Deformational history of the Hida metamorphic rocks in the northern part ofGifu Prefecture, central Japan

Structural analysis reveals that the Central Crystallines in the Garhwal region were subjected to four phases of deformations (D1 to D4). The D1 deformational phase is highly obliterated and usually found as F1 intrafolial (rootless) tight isoclinal folds in migmatites and gneisses. The D2 deformational phase produced strong pervasive S2 schistosity and asymmetric and open fold (F2) plunging 20-30° towards ENE-WSW. The L2 lineation plunge 5-10° towards east-west is well developed in medium grade metamorphic rocks. The D1 deformations were responsible for F3 folds reflected in large scale anticlinal and synclinal, overturned and recumbent folds, which have 10-40° plunges towards NW. The late D3 deformational stresses were responsible for shearing along the middle limbs of F1 folds and they ultimately initiated thrusting. The NNE SSW plunging mineral or stretching lineation (L3), S3 crenulation cleavage and S-C fabrics were developed during the dominant ductile shearing related to the late D3 deformation. The D4 phase characterised by brittle-ductile deformation (minor kinks, puckers, transverse/transcurrent faults, and S-C' fabrics) and extensive cataclasis along thrust- and fault-zones reflects the last episode of deformation. The structural and geochronological data indicate that D1 and D2 deformation episodes may be related to the Precambrian time while D3 and D4 are exclusively of the Tertiary age.

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Deformation history of low-grade schists in the Joetsu region, central Japan. Correlation between the Kawaba and Mizunashigawa metamorphic rocks.

The Journal of the Geological Society of Japan ◽

10.5575/geosoc.108.12_794 ◽

2002 ◽

Vol 108 (12) ◽

pp. 794-805 ◽

Cited By ~ 4

Author(s):

Ko Takenouchi ◽

Yutaka Takahashi

Keyword(s):

Metamorphic Rocks ◽

Low Grade ◽

Deformation History ◽

Central Japan ◽

History Of

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Metasedimentary rocks, intrusions and deformation history in the south-east part of the c. 1800 Ma Ketilidian orogen, South Greenland: Project SUPRASYD 1996

Geological Survey of Denmark and Greenland Bulletin ◽

10.34194/ggub.v176.5063 ◽

1997 ◽

pp. 60-65

Author(s):

Adam A. Garde ◽

Brian Chadwick ◽

John Grocott ◽

Cees Swager

Keyword(s):

Field Work ◽

Deformation History ◽

The South ◽

Present Contribution ◽

East Part ◽

Metasedimentary Rocks ◽

Deformational History ◽

Base Camp ◽

History Of ◽

Geological Map

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Garde, A. A., Chadwick, B., Grocott, J., & Swager, C. (1997). Metasedimentary rocks, intrusions and deformation history in the south-east part of the c. 1800 Ma Ketilidian orogen, South Greenland: Project SUPRASYD 1996. Geology of Greenland Survey Bulletin, 176, 60-65. https://doi.org/10.34194/ggub.v176.5063 _______________ The south-east part of the c. 1800 Ma Ketilidian orogen in South Greenland (Allaart, 1976) is dominated by strongly deformed and variably migmatised metasedimentary rocks known as the ‘Psammite and Pelite Zones’ (Chadwick & Garde, 1996); the sediments were mainly derived from the evolving Julianehåb batholith which dominates the central part of the orogen. The main purpose of the present contribution is to outline the deformational history of the Psammite Zone in the region between Lindenow Fjord and Kangerluluk (Fig. 2), investigated in 1994 and 1996 as part of the SUPRASYD project (Garde & Schønwandt, 1995 and references therein; Chadwick et al., in press). The Lindenow Fjord region has high alpine relief and extensive ice and glacier cover, and the fjords are regularly blocked by sea ice. Early studies of this part of the orogen were by boat reconnaissance (Andrews et al., 1971, 1973); extensive helicopter support in the summers of 1992 and 1994 made access to the inner fjord regions and nunataks possible for the first time.A preliminary geological map covering part of the area between Lindenow Fjord and Kangerluluk was published by Swager et al. (1995). Hamilton et al. (1996) have addressed the timing of sedimentation and deformation in the Psammite Zone by means of precise zircon U-Pb geochronology. However, major problems regarding the correlation of individual deformational events and their relationship with the evolution of the Julianehåb batholith were not resolved until the field work in 1996. The SUPRASYD field party in 1996 (Fig. 1) was based at the telestation of Prins Christian Sund some 50 km south of the working area (Fig. 2). In addition to base camp personnel, helicopter crew and the four authors, the party consisted of five geologists and M.Sc. students studying mafic igneous rocks and their mineralisation in selected areas (Stendal et al., 1997), and a geologist investigating rust zones and areas with known gold anomalies.

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Deformational history of the Caribou strata-bound sulfide deposit, Bathurst, New Brunswick, Canada; a reply

Economic Geology ◽

10.2113/gsecongeo.68.4.572 ◽

1973 ◽

Vol 68 (4) ◽

pp. 572-577

Author(s):

George H. Davis

Keyword(s):

New Brunswick ◽

Sulfide Deposit ◽

Deformational History ◽

History Of

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Plastic deformations in kyanites by tectonometamorphic processes: a single-crystal X-ray diffraction study

Mineralogical Magazine ◽

10.1180/minmag.2009.073.3.359 ◽

2009 ◽

Vol 73 (3) ◽

pp. 359-371 ◽

Cited By ~ 5

Author(s):

G. D. Gatta ◽

N. Rotiroti ◽

M. Zucali

Keyword(s):

Single Crystal ◽

X Ray Diffraction ◽

Plastic Deformations ◽

X Ray ◽

Deformational History ◽

Significant Difference ◽

Elliptical Section ◽

History Of ◽

Diffraction Patterns ◽

Two Stages

AbstractThe crystalch emistry and crystal structure of naturalky anite crystals from the Eclogitic Micaschists Complex of the Sesia-Lanzo Zone, Western Italian Alps, have been investigated by means of optical microscopy, wavelength dispersive X-ray microanalysis, and single-crystal X-ray diffraction. The association of kyanite + garnet + phengitic-mica + chloritoid suggests that the eclogite-facies stages occurred at P ≤ 2.1 GPa and T ≤ 650ºC. Kyanite grains are large (cm-sized) porphyroblasts grown dynamically during one of the deformational events related to the subduction of the Austroalpine continentalcr ust. Under the polarizing microscope, kyanite grains show almost homogeneous cores, whereas rims are sometimes symplectitic aggregates of quartz and kyanite, confirming at least two stages of growth most likely related to the multistage deformational history of these rocks. Chemical analysis shows that Fe3+ is the major substituting cation for Al3+, ranging between 0.038 and 0.067 a.p.f.u.The single-crystal X-ray diffraction investigation of the kyanites shows severely textured patterns on the (h0l)*-plane. Such evidence is not observed in the unwarped diffraction patterns on (0kl)* and (hk0)*. The most significant difference between the structuralp arameters refined in this study, with respect to those of previously published unstrained gem-quality crystals, concerns the displacement parameters. The anisotropic displacement ellipsoids of all the atomic sites are significantly larger than those previously described, and systematically oriented with the largest elliptical section almost perpendicular to [010]. The larger ellipsoids in the kyanite crystal investigated here reflect the displacement of the centre of gravity of the electron distribution, rather than an anomalous atomic thermal motion. The magnitude and orientation of the displacement parameters and the textured/strained diffraction pattern may be the result of two combined effects: (1) that the kyanite crystals are actually composed of several blocks; (2) the crystals are affected by a pervasive residual strain, as a result of tectonometamorphic plastic deformations and re-crystallization.

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A Bayesian approach to age estimation of marine terraces and implications for the history of the great Kanto earthquakes, central Japan

Quaternary Science Reviews ◽

10.1016/j.quascirev.2021.107217 ◽

2021 ◽

Vol 272 ◽

pp. 107217

Author(s):

Junki Komori ◽

Masanobu Shishikura ◽

Ryosuke Ando ◽

Yusuke Yokoyama ◽

Yosuke Miyairi

Keyword(s):

Bayesian Approach ◽

Age Estimation ◽

Central Japan ◽

Marine Terraces ◽

History Of

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Holocene history of intentional fires and grassland development on the Soni Plateau, Central Japan, reconstructed from phytolith and macroscopic charcoal records within cumulative soils, combined with paleoenvironmental data from mire sediments

The Holocene ◽

10.1177/0959683611430409 ◽

2011 ◽

Vol 22 (7) ◽

pp. 793-800 ◽

Cited By ~ 8

Author(s):

Ryota Okunaka ◽

Tatsuichiro Kawano ◽

Jun Inoue

Keyword(s):

Forest Floor ◽

Dwarf Bamboo ◽

Central Japan ◽

Short Cell ◽

The Holocene ◽

Bulliform Cell ◽

History Of ◽

Plateau Central ◽

Macroscopic Charcoal

Phytolith and macroscopic charcoal in cumulative soils on the Soni Plateau, Central Japan, were evaluated to clarify the Holocene history of intentional fires and grassland development, and to compare the findings with those derived from pollen and charcoal records in sediments taken from a nearby mire in the previous study. Prior to ~1500 cal. BP, Bambusoid short-cell phytoliths and Pleioblastus-type and Bambusoideae-type bulliform cell phytoliths were abundant with scarce charcoal particles (<1000 particles/cm3). In contrast, since ~1500 cal. BP Andropogoneae-type bulliform cell phytoliths and Bilobate short-cell phytoliths were dominant with abundant charcoal particles (>1000 particles/cm3). Based on correlating these records with pollen and charcoal records in mire sediments, prior to ~1500 cal. BP, dwarf bamboo flourished on the forest floor under largely fire-free conditions, whereas since ~1500 cal. BP, grassland dominated by Japanese pampas grass has been sustained by periodic intentional burning that has continued until the present day.

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