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Geochemical Features of a Subduction Initiation Ophiolite Type in Habana-Matanzas Region(Western Cuba)
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作者 Angélica Isabel LLANES CASTRO Joaquín Antonio PROENZA FERNáNDEZ Esther María CRUZ GáMEZ 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2017年第S1期18-,共1页
We present new geochemical data for the upper mantle and crustal sections(whole-rock major and trace element compositions)as well as mineral chemical data,from the Northern Carbibbean ophiolites in the Habana-Matanzas... We present new geochemical data for the upper mantle and crustal sections(whole-rock major and trace element compositions)as well as mineral chemical data,from the Northern Carbibbean ophiolites in the Habana-Matanzas region in Western Cuba.These ophiolites are part of the Northern Cuban Ophiolitic Belt(NCOB),extending for more than 1000 km along the island.The upper mantle peridotites are composed mainly of refractory harzburgite with tectonite textures,and show convex-downward patterns depleted in MREE normalized to chondrite values(Mc Donough and Sun,1995).These geochemical trends are characteristic for depleted mantle wedge peridotites metasomatized by slab-derived,LREE enriched melts.The NCOB also includes abyssal peridotites having lower LREE/HREEratiosanddisplayingrelativelyhomogeneous and flat patterns from MREE to HREE.These peridotites represent fragments accreted into the continental margin from a subducted oceanic lithosphere.Gabbro and dolerite units in the NCOB are systematically depleted in High Field Strength Elements(HFSE:Nb,Ta,Hf,Ti)and REE with respect to N-MORB(<1 X N-MORB).Their melt evolution was affected by subduction input.Spatially associated granitic rocks have a volcanic arc geochemical affinity.Some mafic extrusive rocks within the NCOB exhibit boninitic signatures,and may represent the products of subduction initiation magmatism,whereas other extrusive rock occurrences display N-MORB to E-MORB geochemical fingerprints,slightly modified by subduction derived fluids.Using these geochemical data and constraints,we present a tectonomagmatic model for the evolution of the NCOB within the framework of the Caribbean geology. 展开更多
关键词 Western Cuba rock Geochemical features of a Subduction Initiation Ophiolite Type in Habana-Matanzas Region
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Modified homogeneous parameterization for monocular SLAM
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作者 孟旭炯 Jiang Rongxin Chen Yaowu 《High Technology Letters》 EI CAS 2012年第3期238-242,共5页
Feature initialization is an important issue in the monocular simultaneous locahzation ana mapping (SLAM) literature as the feature depth can not be obtained at one observation. In this paper, we present a new featu... Feature initialization is an important issue in the monocular simultaneous locahzation ana mapping (SLAM) literature as the feature depth can not be obtained at one observation. In this paper, we present a new feature initialization method named modified homogeneous parameterization (MHP), which allows undelayed initialization with scale invariant representation of point features located at various depths. The linearization error of the measurement equation is quantified using a depth estimation model and the feature initialization process is described. In order to verify the performance of the proposed method, the simulation is carried out. Results show that with the proposed method, the SLAM algorithm can achieve better consistency as compared with the existing inverse depth parameterization (IDP) method. 展开更多
关键词 monocular simultaneous localization and mapping (SLAM) feature initialization depth estimation homogeneous coordinates extended Kahnan filter
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