DOI: 10.1016/j.tecto.2021.229000
论文题名: Syn-tectonic Dipilto batholith (NW Nicaragua) linked to arc-continent collision: High- and room-temperature AMS evidence
作者: García-Amador B.I. ; Alva-Valdivia L.M. ; Hernández-Cardona A.
刊名: Tectonophysics
ISSN: 00401951
出版年: 2021
卷: 815 语种: 英语
中文关键词: Chortís block
; Dipilto micro-block
; High-temperature AMS
; Ilmenite-Series
; Siuna Intraoceanic Arc
; Syn-collisional batholith
英文关键词: Levees
; Magnesite
; Magnetic anisotropy
; Magnetic susceptibility
; Mica
; Oxide minerals
; Rare earths
; Strike-slip faults
; Arc-continent collision
; Geographical positions
; Hysteresis cycles
; Intra-oceanic arc
; Magnetic lineations
; Room and high temperatures
; Strike-slip fault systems
; Tectonic transport
; Structural geology
英文摘要: The northern Central America region (Honduras and Nicaragua) is characterized by geotectonic units delimited by strike-slip fault systems and shortening zones of poorly constrained ages. The eastern portion of the Chortís block, named the “Dipilto micro-block” or “Patuca” is one of these units that besides with the Siuna Serpentinite Mélange, provides evidence for Early Cretaceous arc-continent collision. Nevertheless, within the Dipilto micro-block is the Early Cretaceous Dipilto batholith (NW Nicaragua), an Ilmenite-Series granitoid suites whose emplacement tectonic setting is unknown. We document the room- and high-temperature anisotropy of magnetic susceptibility (RT-AMS and HT-AMS) and hysteresis cycles from 31 sites in the Dipilto batholith and cross-cutting dikes as well as the oxide mineral microscopy of main lithologies. This is to investigate the magmatic fabric in the granitoids and dikes, and the relation to the emplacement dynamics. The RT-AMS and HT-AMS results show magnetic lineation and foliation (Kmax and Kmax–Kint plane) dominated by paramagnetic minerals (biotite and hornblende). The central parts of the intrusion show a NE-SW Kmax distribution and sites near to boundary of the country-rock a Kmax–Kint plane sub-parallel to the contact. These results and previous structural data in the surrounding Nueva Segovia Schist country-rock support an intrusion emplaced in a contractional setting concurrent with the batholith's NE-SW regional geometry. The Dipilto batholith age (119–112 Ma) implies a syn-collisional origin that together with our results indicate an Early Cretaceous progressive shortening in the region associated with the Siuna Intraoceanic Arc collision (~134–113 Ma). Furthermore, they indicate that the shortening azimuth (i.e., the direction of tectonic transport) is ~127°–137° in its current geographical position, but was 227°–237° in its Early Cretaceous paleo-position, probably related to the final stage of shortening and collision events of the southwestern Mexican paleocontinent. © 2021 Elsevier B.V. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/170808
Appears in Collections: 气候变化与战略
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作者单位: Posgrado en Ciencias de la Tierra, Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad de México, Mexico; Laboratorio de Paleomagnetismo, Instituto de Geofísica, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
Recommended Citation:
García-Amador B.I.,Alva-Valdivia L.M.,Hernández-Cardona A.. Syn-tectonic Dipilto batholith (NW Nicaragua) linked to arc-continent collision: High- and room-temperature AMS evidence[J]. Tectonophysics,2021-01-01,815