K. Omosanya, R. A. Sanni, T. Laniyan, G. O. Mosuro, H. O. Omosanya, L. Falana
{"title":"尼日利亚西南部东北部Ago-Iwoye前中生代岩石学与岩石成因","authors":"K. Omosanya, R. A. Sanni, T. Laniyan, G. O. Mosuro, H. O. Omosanya, L. Falana","doi":"10.3809/JVIRTEX.2012.00313","DOIUrl":null,"url":null,"abstract":"Detailed geological mapping was carried out in a part of Ago-Iwoye NE with a view to identify the rock types and determine their origin. Petrographic and whole rock analysis of seven rock samples collected during the initial mapping exercise was done through thin sectioning, and X-ray fluorescence. Minerals were studied in cross and plane polarized light; their contact angle and boundary interaction were inferred in thin section. Normative mineralogy of the rocks was also determined using CIPW Norm. The study area is underlain by both igneous and metamorphic rocks; the gneisses are migmatized and intruded by granitic rocks and pegmatite. The dominant minerals in thin section include quartz, biotite, muscovite and hornblende. Estimated mineral contact angle is ~56° and ~26° for hornblende-biotite and hornblende-muscovite, respectively. Mineral grain boundaries are planar and undulating in thin section. The geochemical study revealed major oxides such as SiO2, Al2O3, Fe2O3, CaO, MgO, K2O and Na2O. The highest estimated liquid temperature occurred in the gneisses with a value of ~1014°C, mean of ~862°C, range of ~281°C and water content of 1.6% which shows that the rocks are metamorphic in origin. The volume composition shows that quartz has the highest volume in all the seven samples with a percentage value of ~68%. Discriminant plots show that the granites are quartz-rich granitoid and granodiorite while the gneisses have high liquidus temperature; all the rocks samples record high alteration indices and are derived from passive and continental margins. Rocks of the study area are Pan African granitoids emplaced into the polycyclic Pre-Cambrian migmatized complex host rock. Citation: 2012. Petrography and Petrogenesis of Pre-Mesozoic rocks, Ago-Iwoye NE, SW Nigeria. In: (Ed.) Gordon S. Lister, Journal of the Virtual Explorer, volume 40, paper 1, doi: 10.3809/jvirtex.2012.00313 Journal of the Virtual Explorer, 2012 Volume 40 Paper 1 http://virtualexplorer.com.au/","PeriodicalId":201383,"journal":{"name":"Journal of The Virtual Explorer","volume":"404 1","pages":"0"},"PeriodicalIF":0.0000,"publicationDate":"1900-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"2","resultStr":"{\"title\":\"Petrography and Petrogenesis of Pre-Mesozoic rocks, Ago-Iwoye NE, SW Nigeria\",\"authors\":\"K. Omosanya, R. A. Sanni, T. Laniyan, G. O. Mosuro, H. O. Omosanya, L. Falana\",\"doi\":\"10.3809/JVIRTEX.2012.00313\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"Detailed geological mapping was carried out in a part of Ago-Iwoye NE with a view to identify the rock types and determine their origin. Petrographic and whole rock analysis of seven rock samples collected during the initial mapping exercise was done through thin sectioning, and X-ray fluorescence. Minerals were studied in cross and plane polarized light; their contact angle and boundary interaction were inferred in thin section. Normative mineralogy of the rocks was also determined using CIPW Norm. The study area is underlain by both igneous and metamorphic rocks; the gneisses are migmatized and intruded by granitic rocks and pegmatite. The dominant minerals in thin section include quartz, biotite, muscovite and hornblende. Estimated mineral contact angle is ~56° and ~26° for hornblende-biotite and hornblende-muscovite, respectively. Mineral grain boundaries are planar and undulating in thin section. The geochemical study revealed major oxides such as SiO2, Al2O3, Fe2O3, CaO, MgO, K2O and Na2O. The highest estimated liquid temperature occurred in the gneisses with a value of ~1014°C, mean of ~862°C, range of ~281°C and water content of 1.6% which shows that the rocks are metamorphic in origin. The volume composition shows that quartz has the highest volume in all the seven samples with a percentage value of ~68%. Discriminant plots show that the granites are quartz-rich granitoid and granodiorite while the gneisses have high liquidus temperature; all the rocks samples record high alteration indices and are derived from passive and continental margins. Rocks of the study area are Pan African granitoids emplaced into the polycyclic Pre-Cambrian migmatized complex host rock. Citation: 2012. Petrography and Petrogenesis of Pre-Mesozoic rocks, Ago-Iwoye NE, SW Nigeria. In: (Ed.) Gordon S. Lister, Journal of the Virtual Explorer, volume 40, paper 1, doi: 10.3809/jvirtex.2012.00313 Journal of the Virtual Explorer, 2012 Volume 40 Paper 1 http://virtualexplorer.com.au/\",\"PeriodicalId\":201383,\"journal\":{\"name\":\"Journal of The Virtual Explorer\",\"volume\":\"404 1\",\"pages\":\"0\"},\"PeriodicalIF\":0.0000,\"publicationDate\":\"1900-01-01\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"2\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of The Virtual Explorer\",\"FirstCategoryId\":\"1085\",\"ListUrlMain\":\"https://doi.org/10.3809/JVIRTEX.2012.00313\",\"RegionNum\":0,\"RegionCategory\":null,\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"\",\"JCRName\":\"\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of The Virtual Explorer","FirstCategoryId":"1085","ListUrlMain":"https://doi.org/10.3809/JVIRTEX.2012.00313","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"","JCRName":"","Score":null,"Total":0}
引用次数: 2
摘要
在Ago-Iwoye NE的一部分地区进行了详细的地质测绘，以确定岩石类型并确定其起源。通过薄片和x射线荧光，对在初始测绘工作中收集的7个岩石样品进行了岩石学和全岩分析。用交叉偏振光和平面偏振光对矿物进行了研究;在薄片上推导了它们的接触角和边界相互作用。采用CIPW规范确定了岩石的规范矿物学特征。研究区下覆火成岩和变质岩;片麻岩被杂岩化，并被花岗质和伟晶岩侵入。薄片上的主要矿物有石英、黑云母、白云母和角闪石。角闪石-黑云母和角闪石-白云母的矿物接触角分别为~56°和~26°。矿物晶界在薄片上呈平面起伏状。地球化学研究表明，SiO2、Al2O3、Fe2O3、CaO、MgO、K2O和Na2O是主要的氧化物。片麻岩的最高液体温度为~1014℃，平均为~862℃，范围为~281℃，水分含量为1.6%，表明其成因为变质岩。体积组成表明，石英在7个样品中体积最大，占比约68%。判别图显示花岗岩为富石英花岗类和花岗闪长岩，片麻岩具有较高的液相温度;所有岩石样品蚀变指数均较高，均来自被动边缘和大陆边缘。研究区岩石为侵位于前寒武纪多旋回杂岩杂岩中的泛非花岗岩类。引文:2012。尼日利亚西南部东北部Ago-Iwoye前中生代岩石学与岩石成因见:(编)Gordon S. Lister, Journal of the Virtual Explorer，卷40，论文1,doi: 10.3809/jvirtex.2012.00313 Journal of the Virtual Explorer, 2012卷40，论文1 http://virtualexplorer.com.au/
Petrography and Petrogenesis of Pre-Mesozoic rocks, Ago-Iwoye NE, SW Nigeria
Detailed geological mapping was carried out in a part of Ago-Iwoye NE with a view to identify the rock types and determine their origin. Petrographic and whole rock analysis of seven rock samples collected during the initial mapping exercise was done through thin sectioning, and X-ray fluorescence. Minerals were studied in cross and plane polarized light; their contact angle and boundary interaction were inferred in thin section. Normative mineralogy of the rocks was also determined using CIPW Norm. The study area is underlain by both igneous and metamorphic rocks; the gneisses are migmatized and intruded by granitic rocks and pegmatite. The dominant minerals in thin section include quartz, biotite, muscovite and hornblende. Estimated mineral contact angle is ~56° and ~26° for hornblende-biotite and hornblende-muscovite, respectively. Mineral grain boundaries are planar and undulating in thin section. The geochemical study revealed major oxides such as SiO2, Al2O3, Fe2O3, CaO, MgO, K2O and Na2O. The highest estimated liquid temperature occurred in the gneisses with a value of ~1014°C, mean of ~862°C, range of ~281°C and water content of 1.6% which shows that the rocks are metamorphic in origin. The volume composition shows that quartz has the highest volume in all the seven samples with a percentage value of ~68%. Discriminant plots show that the granites are quartz-rich granitoid and granodiorite while the gneisses have high liquidus temperature; all the rocks samples record high alteration indices and are derived from passive and continental margins. Rocks of the study area are Pan African granitoids emplaced into the polycyclic Pre-Cambrian migmatized complex host rock. Citation: 2012. Petrography and Petrogenesis of Pre-Mesozoic rocks, Ago-Iwoye NE, SW Nigeria. In: (Ed.) Gordon S. Lister, Journal of the Virtual Explorer, volume 40, paper 1, doi: 10.3809/jvirtex.2012.00313 Journal of the Virtual Explorer, 2012 Volume 40 Paper 1 http://virtualexplorer.com.au/
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号
