Subduction Duration and Slab Dip
Subduction Duration and Slab Dip
复制标题
DOI：
10.1029/2019gc008862
复制
发表时间：
2020-04-01
影响因子：
3.5
通讯作者：
Gurnis, Michael
中科院分区：
文献类型：
--
作者：
Hu, Jiashun;Gurnis, Michael
板块的倾角是俯冲带最明显的特征之一，但控制它们的因素仍然不清楚。在这里，板倾角和俯冲参数，包括俯冲持续时间，覆盖板的性质，板年龄和收敛速度，确定了153个断面沿着俯冲带的今天。我们提出了一个全面的表俯冲持续时间的基础上同位素年龄的弧开始和地层，构造，板块构造和地震指标的俯冲开始。我们提出两个年龄的俯冲带，长期年龄和再启动年龄。通过互相关和多元回归分析发现：（1）俯冲持续时间是控制板块倾角的主要参数，存在时间越长的俯冲带，板块倾角越小：（2）俯冲持续时间的长期年龄比再启动年龄更能解释板块倾角的变化;（3）上覆板块的性质影响板块的浅倾角，大陆下面的板块倾向于浅倾角：（4）板块年龄对板块倾角有贡献，较年轻的板块倾向于陡的浅倾角;板片倾角与俯冲参数之间的关系是深度相关的，俯冲持续时间和上覆板块性质解释观测变化的能力随深度而降低。分析强调了俯冲历史和俯冲带的长期区域状态在确定板块倾角方面的重要性，并与俯冲的力学模型相一致。
The dip angles of slabs are among the clearest characteristics of subduction zones, but the factors that control them remain obscure. Here, slab dip angles and subduction parameters, including subduction duration, the nature of the overriding plate, slab age, and convergence rate, are determined for 153 transects along subduction zones for the present day. We present a comprehensive tabulation of subduction duration based on isotopic ages of arc initiation and stratigraphic, structural, plate tectonic and seismic indicators of subduction initiation. We present two ages for subduction zones, a long-term age and a reinitiation age. Using cross correlation and multivariate regression, we find that (1) subduction duration is the primary parameter controlling slab dips with slabs tending to have shallower dips at subduction zones that have been in existence longer; (2) the long-term age of subduction duration better explains variation of shallow dip than reinitiation age; (3) overriding plate nature could influence shallow dip angle, where slabs below continents tend to have shallower dips; (4) slab age contributes to slab dip, with younger slabs having steeper shallow dips; and (5) the relations between slab dip and subduction parameters are depth dependent, where the ability of subduction duration and overriding plate nature to explain observed variation decreases with depth. The analysis emphasizes the importance of subduction history and the long-term regional state of a subduction zone in determining slab dip and is consistent with mechanical models of subduction.