Breakup of young oceanic lithosphere in the upper part of a subduction zone: Implications for the emplacement of ophiolites

摘要: It is investigated, by means of numerical modelling, whether the interaction between young oceanic lithosphere and a subduction zone can lead to breakup thin plate. First, thermal model upper part (the region trench volcanic arc) presented. Temperatures are modelled for situations in which age subducting gradually decreases, culminating arrival spreading ridge at trench. used infer strength material within plate from pressure temperature dependent rheology. Next, it investigated finite element modelling forces acting upon lithosphere, recently created center vicinity zone, its breakup. Our results show that very may indeed break up during early phase subduction. Whether occurs depends velocity length segment interacts with If occurs, some situated will be detached other parts The sheet not subducted mantle depths. Instead, trailing plate, opposite side ridge, incorporation this into forearc region. provides mechanism incorporate an arc-trench eventually, closure ocean basin, orogenic belt. shown large subset ophiolites (those harzburgite-dominated section) has properties good agreement emplacement history first phase.