Proceedings of the International Ocean Discovery Program最新文献

{"title":"Expedition 363 summary","authors":"Y. Rosenthal, A. Holbourn, D. Kulhanek, I. Aiello, T. Babila, G. Bayon, L. Beaufort, S. C. Bova, J.-H. Chun, H. Dang, A. Drury, T. Jones, P. Eichler, A.G.S. Fernando, K. Gibson, R. G. Hatfield, D. Johnson, Y. Kumagai, Tonglin Li, B. Linsley, N. Meinicke, G. Mountain, B. Opdyke, P.N. Pearson, C. R. Poole, A. Ravelo, T. Sagawa, A. Schmitt, J. B. Wurtzel, Jian Xu, Masanobu Yamamoto, Yi Ge Zhang","doi":"10.14379/IODP.PROC.363.101.2018","DOIUrl":"https://doi.org/10.14379/IODP.PROC.363.101.2018","url":null,"abstract":"International Ocean Discovery Program Expedition 363 sought to document the regional expression and driving mechanisms of climate variability (e.g., temperature, precipitation, and productivity) in the Indo-Pacific Warm Pool (IPWP) as it relates to the evolution of Neogene climate on millennial, orbital, and geological timescales. To achieve our objectives, we selected sites with a wide geographical distribution and variable oceanographic and depositional settings. Nine sites were cored during Expedition 363, recovering a total of 6956 m of sediment in 875–3421 m water depth with an average recovery of 101.3% during 39.6 days of on-site operations. Two moderate sedimentation rate (~3–10 cm/ky) sites are located off northwestern Australia at the southwestern maximum extent of the IPWP and span the late Miocene to present. Seven of the nine sites are situated at the heart of the Western Pacific Warm Pool (WPWP), including two sites on the northern margin of Papua New Guinea with very high sedimentation rates (>60 cm/ky) spanning the past ~450 ky, two sites in the Manus Basin (north of Papua New Guinea) with moderate sedimentation rates (~4–14 cm/ky) recovering upper Pliocene to present sequences, and three sites with low sedimentation rates (~1–3 cm/ky) on the southern and northern Eauripik Rise spanning the early Miocene to present. The wide spatial distribution of the cores, variable accumulation rates, exceptional biostratigraphic and paleomagnetic age constraints, and mostly excellent or very good foraminifer preservation will allow us to trace the evolution of the IPWP through the Neogene at different temporal resolutions, meeting the primary objectives of Expedition 363. Specifically, the high–sedimentation rate cores off Papua New Guinea will allow us to better constrain mechanisms influencing millennial-scale variability in the WPWP, their links to high-latitude climate variability, and implications for temperature and precipitation in this region under variable mean-state climate conditions. Furthermore, the high accumulation rates offer the opportunity to study climate variability during previous warm periods at a resolution similar to that of existing studies of the Holocene. With excellent recovery, Expedition 363 sites are suitable for detailed paleoceanographic reconstructions at orbital and suborbital resolution from the middle Miocene to Pleistocene and thus will be used to refine the astronomical tuning, biostratigraphy, magnetostratigraphy, and isotope stratigraphy of hitherto poorly constrained intervals within the Neogene timescale (e.g., the late Miocene) and to reconstruct the history of the Asian-Australian monsoon and the Indonesian Throughflow on orbital and tectonic timescales. Results Y. Rosenthal et al. Expedition 363 summary from high-resolution interstitial water sampling at selected sites will be used to reconstruct density profiles of the western equatorial Pacific deep water during the Last Glacial Maximum. Addition","PeriodicalId":20641,"journal":{"name":"Proceedings of the International Ocean Discovery Program","volume":"82 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77591329","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}

{"title":"Site U1490","authors":"Y. Rosenthal, A. Holbourn, D. Kulhanek, I. Aiello, T. Babila, G. Bayon, L. Beaufort, S. C. Bova, J.-H. Chun, H. Dang, A. Drury, T. Dunkley Jones, P. Eichler, A.G.S. Fernando, K. Gibson, R. G. Hatfield, D.L. Johnson, Y. Kumagai, T. Li, B. Linsley, N. Meinicke, G. Mountain, B. Opdyke, P.N. Pearson, C. R. Poole, A. Ravelo, T. Sagawa, A. Schmitt, J. Wurtzel, J. Xu, M. Yamamoto, Y.G. Zhang","doi":"10.14379/iodp.proc.363.111.2018","DOIUrl":"https://doi.org/10.14379/iodp.proc.363.111.2018","url":null,"abstract":"Y. Rosenthal, A.E. Holbourn, D.K. Kulhanek, I.W. Aiello, T.L. Babila, G. Bayon, L. Beaufort, S.C. Bova, J.-H. Chun, H. Dang, A.J. Drury, T. Dunkley Jones, P.P.B. Eichler, A.G.S. Fernando, K. Gibson, R.G. Hatfield, D.L. Johnson, Y. Kumagai, T. Li, B.K. Linsley, N. Meinicke, G.S. Mountain, B.N. Opdyke, P.N. Pearson, C.R. Poole, A.C. Ravelo, T. Sagawa, A. Schmitt, J.B. Wurtzel, J. Xu, M. Yamamoto, and Y.G. Zhang2","PeriodicalId":20641,"journal":{"name":"Proceedings of the International Ocean Discovery Program","volume":"34 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-06-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84678968","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}

{"title":"pXRF and ICP-AES characterization of shipboard rocks and sediments: protocols and strategies","authors":"R. Johnston, J. Ryan","doi":"10.14379/IODP.PROC.366.110.2018","DOIUrl":"https://doi.org/10.14379/IODP.PROC.366.110.2018","url":null,"abstract":"Recovered shipboard solids (rocks and sediments) may be characterized for elemental abundances on International Ocean Discovery Program (IODP) expeditions in several ways, using either the shipboard inductively coupled plasma–atomic emission spectrometer (ICP-AES) or a handheld portable X-ray fluorescence spectrometer (pXRF). These two instruments have overlapping capabilities in terms of the elements they measure but are designed to meet different analytical needs. During Expedition 366, we made extensive use of both instruments to conduct standard bulk elemental analysis of samples and in situ measurements on rock surfaces of cores. The following is a description of current shipboard measurement protocols for recovered rocks and sediments using these instruments, an analysis of the respective methodologies, and recommendations for best analytical practices. Portable X-ray fluorescence spectrometry Based on the success in using portable X-ray fluorescence spectrometry (pXRF) for core characterization during International Ocean Discovery Program (IODP) Expedition 352 (Ryan et al., 2017; Reagan et al., 2015, 2017), pXRF was used both to conduct near–real time characterization of recovered rock samples from cores and to analyze serpentinite rock powders and unconsolidated serpentinite samples during Expedition 366. A new pXRF—an Olympus DeltaX handheld instrument—was acquired by IODP for use during Expedition 366 and future expeditions. Compared to the original Fisher Niton instrument described in Ryan et al. (2017), this new instrument has overall expanded analytical capabilities. The Olympus DeltaX is a self-contained energy-dispersive XRF survey tool that includes data correction packages tailored to geological applications. The data correction methods are based on “fundamental parameters” methodology, which solves a series of nonlinear equations for each analyzed element. The parameters used in these equations comprise metrics for the X-ray source, fluorescence intensities, absorption coefficients, and absorption edge effects for each wavelength analyzed, together with parameters for sample geometry (e.g., van Sprang, 2000) and a Compton normalization scheme (Reynolds, 1963). The “geochemistry/soils” protocol used on the ship presumes a perpendicular sample geometry. The protocol analyzes for elements at two different filter settings to optimize results. Analysis of different core materials Generally, the pXRF instrument is operated by the shipboard scientist(s), typically from the Petrology/Core Description or Geochemistry teams, who are tasked with overseeing its use. The protocol for rock surface analyses used during Expedition 366 is as follows. Rock surface samples The primary shipboard use of the pXRF instrument during Expedition 366 was to conduct quick geochemical assessments of the cored material through direct measurements on rock surfaces of either workingor archive-half core pieces. For these measurements, rock samples that could be","PeriodicalId":20641,"journal":{"name":"Proceedings of the International Ocean Discovery Program","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-05-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91071457","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}