Antigorite: High-pressure stability in the system MgOSiO2H2O (MSH)

Wunder, Bernd; Schreyer, Werner

doi:10.1016/s0024-4937(97)82013-0

Cited by 253 publications

(190 citation statements)

References 28 publications

Supporting

Mentioning

179

Contrasting

Unclassified

Order By: Relevance

“…The serpentinites are extremely buoyant with respect to the oceanic crust that mainly consists of mafic rocks that have been transformed to eclogites during subduction, increasing their density so that they are denser than average mantle rocks (Hermann et al, 2000). Our P-T estimates (2.3-2.7 GPa at 615-680°C for barroisite-bearing and 2.5-2.7 GPa at 650-690°C for barroisite-free eclogites) fit the stability field of antigorite along subduction zone gradients, i.e.~650°C at 2.7 GPa (Wunder and Schreyer, 1997;Agard et al, 2009). Thus, serpentinites may have enhanced exhumation of HP rocks in the Bantimala Complex (Hermann et al, 2000;Ernst, 2010).…”

Section: Tectonic Implicationsmentioning

confidence: 51%

Prograde and retrograde evolution of eclogites from the Bantimala Complex in South Sulawesi, Indonesia

Setiawan

Osanai

Nakano

et al. 2016

Journal of Mineralogical and Petrological Sciences

View full text Add to dashboard Cite

This contribution reports the metamorphic evolution of the high-pressure metamorphic rocks from the Bantimala Complex, South Sulawesi, Indonesia. Barroisite-bearing and barroisite-free eclogites were examined to assess their metamorphic evolutions, which have implications regarding the tectonic conditions in this region. The eclogites mainly consist of garnet, omphacite, phengite, rutile, and epidote, with or without barroisite. The variations in mineral assemblages are interpreted to depend upon local changes in the bulk chemical composition. The barroisite-bearing eclogites contain two types of euhedral garnet: coarse-(1-1.5 mm) and finegrained (<0.5 mm). Mineral inclusions in the coarse-grained garnet core and mantle show epidote + titanite and glaucophane + epidote assemblages, that stabilized at 0.9-1.5 GPa and 350-550°C within epidote blueschist-facies conditions. Mineral chemistry and chemical-mapping analyses indicate that both fine-grained garnet and the rim of coarse-grained garnet formed at peak P-T conditions, which were estimated as 2.3-2.7 GPa at 615-680°C based on the garnet-omphacite-phengite-quartz equilibrium. Peak P-T conditions for barroisitefree eclogite were similar (2.5-2.7 GPa at 650-690°C) to those for barroisite-bearing eclogite. Actinolite rims overgrowing matrix sodic-calcic amphiboles attest to retrogression at P < 0.5 GPa and T < 350°C in a clockwise P-T path. The very low geothermal gradient experienced during the prograde path (~5°C/km) likely suggests the subduction of an old and cold oceanic crust. The low geothermal gradient on the retrograde path suggests decompressional cooling during exhumation, possibly favored by a serpentinite-dominated matrix within a subduction channel environment.

show abstract

Section: Tectonic Implicationsmentioning

confidence: 51%

Prograde and retrograde evolution of eclogites from the Bantimala Complex in South Sulawesi, Indonesia

Setiawan

Osanai

Nakano

et al. 2016

Journal of Mineralogical and Petrological Sciences

View full text Add to dashboard Cite

show abstract

“…So below 25 km depth, the reflections display a lower velocity contrast that may be due to the presence of other alteration phases, such as antigorite serpentinite that is stable at higher temperature (up to 600-650°C) (ref. 47) or some other processes, such as shear zones.…”

Section: Discussionmentioning

confidence: 99%

Seismic evidence of a two-layer lithospheric deformation in the Indian Ocean

Qin

Singh

2015

Nat Commun

View full text Add to dashboard Cite

Intra-plate deformation and associated earthquakes are enigmatic features on the Earth. The Wharton Basin in the Indian Ocean is one of the most active intra-plate deformation zones, confirmed by the occurrence of the 2012 great earthquakes (MwZ8.2). These earthquakes seem to have ruptured the whole lithosphere, but how this deformation is distributed at depth remains unknown. Here we present seismic reflection images that show faults down to 45 km depth. The amplitude of these reflections in the mantle first decreases with depth down to 25 km and then remains constant down to 45 km. The number of faults imaged along the profile and the number of earthquakes as a function of depth show a similar pattern, suggesting that the lithospheric mantle deformation can be divided into two layers: a highly fractured fluid-filled serpentinized upper layer and a pristine brittle lithospheric mantle where great earthquakes initiate and large stress drops occur.

show abstract

“…Thermocalc's calculations of phase relations at P >5 GPa were modified in light of recent experiments by Luth [1995], Ulmer and Trommsdorff [1995], Wunder and Schreyer [1997], Bose and Navrotsky [1998], Wunder [1998] andPawley [2000].…”

Section: Constructing Phase Diagramsmentioning

confidence: 99%

Antigorite: High-pressure stability in the system MgOSiO2H2O (MSH)

Cited by 253 publications

References 28 publications

Prograde and retrograde evolution of eclogites from the Bantimala Complex in South Sulawesi, Indonesia

Prograde and retrograde evolution of eclogites from the Bantimala Complex in South Sulawesi, Indonesia

Seismic evidence of a two-layer lithospheric deformation in the Indian Ocean

Energy-to-moment ratios for damaging intraslab earthquakes: preliminary results on a few case studies

Contact Info

Product

Resources

About