M. Sacchi, G. de Natale, V. Spiess, L. Steinmann, V. Acocella, M. Corradino, S. D. de Silva, A. Fedele, L. Fedele, N. Geshi, C. Kilburn, D. Insinga, M. Jurado, F. Molisso, P. Petrosino, S. Passaro, F. Pepe, S. Porfido, C. Scarpati, H. Schmincke, R. Somma, M. Sumita, S. Tamburrino, C. Troise, M. Vallefuoco, Guido Ventura
Abstract. Large calderas are among the Earth's major volcanic features. They are associated with large magma reservoirs and elevated geothermal gradients. Caldera-forming eruptions result from the withdrawal and collapse of the magma chambers and produce large-volume pyroclastic deposits and later-stage deformation related to post-caldera resurgence and volcanism. Unrest episodes are not always followed by an eruption; however, every eruption is preceded by unrest. The Campi Flegrei caldera (CFc), located along the eastern Tyrrhenian coastline in southern Italy, is close to the densely populated area of Naples. It is one of the most dangerous volcanoes on Earth and represents a key example of an active, resurgent caldera. It has been traditionally interpreted as a nested caldera formed by collapses during the 100–200 km 3 Campanian Ignimbrite (CI) eruption at ∼39 ka and the 40 km 3 eruption of the Neapolitan Yellow Tuff (NYT) at ∼15 ka. Recent studies have suggested that the CI may instead have been fed by a fissure eruption from the Campanian Plain, north of Campi Flegrei. A MagellanPlus workshop was held in Naples, Italy, on 25–28 February 2017 to explore the potential of the CFc as target for an amphibious drilling project within the International Ocean Discovery Program (IODP) and the International Continental Drilling Program (ICDP). It was agreed that Campi Flegrei is an ideal site to investigate the mechanisms of caldera formation and associated post-caldera dynamics and to analyze the still poorly understood interplay between hydrothermal and magmatic processes. A coordinated onshore–offshore drilling strategy has been developed to reconstruct the structure and evolution of Campi Flegrei and to investigate volcanic precursors by examining (a) the succession of volcanic and hydrothermal products and related processes, (b) the inner structure of the caldera resurgence, (c) the physical, chemical, and biological characteristics of the hydrothermal system and offshore sediments, and (d) the geological expression of the phreatic and hydromagmatic eruptions, hydrothermal degassing, sedimentary structures, and other records of these phenomena. The deployment of a multiparametric in situ monitoring system at depth will enable near-real-time tracking of changes in the magma reservoir and hydrothermal system.
{"title":"A roadmap for amphibious drilling at the Campi Flegrei caldera: insights from a MagellanPlus workshop","authors":"M. Sacchi, G. de Natale, V. Spiess, L. Steinmann, V. Acocella, M. Corradino, S. D. de Silva, A. Fedele, L. Fedele, N. Geshi, C. Kilburn, D. Insinga, M. Jurado, F. Molisso, P. Petrosino, S. Passaro, F. Pepe, S. Porfido, C. Scarpati, H. Schmincke, R. Somma, M. Sumita, S. Tamburrino, C. Troise, M. Vallefuoco, Guido Ventura","doi":"10.5194/sd-26-29-2019","DOIUrl":"https://doi.org/10.5194/sd-26-29-2019","url":null,"abstract":"Abstract. Large calderas are among the Earth's major volcanic\u0000features. They are associated with large magma reservoirs and elevated\u0000geothermal gradients. Caldera-forming eruptions result from the withdrawal\u0000and collapse of the magma chambers and produce large-volume pyroclastic\u0000deposits and later-stage deformation related to post-caldera resurgence and\u0000volcanism. Unrest episodes are not always followed by an eruption; however,\u0000every eruption is preceded by unrest. The Campi Flegrei caldera (CFc), located along the eastern Tyrrhenian coastline\u0000in southern Italy, is close to the densely populated area of Naples. It is\u0000one of the most dangerous volcanoes on Earth and represents a key example of\u0000an active, resurgent caldera. It has been traditionally interpreted as a\u0000nested caldera formed by collapses during the 100–200 km 3 Campanian\u0000Ignimbrite (CI) eruption at ∼39 ka and the 40 km 3 eruption of\u0000the Neapolitan Yellow Tuff (NYT) at ∼15 ka. Recent studies\u0000have suggested that the CI may instead have been fed by a fissure eruption from the Campanian Plain, north of Campi Flegrei. A MagellanPlus workshop was held in Naples, Italy, on 25–28 February 2017 to\u0000explore the potential of the CFc as target for an amphibious drilling\u0000project within the International Ocean Discovery Program (IODP) and the International Continental Drilling Program (ICDP). It was agreed that Campi Flegrei is\u0000an ideal site to investigate the mechanisms of caldera formation and associated\u0000post-caldera dynamics and to analyze the still poorly understood interplay\u0000between hydrothermal and magmatic processes. A coordinated onshore–offshore\u0000drilling strategy has been developed to reconstruct the structure and\u0000evolution of Campi Flegrei and to investigate volcanic precursors by\u0000examining (a) the succession of volcanic and hydrothermal products and\u0000related processes, (b) the inner structure of the caldera resurgence, (c) the\u0000physical, chemical, and biological characteristics of the hydrothermal system and\u0000offshore sediments, and (d) the geological expression of the phreatic and\u0000hydromagmatic eruptions, hydrothermal degassing, sedimentary structures, and\u0000other records of these phenomena. The deployment of a multiparametric\u0000in situ monitoring system at depth will enable near-real-time tracking of\u0000changes in the magma reservoir and hydrothermal system.","PeriodicalId":51840,"journal":{"name":"Scientific Drilling","volume":"84 1","pages":"29-46"},"PeriodicalIF":1.2,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83856979","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Cohen, Colleen E. Cassidy, R. Crow, J. Bright, L. Crossey, R. Dorsey, B. Gootee, K. House, K. Howard, K. Karlstrom, P. Pearthree
Abstract. Neogene deposits of the lower Colorado River valley, especially the Miocene(?) and early Pliocene Bouse Formation, have been the focus of intense debate regarding the early paleoenvironmental history of this important continental-scale river system in southwestern North America and its integration with the proto-Gulf of California. Fine-grained units within these Neogene deposits also hold a promising archive of Pliocene paleoclimate history for this part of the world. Because the depocenter deposits of the Bouse Formation and the deposits that overlie and underlie it are poorly exposed and highly weathered, the formation is ripe for study through collection of drill cores. A workshop was held 28 February–3 March 2019 in Parker, AZ, USA, to discuss how scientific drilling might be employed to help resolve the Bouse controversies and improve our understanding of paleoclimate history in the region.
{"title":"The Bouse Formation, a controversial Neogene archive of the evolving Colorado River: a scientific drilling workshop report (28 February–3 March 2019 – BlueWater Resort & Casino, Parker, AZ, USA)","authors":"A. Cohen, Colleen E. Cassidy, R. Crow, J. Bright, L. Crossey, R. Dorsey, B. Gootee, K. House, K. Howard, K. Karlstrom, P. Pearthree","doi":"10.5194/sd-26-59-2019","DOIUrl":"https://doi.org/10.5194/sd-26-59-2019","url":null,"abstract":"Abstract. Neogene deposits of the lower Colorado River valley, especially the\u0000Miocene(?) and early Pliocene Bouse Formation, have been the focus of\u0000intense debate regarding the early paleoenvironmental history of this\u0000important continental-scale river system in southwestern North America and\u0000its integration with the proto-Gulf of California. Fine-grained units within\u0000these Neogene deposits also hold a promising archive of Pliocene\u0000paleoclimate history for this part of the world. Because the depocenter\u0000deposits of the Bouse Formation and the deposits that overlie and underlie it are poorly\u0000exposed and highly weathered, the formation is ripe for study through\u0000collection of drill cores. A workshop was held 28 February–3 March 2019 in\u0000Parker, AZ, USA, to discuss how scientific drilling might be employed to help\u0000resolve the Bouse controversies and improve our understanding of\u0000paleoclimate history in the region.","PeriodicalId":51840,"journal":{"name":"Scientific Drilling","volume":"7 1","pages":"59-67"},"PeriodicalIF":1.2,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73265273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Morishita, S. Umino, J. Kimura, M. Yamashita, S. Ono, K. Michibayashi, M. Tominaga, F. Klein, Michael O. Garcia
Abstract. The architecture, formation, and modification of oceanic plates are fundamental to our understanding of key geologic processes of the Earth. Geophysical surveys were conducted around a site near the Hawaiian Islands (northeastern Hawaiian North Arch region; Hawaiian North Arch hereafter), which is one of three potential sites for an International Ocean Discovery Program mantle drilling proposal for the Pacific plate that was submitted in 2012. The Hawaiian North Arch site is located in 78–81 Ma Cretaceous crust, which had an estimated full spreading rate of 7–8 cm yr −1 . This site fills a major gap in our understanding of oceanic crust. Previously drilling has been skewed to young or older crust ( or >110 Ma) and slow-spread crust. P-wave velocity structure in the uppermost mantle of the Hawaiian North Arch shows a strong azimuthal anisotropy, whereas Moho reflections below the basement are variable: strong and continuous, weak, diffuse, or unclear. We assume that the strength of the Moho reflection is related to the aging of the oceanic plate. The Hawaiian volcanic chain (200 km to the southwest of the proposed drill site) and the nearby North Arch magmatism on the proposed Hawaiian North Arch sites might also have affected recognition of the Moho via deformation and/or magma intrusion into the lower crust of the uppermost mantle. This workshop report describes scientific targets for 2 km deep-ocean drilling in the Hawaiian North Arch region in order to provide information about the lower crust from unrecovered age and spreading rate gaps from previous ocean drillings. Other scientific objectives to be achieved by drilling cores before reaching the target depth of the project are also described in this report.
摘要海洋板块的构造、形成和变化是我们理解地球关键地质过程的基础。在夏威夷群岛附近的一个地点进行了地球物理调查(夏威夷北部拱区东北部;夏威夷北拱门(以下简称“北拱门”)，它是2012年提交的国际海洋发现计划(International Ocean DiscoveryProgram)对太平洋板块进行地幔钻探的三个潜在地点之一。夏威夷北拱遗址位于白垩纪78 ~ 81 Ma地壳中，估计其完全扩张速率为7 ~ 8 cm yr - 1。这个地点填补了我们对海洋地壳认识的一个主要空白。以前的钻探倾向于年轻或更老的地壳(或>110 Ma)和缓慢扩散的地壳。夏威夷北拱最上地幔的纵波速度结构显示出很强的方位各向异性，而基底以下的莫霍反射则是多变的:强而连续、弱、扩散或不清晰。我们假设莫霍反射的强度与大洋板块的年龄有关。夏威夷火山链(位于拟建钻孔点西南200公里处)和附近的北大岩浆活动也可能通过变形和/或岩浆侵入上地幔的下地壳而影响了对莫霍的认识。该研讨会报告描述了在夏威夷北部arcregion进行2公里深海钻探的基本科学目标，以便从以前海洋钻探的未恢复和扩展速率间隙中提供有关下地壳的信息。本报告还描述了在达到项目目标深度之前通过钻取岩心来实现的其他科学目标。
{"title":"Workshop report on hard-rock drilling into mid-Cretaceous Pacific oceanic crust on the Hawaiian North Arch","authors":"T. Morishita, S. Umino, J. Kimura, M. Yamashita, S. Ono, K. Michibayashi, M. Tominaga, F. Klein, Michael O. Garcia","doi":"10.5194/sd-26-47-2019","DOIUrl":"https://doi.org/10.5194/sd-26-47-2019","url":null,"abstract":"Abstract. The architecture, formation, and modification of oceanic plates are\u0000fundamental to our understanding of key geologic processes of the Earth.\u0000Geophysical surveys were conducted around a site near the Hawaiian Islands\u0000(northeastern Hawaiian North Arch region; Hawaiian North Arch hereafter),\u0000which is one of three potential sites for an International Ocean Discovery\u0000Program mantle drilling proposal for the Pacific plate that was submitted in\u00002012. The Hawaiian North Arch site is located in 78–81 Ma Cretaceous crust,\u0000which had an estimated full spreading rate of 7–8 cm yr −1 . This site fills\u0000a major gap in our understanding of oceanic crust. Previously drilling has\u0000been skewed to young or older crust ( or >110 Ma)\u0000and slow-spread crust. P-wave velocity structure in the uppermost mantle of the Hawaiian North Arch shows a strong azimuthal anisotropy, whereas Moho reflections below the basement are variable: strong and continuous, weak, diffuse, or unclear. We assume that the strength of the Moho reflection is related to the aging of the oceanic plate. The Hawaiian volcanic chain (200 km to the southwest of the proposed drill site) and the nearby North Arch\u0000magmatism on the proposed Hawaiian North Arch sites might also have affected\u0000recognition of the Moho via deformation and/or magma intrusion into the\u0000lower crust of the uppermost mantle. This workshop report describes\u0000scientific targets for 2 km deep-ocean drilling in the Hawaiian North Arch\u0000region in order to provide information about the lower crust from unrecovered\u0000age and spreading rate gaps from previous ocean drillings. Other scientific\u0000objectives to be achieved by drilling cores before reaching the target depth\u0000of the project are also described in this report.","PeriodicalId":51840,"journal":{"name":"Scientific Drilling","volume":"45 1","pages":"47-58"},"PeriodicalIF":1.2,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72399840","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
E. Brown, M. Caballero, Enrique Cabral Cano, P. Fawcett, S. Lozano-García, B. Ortega, L. Pérez, A. Schwalb, V. Smith, B. Steinman, M. Stockhecke, B. Valero-Garcés, S. Watt, N. Wattrus, J. Werne, T. Wonik, A. Myrbo, A. Noren, Ryan O’Grady, D. Schnurrenberger
Abstract. The primary scientific objective of MexiDrill, the Basin of Mexico Drilling Program, is development of a continuous, high-resolution ∼400 kyr lacustrine record of tropical North American environmental change. The field location, in the densely populated, water-stressed Mexico City region gives this record particular societal relevance. A detailed paleoclimate reconstruction from central Mexico will enhance our understanding of long-term natural climate variability in the North American tropics and its relationship with changes at higher latitudes. The site lies at the northern margin of the Intertropical Convergence Zone (ITCZ), where modern precipitation amounts are influenced by sea surface temperatures in the Pacific and Atlantic basins. During the Last Glacial Maximum (LGM), more winter precipitation at the site is hypothesized to have been a consequence of a southward displacement of the mid-latitude westerlies. It thus represents a key spatial node for understanding large-scale hydrological variability of tropical and subtropical North America and is at an altitude (2240 m a.s.l.), typical of much of western North America. In addition, its sediments contain a rich record of pre-Holocene volcanic history; knowledge of the magnitude and frequency relationships of the area's explosive volcanic eruptions will improve capacity for risk assessment of future activity. Explosive eruption deposits will also be used to provide the backbone of a robust chronology necessary for full exploitation of the paleoclimate record. Here we report initial results from, and outreach activities of, the 2016 coring campaign.
{"title":"Scientific drilling of Lake Chalco, Basin of Mexico (MexiDrill)","authors":"E. Brown, M. Caballero, Enrique Cabral Cano, P. Fawcett, S. Lozano-García, B. Ortega, L. Pérez, A. Schwalb, V. Smith, B. Steinman, M. Stockhecke, B. Valero-Garcés, S. Watt, N. Wattrus, J. Werne, T. Wonik, A. Myrbo, A. Noren, Ryan O’Grady, D. Schnurrenberger","doi":"10.5194/sd-26-1-2019","DOIUrl":"https://doi.org/10.5194/sd-26-1-2019","url":null,"abstract":"Abstract. The primary scientific objective of MexiDrill, the Basin of Mexico\u0000Drilling Program, is development of a continuous, high-resolution\u0000∼400 kyr lacustrine record of tropical North American\u0000environmental change. The field location, in the densely populated,\u0000water-stressed Mexico City region gives this record particular societal\u0000relevance. A detailed paleoclimate reconstruction from central Mexico will\u0000enhance our understanding of long-term natural climate variability in the\u0000North American tropics and its relationship with changes at higher latitudes.\u0000The site lies at the northern margin of the Intertropical Convergence Zone\u0000(ITCZ), where modern precipitation amounts are influenced by sea surface\u0000temperatures in the Pacific and Atlantic basins. During the Last Glacial\u0000Maximum (LGM), more winter precipitation at the site is hypothesized to have been\u0000a consequence of a southward displacement of the mid-latitude westerlies. It\u0000thus represents a key spatial node for understanding large-scale\u0000hydrological variability of tropical and subtropical North America and is\u0000at an altitude (2240 m a.s.l.), typical of much of western North America. In addition, its sediments contain a rich record of pre-Holocene volcanic\u0000history; knowledge of the magnitude and frequency relationships of the\u0000area's explosive volcanic eruptions will improve capacity for risk\u0000assessment of future activity. Explosive eruption deposits will also be used\u0000to provide the backbone of a robust chronology necessary for full\u0000exploitation of the paleoclimate record. Here we report initial results\u0000from, and outreach activities of, the 2016 coring campaign.\u0000","PeriodicalId":51840,"journal":{"name":"Scientific Drilling","volume":"62 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78616334","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Berndt, S. Planke, D. Teagle, R. Huismans, T. Torsvik, J. Frieling, Morgan T. Jones, D. Jerram, C. Tegner, J. Faleide, H. Coxall, W. Hong
Abstract. The northeast Atlantic encompasses archetypal examples of volcanic rifted margins. Twenty-five years after the last ODP (Ocean Drilling Program) leg on these volcanic margins, the reasons for excess melting are still disputed with at least three competing hypotheses being discussed. We are proposing a new drilling campaign that will constrain the timing, rates of volcanism, and vertical movements of rifted margins. This will allow us to parameterise geodynamic models that can distinguish between the hypotheses. Furthermore, the drilling-derived data will help us to understand the role of breakup magmatism as a potential driver for the Palaeocene–Eocene thermal maximum (PETM) and its influence on the oceanographic circulation in the earliest phase of the northeast Atlantic Ocean formation. Tackling these questions with a new drilling campaign in the northeast Atlantic region will advance our understanding of the long-term interactions between tectonics, volcanism, oceanography, and climate and the functioning of subpolar northern ecosystems and climate during intervals of extreme warmth.
{"title":"Northeast Atlantic breakup volcanism and consequences for Paleogene climate change – MagellanPlus Workshop report","authors":"C. Berndt, S. Planke, D. Teagle, R. Huismans, T. Torsvik, J. Frieling, Morgan T. Jones, D. Jerram, C. Tegner, J. Faleide, H. Coxall, W. Hong","doi":"10.5194/sd-26-69-2019","DOIUrl":"https://doi.org/10.5194/sd-26-69-2019","url":null,"abstract":"Abstract. The northeast Atlantic encompasses archetypal examples of\u0000volcanic rifted margins. Twenty-five years after the last ODP (Ocean Drilling Program) leg on these\u0000volcanic margins, the reasons for excess melting are still disputed with at\u0000least three competing hypotheses being discussed. We are proposing a new\u0000drilling campaign that will constrain the timing, rates of volcanism,\u0000and vertical movements of rifted margins. This will allow us to parameterise\u0000geodynamic models that can distinguish between the hypotheses. Furthermore,\u0000the drilling-derived data will help us to understand the role of breakup\u0000magmatism as a potential driver for the Palaeocene–Eocene thermal maximum\u0000(PETM) and its influence on the oceanographic circulation in the earliest\u0000phase of the northeast Atlantic Ocean formation. Tackling these questions\u0000with a new drilling campaign in the northeast Atlantic region will advance\u0000our understanding of the long-term interactions between tectonics,\u0000volcanism, oceanography, and climate and the functioning of subpolar\u0000northern ecosystems and climate during intervals of extreme warmth.","PeriodicalId":51840,"journal":{"name":"Scientific Drilling","volume":"129 1","pages":"69-85"},"PeriodicalIF":1.2,"publicationDate":"2019-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83992167","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Abstract. Global paleo-climate reconstructions are largely based on observations from the Northern Hemisphere despite increasing recognition of the importance of the Southern Hemisphere mid-latitudes for understanding the drivers of the global climate system. Unfortunately, the required complete and high-resolution terrestrial records from the Southern Hemisphere mid-latitudes are few. However, the maar lakes in the Auckland Volcanic Field (AVF), New Zealand, are crucial in this regard as they form outstanding depositional basins due to their small surface-to-depth ratio, restricted catchment, and absence of ice cover since their formation, hence ensuring continuous sedimentation with anoxic bottom water. Significantly, the estimated age of the AVF of ca. 250 ka may allow development of a continuous sediment record spanning the last two glacial cycles. The Orakei maar lake sediment sequence examined in this study spans the Last Glacial Cycle (ca. 126 to ca. 9.5 ka cal BP) from the phreatomagmatic eruption to the crater rim breach due to post-glacial sea-level rise. Two overlapping cores of >100 m sediment were retrieved and combined to develop a complete composite stratigraphy that is presently undergoing a wide range of multi-proxy analyses.
摘要尽管人们越来越认识到南半球中纬度地区对理解全球气候系统驱动因素的重要性，但全球古气候重建主要基于北半球的观测。不幸的是，所需的南半球中纬度地区完整和高分辨率的陆地记录很少。然而，新西兰奥克兰火山场(AVF)的maar湖在这方面至关重要，因为它们形成了杰出的沉积盆地，因为它们的地表与深度比小，集水区有限，并且自形成以来没有冰覆盖，因此确保了缺氧底水的持续沉积。值得注意的是，AVF的估计年龄约为250 ka，可能允许跨越最后两个冰川旋回的连续沉积记录的发展。本研究考察的Orakei maar湖沉积物序列跨越末次冰期旋回(约126 ~约9.5 ka cal BP)，从火山喷发到冰川后海平面上升导致的火山口边缘破裂。检索了两个>100 m沉积物的重叠岩心，并将其结合起来，形成了一个完整的复合地层，目前正在进行广泛的多代理分析。
{"title":"Stratigraphy and sedimentology of the Orakei maar lake sediment sequence (Auckland Volcanic Field, New Zealand)","authors":"Leonie Peti, P. Augustinus","doi":"10.5194/SD-25-47-2019","DOIUrl":"https://doi.org/10.5194/SD-25-47-2019","url":null,"abstract":"Abstract. Global paleo-climate reconstructions are largely based on observations from\u0000the Northern Hemisphere despite increasing recognition of the importance of\u0000the Southern Hemisphere mid-latitudes for understanding the drivers of the\u0000global climate system. Unfortunately, the required complete and\u0000high-resolution terrestrial records from the Southern Hemisphere\u0000mid-latitudes are few. However, the maar lakes in the Auckland Volcanic Field\u0000(AVF), New Zealand, are crucial in this regard as they form outstanding\u0000depositional basins due to their small surface-to-depth ratio, restricted\u0000catchment, and absence of ice cover\u0000since their formation, hence ensuring continuous sedimentation with anoxic\u0000bottom water. Significantly, the estimated age of the AVF of ca. 250 ka may\u0000allow development of a continuous sediment record spanning the last two\u0000glacial cycles. The Orakei maar lake sediment sequence examined in this study\u0000spans the Last Glacial Cycle (ca. 126 to ca. 9.5 ka cal BP) from the\u0000phreatomagmatic eruption to the crater rim breach due to post-glacial\u0000sea-level rise. Two overlapping cores of >100 m sediment were retrieved\u0000and combined to develop a complete composite stratigraphy that is presently\u0000undergoing a wide range of multi-proxy analyses.\u0000","PeriodicalId":51840,"journal":{"name":"Scientific Drilling","volume":"12 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2019-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82084889","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Andreas Türke, M. Jackson, W. Bach, Wolf-Achim Kahl, B. Grzybowski, B. Marshall, M. Gudmundsson, S. Jørgensen
Abstract. Surtsey, the youngest of the islands of Vestmannaeyjar, is an oceanic volcano created by explosive basaltic eruptions during 1963–1967 off the southern coast of Iceland. The subsurface deposits of the volcano were first sampled by a cored borehole in 1979. In summer 2017, three cored boreholes were drilled through the active hydrothermal system of the volcano by the International Continental Scientific Drilling Program (ICDP) SUSTAIN Expedition 5059. These cores are expected to provide the first glimpse of microbial life in very young and native basaltic tuff of the oceanic crust. To reduce the contamination of the subsurface environment, seawater circulating fluid was filtered and passed through two UV-sterilizing treatments. One of the boreholes has been equipped with a subsurface observatory dedicated in situ experiments for monitoring water–rock interactions and microbial processes in sterile, artificial basaltic glass and in olivine granules. With temperatures ranging from 25 to 125 ∘C, the subsurface observatory provides a precise geothermal window into an active hydrothermal system and thus represents an exceptional natural laboratory for studying fluid–rock–microbe interactions at different temperature regimes and facilitates experimental validation of active submarine microbial processes at the limit of functional life, about 121 ∘C. Comparisons with the 1979 and 2019 drill cores will provide time-lapse observations of hydrothermal processes over a 50-year timescale. Here, we present the technical design of the observatory and the incubation chamber experiments deployed from September 2017 to summer 2019.
{"title":"Design of the subsurface observatory at Surtsey volcano, Iceland","authors":"Andreas Türke, M. Jackson, W. Bach, Wolf-Achim Kahl, B. Grzybowski, B. Marshall, M. Gudmundsson, S. Jørgensen","doi":"10.5194/SD-25-57-2019","DOIUrl":"https://doi.org/10.5194/SD-25-57-2019","url":null,"abstract":"Abstract. Surtsey, the youngest of the islands of Vestmannaeyjar, is an oceanic volcano\u0000created by explosive basaltic eruptions during 1963–1967 off the southern\u0000coast of Iceland. The subsurface deposits of the volcano were first sampled\u0000by a cored borehole in 1979. In summer 2017, three cored boreholes were\u0000drilled through the active hydrothermal system of the volcano by the International Continental Scientific Drilling Program (ICDP)\u0000SUSTAIN Expedition 5059. These cores are expected to provide the first\u0000glimpse of microbial life in very young and native basaltic tuff of the\u0000oceanic crust. To reduce the contamination of the subsurface environment,\u0000seawater circulating fluid was filtered and passed through two\u0000UV-sterilizing treatments. One of the boreholes has been equipped with a\u0000subsurface observatory dedicated in situ experiments for monitoring water–rock\u0000interactions and microbial processes in sterile, artificial basaltic glass\u0000and in olivine granules. With temperatures ranging from 25 to 125 ∘C, the subsurface observatory provides a precise geothermal\u0000window into an active hydrothermal system and thus represents an exceptional\u0000natural laboratory for studying fluid–rock–microbe interactions at different\u0000temperature regimes and facilitates experimental validation of active\u0000submarine microbial processes at the limit of functional life, about 121 ∘C. Comparisons with the 1979 and 2019 drill cores will provide\u0000time-lapse observations of hydrothermal processes over a 50-year timescale.\u0000Here, we present the technical design of the observatory and the incubation\u0000chamber experiments deployed from September 2017 to summer 2019.\u0000","PeriodicalId":51840,"journal":{"name":"Scientific Drilling","volume":"24 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2019-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84440985","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Lisé-Pronovost, M. Fletcher, Tom Mallett, M. Mariani, Richard D. Lewis, P. Gadd, A. Herries, M. Blaauw, H. Heijnis, D. Hodgson, J. Pedro
Abstract. A 70 m long continental sediment record was recovered at Darwin Crater in western Tasmania, Australia. The sediment succession includes a pre-lake silty sand deposit overlain by lacustrine silts that have accumulated in the ∼816 ka meteorite impact crater. A total of 160 m of overlapping sediment cores were drilled from three closely spaced holes. Here we report on the drilling operations at Darwin Crater and present the first results from petrophysical whole core logging, lithological core description, and multi-proxy pilot analysis of core end samples. The multi-proxy dataset includes spectrophotometry, grain size, natural gamma rays, paleo- and rock magnetism, loss on ignition, and pollen analyses. The results provide clear signatures of alternating, distinctly different lithologies likely representing glacial and interglacial sediment facies. Initial paleomagnetic analysis indicate normal magnetic polarity in the deepest core at Hole B. If acquired at the time of deposition, this result indicates that the sediment 1 m below commencement of lacustrine deposition post-date the Matuyama–Brunhes geomagnetic reversal ∼773 ka.
{"title":"Scientific drilling of sediments at Darwin Crater, Tasmania","authors":"A. Lisé-Pronovost, M. Fletcher, Tom Mallett, M. Mariani, Richard D. Lewis, P. Gadd, A. Herries, M. Blaauw, H. Heijnis, D. Hodgson, J. Pedro","doi":"10.5194/SD-25-1-2019","DOIUrl":"https://doi.org/10.5194/SD-25-1-2019","url":null,"abstract":"Abstract. A 70 m long continental sediment record was recovered at Darwin\u0000Crater in western Tasmania, Australia. The sediment succession includes a\u0000pre-lake silty sand deposit overlain by lacustrine silts that have\u0000accumulated in the ∼816 ka meteorite impact crater. A total of 160 m\u0000of overlapping sediment cores were drilled from three closely spaced holes.\u0000Here we report on the drilling operations at Darwin Crater and present the\u0000first results from petrophysical whole core logging, lithological core\u0000description, and multi-proxy pilot analysis of core end samples. The\u0000multi-proxy dataset includes spectrophotometry, grain size, natural gamma\u0000rays, paleo- and rock magnetism, loss on ignition, and pollen analyses. The\u0000results provide clear signatures of alternating, distinctly different\u0000lithologies likely representing glacial and interglacial sediment facies.\u0000Initial paleomagnetic analysis indicate normal magnetic polarity in the\u0000deepest core at Hole B. If acquired at the time of deposition, this result\u0000indicates that the sediment 1 m below commencement of lacustrine deposition\u0000post-date the Matuyama–Brunhes geomagnetic reversal ∼773 ka.\u0000","PeriodicalId":51840,"journal":{"name":"Scientific Drilling","volume":"34 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2019-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74239872","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
T. Haberzettl, G. Daut, N. Schulze, V. Spiess, Junbo Wang, Liping Zhu
Abstract. The Tibetan Plateau is of peculiar societal relevance as it provides freshwater from the so-called “Water Tower of Asia” to a large portion of the Asian population. However, future climate change will affect the hydrological cycle in this area. To define parameters for future climate change scenarios it is necessary to improve the knowledge about thresholds, timing, pace and intensity of past climatic changes and associated environmental impacts. Sedimentary archives reaching far back in time and spanning several glacial–interglacial cycles such as Nam Co provide the unique possibility to extract such information. In order to explore the scientific opportunities that an ICDP drilling effort at Nam Co would provide, 40 scientists from 13 countries representing various scientific disciplines met in Beijing from 22 to 24 May 2018. Besides paleoclimatic investigations, opportunities for paleomagnetic, deep biosphere, tectonic and paleobiological studies were discussed. After having explored the technical and logistical challenges and the scientific opportunities all participants agreed on the great value and need to drill this extraordinary archive, which has a sediment thickness of more than 1 km, likely covering more than 1 Ma.
{"title":"ICDP workshop on scientific drilling of Nam Co on the Tibetan Plateau: 1 million years of paleoenvironmental history, geomicrobiology, tectonics and paleomagnetism derived from sediments of a high-altitude lake","authors":"T. Haberzettl, G. Daut, N. Schulze, V. Spiess, Junbo Wang, Liping Zhu","doi":"10.5194/SD-25-63-2019","DOIUrl":"https://doi.org/10.5194/SD-25-63-2019","url":null,"abstract":"Abstract. The Tibetan Plateau is\u0000of peculiar societal relevance as it provides freshwater from the so-called\u0000“Water Tower of Asia” to a large portion of the Asian population. However,\u0000future climate change will affect the hydrological cycle in this area. To\u0000define parameters for future climate change scenarios it is necessary to\u0000improve the knowledge about thresholds, timing, pace and intensity of past\u0000climatic changes and associated environmental impacts. Sedimentary archives\u0000reaching far back in time and spanning several glacial–interglacial cycles\u0000such as Nam Co provide the unique possibility to extract such information. In\u0000order to explore the scientific opportunities that an ICDP drilling effort at\u0000Nam Co would provide, 40 scientists from 13 countries representing various\u0000scientific disciplines met in Beijing from 22 to 24 May 2018. Besides\u0000paleoclimatic investigations, opportunities for paleomagnetic, deep\u0000biosphere, tectonic and paleobiological studies were discussed. After having\u0000explored the technical and logistical challenges and the scientific\u0000opportunities all participants agreed on the great value and need to drill\u0000this extraordinary archive, which has a sediment thickness of more than\u00001 km, likely covering more than 1 Ma.\u0000","PeriodicalId":51840,"journal":{"name":"Scientific Drilling","volume":"14 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2019-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76808297","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
D. Jerram, D. Jerram, John Millett, J. Kück, D. Thomas, S. Planke, E. Haskins, N. Lautze, S. Pierdominici
Abstract. To help understand volcanic facies in the subsurface, data sets that enable detailed comparisons between down-hole geophysical data and cored volcanic intervals are critical. However, in many cases, the collection of extended core intervals within volcanic sequences is rare and often incomplete due to challenging coring conditions. In this contribution we outline and provide initial results from borehole logging operations within two fully cored lava-dominated borehole sequences, PTA2 and KMA1, on the Big Island of Hawai`i. Data for spectral gamma, magnetic susceptibility, dipmeter resistivity, sonic, total magnetic field, temperature and televiewer wireline logs were successfully acquired for the open hole interval ca. 889 m to 1567 m within the PTA2 borehole. Spectral gamma was also collected from inside the casing of both wells, extending the coverage for PTA2 to the surface and covering the interval from ca. 300 to 1200 m for KMA1. High-quality core material was available for both boreholes with almost complete recovery which enabled high-resolution core-to-log integration. Gamma data are generally low commonly in the range ca. 7–20 gAPI but are shown to increase up to API of ca. 60 with some intrusions and with increases in hawaiite compositions in the upper part of PTA2. Velocity data are more variable due to alteration within porous volcanic facies than with burial depth, with a general degrease down-hole. The high-resolution televiewer data have been compared directly to the core, enabling a comprehensive analysis of the variations in the televiewer responses. This has enabled the identification of key features including individual vesicles, vesicle segregations, strained vesicles, chilled margins, rubble zones, intrusive contacts and pāhoehoe lobe morphologies, which can be confidently matched between the televiewer data and the full diameter core. The data set and results of this study include findings which should enable improved borehole facies analysis through volcanic sequences in the future, especially where down-borehole data and images but no core are available.
{"title":"Understanding volcanic facies in the subsurface: a combined core, wireline logging and image log data set from the PTA2 and KMA1 boreholes, Big Island, Hawai`i","authors":"D. Jerram, D. Jerram, John Millett, J. Kück, D. Thomas, S. Planke, E. Haskins, N. Lautze, S. Pierdominici","doi":"10.5194/SD-25-15-2019","DOIUrl":"https://doi.org/10.5194/SD-25-15-2019","url":null,"abstract":"Abstract. To help understand volcanic facies in the subsurface, data sets\u0000that enable detailed comparisons between down-hole geophysical data and cored\u0000volcanic intervals are critical. However, in many cases, the collection of\u0000extended core intervals within volcanic sequences is rare and often\u0000incomplete due to challenging coring conditions. In this contribution we\u0000outline and provide initial results from borehole logging operations within\u0000two fully cored lava-dominated borehole sequences, PTA2 and KMA1, on the Big\u0000Island of Hawai`i. Data for spectral gamma, magnetic susceptibility, dipmeter\u0000resistivity, sonic, total magnetic field, temperature and televiewer wireline\u0000logs were successfully acquired for the open hole interval ca. 889 m to 1567 m within the PTA2 borehole. Spectral gamma was also collected from inside the\u0000casing of both wells, extending the coverage for PTA2 to the surface and\u0000covering the interval from ca. 300 to 1200 m for KMA1. High-quality core\u0000material was available for both boreholes with almost complete recovery which\u0000enabled high-resolution core-to-log integration. Gamma data are generally low\u0000commonly in the range ca. 7–20 gAPI but are shown to increase up to API of\u0000ca. 60 with some intrusions and with increases in hawaiite compositions in\u0000the upper part of PTA2. Velocity data are more variable due to alteration\u0000within porous volcanic facies than with burial depth, with a general degrease\u0000down-hole. The high-resolution televiewer data have been compared directly to\u0000the core, enabling a comprehensive analysis of the variations in the\u0000televiewer responses. This has enabled the identification of key features\u0000including individual vesicles, vesicle segregations, strained vesicles,\u0000chilled margins, rubble zones, intrusive contacts and pāhoehoe lobe\u0000morphologies, which can be confidently matched between the televiewer data\u0000and the full diameter core. The data set and results of this study include\u0000findings which should enable improved borehole facies analysis through\u0000volcanic sequences in the future, especially where down-borehole data and images\u0000but no core are available.\u0000","PeriodicalId":51840,"journal":{"name":"Scientific Drilling","volume":"113 1","pages":""},"PeriodicalIF":1.2,"publicationDate":"2019-06-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79451537","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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