Experimental Evidence for a Weak Calcic-Amphibole-Rich Deep Crust in Orogens

Wang，X.1,2; Zhang，J. F.1; Tommasi，A.3; Lopez-Sanchez，M. A.3,4; Jing，Z. C.2; Shi，F.1; Liu，W. L.1; Barou，F.3

2023-08-16

10.1029/2022GL102320

Geophysical Research Letters   Impact Factor & Quartile

0094-8276

1944-8007

Amphibole-rich rocks constitute significant components of the mid- to lower continental crust, particularly in active orogens characterized with thick and hot crusts. Nevertheless, experimental data on their viscosity remain scarce. We conducted axial compression deformation experiments on synthetic amphibolites under temperature and pressure conditions resembling deep sections of overthickened crust. A novel flow law for a calcic-amphibole-rich rock (80% amphibole +20% garnet) in the dislocation creep regime is derived from these experiments. Contrary to common assumptions, our results reveal that calcic-amphibolite is 1-2 orders of magnitude weaker than plagioclase-rich amphibolite, granulite, or gabbro. A calcic-amphibole-rich, low viscosity deep crust may not only support the “channel flow” model proposed for the Tibetan Plateau but also explain the observed high crustal seismic anisotropy in the region.

calcic-amphibole dislocation creep flow laws orogen rheology

SCI

English

NI Journal Papers

Others

Postdoctoral Research Foundation of China[2021M701563];National Natural Science Foundation of China[42172250];

Geology

Geosciences, Multidisciplinary

WOS:001041429700001

AMER GEOPHYSICAL UNION

GEOSCIENCES

2-s2.0-85166732516

Scopus

1.State Key Laboratory of Geological Process and Mineral Resources,School of Earth Sciences,China University of Geoscience,Wuhan,China
2.Department of Earth and Space Sciences,Southern University of Science and Technology,Shenzhen,China
3.Géosciences Montpellier,CNRS & Université de Montpellier,Montpellier,France
4.Department of Geology,University of Oviedo,Oviedo,Spain

Wang，X.,Zhang，J. F.,Tommasi，A.,et al. Experimental Evidence for a Weak Calcic-Amphibole-Rich Deep Crust in Orogens[J]. Geophysical Research Letters,2023,50(15).

Wang，X..,Zhang，J. F..,Tommasi，A..,Lopez-Sanchez，M. A..,Jing，Z. C..,...&Barou，F..(2023).Experimental Evidence for a Weak Calcic-Amphibole-Rich Deep Crust in Orogens.Geophysical Research Letters,50(15).

Wang，X.,et al."Experimental Evidence for a Weak Calcic-Amphibole-Rich Deep Crust in Orogens".Geophysical Research Letters 50.15(2023).