Francis Emanuel Salguero-Díaz, L. Solari, O. J. Vásquez, Ricardo Enrique Milián de la Cruz, C. Ortega-Obregón
{"title":"La Unión Monzogranite: geochronology and significance of the Jurassic arc in the Sula Terrane, Guatemala","authors":"Francis Emanuel Salguero-Díaz, L. Solari, O. J. Vásquez, Ricardo Enrique Milián de la Cruz, C. Ortega-Obregón","doi":"10.22201/cgeo.20072902e.2022.2.1675","DOIUrl":null,"url":null,"abstract":"La Unión pluton (LUP) belongs to the metamorphic and igneous Sula Terrane (ST) of Central Guatemala, limited to the north by the Motagua fault (MF) and to the south by the Jocotán-Chamelecón fault system (J-CH-FS). The basement of the ST is characterized by the high-grade metamorphic rocks belonging to the Las Ovejas Complex and the extensive low-grade San Diego phyllite, the latter in tectonic contact with LUP. A combination of field data, petrographic and geochemical analyses as well as geochronologic dating by U-Pb method, allow to classify LUP as a monzogranite with an age of 170 Ma (average of two dated samples), characterized by high-K calcalkaline and peraluminous affinity and with a REE pattern typical of a continental magmatic arc. Some trace-elements behavior and a comparison of similar-age units found elsewhere in eastern, central and southern Mexico, allow to associate its formation to the lithospheric thinning and extension that occurred during the breakup of Pangea and the opening of the Gulf of Mexico.","PeriodicalId":0,"journal":{"name":"","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2022-07-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"1","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.22201/cgeo.20072902e.2022.2.1675","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 1
Abstract
La Unión pluton (LUP) belongs to the metamorphic and igneous Sula Terrane (ST) of Central Guatemala, limited to the north by the Motagua fault (MF) and to the south by the Jocotán-Chamelecón fault system (J-CH-FS). The basement of the ST is characterized by the high-grade metamorphic rocks belonging to the Las Ovejas Complex and the extensive low-grade San Diego phyllite, the latter in tectonic contact with LUP. A combination of field data, petrographic and geochemical analyses as well as geochronologic dating by U-Pb method, allow to classify LUP as a monzogranite with an age of 170 Ma (average of two dated samples), characterized by high-K calcalkaline and peraluminous affinity and with a REE pattern typical of a continental magmatic arc. Some trace-elements behavior and a comparison of similar-age units found elsewhere in eastern, central and southern Mexico, allow to associate its formation to the lithospheric thinning and extension that occurred during the breakup of Pangea and the opening of the Gulf of Mexico.
La Unión岩体(LUP)属于危地马拉中部变质火成岩苏拉地系(ST),北受莫塔瓜断裂(MF)限制,南受Jocotán-Chamelecón断裂系统(J-CH-FS)限制。ST的基底以属于Las Ovejas杂岩的高品位变质岩和广泛的低品位San Diego千层岩为特征,后者与LUP构造接触。结合野外资料、岩石学和地球化学分析以及U-Pb年代学测年,将LUP划分为二长花岗岩,年龄为170 Ma(两个测年样品的平均值),具有高钾钙碱性和过铝亲和性,具有典型的大陆岩浆弧的REE模式。通过对在墨西哥东部、中部和南部其他地方发现的类似年龄单元的一些微量元素行为和比较,可以将其形成与盘古大陆分裂和墨西哥湾开放期间发生的岩石圈变薄和扩张联系起来。