DOI: 10.1016/j.epsl.2018.01.008
Scopus记录号: 2-s2.0-85044764984
论文题名: A STEP fault in Central Betics, associated with lateral lithospheric tearing at the northern edge of the Gibraltar arc subduction system
作者: Mancilla F.D.L. ; Heit B. ; Morales J. ; Yuan X. ; Stich D. ; Molina-Aguilera A. ; Azañon J.M. ; Martín R.
刊名: Earth and Planetary Science Letters
ISSN: 0012821X
出版年: 2018
卷: 486 起始页码: 32
结束页码: 40
语种: 英语
英文关键词: central Betics
; positive tectonic flower structure
; sharp Moho step
; STEP fault
; westernmost Mediterranean subduction system
Scopus关键词: Metamorphic rocks
; Sedimentary rocks
; Transform faults
; central Betics
; Flower structures
; Lithospheric mantle
; Mediterranean region
; Receiver functions
; sharp Moho step
; Subduction-transform edge propagator
; westernmost Mediterranean subduction system
; Structural geology
英文摘要: We study the crustal and lithospheric mantle structure under central Betics in the westernmost Mediterranean region by migrating P-receiver functions along a dense seismic profile (∼2 km interstation distance). The profile, North–South oriented, probes the crustal structure of different geological units, from the Alboran domain in the south with metamorphic rocks, through the External Zones with sedimentary rocks to the Variscan terrains of the Iberian Massif in the north. From north to south, the Moho depth increases from ∼30 km to ∼46 km underneath the Guadix basin, due to the underthrusting of the Iberian crust below the Alboran crust, and suddenly shallows to ∼30 km underneath the Internal Zones with a step of 17 km. This sharp Moho step correlates well with a lithospheric step of ∼40 km, where the thickness of the lithosphere changes abruptly from ∼100 km in the north to ∼50 km in the south. We interpret this sharp and prominent lithospheric step as the termination of the Iberian lithosphere caused by a near-vertical STEP (Subduction-Transform-Edge-Propagator) fault that continues towards the surface as a positive flower tectonic structure of crustal scale. This STEP fault is located at the northern edge of the narrow Westernmost Mediterranean subduction system facilitating the slab rollback motion towards the west. The sharp termination of the Iberian lithosphere occurs under the contact between the Alpujarride and the Nevado-Filabride complexes of the Alboran domain in an ENE-WSW right-lateral transpressive shear zone. The thickest crust and lithosphere do not correlate with the highest topography along the profile suggesting that this high topography is a combined effect of the positive flower structure, and the push up of the asthenosphere produced by the removal of the Iberian lithosphere. © 2018 The Authors Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/110022
Appears in Collections: 影响、适应和脆弱性 气候变化事实与影响
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作者单位: Instituto Andaluz de Geofisica, Universidad de Granada, Campus de Cartuja, Granada, 18071, Spain; Departamento de Fisica Teorica y del Cosmos, Facultad de Ciencias, Universidad de Granada, Campus de Fuente Nueva, Granada, 18071, Spain; Deutsches GeoForschungsZentrum, GFZ, Telegrafenberg, Potsdam, 14473, Germany; Departamento de Geodinámica, Facultad de Ciencias, Universidad de Granada, Campus de Fuentenueva18071, Spain
Recommended Citation:
Mancilla F.D.L.,Heit B.,Morales J.,et al. A STEP fault in Central Betics, associated with lateral lithospheric tearing at the northern edge of the Gibraltar arc subduction system[J]. Earth and Planetary Science Letters,2018-01-01,486