The Tectono-Thermal Events of Taiwan and Their Relationship with SE China

Abstract

We present a new synthesis of the tectono-thermal events of Taiwan, excluding the Coastal Range, based on existing isotopic, geochemical and geochronological data for granitic, metamorphic, volcanic and sedimentary rocks. Nd model ages (T DM ) and the inherited zircon ages consistently yielded Proterozoic ages, suggesting that the source rocks from the exposed rocks in Taiwan were formed in the Proterozoic, starting from about 2 Ga ago. The crustal evolution of Taiwan In comparison with the Cathysia foldbelts, Taiwan demonstrates similar Paleoproterozoic crustal residence ages, coeval Jurassic magmatism (Early Yanshanian) and Late Cretaceous (Late Yanshanian) orogeny. However, subduction-related magmatism was prevalent in Taiwan in comparison with both extension-and subduction-related magmatism in Cathaysia foldbelts during the Yanshanian orogeny. Rifting-related magmatism has continued in the Cathaysia foldbelts ever since Jurassic. Since Late Cretaceous, rifting-related magmatism migrated from the interior toward the coastal region in the Cathaysia foldbelts but it did not reach Taiwan until Paleogene. Since 5 Ma, subduction-related activity started in northern Taiwan. The volcanism in northern Taiwan was attributed to the Late Pliocene extensional collapse of the northern Taiwan mountain belt in response to the oblique collision of the northern Luzon arc with the Asian continent, but not directly related to the magmatism of the Ryukyu subduction zone. However, volcanism resulting from the spreading of the Okinawa trough manifests in the offshore region of northeastern Taiwan.

How the structural architecture of the Eurasian continental margin affects the structure, seismicity, and topography of the south central Taiwan fold‐and‐thrust belt

“…The part of the continental margin of the Eurasian Plate that is currently involved in the Taiwan orogeny is thought to have evolved from a subcontinental subduction system in the Late Cretaceous [ Hall , ; Li et al ., ; Lan et al ., ] to a rifting margin by the early Eocene followed, during the late early Oligocene, by seafloor spreading and, from the early Miocene to the present, the subduction of Eurasian Plate beneath the Philippine Sea Plate [ Hall , ; Lin et al ., ; Huang et al ., ]. Here we define the margin's prerift Mesozoic rocks as the basement upon which the Eocene and younger sediments of the margin were deposited.…”

“…Although the Central Range is outside of our study area, we give a brief description of it because the Mesozoic rocks that crop out there may make up a part of the basement in western Taiwan and in the Taiwan Strait [ Jahn et al ., ]. The Mesozoic rocks in the Central Range comprise predominantly marbles and schists [ Stanley et al ., ; Ernst , ; Ho , ; Lan et al ., ] whose absolute ages are not well constrained, although a number of Permian to Cretaceous isotopic ages have been determined [ Jahn et al ., ; Lo and Onstott , ; Lan et al ., ; Yui et al ., , ; Wintsch et al ., ]. In western Taiwan and its offshore, several boreholes intersect weakly metamorphosed continental to shallow marine siliciclastic deposits that have been interpreted to range in age from Late Permian to Cretaceous [e.g., Jahn et al ., ; Chiu , ; Ho , ; Shaw , ].…”

Three-dimensional ambient noise tomography across the Taiwan Strait: The structure of a magma-poor rifted margin

“…The part of the Eurasian margin that underlies the Taiwan Strait evolved from a subcontinental subduction system in the Late Cretaceous [ Li et al ., ; Lan et al ., ] to a rifting margin by the early Eocene and, during the late early Oligocene, to seafloor spreading and the formation of the South China Sea [ Lin et al ., ; C. Y. Huang et al , ]. The subsequence rift architecture of this part of the Eurasian margin consisted of a broad platform with deep, fault‐bounded basins (i.e., the Taishi and Penghu basins, Figure ) [ Chen and Yang , ; Hsu et al ., ; Lin et al ., ; Li et al ., ; Lin et al ., ; C. Y. Huang et al , ; Yeh et al ., ] that locally accumulated up to approximately 5 km of clastic sediments [e.g., Lin et al ., ].…”

Detrital Zircons U-Pb Age and Hf Isotope from the Western Side of the Taiwan Strait: Implications for Sediment Provenance and Crustal Evolution of the Northeast Cathaysia Block

“…The Taiwan crust experienced five major tectonic-thermal events (Lan et al 2008), which occurred in the early and prior to (56 -9 Ma) and after (< 5 Ma) the Pliocene, but no one in the Caledonian (360 -540 Ma). In contrast, monazites in beaches of western Taiwan (MiaoliHsinchu area) and southern Taiwan (Chiayi-Tainan area) show prominent Caledonian (430 Ma) features (Chen et al 2006), suggesting that these materials are unlikely to have originated from the island of Taiwan.…”