geochronology: Journal of the Geological Soci- corporated. . ety of the Philippines, v. 35, p. 1–30. ——2003b, The Rapu Rapu project: Calgary, Canada, TVI-Pacific Incorpo- Wolfe, R.C., Cooke, D.R., and Joyce, P., 1999, Geology, mineralisation and rated. . genesis of the alkaline Dinkidi Cu-Au porphyry, North Luzon, Philippines: Parkville, Victoria, Australasian Institute of Mining and Metallurgy Publi- cation Series 4/99, p. 509–516.

0361-0128/98/000/000-00 $6.00 32