Geology of the Zamboanga Peninsula, Mindanao, Philippines: an enigmatic South China continental fragment?
Geology of the Zamboanga Peninsula, Mindanao, Philippines: an enigmatic South China continental fragment?
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菲律宾棉兰老岛三宝颜半岛的地质：神秘的华南大陆碎片？
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发表时间：
2004
期刊：
影响因子：
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通讯作者：
J. Cotten
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作者：
G. Yumul;C. Dimalanta;R. A. Tamayo;R. Maury;H. Bellon;M. Polvé;V. B. Maglambayan;Cliff L. Querubin;J. Cotten
菲律宾南部棉兰老岛由两个陆块组成：与岛弧有关的棉兰老岛中东部陆块和大陆性的三宝颜半岛，其中含有多个蛇绿混杂岩体。中新世中期的Siayan-Sindangan缝合带代表了岛弧和陆块之间的构造边界。中中新世碰撞年龄解释晚中新世莫提博特组和下伏中中新世Gunyan Mélange，作为基底的缝合带之间的不整合。中中新世Siayan-Sindangan缝合带以前是一个俯冲带复合体，在棉兰老岛中东部与三宝颜半岛碰撞后重新活化为左旋走滑断层。对三宝颜半岛熔岩流进行的新的40 K-40 Ar全岩测年揭示了中新世中期至晚中新世的年龄，这与早中新世苏禄海沟的可能存在是一致的。三宝颜半岛可能是巴拉望微大陆块体的一部分的可能性已经被以前的工作者提出，由于它们在地层、地质结构和变质岩系方面的相似性。巴拉望微陆块在渐新世-中新世南海开海过程中与中国南部分离。如果三宝颜半岛确实曾经是巴拉望的一部分，那么它就代表了中国东南大陆边缘断裂的最南端。
Abstract Mindanao Island in the southern Philippines is made up of two blocks: the island-arc-related eastern-central Mindanao block and the continental Zamboanga Peninsula, which contains several ophiolitic bodies and mélanges. The Middle Miocene Siayan-Sindangan Suture Zone represents the tectonic boundary between the island-arc and continental blocks. A Middle Miocene age of collision is interpreted from the unconformity between the Late Miocene Motibot Formation and the underlying Middle Miocene Gunyan Mélange, which serves as basement to the suture zone. The Middle Miocene Siayan-Sindangan Suture Zone was formerly a subduction zone complex that was reactivated as a sinistral strikeslip fault following the collision of eastern-central Mindanao with the Zamboanga Peninsula. New 40K-40Ar whole-rock dating of lava flows from the Zamboanga Peninsula has revealed Middle to Late Miocene ages, which is consistent with the possible existence of an Early Miocene Sulu Trench. The possibility that the Zamboanga Peninsula could be part of the Palawan microcontinental block has been forwarded by previous workers, due to their similarity in stratigraphy, geological structure and metamorphic rock suites. The Palawan microcontinental block separated from southern China during the opening of the South China Sea in Oligo-Miocene times. If indeed the Zamboanga Peninsula was once part of Palawan, it represents the southernmost part of the rifted southeastern China continental margin.