Dehydration breakdown of antigorite and the formation of B-type olivine CPO

Nagaya, Teruo; Wallis, Simon; Kobayashi, Hiroaki; Michibayashi, K.; Mizukami, Tomoyuki; Seto, Yusuke; Miyake, Akira; Matsumoto, Megumi

doi:10.1016/j.epsl.2013.11.025

Cited by 38 publications

(38 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The CPO of antigorite is characterized as [001] axes aligned subnormal to the foliation but [010] axes aligned subparallel to the lineation (Figs. 10a-c), consistent with other observations of the CPOs of antigorite in many natural rocks (Hirauchi et al, 2010;Soda and Takagi, 2010;Nishii et al, 2011;Brownlee et al, 2013;Nagaya et al, 2014;Watanabe et al, 2014). However, for reasons that are not yet understood, the alignment of [010] axes subparallel to the lineation is different from the CPO produced by an experimental study (Katayama et al, 2009).…”

Section: Cpos Of Serpentine (Antigorite)supporting

confidence: 86%

“…The Type-C CPO of olivine was generated by a dominant dislocation-accommodated grain boundary sliding (DisGBS) with a minor contribution from the diffusion creep at elevated pressure. Nagaya et al (2014) reported that the Type-B CPO of olivine can form as a result of the static topotactic growth of olivine after the high-temperature breakdown of foliated serpentinite. Wang et al (2013a) reported Type-B CPO of olivine in dunite from Raudkleivane, Amklovdalen and Type-C CPO of olivine in garnet harzburgite from Ugelvik, Otroy in Norway.…”

Section: Other Possibilities For the Formation Of The Cpos Of Olivinementioning

confidence: 99%

See 1 more Smart Citation

Erratum to: Crystal preferred orientations of olivine, orthopyroxene, serpentine, chlorite, and amphibole, and implications for seismic anisotropy in subduction zones: a review

Jung

2018

Geosci J

View full text Add to dashboard Cite

There are errors in the article entitled "Crystal preferred orientations of olivine, orthopyroxene, serpentine, chlorite, and amphibole, and implications for seismic anisotropy in subduction zones: a review" by Haemyeong Jung, which appeared on pages 985-1011 of the December issue in 2017. The author has provided a corrected article which is attached at the end of this erratum. ABSTRACT:This study provides a comprehensive review of the crystal preferred orientation (CPO) of olivine and orthopyroxene in the upper mantle, and of several hydrous minerals in the mantle wedge and at the slab-mantle interface. It discusses the seismic anisotropy of those minerals. Water-induced CPOs of olivine produced by previous experimental studies under high pressure and temperature conditions were found in many natural rocks. It is emphasized that the strong CPOs of hydrous minerals such as serpentine, chlorite, and amphibole, play an important role in interpreting the anomalously strong seismic anisotropy observed in subduction zones.

show abstract

Section: Cpos Of Serpentine (Antigorite)supporting

confidence: 86%

Section: Other Possibilities For the Formation Of The Cpos Of Olivinementioning

confidence: 99%

Erratum to: Crystal preferred orientations of olivine, orthopyroxene, serpentine, chlorite, and amphibole, and implications for seismic anisotropy in subduction zones: a review

Jung

2018

Geosci J

View full text Add to dashboard Cite

show abstract

“…B‐type olivine LPOs have been documented for a range of conditions in nature and the laboratory. For example, based on field and microstructural observations, B‐type fabrics were associated with deformation by dislocation‐accommodated grain boundary sliding [ Précigout and Hirth , ], and with topotactic growth of olivine during dehydration breakdown of antigorite [ Nagaya et al ., ]. In laboratory experiments, B‐type fabrics have been documented for high temperature/low stress conditions in the presence of melt [ Holtzman et al ., ; Kohlstedt and Holtzman , ; Qi et al ., ], dry conditions at high confining pressures [ Couvy et al ., ; Jung et al ., ; Ohuchi et al ., ], during diffusion creep in the presence of orthopyroxene [ Sundberg and Cooper , ], and during dislocation creep under high water contents and high stress magnitudes [ Jung and Karato , ; Jung et al ., ].…”

Section: Discussionmentioning

confidence: 99%

Deformation in the mantle wedge associated with Laramide flat‐slab subduction

Smith

2016

Geochem Geophys Geosyst

View full text Add to dashboard Cite

Laramide crustal deformation in the Rocky Mountains of the west‐central United States is often considered to relate to a narrow segment of shallow subduction of the Farallon slab, but there is no consensus as to how deformation along the slab‐mantle lithosphere interface was accommodated. Here we investigate deformation in mantle rocks associated with hydration and shear above the flat‐slab at its contact with the base of the North American plate. The rocks we focus on are deformed, hydrated, ultramafic inclusions hosted within diatremes of the Navajo Volcanic Field in the central Colorado Plateau that erupted during the waning stages of the Laramide orogeny. We document a range of deformation textures, including granular peridotites, porphyroclastic peridotites, mylonites, and cataclasites, which we interpret to reflect different proximities to a slab‐mantle‐interface shear zone. Mineral assemblages and chemistries constrain deformation to hydrous conditions in the temperature range ∼550–750°C. Despite the presence of hydrous phyllosilicates in modal percentages of up to 30%, deformation was dominated by dislocation creep in olivine. The mylonites exhibit an uncommon lattice preferred orientation (LPO) in olivine, known as B‐type LPO in which the a‐axes are aligned perpendicular to the flow direction. The low temperature, hydrated setting in which these fabrics formed is consistent with laboratory experiments that indicate B‐type LPOs form under conditions of high stress and high water contents; furthermore, the mantle wedge context of these LPOs is consistent with observations of trench‐parallel anisotropy in the mantle wedge above many modern subduction zones. Differential stress magnitudes in the mylonitic rocks estimated using paleopiezometry range from 290 to 444 MPa, and calculated effective viscosities using a wet olivine flow law are on the order of 1019−1023 Pa s. The high stress magnitudes, high effective viscosities, and high strains recorded in these rocks are consistent with models that invoke significant basal shear tractions as contributing to Laramide uplift and contraction in the continental interior.

show abstract

“…Seismic anisotropy measurments that indicate trench-parallel alignment of seismic fast directions in supra-subduction fore-arc regions are consistent with the development of B-type fabrics in these settings 16 37 . Furthermore, the few examples of naturally occurring B-type olivine fabrics are mostly associated with mantle peridotites exhumed from supra-subduction settings such as in the Central Alps (Cima di Gagnone and Val Malenco) 26 29 38 , Carpathian-Pannonian region 30 , north Qilian mountains in China 39 , Shanwang in Eastern China 27 , Higashi-Akaishi, Japan 31 33 34 , the Happo region of Central Japan 40 , the southern Marian trench 28 , southwest Norway 25 32 41 and New-Zealand 42 . The exception is the formation of a complex B-type fabric interpreted to be the result of grain boundary sliding in mylonitic peridotites from the subcontinental mantle 43 .…”

Section: Discussionmentioning

confidence: 99%

Earth's oldest mantle fabrics indicate Eoarchaean subduction

et al. 2016

View full text Add to dashboard Cite

The extension of subduction processes into the Eoarchaean era (4.0–3.6 Ga) is controversial. The oldest reported terrestrial olivine, from two dunite lenses within the ∼3,720 Ma Isua supracrustal belt in Greenland, record a shape-preferred orientation of olivine crystals defining a weak foliation and a well-defined lattice-preferred orientation (LPO). [001] parallel to the maximum finite elongation direction and (010) perpendicular to the foliation plane define a B-type LPO. In the modern Earth such fabrics are associated with deformation of mantle rocks in the hanging wall of subduction systems; an interpretation supported by experiments. Here we show that the presence of B-type fabrics in the studied Isua dunites is consistent with a mantle origin and a supra-subduction mantle wedge setting, the latter supported by compositional data from nearby mafic rocks. Our results provide independent microstructural data consistent with the operation of Eoarchaean subduction and indicate that microstructural analyses of ancient ultramafic rocks provide a valuable record of Archaean geodynamics.

show abstract

Dehydration breakdown of antigorite and the formation of B-type olivine CPO

Cited by 38 publications

References 44 publications

Erratum to: Crystal preferred orientations of olivine, orthopyroxene, serpentine, chlorite, and amphibole, and implications for seismic anisotropy in subduction zones: a review

Erratum to: Crystal preferred orientations of olivine, orthopyroxene, serpentine, chlorite, and amphibole, and implications for seismic anisotropy in subduction zones: a review

Deformation in the mantle wedge associated with Laramide flat‐slab subduction

Earth's oldest mantle fabrics indicate Eoarchaean subduction

Contact Info

Product

Resources

About