THE OLDEST HIGH GRADE TERRANES: POSSIBLE RELICTS OF PRIMEVAL EARTH CRUST
THE OLDEST HIGH GRADE TERRANES: POSSIBLE RELICTS OF PRIMEVAL EARTH CRUST.
| dc.contributor | en-US | |
| dc.contributor | pt-BR | |
| dc.creator | SHULDINER, VICTOR I. | |
| dc.date | 2018-08-10 | |
| dc.date.accessioned | 2023-06-19T15:23:22Z | |
| dc.date.available | 2023-06-19T15:23:22Z | |
| dc.identifier | https://ppegeo.igc.usp.br/index.php/rbg/article/view/12186 | |
| dc.identifier.uri | https://repositorioslatinoamericanos.uchile.cl/handle/2250/6692763 | |
| dc.description | Some of the oldest high-grade terranes developed under very specific conditions that could be there only at the earliest stage of the Earth's evolution, are an important argument in favour of the Pre-Archean age of these terranes (older than 3.5 Ga). The Pre-Archean stage was a period when the primary massive atmosphere of essentially hydrous composiüon existed. The surface temperature was very high (300 ± 100°C). The earliest epoch of this period was specific in its small volume of hydrosphere or its absence due to which lhe lithogenesis of that time was mainly of volcanic nature. The high standing of the geoisotherms resulted in the intensive magma melting at relatively shallow depths, and the quick uplift of nondifferentiated magmas to the surface formed a primitive metabasalt shell. Further development was going on under the conditions of an intensive exogenous differentiation of the basaltic and more acidic volcanic substance coming from the mantle. The temperatures being extremely high as well as the chemical activity of the hydro- and atmosphere. ln this way a thick continental protocrust, of about 40 km, was formed. | en-US |
| dc.description | Some of the oldest high-grade terranes developed under very specific conditions that could be there only at the earliest stage of the Earth's evolution, are an important argument in favour of the Pre-Archean age of these terranes (older than 3.5 Ga). The Pre-Archean stage was a period when the primary massive atmosphere of essentially hydrous composiüon existed. The surface temperature was very high (300 ± 100°C). The earliest epoch of this period was specific in its small volume of hydrosphere or its absence due to which lhe lithogenesis of that time was mainly of volcanic nature. The high standing of the geoisotherms resulted in the intensive magma melting at relatively shallow depths, and the quick uplift of nondifferentiated magmas to the surface formed a primitive metabasalt shell. Further development was going on under the conditions of an intensive exogenous differentiation of the basaltic and more acidic volcanic substance coming from the mantle. The temperatures being extremely high as well as the chemical activity of the hydro- and atmosphere. ln this way a thick continental protocrust, of about 40 km, was formed. | pt-BR |
| dc.format | application/pdf | |
| dc.language | eng | |
| dc.publisher | Sociedade Brasileira de Geologia | pt-BR |
| dc.relation | https://ppegeo.igc.usp.br/index.php/rbg/article/view/12186/11733 | |
| dc.rights | Direitos autorais 2018 Revista Brasileira de Geociências | pt-BR |
| dc.source | Revista Brasileira de Geociências; v. 12, n. 1-3 (1982): Anais do ISAP "International Symposium on Archean and Early Proterozoic Geologic Evolution and Metallogenesis", Salvador, Bahia, Brasil - 3 a 11 setembro, 1982; 45-52 | en-US |
| dc.source | Revista Brasileira de Geociências; v. 12, n. 1-3 (1982): Anais do ISAP "International Symposium on Archean and Early Proterozoic Geologic Evolution and Metallogenesis", Salvador, Bahia, Brasil - 3 a 11 setembro, 1982; 45-52 | es-ES |
| dc.source | Revista Brasileira de Geociências; v. 12, n. 1-3 (1982): Anais do ISAP "International Symposium on Archean and Early Proterozoic Geologic Evolution and Metallogenesis", Salvador, Bahia, Brasil - 3 a 11 setembro, 1982; 45-52 | pt-BR |
| dc.source | 0375-7536 | |
| dc.subject | en-US | |
| dc.subject | pt-BR | |
| dc.title | THE OLDEST HIGH GRADE TERRANES: POSSIBLE RELICTS OF PRIMEVAL EARTH CRUST | en-US |
| dc.title | THE OLDEST HIGH GRADE TERRANES: POSSIBLE RELICTS OF PRIMEVAL EARTH CRUST. | pt-BR |
| dc.type | info:eu-repo/semantics/article | |
| dc.type | info:eu-repo/semantics/publishedVersion | |
| dc.type | pt-BR |