The ophiolite spans the entire Zambales mountain range from 16 to 14.7 N where it partly underlies stratovol-canoes of the Luzon Arc, including Mt. The chromitites occur close to the peridotite/gabbro transition zone. These results provide a Middle Eocene age for the Zambales ophiolite, in agreement with the minimum Late Eocene age of the overlying Aksitero Formation. Chemical and structural characterization of the chromite samples was also carried out using X-ray absorption fine structure (XAFS), X-ray diffraction (XRD) and X … Pinatubo. It underlies the Zambales area in the western part of Luzon Island, Philippines. Both complexes host One of the best-studied complete ophiolite sequences is the Zambales Ophiolite, where tectonized peridotites progress to layered and isotropic gabbro, sheeted dike complex, pillow basalts, and finally pelagic sedimentary rocks. This north-south trending, east-dipping ophiolite suite consists of Already, there is a large set of information available on the geology of these regions that can be … The peridotites are dominantly comprised of residual spinel harzburgites with … Chilean-type ophiolites formed in a back-arc spreading zone like today's Andaman Sea. In this study, XANES spectroscopy has been applied to the characterization of natural chromite samples from ophiolite complexes in the Philippines. An active, left-lateral, strike-slip fault called the Philippine Fault, extending more than 1,300 km. Macquarie-type ophiolites formed in the classic mid-ocean ridge setting like today's Macquarie Island in the Southern Ocean. One of the most well-studied ophiolite complexes in the Philippines is the Zambales Ophiolite Complex (ZOC) (e.g. Rather, the evidence suggests that most—and possibly all—of the ophiolites were generated as back-arc, fore-arc, or intra-arc crust within the Philippine arc complex. Dimalanta: 19965133 The complex geology and tectonic setting of the Philippines, being sandwiched by oppositely-dipping subduction zones, led to the emplacement of these crust-mantle fragments. The Zambales Ophiolite Complex (ZOC) in Luzon, Philippines is a supra-subduction zone ophiolite formed in a marginal basin (e.g. The limited alteration of bentonite Potential targets include the Angat Ophiolite and the Lagonoy ophiolite in southeastern Luzon, as well as the Mesozoic ophiolite outcrops in the central and southern Philippines. International Geology Review, doi: 10.1080/00206814.2020.1746930. Geochronological, geochemical and geological constraints on models of ophiolite generation and ARC growth: Evidence from the northern Philippines. fluids at the Zambales ophiolite in Luzon, Philippines [4]. Yumul, 1996; Yumul and Dimalanta, 1997; Yumul et Experimental Samples were collected from two Philippine ophiolite complexes, Palawan and Dinagat. The Zambales Ophiolite Complex (ZOC) in the western portion of Luzon Island, Philippines represents a typical exposure of an emplaced crust-upper mantle section of an ancient lithosphere. Geophysical Study of the Boundary Between the Cabangan and San Santonio Massifs, Zambales Ophiolite Complex, Philippines by C.B. At the Zambales ophiolite in the Philippines, widespread active serpentinisation results in hyperalkaline groundwaters with measured pH values of up to 11.7, falling into the range typical of low-alkali cement porewaters. The age established by limiting strata is late Eocene. Converging plates created the modern Philippines through subduction related vol-canism, strike slip faulting, continent-arc collision, and ophiolite … The age established by limiting strata is late Eocene. The chromite orebodies are structurally classified into three major types: (1) concordant tabular deposits, (2) strings of pods and (3) pocketlike deposits. [31] The majority of ophiolite in the Philippines was formed in Cretaceous, with a minority formed in Tertiary. Other ophiolitic complexes include those in Isabela, Polillo Island, … Ophiolite emplacement, volcanic activity and sedimentary deposition have been used to reconstruct the geologic evolution of the Philippine Archipelago. A field campaign targeting high pH, H2-, and CH4-emitting serpentinite-associated springs in the Zambales and Palawan Ophiolites of the Philippines was conducted in 2012-2013, and enabled description of several springs sourced in altered pillow basalts, gabbros, and peridotites. Abstract. The Dibuakag pillow lavas were erupted onto the Early Cretaceous Casiguran ophiolite Fig. Philippine Trench on the east. Mössbauer spectroscopy was applied to natural chromite samples from ophiolite complexes in the Philippines. Abstract Mössbauer spectroscopy was applied to natural chromite samples from ophiolite complexes in the Philippines. Lack of evidence of thrust faulting and the general domal disposition of the lithologie units indicate that the ophiolitic rocks are exposed by uplift. Radiolarian dating of ophiolites and the cover turbidites in Philippine Mobile Belt, Northern Luzon Island Keisuke ISHIDA1, Shigeyuki SUZUKI 2, Carla B. DIMALANTA 3 and Graciano P. YUMUL, Jr. 1 Institute of Socio-Arts and Sciences, University of Tokushima 2 Department of Earth Sciences, Okayama University 3 National Institute of Geological Sciences, University of the Philippines A Review of Mechanisms of Ophiolite Emplacement: Philippine Examples by M.A. The Zambales ophiolite of western Luzon, Philippines, exposes a typical succession of basalt flows, diabasic dikes, gabbro and tectonized harzburgite. The chromitite-bearing peridotites of the Zambales mafic-ultramafic complex form the lowermost level of the Zambales ophiolite, which exposes a complete ophiolitic sequence. The transition-zone dunites in the Coto and Acoje blocks of the Zambales Ophiolite Complex are host to chromitites, nickel sulfides, and platinum-group minerals. In this study, petrographic and geochemical characteristics of the mantle section of the Pujada Ophiolite are investigated to determine its tectonic setting and the magmatic processes operating during its formation. John Encarnación, Multiple ophiolite generation preserved in the northern Philippines and the growth of an island arc complex, Tectonophysics, 10.1016/j.tecto.2004.04.010, 392, 1-4, (103-130), (2004). Hence, there is a close spatial association of several ophiolitic terranes of diverse ages spanning ∼150 Myr that formed as part of the arc complex. Philippines. There, it was reported that the bentonite alteration zone was limited to less than 5 mm because of clogging at the interface by secondary formed minerals such as goethite, K-feldspar, and Fe- and Mg-rich smectite. Despite its good preservation, its origin and formation is not constrained due to lacking geologic data. 1b). Encarnacion, John Patrick 1994 Furthermore, some popular ophiolites include: Macquarie Island and Tasmania (Australia); Yakuno, Poroshiri, and Horokanai (Japan); and the Zambales ophiolite complex (Philippines). The Samail ophiolite in southeastern Oman has been studied the most by researchers. We combine field observations of pH, temperature, conductivity, dissolved oxygen, and oxidation-reduction … The dunites are intercalated with harzburgites-lherzolites, layered ultramafic cumulate rocks, and layered gabbros. Two basement terranes, the Zambales ophiolite in the west, and the Angat ophiolite in the east, are exposed on the island of Luzon, separated by a circa 10 km thick and circa 100 km wide sedimentary basin. Podiform chromitites in the lherzolite-dominant mantle section of the Isabela ophiolite, the Philippines The occurrence of ophiolite is common in the Philippines. Complete mantle section of a slow-spreading ridge-derived ophiolite: An example from the Isabela ophiolite in the Philippines By Eric S. Andal, Shoji Arai and Graciano P. Yumul Cite bales ophiolite is a representative supra-subduction ophio-lite of the western Pacific and the largest in the Philippines (Fig. the Philippines, where one of the largest chromite deposits in the world is located. complete ophiolite sequence is the Zambales Ophiolite where tectonized peridotites progress to layered and isotropic gabbro, sheeted dike complex, pillow basalts and finally pelagic sedimentary rocks. The Zambales Ophiolite Complex (ZOC) in the western portion of Luzon Island, Philippines represents a typical exposure of an emplaced crust-upper mantle section of an ancient lithosphere. The Zambales ophiolite of western Luzon, Philippines, exposes a typical succession of basalt flows, diabasic dikes, gabbro and tectonized harzburgite. Two zircon fractions from plagiogranite and one fraction from diorite in the Coto block of the Zambales ophiolite give concordant U‐Pb ages of 45.1 (±0.6) Ma. The deposits treated in this report are those of the Zambales Ultramafic Complex and the Central Palawan Ultramafic Complex both in the form of peridotite-dunite-gabbro complexes typically occurring as portions of ophiolite sequences. Chromitite pods are rimmed by dunite aureoles. It consists [34] Studying ophiolite can help unveil the tectonic evolution of the Philippines. 11 .11Schematic section across northern Luzon, Philippines, from the Eocene Zambales ophiolite, through the Oligocene Itogon ophiolite in the Central Cordillera to the Early Cretaceous Casiguran ophiolite in the Northern Sierra Madre. Aurelio: 19965132. In this contribution, the petrographic and geochemical signatures of refractory and refertilized peridotites comprising the mantle section of the southern Palawan Ophiolite, Philippines are investigated. Melt-rock interaction in the subarc mantle: Records from the plagioclase peridotites of the southern Palawan Ophiolite, Philippines.