scholarly journals Petrogenesis of the crust-mantle transition zone and the origin of lower crustal wehrlite in the Oman ophiolite

2001 ◽  
Vol 2 (9) ◽  
pp. n/a-n/a ◽  
Author(s):  
Kenneth T. Koga ◽  
Peter B. Kelemen ◽  
Nobumichi Shimizu
Keyword(s):  
Transition Zone ◽  
Mantle Transition Zone ◽  
Oman Ophiolite ◽  
Lower Crustal

scholarly journals Mantle roots of the Emeishan plume: an evaluation based on telesismic P-wave tomography

2017 ◽  
Author(s):  
Chuansong He ◽  
M. Santosh
Keyword(s):  
Transition Zone ◽  
Conclusive Evidence ◽  
P Wave ◽  
Mantle Transition Zone ◽  
Core Mantle Boundary ◽  
Igneous Provinces ◽  
Wave Tomography ◽  
Tomographic Data ◽  
Lower Crustal ◽  
Emeishan Lip

Abstract. The voluminous magmatism associated with Large Igneous Provinces (LIP) is commonly correlated to upwelling plumes from the Mantle Transition Zone or the Core-Mantle Boundary (CMB). Here we analyse seismic tomographic data from the Emeishan LIP in southwestern China. Our results reveal vestiges of delaminated crustal and (or) lithospheric material in the cental part of the study area, and upwelling mantle in the southern part. Our results do not provide any conclusive evidence for upwelling mantle plume rooted in the CMB beneath the Emeishan LIP. We therefore suggest that the magmatism and the Emeishan LIP formation might be connected with the melting of delaminated lower crustal and (or) lithospheric components and associated plume-like upwelling from the mantle transition zone.

Theoretical modeling of the regular olivine intergrowths in the mimetic paramorphosis after ringwoodite and wadsleyite

2018 ◽  
pp. 3-12
Author(s):  
B. B. Shkursky
Keyword(s):  
Transition Zone ◽  
Theoretical Modeling ◽  
Mantle Transition Zone ◽  
Misorientation Angles

Theoretical modeling of regular olivine grains misorientations in mimetic paramorphoses after ringwoodite and wadsleyite, the formation of which during the ascension of matter from the Mantle Transition Zone is expected, has been carried out. The coordinates of the misorientation axes and the misorientation angles, characterizing 10 operations of alignment in the pair intergrowths of olivine grains, eight of which are twins, are calculated. Possible conditions for the formation of mimetic paramorphoses predicted here, and the chances of their persistence are discussed. The calculated orientations are compared with the known twinning laws of olivine.

scholarly journals A thin mantle transition zone beneath the equatorial Mid-Atlantic Ridge

Nature ◽  
2021 ◽  
Vol 589 (7843) ◽  
pp. 562-566
Author(s):  
Matthew R. Agius ◽  
Catherine A. Rychert ◽  
Nicholas Harmon ◽  
Saikiran Tharimena ◽  
J.-Michael Kendall
Keyword(s):  
Transition Zone ◽  
Mantle Transition Zone ◽  
Mid Atlantic Ridge
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