{"title":"阿巴拉契亚山脉北部Belvidere山杂岩中最新发现的蓝片岩相变质作用(海蓝绿辉石-石榴石)","authors":"I. Honsberger","doi":"10.1130/ges02582.1","DOIUrl":null,"url":null,"abstract":"An occurrence of blueschist-facies metamorphism in the Appalachian orogen is newly recognized in northwestern New England, United States. Inclusions of glaucophane and omphacite occur in a relict garnet core from a retrogressed garnet-barroisite amphibolite of the Belvidere Mountain Complex in Vermont. Pressure-temperature pseudosection and mineral composition isopleth calculations demonstrate that the Belvidere Mountain Complex blueschist-facies mineral assemblage of glaucophane–magnesio-hornblende–omphacite–chlorite–rutile–quartz–clinozoisite–garnet was stable at ~1.65–2.0 GPa and ~450–480 °C. Garnet-absent amphibolite with barroisite and chlorite inclusions in clinozoisite records high-pressure epidote-amphibolite–facies metamorphism at ~1.0–1.4 GPa and ~515–550 °C. These new findings quantify deep subduction of the Belvidere Mountain Complex during the Cambrian to Ordovician Taconic orogenic cycle and suggest that more blueschist-facies mineral assemblages could be revealed in the Appalachians with detailed analysis of retrogressed rocks.","PeriodicalId":55100,"journal":{"name":"Geosphere","volume":" ","pages":""},"PeriodicalIF":1.7000,"publicationDate":"2023-03-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"Newly recognized blueschist-facies metamorphism (glaucophane-omphacite-garnet), Belvidere Mountain Complex, northern Appalachians\",\"authors\":\"I. Honsberger\",\"doi\":\"10.1130/ges02582.1\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"An occurrence of blueschist-facies metamorphism in the Appalachian orogen is newly recognized in northwestern New England, United States. Inclusions of glaucophane and omphacite occur in a relict garnet core from a retrogressed garnet-barroisite amphibolite of the Belvidere Mountain Complex in Vermont. Pressure-temperature pseudosection and mineral composition isopleth calculations demonstrate that the Belvidere Mountain Complex blueschist-facies mineral assemblage of glaucophane–magnesio-hornblende–omphacite–chlorite–rutile–quartz–clinozoisite–garnet was stable at ~1.65–2.0 GPa and ~450–480 °C. Garnet-absent amphibolite with barroisite and chlorite inclusions in clinozoisite records high-pressure epidote-amphibolite–facies metamorphism at ~1.0–1.4 GPa and ~515–550 °C. These new findings quantify deep subduction of the Belvidere Mountain Complex during the Cambrian to Ordovician Taconic orogenic cycle and suggest that more blueschist-facies mineral assemblages could be revealed in the Appalachians with detailed analysis of retrogressed rocks.\",\"PeriodicalId\":55100,\"journal\":{\"name\":\"Geosphere\",\"volume\":\" \",\"pages\":\"\"},\"PeriodicalIF\":1.7000,\"publicationDate\":\"2023-03-09\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Geosphere\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://doi.org/10.1130/ges02582.1\",\"RegionNum\":3,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q3\",\"JCRName\":\"GEOSCIENCES, MULTIDISCIPLINARY\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Geosphere","FirstCategoryId":"89","ListUrlMain":"https://doi.org/10.1130/ges02582.1","RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q3","JCRName":"GEOSCIENCES, MULTIDISCIPLINARY","Score":null,"Total":0}
An occurrence of blueschist-facies metamorphism in the Appalachian orogen is newly recognized in northwestern New England, United States. Inclusions of glaucophane and omphacite occur in a relict garnet core from a retrogressed garnet-barroisite amphibolite of the Belvidere Mountain Complex in Vermont. Pressure-temperature pseudosection and mineral composition isopleth calculations demonstrate that the Belvidere Mountain Complex blueschist-facies mineral assemblage of glaucophane–magnesio-hornblende–omphacite–chlorite–rutile–quartz–clinozoisite–garnet was stable at ~1.65–2.0 GPa and ~450–480 °C. Garnet-absent amphibolite with barroisite and chlorite inclusions in clinozoisite records high-pressure epidote-amphibolite–facies metamorphism at ~1.0–1.4 GPa and ~515–550 °C. These new findings quantify deep subduction of the Belvidere Mountain Complex during the Cambrian to Ordovician Taconic orogenic cycle and suggest that more blueschist-facies mineral assemblages could be revealed in the Appalachians with detailed analysis of retrogressed rocks.
期刊介绍:
Geosphere is GSA''s ambitious, online-only publication that addresses the growing need for timely publication of research results, data, software, and educational developments in ways that cannot be addressed by traditional formats. The journal''s rigorously peer-reviewed, high-quality research papers target an international audience in all geoscience fields. Its innovative format encourages extensive use of color, animations, interactivity, and oversize figures (maps, cross sections, etc.), and provides easy access to resources such as GIS databases, data archives, and modeling results. Geosphere''s broad scope and variety of contributions is a refreshing addition to traditional journals.