Isla San Pedro Nolasco as a Late Miocene intrusive record at the eastern margin of the Gulf of California:Insights from geological,geochemical and geochronological studies

作     者：L.A.Velderrain-Rojas J.R.Vidal-Solano L.M.Alva-Valdivia R.Vega-Granillo M.López-Martinez L.A.Velderrain-Rojas;J.R.Vidal-Solano;L.M.Alva-Valdivia;R.Vega-Granillo;M.López-Martinez

作者机构：Departamento de GeologíaDivisión de Ciencias Exactas y NaturalesUniversidad de SonoraC.P.83000 HermosilloSonoraMexico Laboratorio de PaleomagnetismoInstituto de GeofísicaUniversidad Nacional Autónoma de MéxicoCircuito de la Investigación CientíficaC.P.04510 MéxicoD.F.Mexico Departamento de GeologíaDivisión de Ciencias de la TierraCentro de Investigación Científica y de Educación Superior de EnsenadaBaja CaliforniaMexico 

出 版 物：《Geoscience Frontiers》 (地学前缘（英文版）)

年 卷 期：2022年第13卷第3期

页      面：100-114页

核心收录：

学科分类：070902[理学-地球化学] 070903[理学-古生物学与地层学(含：古人类学)] 0709[理学-地质学] 07[理学] 

基　　金：supported by Grant #180784 from CONACyT (Mexico) Grant USO315007364 from DCEN UNISON to J.R. Vidal-Solano the financial support from PAPIIT-DGAPA-UNAM internal project IN101521 

主　　题：PAC-NAM plate boundary Gulf of California Intrusive rocks Isla San Pedro Nolasco 

摘      要：Isla San Pedro Nolasco(ISPN)is a structural high bounded by inactive dextral oblique-slip faults in the east-central part of the Gulf of California rift zone and is composed of intrusive rocks not exposed on other Gulf of California *** we present the reconnaissance results from geological mapping,as well as first geochemical and geochronological data for the ISPN intrusive *** intrusive rocks compose a sheet-like body of intermediate and felsic composition intruded by an intermediate and acidic dike *** intrusive rocks(host and dikes)range in age from ca.9 Ma to 10 Ma(^(40)Ar/^(39)Ar)and show a hydrous ferromagnesian mineral association(amphibole and biotite)with a calc-alkalic and transitional *** hydrated mineralogical association has not been recognized in the coeval rocks along the onshore western margin of the North American plate(coastal Sonora).However,such hydrous mineralogical association is found in the coeval rift transitional volcanic rocks from the Baja California Microplate at Santa Rosalía and Bahía de LosÁngeles–Bahía de LasÁ*** ISPN continental block,at least 40 km long,has been pulled apart by transtensional faulting of the late Miocene Gulf of California shear zone before the westward migration of the North America-Pacific plate boundary at ca.3–2 ***,ISPN became isolated as an island during the late Miocene flooding of the Gulf of California seaway.