Polillo Island (Philippines); molybdenum mineralization in an island arc

Arc-related porphyry molybdenum deposit model

“…The low initial strontium values at Canicanian of 0.70351-0.70374 also rule out substantial contribution of crustal melt (Knittel and Burton, 1985).…”

“…The related intrusions at Canicanian display abnormally elevated levels of rubidium compared to typical arc-related porphyry molybdenum deposits and strontium isotopes that do not indicate involvement of old sialic continental crust melt in the magma (Knittel and Burton, 1985).…”

“…Massive contact metamorphic rocks will affect the circulation of later stage hydrothermal fluids through decreased permeability of the environment surrounding the pluton. (Hudson and others, 1981;Ashleman and others, 1997), Burroughs Bay (Hudson and others, 1981), Malala (van Leeuwen and others, 1994), Endako (Whalen and others, 2001), Kitsault (Steininger, 1985), Canicanian (Knittel and Burton, 1985), MAX (Lawley and others, 2010), Thompson Creek (Hall and others, 1984), altered rocks from Red Mountain (Brown and Kahlert, 1995), Little Boulder Creek (Mutschler and others, 1981), and Cannivan Gulch (Mutschler and others, 1981 …”

“…Recognized deposits of this type that are found elsewhere throughout the world ( fig. 2) include Compaccha, Peru in the Andean continental arc (Hollister, 1975) and extremely rare occurrences within island arc environments in the Philippines and Indonesia (Knittel and Burton, 1985;van Leeuwen and others, 1994). Subeconomic deposits that are found on the South Island of New Zealand include Mt Radiant and Knuckle Hill (Tulloch and Rabone, 1993;Christie and Brathwaite, 1995).…”

Porphyry copper assessment of East and Southeast Asia: Philippines, Taiwan (Republic of China), Republic of Korea (South Korea), and Japan

“…Pollilo Island ( fig. G1B), located about 30 km east of Luzon, may have been rifted from Luzon by strike-slip movement along the Philippine Fault or may be the northern end of an island arc accreted to the Mobile Belt (Knittel and Burton, 1985). Polillo Island is included here with the Southern Sierra Madre (although it does lie within present-day extent of the Philippine Arc shown in fig.…”