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Juxtaposed against the remnant forearc basin sequences along thrust faults, the Lichi Me ´lange of the Coastal Range of Taiwan is composed of exotic ophiolite and sedimentary blocks, metric to kilometric in size, and coherent turbidite beds, all embedded in a sheared scaly argillaceous matrix. The Lichi Me ´lange is controversial in origin, being interpreted either as a subduction complex, or as an olistostrome. By separating four main deformation levels within the Lichi Me ´lange and adjacent sedimentary rocks, we establish detailed geological maps and structural profiles in two key areas of the Lichi Me ´lange. We reconstruct also the evolution in cross-section and calculate the approximate minimum amount of shortening that corresponds to folding and thrusting in these areas. Our field studies suggest that the Lichi Me ´lange most likely arose from the shearing of lower forearc sequences rather than from a subduction complex or an olistostrome. This conclusion is supported by the structural analysis, the clay mineral distribution, and some interfingering sedimentary relationships between the Lichi Me ´lange and the lower Takangkou Formation. We also undertake a comprehensive tectonic analysis of the shear surfaces in the Lichi Me ´lange. The direction of the maximum compressional stress that we obtain is N100°~120°E, compatible with that of plate convergence. During the most recent stage of collision, between the Eurasian plate (eastern Central Range of Taiwan) and the Philippine Sea plate (Coastal Range), a major fault zone developed along the innately weak zone of me ´lange, further increasing the shear deformation pattern of the Lichi Me ´lange. This Longitudinal Valley Fault separates the Eurasian plate and the Philippine Sea plate and is one of the most active faults in Taiwan. It can be considered as the present plate boundary in the Taiwan arc-continent collision terrane. According to our reconstruction, this plate boundary of the Longitudinal Valley originated as a submarine arc-prism boundary.

This article investigates the temperature distribution and flowing characteristics of the dissociated gas and water from hydrate in porous sediment by utilizing a one-dimensional experimental model setup. With the developed apparatus, the experiments have been run for the thermal stimulation method by injecting hot water with different temperatures and rates. The experimental result suggested that the gas production rate increases with time until it reaches a maximum, and then it begins to decrease. However, the water production rate keeps nearly constant during the whole production process. The injection water temperature and rate, as well as the hydrate content in the sediment, all influence the energy ratio of thermal stimulation production.

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[1] Detrital zircon U-Pb geochronology was applied to Cenozoic fluvial sedimentary rocks from the Jianchuan Basin, Yunnan Province, China to constrain the provenance and the nature of paleo-drainage. Local geology testifies to a large river flowing through the Jianchuan Basin during the Paleogene and this previously has been linked to a paleo drainage system that connected the Qiangtang and Lhasa blocks to the South China Sea. The detrital zircon results from this study do not fit with this model and instead show provenance consistent with a river draining a watershed within the Songpan-Garze Complex, most likely from the northeast. From the late Oligocene and thereafter zircon provenance records greater contributions from erosion of local sources that surround the basin including the South China Block and Yidun Arc rocks that suggest loss of the northern sources. The timing for these changes overlap with regional deformation related to strike-slip faulting or displacement by shear strain rather than the later uplift associated with an expanding margin of the Tibetan Plateau.Components: 5200 words, 6 figures.