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International Ocean Discovery Program (IODP) Site U1556, located on a basement high above Site U1557, is one of the oldest sites drilled on the South Atlantic Transect with a basement age of ~61 Ma. Here, we present semiquantitative X-ray fluorescence core scan data from the Site U1556 splice and compare them with shipboard magnetic susceptibility and natural gamma ray (NGR) measurements to characterize elemental composition changes downcore. Elements primarily associated with detrital (e.g., Al, Fe, K, Ti, and Zr) and biogenic (e.g., Ca) sources are inversely correlated. Biogenic and detrital sourced elements vary synchronously with magnetic susceptibility and NGR measurements following alternations between silty clay and calcareous nannofossil ooze/chalk in Unit I, whereas biogenic sourced elements tend to dominate Unit II, corresponding to a lithology change to predominantly calcareous nannofossil ooze/chalk. 

International Ocean Discovery Program (IODP) Expeditions 390C, 395E, 390, and 393 recovered deepwater sediments from the western flank of the Mid-Atlantic Ridge in the South Atlantic Ocean along the South Atlantic Transect (SAT) at ~31°S. Collectively, these expeditions recovered ~2 km of sediment cores that have the potential to capture key features of Cenozoic climate change. In this report, we show semiquantitative bulk elemental results from X-ray fluorescence (XRF) scanning of the sediment cores from IODP Site U1560 recovered during Expeditions 395E and 393. The oceanic basement at this site is ~15 My old, making it the second youngest of the SAT sites located west of the Mid-Atlantic Ridge. Here, XRF data are compared with pass-through magnetic susceptibility and natural gamma radiation of the sediment cores, measured aboard JOIDES Resolution. The resulting trends and correlations highlight elemental variations through time, mainly reflecting lithologic and compositional differences. At Site U1560, Ca counts reflect the occurrence of nannofossil ooze, which is the dominant lithology for the whole site. In the Miocene-aged Lithologic Units IE–IA from 140 to 50 m core composite depth below seafloor (CCSF), several high-intensity spikes of detrital elements (i.e., Fe, Ti, Al, Si, and Zr) correspond to intervals of clay-rich nannofossil ooze. Detrital elemental counts in the entire Pliocene record (50 to ~25 m CCSF) are the lowest. A sharp shift is observed at the Pliocene/Pleistocene boundary at ~25 m CCSF, with the uppermost Pleistocene record showing high-frequency and high-intensity variations in siliciclastic elements, which correlates well with the pass-through magnetic susceptibility. 

We report semiquantitative elemental data from X-ray fluorescence (XRF) scanning of Site U1558 sediment cores drilled during International Ocean Discovery Program Expeditions 390C and 393. These expeditions, together with Expeditions 395E and 390, form the South Atlantic Transect, which collected sediment and basement cores from the western flank of the southern Mid-Atlantic Ridge. XRF scanning of the continuous splice of Site U1558, using Holes U1558A and U1558F, was conducted at three acceleration voltages to capture a range of major, minor, and trace elements. At Site U1558, positive correlations exist between terrigenous-sourced elements (Al, Si, Ti, and Fe) and a negative correlation exists between the terrigenous-sourced elements and Ca. XRF geochemistry is correlated with lithologic changes, most notably at the boundary of Lithologic Units I and II, where Unit I is brown and reddish brown nannofossil-rich clay and Unit II is pink, pinkish white, pinkish gray, and light brown nannofossil ooze and chalk with varying amounts of clay and foraminifera. Peaks in XRF data align with the boundaries of Lithologic Subunits IIA and IIB and Subunits IIB and IIC. 

Site U1557 is the deepest and one of the oldest sites drilled during International Ocean Discovery Program Expeditions 390C, 395E, 390, and 393 on the South Atlantic Transect. It differs from the nearby Site U1556, which also sits on early Paleocene crust, by its stratigraphically expanded Paleocene–Eocene section. Here, we present the results of programmatic X-ray fluorescence (XRF) core scanning of the entire thickness of the sedimentary section at Site U1557. We find a major shift in XRF geochemistry at the boundary between Lithologic Units I and II, coincident with a shift in spectral gamma ray and magnetic susceptibility, as well as a shift from alternating pelagic carbonate and pelagic clay in Unit I to pelagic carbonate in Unit II. Within Unit I, shifts in major elemental composition of core material track alternations between carbonate-rich and clay-rich intervals. 

The western South Atlantic Ocean is a relatively understudied area of the world’s ocean, in part because of the lack of scientific ocean drilling and complete sedimentary sequences. During 2020–2022, a series of International Ocean Discovery Program Expeditions (390C, 395E, 390, and 393; South Atlantic Transect) sailed to this area, recovering material from the western flank of the Mid-Atlantic Ridge at a latitude of ~31°S. Here, we used X-ray fluorescence scanning of the sediment cores recovered and combined the data with shipboard magnetic susceptibility and natural gamma radiation to generate long-term geochemical records at Site U1561. These records enable us to document climatic and environmental perturbations on varying timescales and explore the paleoclimatic and paleoceanographic history of the western South Atlantic Ocean during the Cenozoic. 

During International Ocean Discovery Program (IODP) Expeditions 390C, 395E, 390, and 393, deepwater sediments were recovered from the western flank of the southern Mid-Atlantic Ridge along a crustal flow line at ~31°S. This multidisciplinary experiment allowed the recovery of data fundamental to reconstructing past climate changes as well as variations in ocean circulation, productivity, and chemistry (i.e., fluctuations in the carbonate compensation depth) in the South Atlantic Ocean. Here, we report semiquantitative elemental results from X-ray fluorescence (XRF) scanning of the sediment package cored at IODP Site U1559 in the South Atlantic Ocean. Located at 15°02.0941′W, Site U1559 is the easternmost site of the South Atlantic Transect and the closest to the Mid-Atlantic Ridge, located on ~6.6. Ma ocean crust. The XRF data are also compared with magnetic susceptibility and natural gamma radiation measured on the R/V JOIDES Resolution to assess correlations with the different lithologic units/subunits. At Site U1559, sediments are predominantly nannofossil ooze with varying amounts of foraminifera, which is reflected by the dominant Ca counts. Trends in elemental counts reflect the slight variations in siliciclastic materials within the Pleistocene. Major shifts in elemental counts were observed at the sharp contact between Pliocene–Pleistocene Subunits IC and ID, as well as the Miocene–Pliocene transition. 

The western South Atlantic Ocean has not been drilled since the end of the Deep Sea Drilling Program, leading to a dearth of sedimentary sequences available from this sector of the Atlantic Ocean. In 2020–2022, a transect of new sites was drilled during International Ocean Discovery Program Expeditions 390C, 395E, 390, and 393 at 31°S and spanning from 28.8°W to 15.2°W. Here, we use X-ray fluorescence data, combined with shipboard magnetic susceptibility and natural gamma radiation, to characterize the sediments below the oligotrophic South Atlantic Gyre at Site U1583. These geochemical data add to the otherwise understudied southwest Atlantic Ocean. 

Site U1559 (30°15.6336′S, 15°02.0941′W; proposed Site SATL-13A) is in the central South Atlantic Ocean at a water depth of 3055 meters below sea level (mbsl), ~130 km west of the Mid-Atlantic Ridge (see Figure F1 and Tables T1, T2, all in the Expedition 390/393 summary chapter [Coggon et al., 2024d]) on crust that formed at a slow half-spreading rate of ~17.0 mm/y (Kardell et al., 2019; Christeson et al., 2020) (see Figure F7 in the Expedition 390/393 summary chapter [Coggon et al., 2024d]). With an estimated age of 6.6 Ma, Site U1559 is the youngest location of the South Atlantic Transect (SAT) campaign (International Ocean Discovery Program [IODP] Expeditions 390C, 395E, 390, and 393). 

Site U1583 (30°42.6175′S, 20°26.0336′W; proposed Site SATL-33B) is in the central South Atlantic Ocean at a water depth of ~4210 meters below sea level (mbsl), ~652 km west of the Mid-Atlantic Ridge (see Figure F1 and Tables T1, T2, all in the Expedition 390/393 summary chapter [Coggon et al., 2024b]) on crust that formed at an intermediate half spreading rate of ~24 mm/y, which is close to the highest spreading rate in the study region (Kardell et al., 2019; Christeson et al., 2020) (see Figure F7 in the Expedition 390/393 summary chapter [Coggon et al., 2024b]). With an estimated age of 30.6 Ma, Site U1583 is close to the median age of the South Atlantic Transect (SAT) campaign (International Ocean Discovery Program [IODP] Expeditions 390C, 395E, 390, and 393), and it is closest to the geographic midpoint.