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1. Data report: X-ray fluorescence studies of Site U1457 sediments, Laxmi Basin, Arabian Sea

   https://doi.org/10.14379/iodp.proc.355.203.2018  

   Lyle, M. ; Kulhanek, D.K. ; Bowen, M.G. ; Hahn, A. ( December 2018 , Proceedings of the International Ocean Discovery Program)

   null (Ed.)

   Bulk sediment chemistry was measured at 2 cm resolution along cores from International Ocean Discovery Program (IODP) Site U1457 using the X-ray fluorescence (XRF) core scanner at the IODP Gulf Coast Repository. The Pleistocene splice section assembled from Holes U1457A and U1457B was scanned in its entirety, and nearly continuous sediment bulk chemistry profiles were constructed to a depth of 125 m core composite depth below seafloor (CCSF). Some sections of Hole U1457C were also scanned: (1) an upper Miocene hemipelagic section and (2) a 30 m lower Paleocene section directly overlying basalt. In the Pleistocene spliced sections, 2 cm spacing represents a sampling resolution of 150–300 y, whereas in the upper Miocene section this spacing represents about 500 y between samples. We report data and acquisition conditions for major and many minor elements. We find large variability in CaCO3 content in the Pleistocene section, from around 14 to 89 wt%. We used discrete shipboard CaCO3 measurements to calibrate the XRF Ca data. CaCO3 has cyclic variability and correlates with light sediment colors. Variation in aluminosilicate elements is largely caused by changes in dilution by CaCO3. The lower part of the spliced section, presumably representing distal Indus Fan deposits, has a distinctive but more uniform composition than the upper part. 

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2. Data report: revised composite depth scale and splice for IODP Expedition 363 Site U1483

   https://doi.org/10.14379/iodp.proc.363.201.2020  

   Gong, L. ; Lübbers, J. ; Beil, S. ; Holbourn, A. ( June 2020 , Proceedings of the International Ocean Discovery Program)

   null (Ed.)

   The shipboard sediment splice of International Ocean Discovery Program Expedition 363 Site U1483, drilled in 1733 m water depth on the Scott Plateau off Northwest Australia, was primarily based on a composite of the magnetic susceptibility records at 2.5 cm resolution from three holes drilled at this site. We performed X-ray fluorescence (XRF) core scanning at 2 cm intervals with overlaps of ~1–2 m at splice tie points and used these new data to verify the tie points along the original splice from 0 to 211.53 m core composite depth below seafloor (CCSF). Based on the XRF records, we revised the position of three original tie points and present a revised composite depth scale for Site U1483. These revisions resulted in shifts of up to 94 cm relative to the original shipboard offsets and a continuous section extending down to 211.62 m revised core composite depth below seafloor (r-CCSF). 

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3. Data report: revision of IODP Expedition 363 Site U1482 shipboard sediment splice based on X-ray fluorescence scanning elemental data

   https://doi.org/10.14379/iodp.proc.363.202.2020  

   Lübbers, J. ; Holbourn, A.E. ; Kuhnt, W. ; Beil, S. ( September 2020 , Proceedings of the International Ocean Discovery Program)

   null (Ed.)

   International Ocean Discovery Program (IODP) Expedition 363 recovered extended Neogene to Quaternary carbonate- and clay-rich sedimentary successions at Site U1482 (15°3.32ʹS, 120°26.10ʹE; 1466 m water depth), drilled at the southwestern edge of the Indo-Pacific Warm Pool off northwest Australia (Rosenthal et al., 2018b). Four holes were drilled with the advanced piston corer (APC) system at this site and deepened with the half-length APC (HLAPC) and extended core barrel (XCB) systems. A shipboard splice, from 0 to 451.26 m core composite depth below seafloor (CCSF), was established. After the expedition, the cores were scanned at high-resolution (1–2 cm) using an Avaatech X-ray fluorescence (XRF) core scanner. Scanning was performed along the shipboard splice with approximately 1 m overlap at the splice tie points for verification. Based on this new data set, we revised nine of the original splice tie points. The revised splice for Site U1482 now extends to 445.11 m revised CCSF and is available from the IODP Laboratory Information Management System (LIMS) database. 

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4. Can We See Dust from the 1992 Fall of the Peekskill Meteorite in Hudson River Sediments and Can We Use It as a Stratigraphic Marker?(Regional and Local Stratigraphic Markers in Three Hudson River Cores Taken Near Peekskill, New York: LWB4-1)

   Diallo, M. B. ; McCann, B. ; Abdul, B. ; Adeghe, S. ; Abbott, D. H. ; Bostick, B. C. ; Chang, C. ; Block, K. A. ( December 2018 , American Geophysical Union, Fall Meeting 2018, abstract #B53I-2168)

   We have been studying the stratigraphy of core LWB4-1 taken in 2001 in the Hudson River about 100 meters north of the calculated transit path of the Peekskill meteorite in October 1992. We measured magnetic susceptibility at 1cm intervals from 0 -70 cm depth and found a layer with a magnetic susceptibility of 11 cgs units at 6 cm depth. This is the highest susceptibility in the top 40 cm of the core. Scanning X-Ray Fluorescence spectroscopy revealed the high susceptibility layer at 6 cm depth is part of a 3 cm interval with a high Ni/Cr ratio, but the depth of the peak in the Ni/Cr ratio is poorly resolved due to measurement error. We plan to dry and homogenize discreet samples for analysis on bench top XRF to reduce Ni and Cr error. Based on our identification of the base of modern Pb at 68 cm depth, the top 40 cm of the core covers the time interval from 2001 to 1930. From previous work on Central Park Lake, the base of modern Pb represents the year 1880 A.D. A uniform sedimentation rate model is supported a peak in Pb and As at 8 cm depth. The peak might represent the 1988 ban on the use of Pb arsenide and the start of use of DDT as a pesticide. We found a second peak in Pb at 37.5cm potentially from 1938, the date at which incineration was banned in New York City. We found a third peak in Pb at 50.5cm that might be from World War I around 1914. We found two deeper susceptibility peaks of 12 cgs at 43 cm and 8 cgs at 59 cm. These peaks could represent major Hudson River floods in 1927 and 1903. 137Cs and 210Pb 210 dating are in progress and will help us to determine if our age model is correct. Also, our core exhibits a distinct increase in Ca content starting at 18-25 cm depth and increasing towards the top of the core. This increase could be due to increased erosion, anthropogenic inputs or increased dissolution of CaCO3 rich rocks. We are measuring CaCO3 in the core to better determine the origin of this increase of Ca. 

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5. Data report: X-ray fluorescence scanning of Site U1574, Vøring Plateau, IODP Expedition 396

   Alvarez_Zarikian, CA ; Yager, SL ; Harper, DT ; Christopoulou, M ; Clementi, VJ ; Varela, N ( October 2024 , Proceedings of the International Ocean Discovery Program Expedition reports)

   Semiquantitative elemental results from X-ray fluorescence (XRF) scanning of sediment cores from International Ocean Discovery Program (IODP) Site U1574 in the Vøring Plateau, Norwegian Margin, are presented in this report. XRF elemental data were collected every 1 cm from a stratigraphically complete and continuous cored section with 102% recovery from the sea bottom to ~170 meters below seafloor in Hole U1574C. We report raw element intensities (counts) for Al, Si, K, Ca, Ti, Fe, Br, Sr, and Zr and identify covariation patterns consistent with lithofacies variations. Our high-resolution XRF scanning was conducted to better characterize the sediment depositional history at Site U1574 and to aid interpretation of past environmental and oceanographic conditions in the Norwegian Margin, targeting the earliest incursion of deep water into the young North Atlantic Ocean during the Early to Middle Eocene. The high-resolution XRF data also may help improve the age-depth model for the sediment succession at Site U1574. 

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