MIS32-01

Room:304

Time:May 24 09:00-09:15

Miocene to Pliocene osmium isotopic record of Mediterranean sediments: new insights
into the Messinian Salinity Crisis
KURODA, Junichiro1∗ ; JIMENEZ-ESPEJO, Francisco1 ; NOZAKI, Tatsuo1 ; YOSHIMURA, Toshihiro1 ;OHKOUCHI, Naohiko1
1

JAMSTEC

In the late Miocene the Mediterranean Sea experienced a salinity crisis and formation of thick sequences of evaporites precipitated across the basin (Messinian salinity crisis). In this presentation we briefly review the Messinian salinity crisis, and report
Os isotopic ratio from drilled cores in the Mediterranean to investigate hydrological evolution in the Mediterranean Sea. Pliocene
sediments at all sites show Os isotopic ratios close to that of the coeval ocean water. This indicates that the Mediterranean wasconnected to the North Atlantic. Evaporitic sediments deposited during the late Miocene however, have lower isotopic ratios thancoeval ocean water values. Os isotopic ratios of the pre-evaporite sediments in the western Mediterranean are almost identical tothat of the coeval ocean water. In contrast, equivalent sediments from the Florence Rise have significantly lower isotopic values.
The offset of Mediterranean evaporite Os isotopic ratios is attributed to limited exchange with the North Atlantic during theMessinian Salinity Crisis. The source of unradiogenic Os is likely to be weathering of ultramafic rocks (ophiolites) cropping out
in the Mediterranean’s drainage basins. Our Os isotopic record, that suggests limited exchange of seawater between the North
Atlantic and Mediterranean Sea, is consistent with the previous Sr isotopic records. The offset in the Os ratio on the eastern
Mediterranean Sea is attributed either to limited water exchange between eastern and western Mediterranean, or to local effects
associated with exhumation of ophiolites around the eastern Mediterranean Sea. In the presentation, we also introduce a drilling
project entitled ’Uncovering a salt giant’, that is proposed by an international scientific community.
Keywords: Messinain Salinity Crisis, Os isotopes

1/1

MIS32-02

Room:304

Time:May 24 09:15-09:30

Past 60 kyr changes in the diatoms and glacial sediment supply to the Gulf of Alaska(IODP Exp. 341 Site U1419)
SUTO, Itsuki1∗ ; FUKUMURA, Akemi2 ; KONNO, Susumu3 ; ASAHI, Hirofumi4 ; MIX, A.c.5 ;DAVIES-WALCZAK, M.5 ; IODP, Exp. 341 scientists6
1

Graduate School of Environmental Studies, Nagoya Univ., 2 Graduate School of Science, Hokkaido Univ., 3 Faculty of Sciences,
Kyushu Univ., 4 Korea Polar Res. Inst., S. Korea, 5 Coll. Earth Ocean Atmos. Sci., Oregon State Univ., USA, 6 IODP Exp. 341
Scientists
Integrated Ocean Drilling Program (IODP) Expedition 341 during May to July, 2013 has achieved collecting continuous sediment records in the Gulf of Alaska (GoA) to examine the response of an orogenic system to the establishment of a highly
erosive glacial system. Obtained Cenozoic sediments permit to seek their relationship to the circum-North Pacific paleoenvironmental changes at extremely high time-resolution. Together with distal location of drilling sites to the ice-sheet and regional
sedimentation process of less influenced by the on-land systems of sedimentation, transportation and supply, ensures execute
aforementioned research objectives.
In this presentation, we will present preliminary outlines, including analyses of diatoms, physical properties and foraminiferal
oxygen isotopes, using the Holocene sediment samples drilled at the continental shelf (Site U1419). According to off-shore analyses, the estimated sedimentation rate at this site was 200 m/100 kyrs. The fossil diatom assemblages consists not only of several
taxa which indicate the paleoceanographic changes but also of coastal and freshwater species and resting spores, which show theinfluences of continental environments and the nutrient fluctuation in water column. Their abundances with significant fluctuation show the paleoceanographic variation, changes in the development of ice sheets, the sedimentation rate with erosion andsupply, and grain size of supplied sediments affecting the volume of pore water, as well as the dissolution of siliceous/calcareous
microfossils during 100 ka to the present in the GoA.
Keywords: IODP Exp. 341, Diatom fossils, Paleoenvironmental chang, Glaciation, Gulf of Alaska

1/1

MIS32-03

Room:304

Time:May 24 09:30-09:45

Diatom analysis of IODP Exp.341 Site U1418 in the Gulf of Alaska
KONNO, Susumu1∗ ; SUGA, Sei-ichiro1 ; OKAZAKI, Yusuke1 ; ASAHI, Hirofumi2 ; FUKUMURA, Akemi3 ;MATSUZAKI, Kenji M.4 ; SUTO, Itsuki5
1

Graduate School of Sciences, Kyushu University, 2 Korea Polar Research Institute, 3 Hokkaido university, 4 Geological Surveyof Japan, AIST, 5 Graduate School of Environmental Studies, Nagoya University
In early summer 2013 (May, 29th-July, 29th), the Integrated Ocean Drilling Program (IODP), Expedition 341, has drilled fivesites along the transect from the distal end of the ice edge in southern Alaska until the proximal continental shelf, and the Gulf
of Alaska (GOA) (Expedition 341 Scientists 2014; Suto et al., 2014).The geomorphology of the GOA shelf sea floor has beenstrongly influenced by active tectonics and glacial strata formation overprinted by glacial erosion (Carlson et al., 1982; Elmore
et al., 2013). The GOA is rich in in terrigenous sediments and nutrients supplied by fresh water originated by ice cover melting.
Until now, studies on sediment samples in the GOA coastal areas, indicate that sedimentation rate was very fast for the last glacial
period (Jaeger et al., 2008; Davies et al., 2011).
The core collected from site U1418 revealed that only 1 Ma is reached at the depth of 900 m CCSF-B after the microfossils
and paleo magnetism preliminary results (Expedition 341 Scientists 2014). In this study, we propose to report the offshore dataobtained during the expedition, supplemented by the data obtained onshore.

Keywords: IODP Exp.341, U1418, Diatom

1/1

MIS32-04

Room:304

Time:May 24 09:45-10:00

Holocene sedimentation in estuaries of the Baltic Sea (Exp. 347)
OBROCHTA, Stephen1∗ ; KOTILAINEN, A.t.2 ; HYTTINEN, O.3 ; ANDREN, T.4 ; RYABCHUK, D.5 ;SNOWBALL, I.6 ; YOKOYAMA, Y.7 ; EXP. 347, Science party8
1

Akita University Faculty of International Resource Science, 2 Geological Survey of Finland (GTK), 3 University of Helsinki,
Department of Geosciences and Geography, 4 Sodertorn University, School of Natural Sciences, 5 A.P. Karpinsky Russian Research Geological Institute (VSEGEI), 6 Uppsala University, Department of Earth Sciences - Natural Resources and Sustainable
Development, 7 University of Tokyo Atmosphere and Ocean Research Institute, 8 International Ocean Discovery Program (IODP)The IODP Expedition 347 ”Baltic Sea Paleoenvironment” drilled two sites in the Angermanalven River estuary. Sites M0061
and M0062 are located in an area that was deglaciated ca. 10 ka ago. It has long been known that varves continue to form inthis estuary and previous work has shown that a correlation exists between maximum daily discharge and mean varve thickness
at least AD 1901-1971 in the Angermanalven River. One aim of the IODP drilling was to recover a uniquely long varve record
from the two sites in Angermanalven and study varve thickness and sediment geochemistry, potentially yielding estimations onpast changes in discharge and sedimentation processes in the estuary.
In this presentation, we show the preliminary results from site M0062. The core recovery was ˜36 m and the sediment sequence
was divided into two lithological units. Unit 2 (17.09-35.9 mbsf) consists of well-sorted sand, deposited by a (glacio)fluvial
system. Unit 1 (0-17.09 mbsf) contains a transition from clastic varves typical of a glaciolacustrine environment to coupletscharacteristic of a glaciomarine, or brackish environment. The uppermost 18 metres were analysed for grain-size and elemental
geochemistry every 0.3-0.5 m. The uppermost 26 m were scanned by XRF at 1-cm resolution, and select intervals at 1-mm
resolution.

1/1

MIS32-05

Room:304

Time:May 24 10:00-10:15

Changes in Paleocene ostracodes at IODP Site U1407, off Newfoundland, with specialreference to the hyperthermal events
YAMAGUCHI, Tatsuhiko1∗ ; MATSUI, Hiroki2 ; NISHI, Hiroshi2
1

Kochi University, 2 Tohoku University, 3 Tohoku University

During the Paleogene greenhouse period, a series of global warming events called the hyperthermal events occurred. The
events may be driven by the orbital forcing of carbon cycling alike the Oligocene and Miocene climates (Kirtland Turner etal., 2014, Nat. Geosci., 7, 748-751). A primary objective of IODP Expedition 342 is to answer questions about the rate andmagnitude of ecosystem changes during the greenhouse period with the hyperthermal events. Exp 342 drilled off Newfoundlandand obtained successive cores of the Paleogene sediments that formed in high sedimentation rates (Exp 342 Scientists, 2012,
IODP Prel. Rep., 342, 1-263).
We study benthic ostracodes from the Paleocene cores (146-218 mcd) at Site U1407 to understand changes in ostracode faunas
during the Paleocene hyperthermal events such as the Latest Danian Event (LDE; 61.8 Ma) and the Mid-Paleocene Biotic Event(MPBE; 59.2 Ma). The core sediments are calcareous nannofossil ooze with radiolarians. They show light greenish grey toradish brown in color. The carbonate content ranges from 54 to 92%. The sediment color reflects the carbonate content. Using
the calcareous nannofossil biostratigraphy, the sediments were dated to 66.3-57.4 Ma. The sedimentation rates were estimatedas 1.3 to 2.4 cm/kyr. We obtained 3353 ostracode specimens from 226 samples and identified 37 species.
The ostracode faunas are composed mainly of Krithe crassicaudata, Krithe dolichodeira, Krithe pernoides , Cytherella sp., andNeonesidea sp. Species richness and abundance range from one to twelve and from one to 75, respectively. We binned samples
in the interval of 100 kyrs and calculated expected species richness at 30 specimens, E(S30) , and equitability, Eq ., of 50 binned
samples, following Hurlbert (1971, Ecology, 52, 577-586) and Buzas and Gibson (1969, Science, 163, 72-75). E(S30) values
fluctuate between 5.4 and 10.5, whereas Eq. values amplify between 0.62 and 0.91. During the LDE, both E(S30) and Eq .
dropped off, indicating stressful condition (e.g., Graham et al., 2009, Ecol. Indic., 9, 866-877). During the MPBE, E(S30)
decreased, but Eq. did not drop. The LDE switched seafloors into stressful condition for benthic communities alike the PaleoceneEocene Thermal Maximum (Webb et al., 2009, Geology, 37, 783-786).
Keywords: Hyperthermal events, Northwestern Atlantic, taxonomic diversity, Ostracoda, Paleocene

1/1

MIS32-06

Room:304

Time:May 24 10:15-10:30

Probing the Tectonic Evolution of the South China Sea: International Ocean Discovery
Program Expedition 349
TEJADA, Maria luisa1∗ ; LI, Chun-feng2 ; LIN, Jian3 ; KULHANEK, Denise4 ; WILLIAMS, Trevor5 ;BAO, Rui6 ; BRIAIS, Anne7 ; CHEN, Yifeng8 ; CLIFT, Peter9 ; COLWELL, Frederick10 ; DADD, Kelsie11 ;DING, Weiwei12 ; HERNANDEZ-ALMEIDA, Ivan13 ; HUANG, Xiao-long8 ; HYUN, Sangmin14 ; JIANG, Tao15 ;KOPPERS, Anthony10 ; LI, Qianyu2 ; LIU, Chuanlian2 ; LIU, Qingsong16 ; LIU, Zhifei2 ;NAGAI, Renata17 ; PELEO-ALAMPAY, Alyssa18 ; SU, Xin19 ; SUN, Zhen20 ; TRINH, Hai son21 ;YEH, Yi-ching22 ; ZHANG, Chuanlun2 ; ZHANG, Fan3 ; ZHANG, Guo-liang23 ; ZHAO, Xixi2
1

Department of Solid Earth Geochemistry, Japan Agency for Marine-Earth Science and Technology, Japan, 2 State Key Laboratory of Marine Geology, Tongji University, China, 3 Woods Hole Oceanographic Institution, USA, 4 IODP, Texas A&M University, USA, 5 Lamont-Doherty Earth Observatory of Columbia University, USA, 6 Geologisches Institut, Swiss Federal Institute ofTechnology, Switzerland, 7 Centre National de la Reserche Scientifique, University of Toulouse, France, 8 Guangzhou Instituteof Geochemistry, Chinese Academy of Sciences, China, 9 Department of Geology and Geophysics, Louisiana State University,
USA, 10 College of Earth, Ocean and Atmospheric Sciences, Oregon State University, USA, 11 Department of Earth and Planetary
Sciences, Macquarie University, Australia, 12 Second Institute of Oceanography, State Oceanic Administration, China, 13 Instituteof Geography/Oeschger Centre for Climate Change Research, Univ. of Bern, Switzerlandl, 14 Korea Institute of Ocean Scienceand Technology, Republic of Korea, 15 Faculty of Earth Resources, China University of Geosciences, China, 16 State Key Laboratory of Lithospheric Evolution, Institute of Geology and Geophysics, CAS, China, 17 Department of Physical, Chemical andGeological Oceanography, Universidade de Sao Paulo, Brazil, 18 National Institute of Geological Sciences, Univ. of the Philippines, Philippines, 19 School of Marine Geosciences, China University of Geosciences, China, 20 South China Sea Institute of
Oceanology, Chinese Academy of Sciences, China, 21 Department of Science and Technology, Min. of Natural Resources andEnvironment, Vietnam, 22 Taiwan Ocean Research Institute, Taiwan, Republic of China, 23 Key Laboratory of Marine Geology
and Environment, Institute of Oceanology, CAS, China

Expedition 349, South China Sea (SCS) Tectonics, was the first voyage of the JOIDES Resolution under the new International
Ocean Discovery Program. The objectives of this expedition were to: 1) determine the timing, mechanisms, and sequence ofthe opening and closing of different subbasins of the SCS by coring and directly dating the oceanic crust; 2) investigate thetectonic history of the SCS by conducting biostratigraphic and magnetostratigraphic investigations on the sedimentary sequences
to help constrain the timing and sequence of geologic events and the sedimentary responses to tectonic evolution of the basin;3) measure the geochemical composition, magnetization, and physical properties of the oceanic crust and seamount volcanic
products to understand crustal accretion and deep mantle processes associated with the tectonic development of the basin; and 4)
test the different proposed driving mechanisms that led to continental breakup and seafloor spreading. To attain these objectives,
we cored near the ocean-continent boundary (U1432 and U1435) inferred to be underlain by the oldest oceanic crust, and near
the fossil spreading centers in the East Subbasin (U1431) and the Southwest Subbasin (U1433 and U1434) where the youngest
crust formed. The main scientific outcomes of Expedition 349 include 1) in-situ SCS oceanic crust was recovered for the firsttime, providing critical control on the timing of termination of spreading in the SCS; 2) the cessation age of spreading in boththe East and Southwest Subbasins are similar (˜16 Ma), based on shipboard biostratigraphy from reddish-brown clays overlying
and within the oceanic crust at Sites U1431 and U1433; and 3) determination of the nature of the structural high at Site U1435,
where a sharp, possibly rift-related unconformity was recovered, providing indirect evidence for the onset of seafloor spreadingat ˜33 Ma. In addition, 4) the nature of post-spreading seamount volcanism will be examined from the volcaniclastic sediments
recovered at Sites U1431 and U1434; and 5) the past environmental, climatic, and oceanographic conditions related to the tectonic evolution of the SCS will be gleaned from studies of the 1524 m of sedimentary deposits recovered from all sites.
Keywords: South China Sea, tectonic evolution, seafloor spreading, International Ocean Discovery Program, Expedition 349,
oceanic crust drilling

1/1

MIS32-07

Room:304

Time:May 24 10:30-10:45

Introduction to the International Continental Scientific Drilling Program in the Samail
Ophiolite, Sultanate of Oman
KELEMEN, Peter2 ; MORISHITA, Tomoaki1∗
1

Kanazawa University, 2 Lamont-Doherty Earth Observatory

The Samail ophiolite in Oman is the largest, best-exposed, and most-studied ophiolite in the world. The Scientific Drillingin the Samail Ophiolite has been approved by the International Continental Drilling Project. In the presentation, we introduce
the scientific objectives, geology of the potential sites, and practical and educational perspectives of the proposal. The scientificobjectives are as follows: quantify 1) the nature and timing of solid upwelling beneath a spreading ridge using crystal shape andlattice preferred orientation data systematically collected on core from the periphery of a mantle diaper, 2) the nature and structural relationships of melt transport features in the shallow mantle, to evaluate mechanisms that focus transport from a melting
region to the ridge, 3) chemical variability deformation structures in the crust-mantle transition zone and plutonic lower crust, todetermine the depth of crystallization, the nature of ductile flow, and mechanisms of melt transport to the lower crust through the
MOHO, 4) hydrothermal alteration and cooling of the plutonic lower crust using mineral compositions, diffusion profiles, andstable isotopes to determine the importance of hydrothermal convection in heat and mass transfer and 5) investigate processes in
the critical dike-gabbro transition via study of cross-cutting igneous relationships, metamorphic mineral assemblages, and geochemical alteration, for igneous and metamorphic processes at oceanic spreading centers. The drillings can also adders 1) masstransfer from subducted sediments into overlying peridotite via petrologic and geochemical studies, with special focus on carbon
cycling, and 2) ongoing-subsurface alteration of mantle peridotite, including fluid compositions, hydrology, characterization of
fracture and vein spacing, studies of mineral assemblages formed by carbonation, hydration (serpentinization) and oxidation
and resulting mass transfer, and characterization of the subsurface microbial biosphere that derives energy from catalysis of low
temperature alteration.
Lead proponents are Peter B. Kelemen, Jurg Matter and Damon A. Teagle. Other principal investigators are Raeid Abed, Ali
Al Rajhi, Shoji Arai, Wolfgang Bach, Kier Becker, Francoise Boudier, Georges Ceuleneer, Laurence Coogan, Kathyrn Gillis,
Marguerite Godard, Steve Goldstein, Philippe Gouze, Greg Hirth, Albrecht Hofmann, Benoit Ildefonse, Bjorn Jamtveit, Frieder
Klein, Jurgen Koepke, Charles Langmuir, Chris MacLeod, Craig Manning, Katsu Michibayashi, Jay Miller, Sumio Miyashita,
Sobhi Nasir, Adolphe Nicolas, Matthew Schrenk, Barbara Sherwood-Lollar, Everett Shock, Satish Singh, Rob Sohn, Martin
Stute, Eiichi Takazawa, Alexis Templeton, Susumu Umino, Jessica Warren.

Keywords: Oman Ophiolite, Mid-Ocean Ridge, Island Arc, Serpentinization, Carbonation, Subsurface microbial biosphere

1/1

MIS32-08

Room:304

Time:May 24 11:00-11:15

The volcanic, geodynamic and climatic evolution of alkaline Lake Van, eastern Anatolia(ICDP Paleovan Drilling project)
SUMITA, Mari1∗ ; SCHMINCKE, Hans-Ｕ lrich1 ; Paleovan Scientific Team1
1

GEOMAR Helmholtz Centre for Ocean Reasearch

Alkaline Lake Van and adjacent active stratovolcanoes Nemrut and Suphan represent a coupled system that evolved over ca.
570 000 years. We present a preliminary synthesis of chronological, chemical, mineralogical, volcanological and sedimentological data obtained on ca. 170 of a total of ca. 450-500 tephra layers drilled at Site 2 of the ICDP Paleovan drilling project (2010).
We compare these with the chemistry, mineralogy and volcanology of the ca. 570 ka onshore record of Nemrut Volcano adjacent
to, and underlying, western Lake Van.
Nemrut explosive activity extends from ca. 570 ka to historic in age onshore and from ca. 580 ka to Holocene in the core. Most
individual tephra layers are slightly peralkaline trachytes, larger volumes of rhyolitic tephras having been erupted at intervals of
30-40 ka. Fallout deposits dominate while the larger rhyolite eruptions are generally associated with ignimbrites onshore, thickmassive tephra deposits drilled being interpreted as syn-ignimbrite turbidites. We infer stages of caldera collapse to be associatedwith large-volume rhyolitic eruptions.
Eruptive rates at Nemrut volcano apparently increased (onshore and core evidence) at ca. 200 ka. Tephras from adjacentsubalkalic Suphan volcano dominate the felsic tephras drilled prior to about 200 ka. Nemrut volcanic explosive activity appears
to have been roughly periodic while that of Suphan was more episodic and seems to have strongly waned during the past 200 ka
with external forcing (seismic, hydroclastic) having been characteristic forcing mechanisms, the Nemrut magma system having
been open throughout its recorded lifetime.
Basaltic tephras are most common in the lower ca. 100 m of the core and appear to represent dominantly subaqueous eruptions. The dominantly high-Al composition suggests parent magma to subalkalic Suphan system. A huge subaqueous to subaerial
basaltic eruption at ca. 80 ka is represented onshore by large Incekaya tephra cone and widespread fallout onshore and throughout
western Lake Van. It is the most widespread and voluminous seismic marker bed and represents one of largest basaltic explosive
eruption globally with a volume of >1 km3 (DRE).
We estimate about 30 % of the cored tephra layers to be reworked by various mechanisms. Wind-transported tephras appear
most common and mostly associated with dry climate intervals. They range from nearly pure to mixed tephras containing alarge proportion of xenocrysts and nonvolcanic and organic particles. We define thick fallout deposits consisting of fine-grained
basal tephra and variously rounded pumice lapilli at the top as pumice raft deposits reflecting prolonged abrasion in pumice rafts
covering the lake surface. Most significant are poorly sorted reworked tephra deposits containg abundant organic debris (plants,
shell fragments), many also containing gypsum crystals and are interpreted as recording extended periods of low lake levels.
Core intervals with abundant reworked tephra layers appear to correlate with seismically defined low lake level periods.
The initial fundamental precise stratigraphic and temporal correlation of the upper part of cores from sites 1 and 2, as well aswith the onshore tephra record was based on several fallout tephra layers defined by chemical composition, highly concordant
40
Ar/39 Ar ages and nature of the tephra deposit.
There is a tentative correlation of higher eruption frequency with warm climate periods both within the cores and on landsuggesting magma generation/eruption control via lithosphere loading.

Keywords: Lake Van, Nemrut Volcano, Alkaline lake, lake sediment, tephra, ICDP Paleovan project

1/1

MIS32-09

Room:304

Time:May 24 11:15-11:30

IODP Expedition 351 Izu-Bonin-Mariana Arc Origins: Temporal evolution of arc volcanism inferred from melt inclusions
HAMADA, Morihisa1∗ ; BRANDL, Philipp2
1

Japan Agency for Marine-Earth Science and Technology, 2 Research School of Earth Sciences, The Australian National University
International Ocean Discovery Program (IODP) Expedition 351 (June-July 2014) cored 1611-m-long cores composed of 1461m-long sediments and 150-m-long igneous basement rocks from Site U1438 in the Amami Sankaku Basin (ASB), west of the
Kyushu-Palau-Ridge (KPR) which represents a remnant part of the now active Izu-Bonin-Mariana (IBM) arc. Based on lithostratigraphy, the sedimentary section is divided into four units. The uppermost Unit I (160.3-m long) is composed of Neogene
hemi-pelagic sediments with interspersed discrete ash layers derived from explosive volcanism probably from the Ryukyu andKyushu arcs. Unit II (139.4-m long) is composed of late-Oligocene turbidites. Unit III (1046.4 m long) is composed of Oligocene
to Eocene coarser-grained turbidites. Unit IV (99.7-m long) is composed of siliceous pelagic sediments interbedded by tuffaceous sandstones.
In order to study the temporal evolution of island arc volcanism at an earlier stage of the IBM arc, we analyzed major andvolatile elements (Cl and S) of melt inclusions collected from Unit III (30-40 Ma based on onboard biostratigraphy) using electronprobe microanalyzers (EPMAs) installed at JAMSTEC and ANU. Most of the host minerals of melt inclusions are clinopyroxene
and plagioclase and the compositions of melt inclusions are diverse, ranging from basalt through rhyolite, and also ranging fromlow-K to medium-K series. In terms of major elements, low-K series melt inclusions are consistent with the melt compositions
reported from forearc region and volcanic front of the IBM arc. Major element composition of medium-K series melt inclusions
overlaps with the melt composition reported from the IBM rear-arc, such as volcanoes on the KPR and/or near the ASB. Theseobservation suggests that the turbidites accumulated at the ASB originate not only from the IBM rear arc, but also from the IBM
forearc and/or frontal-arc.
Both low-K and medium-K melt inclusions older than ∼35 Ma are basaltic and andesitic melts. Rhyolitic melts suddenly occur
at ∼35 Ma and afterward. The number of melt inclusions containing intermediate composition (66-74 wt.% SiO2 ) is smaller,suggesting that such intermediate melts represent mixtures of mafic and rhyolitic melts. We infer that the middle crust beneaththe arc volcanoes would have been growing and thickening until ∼35 Ma after subduction had been initiated at ∼50 Ma, and thatthe rhyolitic magmas would have been generated by partial melting of the middle crust at ∼35 Ma and afterward.
Keywords: IODP, IBM arc, Kyushu-Palau ridge, Amami Sankaku Basin, melt inclusion

1/1

MIS32-10

Room:304

Time:May 24 11:30-11:45

IODP Expedition 352 FAB and boninite
SAKUYAMA, Tetsuya2∗ ; MICHIBAYASHI, Katsuyoshi1 ; PYTHON, Marie3 ; SHIMIZU, Kenji4 ;IODP EXP352, Shipboard scientists5
1

Institute of Geosciences, Shizuoka University, 2 Osaka City University, 3 Hokkaido University, 4 JAMSTEC, 5 IODPThe Izu-Bonin-Mariana (IBM) system consists of oceanic crustal related to convergence between the Philippine Sea Plateand the Pacific Plate. International Ocean Discovery Program (IODP) Expedition 352 has drilled through the entire volcanic
sequence of the Bonin fore arc (1) to obtain a high-fidelity record of magmatic evolution during subduction initiation and earlyarc development, (2) to test the hypothesis that fore-arc lies beneath boninite and understand chemical gradients within these units
and across the transition, (3) to use drilling results to understand how mantle melting processes evolve during and after subduction
initiation, and (4) to test the hypothesis that the fore-arc lithosphere created during subduction initiation is the birthplace ofsuprasubduction zone (SSZ) ophiolites (Expedition 352 Preliminary Report, 2015). During Expedition 352, 1.22 km of igneous
basement and 0.46 km of overlying sediment were cored, including fore-arc basalts (FAB) and boninite related to seafloor
spreading and earliest arc development. We present preliminary results obtained during Expedition 352, focusing on physicaland chemical properties of igneous rocks.
Keywords: IODP, Expedition, Forearc, IBM, FAB, boninite

1/1

MIS32-11

Room:304

Time:May 24 11:45-12:00

Advanced Technologies of CHIKYU to Challenge the Deep Earth’s Interior
KYO, Masanori1∗
1

Japan Agency for Marine-Earth Science and Technology

JAMSTEC developed the deep sea scientific drilling vessel Chikyu to drill the sea floor, recover core samples, and analyze
these on board to obtain important scientific information targeted by International Ocean Discovery Program (IODP, in previous, Integrated Ocean Drilling Program), which includes the studies of deep biosphere, environmental change, and solid earth
dynamics. Chikyu was delivered to JAMSTEC in July 2005 and the shakedown, training, System Integration Tests (SITs) were
initiated shortly thereafter. Then, JAMSTEC started the scientific drilling operation for IODP beginning in September 2007.
Chikyu already conducted such major scientific projects as 1) Nankai Trough Seisomogenic Zone Experiment (NanTroSEIZE),2) Deep Hot Biosphere, 3) Japan Trench Fast Drilling (JFAST), 4) Deep Coalbed Biosphere off Shimokita, and so on. Any ofthese expeditions could satisfyingly contribute to understanding of the earth system. However, in order to successfully achievethese brilliant scientific results, we challenges many technical difficulties related to strong current, high wave, rough sea, deep
water, deep penetration, which have not been experienced even in the oil industries nor the previous ocean drilling programs.
For example, the NanTroSEIZE C0002 deep riser hole site is located in a water depth of approximately 2,000 m and persistently experiences the Kuroshio Current, which is a strong/deep current with mean surface currents of 3.5 knots, and a 1-yr
extreme current of approximately 7.0 knots. When drill pipe is placed in a strong current, an alternating Karman vortex forms
on the downstream side. Vibration occurs when two of these vortices alternately pull at one another, known as VIV, which
potentially cause serious damage on riser pipe, drill pipe, and the instruments attached along. The NanTroSEIZE site also experiences intense typhoons during the summer and autumn. Thus all operational phases should need to be analyzed thoroughly
for high currents and potential typhoons; evacuation criteria are developed for each operational condition. Considering the major
operational concerns, we developed the VIV reduction countermeasures for riser/drill pipe, real-time riser VIV monitoring system to estimate the fatigue, to successfully conduct riser drilling operation and riserless borehole observatory deployment at the
NanTroSEIZE sites.
To realize the JFAST operation which was a challenging drilling program (water Depth: 6,897.5 m, penetration depth: 854.81
mbsf), thorough investigation of the strength of drill pipe was conducted, and operation criteria was determined based on thestrength evaluation by considering such combined forces as the drill pipe weight in water, dynamic load caused by heaving motion, over pull force caused by hole condition, and bending force caused by ship motion and current.
As the other developments, we are developing the Turbine Driven Coring System (TDCS) to improve core quality and recovery
especially for hard rock, the new material riser pipe such as the Carbon Fiber Reinforced Plastic (CFRP), the precise dynamic
analysis for deep water drill pipes, the Long Term Borehole Monitoring System (LTBMS) for riser hole and so on.
IODP will start afresh in the new era from 2013 to implement the Mohole project which is long-cherished dream for scientificdrilling communities. Chikyu continues to evolve furthermore toward this great challenge of unexplored scientific mission.

Keywords: Scientific drilling, Deep water, Deep penetration, NanTroSEIZE, JFAST

1/1

MIS32-12

Room:304

Time:May 24 12:00-12:15

High paleo-heat flow in Costa-Rica seismogenic zone, off Osa peninsula (CRISP Exp344)
SAKAGUCHI, Arito1∗ ; YAMASHITA, Junpei31

Graduate School of Science and Engineering, Yamaguchi University, 2 JAMSTEC, 3 Dept.Geosphere Sciences, Fac. Sciences,
Yamaguchi University
Seismogenic depth of the plate subduction large earthquake may depend on thermal condition of the plate boundary (Hyndman
et al., 1990). Thermal condition is one of important data to drill the seismogenic zone. Two types of plate subduction zones of theaccretion and erosive are developed in the world, and the Costa-Rica subduction zone is one of the typical erosive margin. The
Cocos ridge originated from the Galapagos hotspot subducts in the southern part of the Costa-Rica and uplifts the seismogenic
zone to drillable depth for CHIKYU riser drilling system. The IODP Exp.344 drilled and took the core samples at the upper
plate wedge of the Costa-Rica margin (Harris et al., 2013). The site U1380 and U1413 penetrated upper pate rock above theseismogenic zone. We estimated paleo-heat flow in these sites using the technique of the vitrinite reflectance.
In the results, 11 and 13 samples of the vitrinite reflectance are obtained at site U1380 (500-800 mbsf) and U1413 (0-600mbsf) respectively. The value of the vitrinite reflectance increases with depth from 0.15 to 0.60 %. The average increase rate of
0.51 %/km at site U1380 and 0.53 %/km at site U1413 correspond to the heat flow of 115-123 mW/m2. This heat flow is twotimes higher than the present heat flow of 44.2-56.2 mW/m2 obtained from borehole temperature measurement (Harris et al.,2013). Pore-fluid chemistry found fluid seepage from deep level within middle slope sediment (Harris et al., 2013). Such fluid
flow from deep portion can transfer heat and possibly have caused high thermal-event.

Keywords: IODP, Seismogenic zone drilling, CostaRica, Heat flow, Vitrinite reflectance

1/1

MIS32-13

Room:304

Time:May 24 12:15-12:30

Deep Fault Drilling Project, Alpine Fault, New Zealand
SHIGEMATSU, Norio1∗ ; OKADA, Tomomi3 ; KATO, Naoki2 ; KOMETANI, Yusuke4 ; MORI, Hiroshi1 ;NISHIKAWA, Osamu5 ; YOSHIDA, Keisuke6 ; TAKAGI, Ryota7 ; LIN, Weiren8 ; MATSUMOTO, Norio1 ;TOGO, Tetsuhiro1
1

Institute of Earthquake and Volcano Geology, AIST, 2 Tohoku University, 3 Graduate School of Science, Osaka University,
Yamaguchi University, 5 Graduate School of Engineering and Resource Sciences, Akita University, 6 National research institutefor earth science and disaster prevention, 7 ERI, The University of Tokyo, 8 JAMSTEC
4The Alpine Fault is mature (>460 km offset), active (25 mm/yr), and late in its seismic cycle. It ruptured in AD 1717, has
a 330 yr return time, and M8 earthquake probability is c. 30% in the next 50 yrs (Berryman et al. 2013). The objective of
the Deep Fault Drilling Project (DFDP) is to collect materials, measure ambient conditions, and monitor at depth on the Alpine
Fault, to understand earthquake processes and the formation of a continental orogen. Second phase of DFDP was carried out at
the Whataroa River.
An open hole with depth of 893.18 m was drilled without coring during the DFDP-2. The drilling revealed the several featuresof the hanging wall of the Alpine Fault. The thickness of quaternary sediments at the Whataroa River is about 240 m. Cutting
samples were collected with interval of 2 m and the microstructural changes within the fault zone were revealed. Geophysicalwire-line loggings were carried out. The result of temperature logging indicates that the geothermal gradient in the hanging wall
is as high as 100 ℃/km.
Water level, density, viscosity and other properties of mud water were continuously monitored, which are expected to constrain
the hydrological property of fault zone.
DFDP-2 unfortunately failed to get the drill-core samples and penetrate the Alpine fault due to several problems during drilling.
One of the objectives of DFDP-2 was to reveal fault behavior at depth and core-log integration is essential. However it is
impossible to achieve this. The Alpine fault is a unique and scientifically intriguing fault, and it is worth being drilled again at
the Whataroa River. A strategy for succeeding at the drilling should be important.
Keywords: Fault Zone Drilling, Alpine Fault

1/1

MIS32-14

Room:304

Time:May 24 12:30-12:45

Drilling into seismogenic zones of M2.0 - M5.5 earthquakes in deep South African gold
mines (DSeis)
OGASAWARA, Hiroshi1∗ ; YABE, Yasuo2 ; ITO, Takatoshi2 ; VAN ASWEGEN, Gerrie3 ; CICHOWICZ, Artur4 ;DURRHEIM, Raymond5 ; PARTICIPANTS, Related meeting6
1

Ritsumeikan Univ., 2 Tohoku Univ., 3 Inst. Mine Seismology, South Africa, 4 Council for Geoscience, South Africa, 5 CSIR /Witwatersrand Univ., South Africa, 6 Participants of J-DESC SATREPS WS and related meetings
Several fault-zone drilling projects have been carried out around the world (e.g. the Nojima, San Andreas, Chelungpu,
Wenchuan, and Alpine faults, Gulf of Corinth, Nankai Trough, Japan Trench, and Costa Rica). Building on these, the 2013
ICDP Science Conference (Mori and Ellsworth, 2013) proposed that in the next decade ICDP focuses on fault drilling topics
such as:- How do earthquakes nucleate and propagate? Why do they stop?
- What controls the frequency and size of earthquakes?
- How does fault permeability and fluid pressure vary during earthquakes?
- How does stress vary during the earthquake cycle?
However, necessary near-field borehole observations have always been difficult where earthquakes nucleate.

Mining-induced earthquakes with magnitudes ≧ 2 take place only a few tens of meters away from active workings in South
African (SA) gold mines at depths of up to 3.4 km, where recent work (e.g. Ogasawara et al. 2014) yielded unique results.
The largest event recorded around SA mining region, a M5.5 earthquake, took place near Orkney on 5 August 2014, with theupper edge of the activated fault being only some hundred meters below the nearest mine workings (3.0 km depth). This is
one of the rare events for which detailed seismological data are available (Figure). We also have some additional sites where
M'2 hypocenters are located within several tens of meters. So, drilling is possible with a significantly better spatial coverage(including nuclei of ruptures, strong motion sources, asperities, and rupture edges) and a lower risk and at much smaller costs.
In seismogenic zones in a critical state of stress, difficult is to measure 3D absolute stress reliably. However, we have overcome
this problem. Better recovery of cores with less stress-induced damage is also feasible. These will allow us the following work:(1) DIRECT MEASUREMENT of 3D ABSOLUTE STRESS.
(2) INTEGRATED STRESS ANALYSIS of hydro-fracturing and stress damage in boreholes and cores, compared with the 3D
absolute stress.
(3) ANALYSIS of AVAILABLE SEISMIC DATA to delineate co- and post-seismic rupture processes, strong motion sources,
stress inversion, spatio-temporal variation of stress drop, Coulomb failure stress, b-value, and pore pressure to compare with theresults of drilling and measurements.
(4) TESTING of HYOPOTHETICAL M5.5 SOURCE MECHANISMS: the Orkney M5.5 was significantly deeper than themining horizon with a strike-slip faulting mechanism, being different from nearby mining induced events typically on mining
horizons with normal faulting mechanisms. The stress in-situ measured at ˜3km depth just above the M5.5 fault didn ′ t accountfor strike-slip faulting, suggesting the fault was weak or stress abruptly changes somewhere.
(5) INSTALLATION of SENSORS CLOSE to the M5.5 FAULT to monitor seismicity, and spatio-temporal changes in strain,pore pressure, and velocity structure, enabling investigation into background loading, fault-healing, and stress perturbation
sources.
Our potential future work reported here was built on the outcome by the researchers from Ritsumeikan, Tokyo, Tohoku, Kyoto,
Kagoshima, and Hokkaido universities, AIST, TRIES, NIED, CSIR, Wits University, and Council for Geoscience, and the engineers at gold mines and associated companies (Angogold, Sibanye, Goldfields, GoldOne, First Uranium, Seismogen, OHMS,
Groundwork, 3D Geoscience, Akema Boring, Homeseismo, Techno Sugaya), and funded by SATREPS, JSPS (No. 21224012,
21246134), Obs. Res. Prog. Prediction Earthq. Volc. Erupt., Ritsumeikan Univ., Tohoku Univ. COE, SA DST, and SA Research
Chairs initiative.
Figure Caption: Main and aftershocks of the Orkney M5.5 (green circles), surface strong motion stations (light blue triangles),strainmeters and stress measurement site at ˜3km depth (a pink square), and a tunnel at 3km depth for potential drilling (white
thin rectangle).

1/2

MIS32-14

Room:304

Time:May 24 12:30-12:45

Keywords: Drilling into seismogenic zones, Deep South African gold mines, Physics of earthquakes, Stress and Strength, Comparison with seismological analyses

2/2MIS32-15

Room:304

Time:May 24 14:15-14:30

Crush Zone Drilling Project for Development of Fault Activity Evaluation Methods
MIYAWAKI, Masahiro1∗ ; UCHIDA, Jun-ichi1
1Regulatory Standard and Research Department, Secretariat of Nuclear Regulation Authority (S/NRA/R)

Fault activity is often revealed from trench excavating investigations that clarify the cross-cutting relationship and depositionalage of overlying sediments. However, in some area, these methods cannot be applied because of the lack of overlying sediments
and samples indicating depositional age. In such case, fault activity is evaluated on the basis of identification of depositional age
and/or characteristics of the crush zone, however, these fault activity evaluation methods with sufficient resolution have not been
established yet. For example, material sampled from surface or near surface outcrops of crush zone indicates sometimes older
active age than actual one. Considering this situation, S/NRA started up a crash zone drilling project to improve fault activity
evaluation methods.
This project consists of borehole surveys, dating analysis, laboratory tests, and integrated analysis. In borehole surveys weconduct a deep borehole drilling, physical logging, various borehole tests, and structural analysis by use of borehole and boreholecore samples through the crush zone of a target fault with known activities to reveal the physical (temperature and pressure) andgeological conditions in which the sample with a reliable dating can be acquired. We are implementing the crush zone drilling
project in Gomura-Yamada Faults and Nojima Fault. Gomura-Yamada Faults ruptured during the 1927 Kita-Tango Earthquake
and Nojima Fault ruptured during the 1995 Hyogo-ken Nanbu Earthquake. In each drilling site, the target depth of drilling is
1,000-2,000m to understand the conditions in which fault activation age estimated from fault gouge is initiated. In dating analysis,
we plan to apply luminescent and ESR dating methods to sample from crush zone in the vicinity of the latest active fault plane in
the zone. Furthermore, in laboratory tests, rotary-shear high-velocity friction tests using natural fault gouge under water-pressure
conditions will be able to estimate frictional behavior of faulting and condition of initiation of fault activation age estimated fromfault gouge in our plan. In addition, we will also study how to improve the conventional method of fault activity evaluations
based on qualitative characteristics of the crush zone. Combining some results from multi-methods, integrated analysis on fault
activity will be performed.
We will principally investigate fault activity research focused on the crush zone and attempt to get practical results within thenext few years.

Keywords: Crush Zone Drilling, Fault Activity Evaluation, Nojima Fault, Gomura-Yamada Faults

1/1

MIS32-16

Room:304

Time:May 24 14:30-14:45

Anisotropic resisitiviy profiles and fault rock microstructures in fault zones
OMURA, Kentaro1∗
1Nat’l Res Inst Earth Sci Disast Prev

Structure and frictional characteristic in a fault zone are not homogeneous, and the inhomogeneity should be related to earthquake generation mechanism. However, main features of the inhomogeneity in fault zones are not yet sufficiently understood. I
consider it is effective to compare geophysical data, such as seismological and/or physical survey data, and fault rock microstructures and mineral compositions in the fault zone. In this presentation, I report the results of comparisons of two cases of Hatagawa
and Atotsugawa fault and suggest the factors affecting the inhomogeneity of fault structure. We compared the anisotropic resistivity profile by laboratory measurements of fault rocks and physical survey across the fault zones with microscopic observations
and mineral composition analysis of fault rocks provided by drilling into the fault zone. As a result, the anisotropic resistivity
profiles are strongly related to foliation structure of fault rocks. It is suggested that, during earthquake recurrences, foliation
fabric is developed and resistivity profile becomes anisotropic progressively, and that, in other words, the anisotropic resistivity
profile of fault zone reflect the fault activity history.
Keywords: resisitivity, anisotropy, physical survey, fault zone, microstructure, activity history

1/1

MIS32-17

Room:304

Time:May 24 14:45-15:00

Assessment of In-Situ Stress from Deep Borehole in the Middle Coastal Plain and Its
Implications for Taiwan CCS Project
YEH, En-chao1∗ ; LI, Wei-cheng1 ; CHIANG, Tung-chin1 ; WU, Feng-yi1 ; CHENG, Chuan-li1 ;LIN, Weiren2 ; WANG, Tai-tien3 ; YU, Chi-wen4 ; CHIAO, Chung-hui5 ; YANG, Ming-wei61

Department of Earth Sciences, National Taiwan Normal University, Taipei, Taiwan, ROC, 2 Kochi Institute for Core Sample
Research, Japan Agency Marine-Earth Science and Technology, Japan, 3 Institute of Mineral Resources Engineering, National
Taipei University of Technology, Taipei, Taiwan, 4 Sinotech Engineering Consultants, Inc., Taipei 114, Taiwan, ROC, 5 Taiwan
Power Company, Taipei 100, Taiwan, ROC, 6 Taiwan Power Research Institute, Taipei 238, Taiwan, ROC
Global warming have been becoming an important issues around the world. One of efficient ways to reduce the global warming
and decrease CO2 in the atmosphere is to sequestrate the supercritical CO2 into the underground structures or formations. To
evaluate the risk of CO2 leakage, the knowledge of in-situ stress state and integrity and rock strength of cover formation isessential. Besides, the assessment of in-situ stress state is significant for drilling-casing plan. Furthermore, understanding therelationship between fracture and in-situ stress is one of key information to evaluate the potential of fracture seal/conduit andfracture reactivity for such underground projects.
Formations under the Coastal Plain in Taiwan have been evaluated as saline-water formations with gently east-dipping and no
distinct fractures endured by regional tectonics of obliquely arc-continental collision with N35W compression. The formation ischaracterized as a suitable place for carbon sequestration. In this study, we will integrate the comprehensive results of different
in-situ stress determinations such as anelastic strain recovery (ASR), diameter core deformation analysis (DCDA), borehore
breakout, hydraulic fracturing from a 3000m borehole of carbon sequestration testing site and further evaluate the seal feasibility
in terms of rock mechanics and tectonic implication in the context of stress state.
Results of 30 ASR experiments between the depth of 1500m and 3000m showed the consistent normal faulting stress regime.
Stress gradient of vertical stress, horizontal maximum stress and horizontal minimum stress with depth is estimated as 22, 20, and
18MPa/km, respectively. The distribution of borehole breakout is not completely throughout all of interval in 1500-3000m. The
mean orientation of breakout is about 175deg and mean width of breakout is 84 deg. Based on rock mechanic data, maximum
injection pressure of carbon sequestration can be estimated. Furthermore, although it is normal faulting stress regime consistent
with core observations and borehole image logging, the horizontal maximum stress of 85deg inferred from breakout suggested
that this place has been affected by the compression of oblique collision. The comparison of stress magnitudes estimated from
ASR, DCDA, breakout and hydraulic fracturing cab further verified current results.
Keywords: In-Situ Stress, CCS, Taiwan, ASR, Breakout, Hydraulic Fracturing

1/1

MIS32-18

Room:304

Time:May 24 15:00-15:15

An enhanced geothermal system
DMITRIEV, Alexei1∗ ; KURYANOV, Roman2
1Institute of Space Science, National Central University, Jungli City, Taiwan, 2 Private Job

We introduce a new technology of heat extraction from the deep crustal rocks known as an enhanced geothermal system(EGS). EGS is based on an innovative way to drill deep and ultra-deep (6-12 km) geothermal wells with a speed of up to 30
meters per hour, with a diameter of 250 mm to 500 mm at a temperature in the bottom of the well up to 400C. This allows
building environmentally friendly petrothermal power plants and heat sources. EGS are built in a number of regions in Russia
from the European part to Siberia and Far East. The pilot scientific and experimental petrothermal power plant is characterized
by rated capacity of 24 MW with an annual power generation of 187,4 millions KWh and heat supply of 905 thousand Gcal/year.
The estimated technical & economical parameters of the petrothermal power plant are the following (all costs are in 2010 year
prices):- construction period - 6-10 months ;- cost of electricity produced - 0,01 USD/kWh;- cost of heat produced - 1,30 USD/Gcal;- total investment in the power plant - 44 million USD;
- lifetime - 40 years;- average payback period - 2 years.
Contact person for further information: Roman M. Kuryanov, e-mail: roman.taiwan@gmail.com

Keywords: deep and ultra-deep drilling, geothermal energy, petrothermal power plants

1/1

MIS32-19

Room:304

Time:May 24 15:15-15:30

Preliminary report on logging while drilling conducted at Iheya-North Knoll, Okinawa
Trough
SAITO, Saneatsu1∗ ; SANADA, Yoshinori1 ; MOE, Kyaw1 ; KIDO, Yukari1 ; HAMADA, Yohei1 ;KUMAGAI, Hidenori1 ; TAKAI, Ken1 ; SUZUKI, Katsuhiko1 ; CK14-04, Cruise member1
1

JAMSTEC

In July 2014, a scientific drilling expedition, CK14-04/Expedition 907 was conducted at an active hydrothermal field on
the Iheya-North Knoll by D/V Chikyu as a part of “Next-generation Technology for Ocean Resources Survey” of the Crossministerial Strategic Innovation Promotion Program (SIP). During the expedition logging while drilling (LWD) was deployed toconstrain the area of the fluid reservoir beneath seafloor followed by three coring holes down to 150 meter below the seafloor(mbsf). The LWD system is composed of arcVISION for resistivity and natural gamma ray measurement and TeleScope forreal-time transmission of drilling parameters and arcVISION data. Both tools also measure annular pressure and temperature
at two different depths. To protect the LWD tools from the anticipated high temperature of hydrothermal fluids, exceeding 300℃, a continuous pumping system (Non Stop Driller) was applied to maintain fluid circulation continuously even during pipe
connection.
Five sites (C9011-C9015) at the Iheya-North Original Site and one site (C9016) at Aki Site were drilled with LWD. At C9012
and C9016, the arcVISION detected temperature anomaly up to 84 ℃ at 234 mbsf and up to 39 ℃ at 80 mbsf, respectively. The
temperature quickly increases at that depth and it would reflect the existence of high-temperature heat source along borehole.
Due to the continuous fluid circulation during drilling, the measured temperature does not indicate in-situ temperature, but it
reflects the heat disturbed by the cold circulated water instead.
High quality resistivity and natural gamma ray data were acquired at six sites. The log curves at Site C9016 show characteristic
response; the natural gamma ray log exhibits extremely high radiation (>500 gAPI) at 7-13 and 23-31 mbsf (Zone A). In theunderlying interval of 31-40 mbsf, the resistivity log exhibits extremely low value (<0.2 ohm-m) (Zone B). Then the resistivity
log exhibits higher value (˜10 ohm-m) and the natural gamma ray log shows very low radiation (<50 gAPI) at the interval of
41-48 mbsf (Zone C). The log characteristics in Zone A, B, and C can be interpreted as a series of K-rich alteration zone, sulfide zone, and low-K hard (silicified) sediments, respectively. The LWD-based lithological interpretation was confirmed by thefollowing core description. Zones A and B can be correlated to altered clay zone and sulfide zone including sphalerite, galena,chalcopyrite, and pyrite. Our results show that LWD is a powerful tool for the scientific investigation of submarine hydrothermal
deposits and LWD survey enhances the successful recovery of sulfide samples.
∗CK14-04 Cruise member: TAKAI, Ken; KUMAGAI, Hidenori; KUBO, Yusuke; SAITO, Saneatsu; NOZAKI, Tatsuo; YAMAMOTO, Hiroyuki (JAMSTEC); YAMASAKI, Toru (AIST/GSJ); KAWACHI, Masanobu (NIES); Moe Kyaw Thu; FUKUSHIMA,
Tomohiko; TAKAMI, Hideto; ARAI, Wataru; SINNIGER, Frederic; MASAKI, Yuka; NAKAJIMA, Ryota; MIYAZAKI, Jun’ichi;
KAWAGUCCI, Shinsuke; TAKAYA, Yutaro; SARUHASHI, Tomokazu; SUGIHARA, Takamitsu; SANADA, Yoshinori; KIDO,
Yukari; NITTA, Suehiro (JAMSTEC); TSUTSUMI, Saki; TOTSUKA, Shuhei (JAMSTEC & Univ. Kyushu)
Keywords: CHIKYU, Okinawa Trough, Iheya-North Knoll, Logging while drilling, SIP

1/1

MIS32-20

Room:304

Time:May 24 15:30-15:45

Intact preservation of environmental samples by freezing under an alternating magnetic
field
MORONO, Yuki1∗ ; TERADA, Takeshi3 ; YAMAMOTO, Yuhji5 ; XIAO, Nan1 ; HIROSE, Takehiro1 ;SUGENO, Masaya4 ; OHWADA, Norio4
1

Kochi Institute for Core Sample Research, JAMSTEC, 2 Research and Development Center for Submarine Resources, JAMSTEC, 3 Marine Works Japan Ltd., 4 Center for Advanced Marine Core Research, Kochi University, 5 ABI Co. Ltd.
The study of environmental samples requires a preservation system that stabilizes the sample structure, including cells andbiomolecules. To address this fundamental issue, we tested the cell alive system (CAS)-freezing technique for subseafloor sediment core samples. In the CAS-freezing technique, an alternating magnetic field is applied during the freezing process to produce
vibration of water molecules and achieve a stable, super-cooled liquid phase. Upon further cooling, the temperature decreases
further, achieving a uniform freezing of sample with minimal ice crystal formation. In this study, samples were preserved using
the CAS and conventional freezing techniques at 4, -20, -80 and -196 (liquid nitrogen)oC. After 6 months of storage, microbial
cell counts by conventional freezing significantly decreased (down to 10.7% of initial), whereas that by CAS-freezing resulted inminimal. When Escherichia coli cells were tested under the same freezing conditions and storage for 2.5 months, CAS-frozen
E. coli cells showed higher viability than the other conditions. In addition, an alternating magnetic field does not impact on the
direction of remanent magnetization in sediment core samples, although slight partial demagnetization in intensity due to freezing was observed. Consequently, our data indicate that the CAS technique is highly useful for the preservation of environmental
samples.
Keywords: Subseafloor sediment, Freezing, Cell Alive System

1/1