Geological Study of Active Cold Seeps in the Syn-collision Accretionary Prism Kaoping Slope off SW Taiwan

Huang, Chi-Yue; Chien, Chih-Wei; Zhao, Meixun; Li, Hongchun; Iizuka, Yoshiyuki

doi:10.3319/tao.2006.17.4.679(gh)

Cited by 40 publications

(45 citation statements)

References 38 publications

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“…Further evidence of gas vents came from seafloor photographs taken by a deep-tow camera system that show authigenic carbonates, carbonate mounds, chimney structures, and clam communities associated with bacterial mats on the sea floor where geochemical proxies for methane flux are high (S. Lin, personal communication). With all the geophysical data presented in this study, together with many geological observations (e.g., Jiang et al 2006;Huang et al 2006;Horng and Chen 2006) and geochemical analyses results (e.g., Lin et al 2006;Chuang et al 2006;Yang et al 2006), we suggest that enormous amounts of gas hydrate should exist beneath the seafloor off SW Taiwan.…”

Section: Discussion and Summarysupporting

confidence: 60%

Distribution and Characters of Gas Hydrate Offshore of Southwestern Taiwan

Liu¹,

Schnürle²,

Wang³

et al. 2006

Terr. Atmos. Ocean. Sci.

149

108

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ABSTRACT1 Institute of Oceanography, National Taiwan University, Taipei, Taiwan, ROC 2 Central Geologic Survey, Taipei, Taiwan, ROC 3 Exploration Department, Chinese Petroleum Company, Miaoli, Taiwan, ROC * Corresponding author address: Prof. Char-Shine Liu, Institute of Oceanography, National Taiwan University, Taipei, Taiwan, ROC; E-mail: csliu@ntu.edu.tw Bottom simulating reflector (BSR) is a key indicator for the presence of gas hydrate beneath the sea floor. Widely distributed BSRs have been observed in the area offshore of southwestern Taiwan where the active accretionary complex meets with the passive China continental margin. In order to better understand the distribution and characters of the gas hydrate in the region, closely spaced (1.86-km line spacing) multichannel seismic reflection surveys have been conducted in recent years under the support of the Central Geological Survey, ROC. Over 10000 km of multichannel seismic reflection profiles have been collected that cover an area of about 10000 km 2 offshore of southwestern Taiwan. BSRs can be identified along 50% of the seismic profiles that we collected. A newly compiled BSR distribution map suggests that gas hydrates are distributed both in the passive margin of the China continental slope as well as in the submarine Taiwan accretionary wedge, from water depths of 500 to over 3000 m. Gas hydrates are most concentrated underneath anticlinal ridges in the accretionary wedge, and underneath the slope ridges of the passive continental margin that were formed due to sedimentary processes. Active fluid activities are evident from various features observed on seismic reflection and chirp sonar profiles, such as mud volcanoes, gas plumes and gas charged shallow sedimentary layers. Fluid migration model has been established from a set of pseudo 3D seismic reflection data. The predicted locations of high fluid Terr. Atmos. Ocean. Sci., Vol. 17, No. 4, December 2006 616 flux correlate well with those interpreted from geochemical analyses that show very high methane concentrations and very shallow sulfate-methane interfaces (SMI). This demonstrates the importance of structural control over gas hydrate emplacement. From the observed gas hydrate distribution and characters, the area offshore of southwestern Taiwan provides an ideal place to study and compare the formation and migration of gas hydrates under different tectonic settings.

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Section: Discussion and Summarysupporting

confidence: 60%

Distribution and Characters of Gas Hydrate Offshore of Southwestern Taiwan

Liu¹,

Schnürle²,

Wang³

et al. 2006

Terr. Atmos. Ocean. Sci.

149

108

View full text Add to dashboard Cite

show abstract

“…This indicates that abundant gas hydrate deposits may exist in the sediments of both the passive and active continental margins offshore of SW Taiwan. In addition to the BSRs, geological and geochemical data also support the interpretation that gas hydrates may exist in southwestern Taiwan continental margin sediments (Chao and You 2006;Chuang et al 2006;Horng and Chen 2006;Huang et al 2006;Jiang et al 2006;Lin et al 2006;Oung et al 2006;Shyu et al 2006). Hence, the region has been considered a gas hydrate potential area.…”

Section: Introductionmentioning

confidence: 85%

Methane Venting in Gas Hydrate Potential Area Offshore of SW Taiwan: Evidence of Gas Analysis of Water Column Samples

Yang¹,

Chuang²,

Lin³

et al. 2006

Terr. Atmos. Ocean. Sci.

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“…Gas hydrate formation is most favorable in water depths of 1-3.5 km within these three prospective areas [9]. Sampling evidence for gas hydrate deposits have now been found in the SCS, with several prospects having been initiated [7,[11][12][13]. Gas hydrate specimens have been sampled 200 m under the sediment surface in the Shenhu Area [14].…”

Section: Geological Setting Of the Study Areamentioning

confidence: 99%

“…Margins of the SCS exhibit a unique and complex tectono-sedimentary framework [5]. Since the Mesozoic era, the SCS has developed several basins and terraces abundant in organic materials following a series of structural movements, and thus formed a favorable place for the deposition of gas hydrates [6][7][8]. It is generally accepted that the extensive stretching and thinning of the continental crust between China and Borneo took place in late Mesozoic era, as a result of sustained subduction at the western margin of the Pacific plate.…”

Section: Geological Setting Of the Study Areamentioning

confidence: 99%

Nano-sized graphitic carbon in authigenic tube pyrites from offshore southwest Taiwan, South China Sea, and its implication for tracing gas hydrate

Zhang

Sun

et al. 2011

Chin. Sci. Bull.

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Gas hydrates are a significant energy resource and are usually detected by bottom simulating reflection and submarine geochemical anomalies. Authigenic minerals are related to gas hydrates, with carbonates, sulfates and sulfides being important tracing minerals. Authigenic tubular pyrites were collected from offshore southwest Taiwan in the South China Sea, and were investigated by scanning electron microscopy(SEM) and high-resolution transmission electron microscopy (HRTEM). Authigenic tubular pyrite was composed of framboidal pyrite, within which nanosized graphitic carbon of low crystallinity was discovered. The graphitic carbon coexisted with pyrite and had a texture similar to carbon nanotubes and nanocones, indicating that they likely precipitated from carbon supersaturated C-H-O fluid. Pyrite may act as a catalyst for the conversion of CH 4 to C. The discovery of nanosized graphitic carbon in pyrite indicated it was deposited in sediments that were supersaturated with methane fluid. Thus, nanosized graphitic carbon may be another tracing species for submarine gas hydrates. The discovery of nanosized graphitic carbon deposited in a low temperature environment will enlighten our understanding of the laboratory synthesis and industrial production of graphitic carbon.nano-sized graphitic carbon, authigenic tube pyrite, gas hydrate, South China Sea Citation:Zhang M, Sun X M, Xu L, et al. Nano-sized graphitic carbon in authigenic tube pyrites from offshore southwest Taiwan, South China Sea, and its implication for tracing gas hydrate. Chinese Sci Bull, 2011Bull, , 56: 2037Bull, −2043Bull, , doi: 10.1007 Gas hydrates are an ice-like crystalline material consisting predominantly of methane and water molecules, and are formed under high pressure and low temperature on continental slopes/rises [1]. As a newly discovered clean energy source during the last two decades, gas hydrates are gaining worldwide attention on account of their importance in energy exploration, and through increasing awareness of seafloor structure geo-hazards (stability) and global climate change. Gas hydrates predominantly occur at depths of 300-3000 m around the edges of continents and in marginal marine basins. Most information on the distribution, concentration, composition and origin of gas hydrates in deep marine sediments comes from geophysical evidence such as bottom simulating reflection and strong seafloor acoustic reflectivity. These techniques are commonly used to infer the distribution of gas hydrates on continental margins, in addition to gas hydrate samples collected during the deep sea drilling project and ocean drilling program. Pyrite is a common authigenic mineral within the marine sediments of the continental margin. It is the product of

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Geological Study of Active Cold Seeps in the Syn-collision Accretionary Prism Kaoping Slope off SW Taiwan

Cited by 40 publications

References 38 publications

Distribution and Characters of Gas Hydrate Offshore of Southwestern Taiwan

Distribution and Characters of Gas Hydrate Offshore of Southwestern Taiwan

Methane Venting in Gas Hydrate Potential Area Offshore of SW Taiwan: Evidence of Gas Analysis of Water Column Samples

Nano-sized graphitic carbon in authigenic tube pyrites from offshore southwest Taiwan, South China Sea, and its implication for tracing gas hydrate

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