Hot fluids, burial metamorphism and thermal histories in the underthrust sediments at IODP 370 site C0023, Nankai Accretionary Complex

Man-Yin Tsang, Stephen A. Bowden* (Corresponding Author), Zhibin Wang, Abdalla Mohammed, Satoshi Tonai, David K. Muirhead, Kiho Yang, Yuzuru Yamamoto, Nana Kamiya, Natsumi Okutsu, Takehiro Hirose, Myriam Kars, Florence Schubotz, Akira Ijiri, Yasuhiro Yamada, Yusuke Kubo, Yuki Morono, Fumio Inagaki, Verena B. Heuer, Kai-Uwe Hinrichs

*Corresponding author for this work

Research output: Contribution to journalArticle

4 Downloads (Pure)

Abstract

Drilling during International Ocean Discovery Program (IODP) Expedition 370 at Site C0023 encountered instances of hydrothermal mineralization from 775 to 1121 m below seafloor. Fluid inclusion homogenization temperatures measured on barite veins within this interval indicate precipitation from fluids with temperatures up to 220 °C, and salinities ten times higher than interstitial water (16–25 c.f. 2.8–3.6 wt % NaCl). Patches of stratabound mineralization (rhodochrosite, calcite, barite and anhydride) are largely confined to the vicinity of veins and have vertical thicknesses and extents that can be explained by precipitation within the thermal aureoles of veins. Thermal maturities measured on petroleum biomarkers in underthrust sediments record a rise from pre-oil window to early oil window thermal maturities. Basin models show that increases in thermal maturity can be explained by burial metamorphism, and kinetic-based calculations suggest that hot fluids would only have had a minimal effect on hydrocarbon generation. However, the movement of hot fluids still has geochemical implications and creates a complex thermal history where both short-duration, localized heating within fracture zones at hot temperatures (~200 °C for less than 1 yr) and heating during burial over long durations (80–110 °C for 0.5–2 Myrs) need to be considered.

Original languageEnglish
Article number104080
JournalMarine and Petroleum Geology
Volume112
Early online date11 Oct 2019
DOIs
Publication statusPublished - Feb 2020

    Fingerprint

Keywords

  • hot fluids
  • biomarkers
  • hydrothermal mineralization
  • fluid inclusions
  • IODP 370 temperature limits
  • International Ocean Discovery Program
  • Hot fluids
  • Hydrothermal mineralization
  • Biomarkers
  • Fluid inclusions
  • BASINS
  • 5000-BAR
  • PARAMETERS
  • MODEL
  • FLOW
  • SOLUBILITIES
  • SYSTEM H2O-NACL
  • 0-X-NACL
  • 0-DEGREES-C
  • 1000-DEGREES-C

ASJC Scopus subject areas

  • Economic Geology
  • Geology
  • Geophysics
  • Oceanography
  • Stratigraphy

Cite this

Tsang, M-Y., Bowden, S. A., Wang, Z., Mohammed, A., Tonai, S., Muirhead, D. K., Yang, K., Yamamoto, Y., Kamiya, N., Okutsu, N., Hirose, T., Kars, M., Schubotz, F., Ijiri, A., Yamada, Y., Kubo, Y., Morono, Y., Inagaki, F., Heuer, V. B., & Hinrichs, K-U. (2020). Hot fluids, burial metamorphism and thermal histories in the underthrust sediments at IODP 370 site C0023, Nankai Accretionary Complex. Marine and Petroleum Geology, 112, [104080]. https://doi.org/10.1016/j.marpetgeo.2019.104080