Geological features of a collision zone marker: The Antique Ophiolite Complex (Western Panay, Philippines)
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- 作者：Graciano P. Yumul Jr.a ; b ; rwgmails@yahoo.com ; Carla B. Dimalantaa ; Rodolfo A. Tamayo Jr.a ; &dagger ; ; Decibel V. Faustino-Eslavac
- 关键词：Antique ; Collision ; Marginal basin ; Ophiolite ; Subduction ; Philippines
- 刊名：Journal of Asian Earth Sciences
- 出版年：2013
- 出版时间：25 March, 2013
- 年：2013
- 卷：65
- 期：Complete
- 页码：53-63
- 全文大小：1923 K
文摘
The Antique Ophiolite Complex exposed along the western side of Panay Island, central Philippines was derived from the Jurassic to Cretaceous proto-South China Sea oceanic leading edge of the Palawan microcontinental block. The subduction and ultimate closure of this ocean basin resulted in the emplacement and exposure of this lithospheric fragment along the collisional boundary of the microcontinental block and the oceanic- to island arc-affiliated Philippine mobile belt. The ophiolite complex has volcanic rocks having normal- to transitional mid-ocean ridge basalt (MORB) to island arc tholeiitic (IAT) geochemistry consistent with the transitional MORB-IAT characteristics of its peridotites. The chromitites manifest subduction signature suggestive of the involvement of water in its generation. All of these would be consistent with generation in a supra-subduction zone environment, specifically in a subduction-related marginal ocean basin. The collision of the Palawan microcontinental block with the Philippine mobile belt along western Panay resulted, aside from ophiolite emplacement, into arc curvature, island rotation, serpentinite diapirism and thrusting along the forearc side. The offshore bathymetric expression of the microcontinental block along the collision zone shows the leading edge of this oceanic bathymetric high to have spread laterally. This is indicative of its being buoyant resulting to non-subduction as supported by available earthquake hypocenter data.