MIS32-P01

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

アラスカ沖における第四期放散虫生層序 (IODP Exp.341 Site U1417)
Quaternary radiolarians biostratigraphy in the Alaska margin (IODP Exp.341 Site U1417)
松崎 賢史 1∗ ; 朝日 博史 2 ; 福村 朱美 3 ; 今野 進 4 ; 須藤 斎 5
MATSUZAKI, Kenji M.1∗ ; ASAHI, Hirofumi2 ; FUKUMURA, Akemi3 ; KONNO, Susumu4 ; SUTO, Itsuki51

産業技術総合研究所 地質情報研究部門, 2 韓国極地研究所, 3 北海道大学大学院 理学院 自然史科学専攻, 4 九州大学 大学院理学研究院 地球惑星科学部門, 5 名古屋大学環境学研究科
1
Geological Survey of Japan, AIST, 2 Korea Polar Research Institute, 3 Hokkaido University Graduate School of Science, 4 Kyushu
University Graduate School of Science, 5 Nagoya University Graduate School of Environmental Studies

The Gulf of Alaska is marked by the St. Elias orogen largely influenced by the ice-sheet expansion over the past 10 Myr. In thiscontext, the Integrated Ocean Drilling Program (IODP) Expedition 341 drilled several sites in southern Gulf of Alaska in orderto determine the linkage between the tectonic uplift, erosion by ice sheet and climate changes since Miocene. Concerning the
paleontological aspect of the collected cores, siliceous microfossils were not abundant. Cores collected from Site U1417 present
the highest abundance in siliceous microfossils. Indeed, in Site U1417, siliceous microfossils present moderate abundance forthe upper 200 meters CCSF-B, which correspond to the Pleistocene. This interval is composed of dark gray mud with several
interbeds of diatomaceous oozes. For deeper intervals, siliceous microfossils abundances were low, with numerous barren intervals.
Therefore, in this study, samples from the upper 200 m CCSF-B of Site U1417 were analyzed in order to establish the depth-age
model based on shipboard diatom/radiolarian biostratigraphy and paleomagnetic polarity stratigraphy for enables further paleoceanographic studies. Indeed, several radiolarian datum events such as the last occurrences (LOs) of Stylatractus universus ,Lychnocanoma sakaii and Amphimelissa setosa appear to be important for chronostratigraphic use. Particularly, temporal distribution of Amphimelissa setosa is highly interesting because the LO records at the MIS 4/ 5 boundary (77 ka) in the North Pacific,
while this species is still extant in the Arctic Ocean, Norwegian Sea, or in the Labrador Sea. In this study, we could establish
the LOs of Sphaeropyle robusta (1,500 ka, 161.9 m CCSFB at the median depth), Eucyrtidium matuyamaii (1,250 ka, 143.3 m),
Stylatractus universus (450 ka, 74.9 m), Axoprunum acquilonium (350 ka, 61.5 m) and Amphimelissa setosa (77 ka, 25.0 m),
and acme of Lychnocanoma sakaii (61 ka, 18.81 m). On the other hand, the FO of Amphimelissa setosa could be established forthe first time in the northeastern Pacific between the LO of Eucyrtidium matuyamaii and the base of Jaramillo magnetic normal
polarity epoch (1,072 ka).
キーワード: 第四期, 放散虫, 生層序
Keywords: Quaternary, Radiolarians, Biostratigraphy

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MIS32-P02

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

Last glacial to deglacial biotic changes on the Great Barrier Reef from offshore boreholes
Last glacial to deglacial biotic changes on the Great Barrier Reef from offshore boreholes
HUMBLET, Marc1∗ ; WEBSTER, Jody M.2 ; BRAGA, Juan carlos3 ; IRYU, Yasufumi4 ; POTTS, Don C.5 ;YOKOYAMA, Yusuke6 ; ESAT, Tezer M.7 ; FALLON, Stewart8 ; THOMPSON, William G.9 ;THOMAS, Alexander L.10
HUMBLET, Marc1∗ ; WEBSTER, Jody M.2 ; BRAGA, Juan carlos3 ; IRYU, Yasufumi4 ; POTTS, Don C.5 ;YOKOYAMA, Yusuke6 ; ESAT, Tezer M.7 ; FALLON, Stewart8 ; THOMPSON, William G.9 ;THOMAS, Alexander L.10
1

Dep. of Earth and Planetary Sc., Nagoya Univ., 2 Geocoastal Research Group, Univ. of Sydney, 3 Dep. de Estrat. y Paleont.,
Univ. de Granada, 4 Inst. of Geol. and Paleont., Tohoku Univ., 5 Dep. of Ecol. & Evol. Bio., Univ. of California, 6 AORI, Univ.
of Tokyo, 7 ANSTO, Inst. for Env. Res., Australia, 8 Res. Sch. of Earth Sc., Austral. Nation. Univ., 9 Lamont-Doherty Earth
Observatory, USA, 10 School of GeoSciences, Univ. of Edinburgh
1Dep. of Earth and Planetary Sc., Nagoya Univ., 2 Geocoastal Research Group, Univ. of Sydney, 3 Dep. de Estrat. y Paleont.,
Univ. de Granada, 4 Inst. of Geol. and Paleont., Tohoku Univ., 5 Dep. of Ecol. & Evol. Bio., Univ. of California, 6 AORI, Univ.
of Tokyo, 7 ANSTO, Inst. for Env. Res., Australia, 8 Res. Sch. of Earth Sc., Austral. Nation. Univ., 9 Lamont-Doherty Earth
Observatory, USA, 10 School of GeoSciences, Univ. of Edinburgh

IODP Expedition 325 drilled 34 boreholes into submerged reef structures along the shelf edge of the Great Barrier Reef (GBR).
The boreholes were drilled between 42 and 167 mbsl at 17 sites along four transects at three geographic locations (Hydrographers
Passage, Noggin Pass, and Ribbon Reef). The last glacial to deglacial reef sequence (˜8 ka to ˜27 ka) varies in thickness from˜5.5 m to ˜34 m and consists primarily of coralgal boundstone with various proportions of microbialite. We use a detailed
chronostratigraphic scheme based on numerous C14 and U-Th ages to discuss the evolution of the coralgal communities since
the last glaciation. Exp. 325 cores show that different phases of sea level change promoted different shallow reef-building coral
species at the study sites. The onset of the deglacial (16-19 ka) is characterized by a peak abundance of Seriatopora and Tubipora
whereas the following rapid sea level rise (<16 ka) is marked by the dominance of massive Isopora and Acropora with mediumto robust-size branches. The shift in composition of coral communities around 16 ka coincides with the flooding of a pre-LGM
MIS2 reef terrace, an event which had a major influence on reef growth and reef composition. We discuss the impact of thisevent on coralgal communities in the GBR and its significance for Quaternary reef evolution in general.
キーワード: IODP Expedition 325, Great Barrier Reef, Coralgal assemblages, Sea level changes, Glacial, Deglacial
Keywords: IODP Expedition 325, Great Barrier Reef, Coralgal assemblages, Sea level changes, Glacial, Deglacial

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MIS32-P03

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

IODP 第 350 次航海伊豆背弧掘削で得られた火山岩化学組成の予察的結果
Geochemical variation of Izu rear-arc volcanic rocks at drill Site U1437: Preliminary
results from IODP Expedition 350
佐藤 智紀 1∗ ; 田村 芳彦 1 ; 宮崎 隆 1 ; Gill James B.2 ; Hamelin Cedric3 ; 仙田 量子 1 ;Vaglarov Bogdan S.1 ; 原口 悟 1 ; 常 青 1 ; 木村 純一 1 ; IODP 第 350 次航海 乗船研究者 4
SATO, Tomoki1∗ ; TAMURA, Yoshihiko1 ; MIYAZAKI, Takashi1 ; GILL, James B.2 ; HAMELIN, Cedric3 ;SENDA, Ryoko1 ; VAGLAROV, Bogdan S.1 ; HARAGUCHI, Satoru1 ; CHANG, Qing1 ; KIMURA, Jun-ichi1 ;IODP EXPEDITION 350, Scientists41

独立行政法人海洋研究開発機構, 2 Earth and Planetary Sciences, University of California, Santa Cruz, 3 Centre for Geobiology,
University of Bergen, 4 国際深海科学掘削計画
1Japan Agency for Marine-Earth Science and Technology, 2 Earth and Planetary Sciences, University of California, Santa Cruz,
3
Centre for Geobiology, University of Bergen, 4 International Ocean Discovery Program

The Izu-Bonin-Mariana (IBM) arc is a good place to understand oceanic arc evolution. Crustal composition of the Izu segmentof the arc differs beneath the arc-front and rear-arc (e.g. in terms of K, LREEs) (e.g. Hochstaedter et al., 2001; Ishizuka et al.,
2003; Tamura et al., 2007). However, the magmatic history of the Izu rear-arc has not been well studied because Oligocene
and Eocene Izu rear-arc lavas and volcaniclastics produced before the opening of the Shikoku basin have not been recoveredby dredging or ROV sampling. Site U1437, drilled during IODP Expedition 350, is the first drill site in the Izu rear-arc andaimed to recover a record of volcanism in the rear arc from the present day to the Paleogene. This study will present preliminary
major element (measured by X-ray fluorescence, XRF), trace element (measured by XRF and inductively coupled plasmamass spectrometry, ICP-MS) and isotope ratios such as Sr, Nd, Pb and Hf (measured by ICP-MS and thermal ionization mass
spectrometry, TIMS) to examine the geochemical signature of the recovered material and whether it can be related to the present
day rear-arc or arc-front.
Site U1437 is located in a basin between the Manji and Enpo rear-arc seamount chains, about 90 km west of Myojinsho
volcano on the Izu arc-front. Drilling reached 1806.5 meters below seafloor (mbsf), and the recovered rocks were divided into
seven lithostratigraphic units and one igneous unit (a rhyolite intrusion). Lithostratigraphic Units I to V (0-9 Ma) dominantly
consist of tuffaceous mud/mudstone. Below 1320 mbsf, Units VI and VII (older than 9 Ma) are composed chiefly of volcaniclastic
layers, including coarser (>2 cm) volcanic clasts that are possibly derived from more proximal sources (Tamura et al., 2015).
Initially we have analyzed the major and trace element compositions of the volcanic clasts from Units VI and VII. Those showa wide range of compositions, from basalt to rhyolite, but are mainly intermediate (average SiO2 = 54.1 wt%). The K2 O contentsof the basalt to andesite clasts within the volcaniclastics are <0.9 wt%, with the exception of one clast, and their Zr/Y are <3.2
(average = 2.4), with the exception of two clasts. These characteristics are within the range of both the present day Izu arc-front
and rear-arc. The present rear-arc type lavas are strongly enriched in LREEs, whereas the arc-front type are depleted. However,the chondrite normalized REE patterns of the clasts are flat (La/Yb ∼ 1.0) or show slight depletions in LREEs relative to HREEs,
so it is not clear if these proximal clasts are similar to the current arc-front or rear-arc. The deepest clasts that have been analyzed(from 1797.26 and 1798.57 mbsf) are basaltic andesites and have relatively high Zr/Y (3.5 and 4.1, respectively), similar to thepresent day rear-arc. However, their K2 O contents (0.89 and 0.35 wt%, respectively) and flat REE patterns are not.
The wide range of clast compositions make it difficult to distinguish whether the clasts from the deeper part of Site U1437 arederived from the present day Izu arc-front or rear-arc and whether or not this geochemical distinction existed when this material
was erupted on the basis of major and trace elements alone. Analyses from additional samples and the isotope compositions of
the clasts may be more diagnostic.

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MIS32-P04

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

海底掘削試料中のクロミタイトに記録されている高温変成作用についてHigh temperature metamorphism recorded on chromitite samples in drilling cores fromocean floor
阿部 なつ江 1∗ ; 針金 由美子 2
ABE, Natsue1∗ ; HARIGANE, Yumiko2
1
1

独立行政法人海洋研究開発機構海洋掘削科学研究開発センター, 2 産業技術総合研究所地質情報研究部門
R&D Ocean Drilling Science, JAMSTEC, 2 Institute of Geology and Geoinformation, AIST

ODP、IODP における海洋地殻および蛇紋岩掘削では、下部地殻下部?モホ遷移帯に相当すると思われるはんれい岩や蛇紋岩化かんらん岩、さらにはポディフォーム型クロミタイトなどが採取されている（ODP Leg 209, IODP Exps. 304/305,345）。それらの試料の一部は、著しく変質しており、変はんれい岩や蛇紋岩になっている。一見、非変質と思われる高温
角閃石や、クロムスピネルなども、詳細に観察すると、緑色岩相?角閃岩相相当の高温変成作用を受けて（Alt et al., 2003;
Abe, 2011 など）。とくに、低温で変質に比較的強いと考えられているクロムスピネルの高温変成作用中の変化について
は、オフィオライトやコマチアイト試料についての研究例はあるが、海底試料においては少なく、近年の海洋科学掘削の大きな成果の一つであろう。
本発表では、ODP Leg 209 および IODP Exp. 345 の成果を踏まえ、低速拡大および高速拡大プレートにおいて、下部地殻?最上部マントル付近の深さまで熱水が循環していた可能性を検討したい。
キーワード: クロミタイト, IODP Exp. 345, 高温変成, モホ遷移帯, 海洋地殻, ODP Leg 209
Keywords: chromitite, IODP Exp. 345, high temperature metamorphism, Moho transition zone, oceanic crust, ODP Leg 209

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MIS32-P05

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

ハードロック掘削での泥水検層とその意義
Mud logging in hard rock drilling
杉原 孝充 1∗ ; モーキョー スー 2 ; 青池 寛 1
SUGIHARA, Takamitsu1∗ ; MOE KYAW, Thu2 ; AOIKE, Kan1
1
1

海洋研究開発機構 地球深部探査センター, 2 海洋研究開発機構 海洋掘削科学研究開発センター
CDEX/JAMSTEC, 2 ODS/JAMSTEC

Mud logging in a riser drilling operation has been powerful tool in the scientific drilling. Since fast and safe drilling areminimum requirements in the deep drilling operation, it is generally difficult that continuous coring is carried out to obtaingeological sample (rocks and fluid). Therefore, cuttings survey and mud gas monitoring in mud logging are essentially importantin the riser drilling for scientific research. Some hard rock drilling operations by using the Chikyu have been planned (e.g.,IBM, MoHole). Since continuous coring in the hard rock drilling is technically more difficult as compared with the drillingfor sedimentary rocks and slow rate of penetration results in consuming much of operation time, the cuttings survey is a uniqueapproach for lithological characterization in the hard rock drilling. In addition, fluid sampling from hard rock core is also difficult,even if core sample is obtained. Thus, the mud logging is especially important for the hard rock drilling, not only minimizing
operation time but also maximizing scientific result. In this presentation, we will introduce current technology of advanced mud
logging and discuss on potential of the mud logging for the hard rock drilling.
キーワード: 泥水検層, 大深部掘削, ハードロック掘削, ライザー掘削, マッドガスモニタリング, カッティングス
Keywords: Mud logging, Deep drilling, Hard rock drilling, Riser drilling, Mud gas monitoring, Cuttings

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MIS32-P06

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

IODP Expedition 344 コスタリカ沖の堆積物物性と間隙水圧
Distribution of physical properties and pore pressure of sediments off Costa Rica: IODP
Expedition 344
佐伯 綾香 1∗ ; 橋本 善孝 1
SAIKI, Ayakia1∗ ; HASHIMO, Yoshitaka1
1
1

高知大学
Kochi University

Evolution of physical properties in subduction zone is a key to understand lithification processes, location of decollement, stress
distribution. In this study, we examined the physical properties of sediments using on-board data and laboratory experimental
data on sediments obtained off Costa Rica margin to understand the distribution of compaction states.
Target sites are in the Integrate Ocean Drilling Program (IODP) Expedition 344 off Costa Rica, including reference sites(U1381 and U1414), frontal prism site (U1412), mid-slope site (U1380) and upper-slope site (U1413).
Laboratory experiments for velocity and porosity measurements were conducted with variation of effective pressure.
Porosity ranges from about 80% to about 53% during experiments. P-wave velocity ranges from about 1.4 to about 1.7 km/s.
S-wave velocity ranges from about 0.75 to 0.93 km/s. Vp/Vs ranges from about 1.73 to 2.04. bulk modulus ranges 1.7 to 2.7.
shear modulus ranges from about 0.8 to 1.4. Vp-porosity relationships from on-board data and from laboratory experiments
are comparable nicely. This comparable trend in Vp-porosity relationship suggests that the relationship between porosity andeffective pressure can be applied to most of sediments.
The porosity-effective pressure curves under isotropic condition were converted to the curves under uniaxial condition (Teeuw,
1971). Using the normal consolidation curves under isotropic and uniaxial stress conditions, we converted the on-board porosity
to effective pressure and fluid pressure.
In balk modulus-shear modulus graph, bulk modulus is not seen much change, but shear modulus there are variations.
For U1381 Unit I, hydrostatic fluid pressure was estimated as expected as a reference site.
For U1414 in another reference site, hydrostatic pressure was observed in Unit I, but lower fluid pressure than hydrostaticpressure was estimated in the upper part of Unit II. Below that, the pore pressure returned along hydrostatic pressure. Thisboundary can be weakened by higher fluid pressure below the boundary, suggesting that this boundary is likely a precursor of
decollement.
For Unit 1412 in frontal prism, pore fluid pressure is lower than hydrostatic pressure, suggesting that they have lower porosity
possibly caused by tectonic stress.
For 1380 in mid-slope andU1413 in upper slope, very low fluid pressure is observed. Because there is almost no age differenceat the boundary, the extremely low porosity can be caused by rapid sedimentation and erosion on the seafloor or tectonic stressenhanced-dehydration.

キーワード: 掘削, コスタリカ, 海底堆積物, 物性, 間隙水圧
Keywords: Drilling, IODP, Costa Rica, Expedition 344, Physical properties

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MIS32-P07

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

南海付加体，巨大分岐断層浅部コア試料に認められる変形構造：IODP Exp. 338 解析結果Structures characterizing the megasplay fault across shallow slope sediments of the Nankai
accretionary prism
大橋 聖和 1∗ ; Olivier Fabbri2 ; 山口 飛鳥 3
OOHASHI, Kiyokazu1∗ ; OLIVIER, Fabbri2 ; YAMAGUCHI, Asuka3
1

山口大学大学院理工学研究科, 2 University of Franche-Comte, Besancon, France, 3 東京大学大気海洋研究所
Graduate School of Science and Engineering, Yamaguchi University, 2 University of Franche-Comte, Besancon, France, 3 Atomosphereand Ocean Research Institute, The University of Tokyo
1

LWD measurements at Hole C0022A and coring at Hole C0022B during IODP Expedition 338 confirm the early suggestion
from seismic reflection imaging that a branch of the mega-splay fault crosses shallow slope sediments and may thus get close
to the sea bottom. At C0022A, the evidence include (1) the presence of moderately to steeply dipping fractures between 86.6
and 105.5 mbsf and (2) the presence of a low-resistivity zone at the same interval, with a particularly low resistivity interval
at 100-101 mbsf. At C0022B, the evidence include (1) three age reversals recognized between 76.48 and 84.48 mbsf, between
132.38 and 142.70 mbsf, and between 142.70 and 148.46 mbsf, (2) a bedding disturbed interval from 73.49 to 143.82 mbsf,(3) poor core recovery in the interval of 94.5-99.5 mbsf, suggesting highly fractured or disturbed material, and (4) the presenceof three intervals of clay characterized by a composite planar fabric (338-C0022B-10T-5, 49-51 cm, 10T-CC, 19-20 cm, and
11H-1, 18-19 cm). By comparison with the nearby 3D seismic reflection image, the C0022A low-resistivity image at 100-101
mbsf could correspond to the megasplay fault core zone where displacement is supposed to be the largest. The sudden drop incore recovery at this interval indicates that coring at Site C0022 likely missed the megasplay fault core zone. Conversely, coring
likely sampled secondary fault zones characterizing the damage zone of the megasplay fault branch at Site C0022. Post-cruise
investigations aim at examining all structures and microstructures associated with this supposed damage zone.
Based on CT scan images, seven intervals were selected from Core 10T (three from section 5, one from core catcher) and fromCore 11T (three intervals). For each interval, a slab was cut, dried, epoxied and polished before being analysed by XRF scannerfor compositional mapping. Polished thin sections were made from the most deformed-looking parts of the slabs.
XRF scanning analysis brings two main results: At least three gently dipping planar surfaces outlined by iron sulphide (mostlikely pyrite) cross the cores. It is not clear whether these surfaces are faults or not but, in one case (11T-1, 72-83 cm), thesurface separates clays with different Ca contents, suggesting some offset. The presence of iron sulphide along the surfaces may
be related to fluid flow having allowed recrystallization of this mineral species. Shipboard observation revealed three intervals
characterized by weakly marked planar fabrics. Two of these intervals (338-C0022B-10T-5, 49-51 cm and 11H-1, 18-19 cm) arecharacterized by a depletion in Ca and Sr and an enrichment in K with respect to the surrounding sediments.
Lastly, preliminary optical microscope observation indicates that some incipient non-coaxial shear deformation (asymmetricalsand lenses and composite planar fabric) affected the intervals with planar fabrics. Put together, these results indicate that deformation so far recognized in C0022B cores is weak to moderate. This is not an unexpected result given (1) the young age of thesediments and (2) the fact that samples likely come from the damage zone a few meters and not from the core zone.
[Acknowledgements]
We thank the crew of D/V Chikyu and all drilling personnel who contributed to the overall success of Expedition 338. We also
thank Kyuichi Kanagawa, Takehiro Hirose and Kentaro Hatakeda for constructive discussions and technical help. This researchused samples and data provided by the Integrated Ocean Drilling Program (IODP). Funding for this post- expedition research
was provided by CDEX, JAMSTEC.

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MIS32-P08

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

IODP 第 338 次および第 348 次航海で採取された堆積物コアの有機地球化学的研究
Distribution and evolution of organic matters in deep seafloor sediments collected during
IODP Exp.338 and 348
淵田 茂司 1∗ ; 益田 晴恵 1 ; 岡崎 香生里 1 ; 黒川 将貴 2
FUCHIDA, Shigeshi1∗ ; MASUDA, Harue1 ; OKAZAKI, Kaori1 ; KUROKAWA, Syoki2
1
1

大阪市立大学大学院理学研究科, 2 石油資源開発株式会社
Department of Geoscience, Osaka City University, 2 Japan Petroleum Exploration Co., Ltd. (JAPEX)

Seafloor sediments are important as a significant reservoir of organic matter, especially organic carbon and nitrogen. Sedimentary organic matters are mainly supplied through a photosynthetic process of phytoplankton biomass and other metabolismsof zooplankton and maturated during diagenesis (Lee et al ., 1988). Proteins, peptides, and amino acid monomers are the main
components and account for 30 ‒ 40% of the total nitrogen and 10 ‒ 15% of the total organic carbon content of seafloor
sediments (Burdige and Martens, 1988). Some studies revealed the distribution and concentration of organic matters includinghydrolyzable amino acids in shallow seafloor area (e.g., Cowie and Hedges, 1992; Kawahata and Ishizuka, 1993). The recent
Integrated Ocean Drilling Program (IODP) Nankai Trough Seismogenic Zone Experiment (NanTro SEIZE) Expedition 338 and
348 at Site C0002 drilled and cored successfully up to 3059 mbsf. In this study, concentrations of hydrolyzable amino acids andmaturation stage of organic matters in the sediments collected during the expeditions were determined in order to evaluate the
distribution and evolution of sedimentary organic matters during diagenesis in deep seafloor.
Sediment core samples collected at Site C0002 (202.1 ‒ 2216.9 mbsf), C0021 (3.7 ‒ 186.4 mbsf), and C0022 (1.2 ‒ 411.4
mbsf) were dried and powdered manually with an agate mortar on shore. The type and maturity of sedimentary organic matterswere determined using Rock ‒ Eval pyrolysis method at Japan Petroleum Exploration CO., LTD.
A part of the sediments were hydrolyzed to extract the amino acids from the hydrolyzable peptides and proteins. 1.0 g of thedried sediment was reacted with 6 N HCl at 110 ℃ for 22 h. The amount of total hydrolyzable amino acids (THAA) in the treatedsample solutions were measured by high performance liquid chromatograph using postcolumn ortho-phthalaldehyde derivation.
The concentrations of THAA in the core collected at Site C0002 vary between 819.9 ‒ 177.1 nmol/g, and Gly was the mostabundant amino acid followed by Asp, Ser, Ala, Val, and Phe. At Site C0021 and C0022, the concentrations of THAA were4679.2 and 6729.7 nmol/g at surface, respectively, and decreased drastically with depth. The THAA carbons account for <1%of total organic carbon and nitrogen, indicating that most of the biogenic organic matters would be changed into kerogens.
The amounts of hydrocarbons generated through thermal cracking of non-volatile sedimentary organic matter (S2 ) were 1.2 ‒0.15 mg/g. The low S2 values and TOC (1.2 ‒ 0.3 %) indicate that most of kerogen in the cores is categorized as type III. The
temperatures at which the maximum release of hydrocarbons from thermal cracking of kerogen occurs during pyrolysis (Tmax )were 379 ‒ 416 ℃ at the shallow area (1.2 ‒ 91.7 mbsf), increased gradually with depth, and reached to 439 ℃ at 2216.9 mbsf.
Rock ‒ Eval data indicate that the maturation of kerogens could be progressed with depth in seafloor sediment.

キーワード: ロックエバル, ケロジェン, アミノ酸
Keywords: Rock Eval, Kerogen, Amino Acids

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MIS32-P09

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

IODP 第 348 次航海で得られたカッティングス中の炭質物ビトリナイト反射率
Vitrinite reflectance of carbonaceous materials in cuttings retrieved during the IODP Expedition 348
福地 里菜 1∗ ; 山口 飛鳥 1 ; 山本 由弦 2 ; 芦 寿一郎 1
FUKUCHI, Rina1∗ ; YAMAGUCHI, Asuka1 ; YAMAMOTO, Yuzuru2 ; ASHI, Juichiro1
1

東京大学大気海洋研究所, 2 海洋研究開発機構
Atmosphere and Ocean Research Institute, The University of Tokyo, 2 Japan Agency for Marine-Earth Science and Technology(JAMSTEC)
1

Integrated Ocean Drilling Program (IODP) Nankai Trough Seismogenic Zone Experiment (NanTroSEIZE) Expedition 348
took place from 13 September 2013 to 29 January 2014. During the Exp. 348, cuttings, core samples, mud gas, and logging data
were collected from Holes C0002N and C0002P down to 3058.5 mbsf. Four lithologic units were identified at Site C0002 basedon geological and geochemical characteristics of core and cuttings samples: Unit II (475-512.5 mbsf in Hole C0002M), Unit III(875.5-975.5 mbsf in Hole C0002N), Unit IV (975.5-1665.5 mbsf in Hole C0002N), and Unit V (1665.5-2325.5 mbsf in Hole
C0002N, and 1965.5-3058.5 mbsf in Hole C0002P)(Tobin et al., 2015).
To evaluate whole thermal structure of the Site C0002, we performed vitrinite reflectance analysis for cuttings samples collected every 100 m of Holes C0002N and C0002P. Vitrinite reflectance (Ro ) is an indicator to estimate maximum paleotemperature, which has been widely applied to reveal tectonic evolution of on-land accretionary complex (e.g. Underwood et al., 1992;
Sakaguchi, 1996; Ohomori et al., 1997) and thermal anomalies along fault slip zones reflecting frictional heating due to seismic
slip (e.g. Sakaguchi et al., 2007; Sakaguchi et al., 2011). This is the first study that applied vitrinite analyses systematically tothe entire modern accretionary prisms.
In this presentation, we report preliminary results of vitrinite reflectance analysis. Ro values are 0.15 to 0.20 in Unit III (forearc
basin strata), 0.20 to 0.27 in Unit IV (accretionary prism strata), and 0.20 to 0.45 in Unit V (hemipelagic sediment). In general,
Ro values tend to be gradually and continuously increasing with depth. Estimated paleotemperatures of Unit IV and V are approximately 40 ℃ and 90 ℃, respectively, which are consistent with estimated modern temperatures (Sugihara et al., 2014).
キーワード: ビトリナイト反射率, 炭質物, 最高被熱温度, 付加体
Keywords: vitrinite reflectance, carbonaceous matter, paleotemperature, accretionary prism

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MIS32-P10

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

統合国際深海掘削計画第 337 次研究航海の非弾性ひずみ回復（ASR）測定結果
Preliminary results of anelastic strain recovery (ASR) measurements during IODP Expedition 337
林 為人 1∗ ; 谷川 亘 1 ; 山本 裕二 2 ; 森田 澄人 3 ; 山田 泰広 4 ; 稲垣 史生 1
LIN, Weiren1∗ ; TANIKAWA, Wataru1 ; YAMAMOTO, Yuhji2 ; MORITA, Sumito3 ; YAMADA, Yasuhiro4 ;INAGAKI, Fumio1
1
1

海洋研究開発機構 高知コア研究所, 2 高知大学, 3 産業技術総合研究所, 4 海洋研究開発機構
Kochi/JAMSTEC, 2 Kochi University, 3 GSJ/AIST, 4 ODS/JAMSTEC

掘削科学センター

IODP (Integrated Ocean Drilling Program) による下北八戸沖石炭層生命圏掘削（第 337 次研究航海、Exp337）は、青森
県八戸市の沖合約 80km、水深 1,180m の地点（C0020）において「ちきゅう」によるライザー掘削を行い、当時の海洋科
学掘削史上の最深記録となる海底下深度 2,466 ｍまで到達した。海底下深度 1,276.5m〜2,466m の範囲において、コア試料の採取を行った。本研究は、当該掘削のコア試料を用いて、地層の三次元応力情報を得る目的で、コア試料の非弾性
ひずみ回復（Anelastic strain recovery、ASR と略称）を「ちきゅう」船上で測定した。
コア試料が地下で負荷していた応力が掘削により解放された場合、岩石の弾性ひずみは瞬間的に解放され、その解放のプロセスは測定することができない。しかし、非弾性ひずみは徐々に回復するので、コア試料が船上に上がってからでも、その一部を測定することが可能である。このコア試料の非弾性ひずみテンソルと解放された応力テンソルとの関連性を利用した応力測定法は、非弾性ひずみ回復法（ASR 法）といい、IODP Exp315 と Exp316 においては海洋科学
掘削の分野において初めて成功に適用された（Byrne et al., 2009; GRL, Vol.36, L23310）。
Exp337 においては、海底下深度 1,370〜2,448m の範囲から計 7 つのコア試料を採取して、6 つのコア試料について
良質な非弾性ひずみ回復の時間連続変化データを得ることができた。海底下深度 2,448m から採取されたコア試料の ASR
測定は、海洋科学掘削計画では最深の適用例である。本研究では ASR の測定方法として、Byrne et al. (2009) と同様な方法・装置・実験手順で行った。また、非弾性ひずみ回復測定後のコア試料を用いて、古地磁気測定によるコアの定方位を行なった。その結果、浅部の 5 試料で測定した応力状態は、基本的に正断層型、すなわち、最大主応力の方向はほぼ鉛直方向であった。最深（2,448 mbsf）のコア試料の非弾性ひずみ回復から得られた最大主応力は、約 30°の傾斜ではあるが、概ね逆断層型の応力状態を呈した。一方、水平面内の二次応力状態でみれば、すべての深度の最大水平主応力の方向は、東南東-西北西から東北東-西南西までの範囲に分布しており、平均的に東西方向であった。
謝辞：本研究で使用したコア試料は IODP の提供によるものである。また、船上での実施については Exp337 Scientists,「ちきゅう」の掘削オペレーションチーム、ラボのテクニシャーンの協力を得たので、ここに深謝の意を申し上げる。

キーワード: 応力, 非弾性ひずみ回復法, IODP, Exp 337
Keywords: Stress, ASR, IODP, Exp 337

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MIS32-P11

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

Stress State in the Tip of Ilan Plan and Its Applications for Taiwan Geothermal Plan
Stress State in the Tip of Ilan Plan and Its Applications for Taiwan Geothermal Plan
WU, Fang-yih1∗ ; YEH, En-chao1 ; KAO, Tsu-en1 ; SHIU, Chi-shun1 ; LIN, Weiren2 ; WANG, Tai-tien3 ;HUNG, Jih-hao4 ; SONG, Sheng-rong5
WU, Fang-yih1∗ ; YEH, En-chao1 ; KAO, Tsu-en1 ; SHIU, Chi-shun1 ; LIN, Weiren2 ; WANG, Tai-tien3 ;HUNG, Jih-hao4 ; SONG, Sheng-rong5
1

Department of Earth Sciences, National Taiwan Normal University, Taipei, Taiwan, 2 Kochi Institute for Core Sample Research,
Japan Agency for Marine-Earth Science and Technology, 3 Institute of Mineral Resources Engineering, National Taipei Universityof Technology, Taipei, Taiwan, 4 Department of Earth Sciences, National Central University, Jhongli, Taiwan, 5 Department ofGeosciences, National Taiwan University, Taipei, Taiwan
1
Department of Earth Sciences, National Taiwan Normal University, Taipei, Taiwan, 2 Kochi Institute for Core Sample Research,
Japan Agency for Marine-Earth Science and Technology, 3 Institute of Mineral Resources Engineering, National Taipei Universityof Technology, Taipei, Taiwan, 4 Department of Earth Sciences, National Central University, Jhongli, Taiwan, 5 Department ofGeosciences, National Taiwan University, Taipei, Taiwan
Understanding the relationship between in-situ stress and fluid-conduits is one of the most important keys for developing theenhanced geothermal system. At the same time, understanding this relationship also provide insights into evaluating the welllocations and drilling direction.
The Ilan Plain of northeastern Taiwan is located between the Hsuehshan Range and Backbone Range and is influenced by
the compression of mountain building between the Eurasian and Philippine Sea Plates and the back-arc extension of Okinawa
Trough simultaneously. As a result, the 3D stress field is complicated and the attitude and spatial distribution of fluid conduits
is not clear. To develop the technology of the enhanced geothermal system, this study focused on the evaluation of in-situ stressstate on multiple scales.
Stress inversion of regional focal mechanism suggests that the stress state varies dramatically in the region and it is strike-slip
faulting stress regime with NNE-SSW compression in the tip of Ilan Plain. The paleostress inversion results from the southernfoothills show that the stress pattern of strike-slip faulting and normal faulting regime took place repeatedly and horizontal
minimum stress orientation switched between N-S and W-E orientation. Analysis of anelastic strain recovery experiments on the
retrieved cores of 720-920m indicates that a strike-slip faulting stress regime with NNW compression and NEE tension. Several
hydraulic fracturing tests were conducted in the interval of 750-765m. The shut-in pressure is determined as 13.57MPa andreopening pressure is estimated as 12.66MPa. Diameter Core Deformation Analysis and rock mechanics experiments are also
conducted. Integration of different stress assessments and rock strength data will provide insights to understanding the reasonable
3D in-situ stress in the tip of Ilan plain and further help the development of enhanced geothermal system.

キーワード: in-situ stress, enhanced geothermal system, Taiwan, Ilan Plain, hydraulic fracturing, ASR
Keywords: in-situ stress, enhanced geothermal system, Taiwan, Ilan Plain, hydraulic fracturing, ASR

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MIS32-P12

会場:コンベンションホール

時間:5 月 24 日 18:15-19:30

新型 XRF コアスキャナーの性能と海洋コア研究への応用
Introduction of a new XRF core scanner and application of marine core science
村山 雅史 1∗ ; 松崎 琢也 1 ; 入野 智久 2 ; 多田 隆治 3
MURAYAMA, Masafumi1∗ ; MATSUZAKI, Takuya1 ; IRINO, Tomohisa2 ; TADA, Ryuji31
高知大学海洋コア総合研究センター, 2 北海道大学大学院地球環境科学研究院, 3 東京大学大学院理学系研究科地球惑星科学専攻
1Center for Advanced Marine Core Research, Kochi University, 2 Faculty of Environmental Earth Science, Hokkaido University,
3
Department of Earth and Planetary Science, Graduate School of Science, The University of Tokyo

2014 年，高知大学海洋コア総合研究センターでは増設建て屋が完成し， 同 8 月に新型 XRF コアスキャナー（COX 社
製）が導入された． 従来機器に比べ，微小領域の元素マッピングが可能になり， 高分解能，高解像度でコア試料が連続測定できる．機器の特徴として，以下が挙げられる．
１）測定幅が小さい（200 μ m × 8mm）ため，微少な堆積構造（ラミナやバーブなど）の元素分布を連続的に非破壊で，高解像度の測定が可能である．
２）従来の機器に比べ管電流が高く，検出器の感度が高いため，１測点あたりに要する測定時間が短くても，十分な強度が得られる．
３）XRF 測定と同時に，X 線透過画像，カラーイメージが撮影でき，かつ，3 つのデータを統合して解析が可能である．
今後の海洋コア研究への応用が期待される．
キーワード: XRF コアスキャナー, ITRAX, 海洋コア
Keywords: XRF core scanner, ITRAX, marine core science

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