Japan Geoscience Union Meeting 2016

Presentation information


Symbol M (Multidisciplinary and Interdisciplinary) » M-IS Intersection

[M-IS16] Drilling Earth Science

Thu. May 26, 2016 1:45 PM - 3:15 PM 103 (1F)

Convener:*Yasuhiro Yamada(Japan Agency for Marine-Earth Science and Technology (JAMSTEC), R&D Center for Ocean Drilling Science (ODS)), Minoru Ikehara(Center for Advanced Marine Core Research, Kochi University), Yusuke Suganuma(National institute of Polar Research), Kazuno Arai(Japan Agency for Marine-Earth Science and Technology), Keita Umetsu(Japan Agency for Marine Earth Science and Technology), Chair:Tomoaki Morishita(School of Natural System, Colleage of Science and Technology, Kanazawa University), Katsuyoshi Michibayashi(Institute of Geosciences, Shizuoka University)

1:45 PM - 2:00 PM

[MIS16-13] The Lord Howe Rise (LHR) Drilling Project: tectonics, paleoclimate and deep life on the LHR high-latitude continental ribbon

Ron Hackney1, Yasuhiro Yamada2, Kliti Grice3, *Junichiro Kuroda2, Jessica H. Whiteside4, Marco J.L. Coolen3, Fumio Inagaki2, Richard Arculus5, Dietmar R. Müller6, Saneatsu Saito2, Hiroshi Nishi7 (1.Geoscience Australia, 2.Japan Agency for Marine-Earth Science and Technology, 3.Curtin University, 4.University of Southampton, 5.Australian National University, 6.University of Sydney, 7.Tohoku University)

Keywords:Cretaceous climate, continental crustal ribbons, Lord Howe Rise

The Lord Howe Rise (LHR) is an elongate ribbon of submerged and extended continental crust that separated from Australia during the Late Cretaceous. Because the LHR is concealed beneath the Tasman Sea in water depths of 1000–3000 m, current knowledge of LHR geology based only on sparse geophysical data, few dredge samples, and sparse shallow (<600 m below-seafloor) drilling into Cenozoic and latest Cretaceous pelagic sediments (Deep Sea Drilling Project DSDP Leg 21 Sites 207 and 208).
Existing data provide a broad understanding of the LHR’s crustal structure, sedimentary basin architecture and resource potential. However, building more detailed knowledge of LHR geology, and understanding the geological evolution of the southwest Pacific more broadly, requires drilling into rocks that record the >100-million-year geological, tectonic and climatic history of the region. To this end, Geoscience Australia (GA) and the Japan Agency for Marine Earth Science and Technology (JAMSTEC) are leading an international effort to drill a deep (up to 3500 m below the seafloor) stratigraphic hole through a LHR basin that will recover Mesozoic sediments and potentially basement rocks.
A proposal for the drilling using the JAMSTEC drilling vessel CHIKYU was submitted to the International Ocean Discovery Program (IODP) in October 2015 (Proposal 871-CPP). The objectives outlined in this proposal are to: 1) define the role and importance of "continental crustal ribbons", like the LHR, in plate tectonic cycles and continental evolution; 2) recover new southern high-latitude data in the southwest Pacific to better constrain Cretaceous paleoclimate, and linked changes in ocean biogeochemistry; and 3) test fundamental evolutionary concepts for sub-seafloor microbial life over a 100-million-year timeframe. Drilling vessel Chikyu is the only platform that is capable to drill through the great depth at LHR, to accomplish this project.