Lea Ostorero , Rosario Esposito , Pierre Bouilhol , Paolo Ballato , Veleda Astarte Müller , Maria Luce Frezzotti , Pietro Sternai
{"title":"伊朗新特提斯岩浆在中始新世气候最适期是一个重要的CO2源","authors":"Lea Ostorero , Rosario Esposito , Pierre Bouilhol , Paolo Ballato , Veleda Astarte Müller , Maria Luce Frezzotti , Pietro Sternai","doi":"10.1016/j.lithos.2025.108216","DOIUrl":null,"url":null,"abstract":"<div><div>CO<sub>2</sub> emissions from magmatic arcs can affect the atmosphere composition, thereby driving long-term global climate changes. Early Cenozoic climate trends are generally associated with changes in global silicate weathering related to Neo-Tethyan geodynamics, but the likely climatic effects of changes in degassing from Neo-Tethyan magmatic arcs have been poorly quantified. Here, we characterize the petrography and provide the first measures of the volatile content (CO<sub>2</sub>, H<sub>2</sub>O, F, Cl, and S) of pre-eruptive melts based on glassy, bubble-bearing and reheated melt inclusions within plagioclase and clinopyroxene crystals in Early Cenozoic trachyandesites from the Alborz and Tabriz regions (Iran). CO<sub>2</sub> concentrations in these melt inclusions reach up to 6733 ppm, thus providing a minimum estimate of the total amount of CO<sub>2</sub> degassed from Iranian magmas during the middle-late Eocene of 1.01 × 10<sup>19</sup> (± 4.04 × 10<sup>17</sup>) g CO<sub>2</sub>, with a total C flux released of 0.306 (± 0.012) Mt. C/yr, which is within the carbon imbalance predictions estimated based on other proxies. Our measures validate earlier hypotheses that magmatic CO<sub>2</sub> degassing from the targeted igneous provinces contributed to the Middle Eocene Climatic Optimum. Further measurements of the volatiles content of Neo-Tethyan magmas are thus critical to assess the drivers of Early Cenozoic climate trends and understand the global volatile cycling over geological timescales.</div></div>","PeriodicalId":18070,"journal":{"name":"Lithos","volume":"514 ","pages":"Article 108216"},"PeriodicalIF":2.5000,"publicationDate":"2025-08-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Iranian Neo-Tethyan magmas as a significant CO2 source during the Middle Eocene Climatic Optimum\",\"authors\":\"Lea Ostorero , Rosario Esposito , Pierre Bouilhol , Paolo Ballato , Veleda Astarte Müller , Maria Luce Frezzotti , Pietro Sternai\",\"doi\":\"10.1016/j.lithos.2025.108216\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>CO<sub>2</sub> emissions from magmatic arcs can affect the atmosphere composition, thereby driving long-term global climate changes. Early Cenozoic climate trends are generally associated with changes in global silicate weathering related to Neo-Tethyan geodynamics, but the likely climatic effects of changes in degassing from Neo-Tethyan magmatic arcs have been poorly quantified. Here, we characterize the petrography and provide the first measures of the volatile content (CO<sub>2</sub>, H<sub>2</sub>O, F, Cl, and S) of pre-eruptive melts based on glassy, bubble-bearing and reheated melt inclusions within plagioclase and clinopyroxene crystals in Early Cenozoic trachyandesites from the Alborz and Tabriz regions (Iran). CO<sub>2</sub> concentrations in these melt inclusions reach up to 6733 ppm, thus providing a minimum estimate of the total amount of CO<sub>2</sub> degassed from Iranian magmas during the middle-late Eocene of 1.01 × 10<sup>19</sup> (± 4.04 × 10<sup>17</sup>) g CO<sub>2</sub>, with a total C flux released of 0.306 (± 0.012) Mt. C/yr, which is within the carbon imbalance predictions estimated based on other proxies. Our measures validate earlier hypotheses that magmatic CO<sub>2</sub> degassing from the targeted igneous provinces contributed to the Middle Eocene Climatic Optimum. Further measurements of the volatiles content of Neo-Tethyan magmas are thus critical to assess the drivers of Early Cenozoic climate trends and understand the global volatile cycling over geological timescales.</div></div>\",\"PeriodicalId\":18070,\"journal\":{\"name\":\"Lithos\",\"volume\":\"514 \",\"pages\":\"Article 108216\"},\"PeriodicalIF\":2.5000,\"publicationDate\":\"2025-08-06\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Lithos\",\"FirstCategoryId\":\"89\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S0024493725002750\",\"RegionNum\":2,\"RegionCategory\":\"地球科学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"GEOCHEMISTRY & GEOPHYSICS\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Lithos","FirstCategoryId":"89","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0024493725002750","RegionNum":2,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"GEOCHEMISTRY & GEOPHYSICS","Score":null,"Total":0}
Iranian Neo-Tethyan magmas as a significant CO2 source during the Middle Eocene Climatic Optimum
CO2 emissions from magmatic arcs can affect the atmosphere composition, thereby driving long-term global climate changes. Early Cenozoic climate trends are generally associated with changes in global silicate weathering related to Neo-Tethyan geodynamics, but the likely climatic effects of changes in degassing from Neo-Tethyan magmatic arcs have been poorly quantified. Here, we characterize the petrography and provide the first measures of the volatile content (CO2, H2O, F, Cl, and S) of pre-eruptive melts based on glassy, bubble-bearing and reheated melt inclusions within plagioclase and clinopyroxene crystals in Early Cenozoic trachyandesites from the Alborz and Tabriz regions (Iran). CO2 concentrations in these melt inclusions reach up to 6733 ppm, thus providing a minimum estimate of the total amount of CO2 degassed from Iranian magmas during the middle-late Eocene of 1.01 × 1019 (± 4.04 × 1017) g CO2, with a total C flux released of 0.306 (± 0.012) Mt. C/yr, which is within the carbon imbalance predictions estimated based on other proxies. Our measures validate earlier hypotheses that magmatic CO2 degassing from the targeted igneous provinces contributed to the Middle Eocene Climatic Optimum. Further measurements of the volatiles content of Neo-Tethyan magmas are thus critical to assess the drivers of Early Cenozoic climate trends and understand the global volatile cycling over geological timescales.
期刊介绍:
Lithos publishes original research papers on the petrology, geochemistry and petrogenesis of igneous and metamorphic rocks. Papers on mineralogy/mineral physics related to petrology and petrogenetic problems are also welcomed.