This file was created by the TYPO3 extension publications --- Timezone: CEST Creation date: 2026-04-23 Creation time: 20:02:18 --- Number of references 7 article Schiferl2023 Article 2023 10.1038/s41467-023-43231-0 Nature Communications 14 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85176766328&doi=10.1038%2fs41467-023-43231-0&partnerID=40&md5=d77b9f59528c896f87a1cb8772663a73 Cited by: 7; All Open Access, Gold Open Access, Green Open Access J. Schiferl M. Kingston C.M. Åkesson B.G. Valencia A. Rozas-Davila D. McGee A. Woods C.Y. Chen R.G. Hatfield D.T. Rodbell M.B. Abbott M.B. Bush article Rodbell2022301 Our understanding of the climatic teleconnections that drove ice-age cycles has been limited by a paucity of well-dated tropical records of glaciation that span several glacial–interglacial intervals. Glacial deposits offer discrete snapshots of glacier extent but cannot provide the continuous records required for detailed interhemispheric comparisons. By contrast, lakes located within glaciated catchments can provide continuous archives of upstream glacial activity, but few such records extend beyond the last glacial cycle. Here a piston core from Lake Junín in the uppermost Amazon basin provides the first, to our knowledge, continuous, independently dated archive of tropical glaciation spanning 700,000 years. We find that tropical glaciers tracked changes in global ice volume and followed a clear approximately 100,000-year periodicity. An enhancement in the extent of tropical Andean glaciers relative to global ice volume occurred between 200,000 and 400,000 years ago, during sustained intervals of regionally elevated hydrologic balance that modified the regular approximately 23,000-year pacing of monsoon-driven precipitation. Millennial-scale variations in the extent of tropical Andean glaciers during the last glacial cycle were driven by variations in regional monsoon strength that were linked to temperature perturbations in Greenland ice cores1; these interhemispheric connections may have existed during previous glacial cycles. © 2022, The Author(s). Article 2022 English 00280836 10.1038/s41586-022-04873-0 Nature 607 Nature Research 301 – 306 7918 Greenland; Ice Cover; Temperature; Amazon River; Arctic; Greenland; glaciation; monsoon; Pleistocene; teleconnection; article; glaciation; Greenland; information center; periodicity; precipitation; ice cover; temperature https://www.scopus.com/inward/record.uri?eid=2-s2.0-85133993341&doi=10.1038%2fs41586-022-04873-0&partnerID=40&md5=53751a36b337ca6f5e930ee15338265f Cited by: 2; All Open Access, Green Open Access, Hybrid Gold Open Access D.T. Rodbell R.G. Hatfield M.B. Abbott C.Y. Chen A. Woods J.S. Stoner D. McGee P.M. Tapia M. Bush B.L. Valero-Garcés S.B. Lehmann S.Z. Mark N.C. Weidhaas A.L. Hillman D.J. Larsen G. Delgado S.A. Katz K.E. Solada A.E. Morey M. Finkenbinder B. Valencia A. Rozas-Davila N. Wattrus S.M. Colman M.G. Bustamante J. Kück S. Pierdominici article Woods2020 Abrupt warming events recorded in Greenland ice cores known as Dansgaard-Oeschger (DO) interstadials are linked to changes in tropical circulation during the last glacial cycle. Corresponding variations in South American summer monsoon (SASM) strength are documented, most commonly, in isotopic records from speleothems, but less is known about how these changes affected precipitation and Andean glacier mass balance. Here we present a sediment record spanning the last ~50 ka from Lake Junín (Peru) in the tropical Andes that has sufficient chronologic precision to document abrupt climatic events on a centennial-millennial time scale. DO events involved the near-complete disappearance of glaciers below 4700 masl in the eastern Andean cordillera and major reductions in the level of Peru’s second largest lake. Our results reveal the magnitude of the hydroclimatic disruptions in the highest reaches of the Amazon Basin that were caused by a weakening of the SASM during abrupt arctic warming. Accentuated warming in the Arctic could lead to significant reductions in the precipitation-evaporation balance of the southern tropical Andes with deleterious effects on this densely populated region of South America. © 2020, The Author(s). Article 2020 English 20411723 10.1038/s41467-020-19000-8 Nature Communications 11 Nature Research 1 Amazon Basin; Andes; Arctic; Greenland; Peru; cordillera; Dansgaard-Oeschger cycle; drought stress; glacier retreat; hydrometeorology; Last Glacial; monsoon; precipitation assessment; seasonality; Arctic; article; deglaciation; drought; evaporation; glacial period; Greenland; Peru; precipitation; sediment; summer; warming https://www.scopus.com/inward/record.uri?eid=2-s2.0-85092453814&doi=10.1038%2fs41467-020-19000-8&partnerID=40&md5=18b87956157dad37f021d9738d15d372 Cited by: 5; All Open Access, Gold Open Access, Green Open Access Arielle Woods Donald T. Rodbell Mark B. Abbott Robert G. Hatfield Christine Y. Chen Sophie B. Lehmann David McGee Nicholas C. Weidhaas Pedro M. Tapia Blas L. Valero-Garcés Mark B. Bush Joseph S. Stoner article Hatfield2020 Normalized remanence, a proxy for relative geomagnetic paleointensity, along with radiocarbon and U-Th age constraints, facilitates the generation of a well-constrained chronology for sediments recovered during International Continental Scientific Drilling Program (ICDP) coring of Lake Junín, Peru. The paleomagnetic record of the ∼88 m stratigraphic section from Lake Junín was studied, and rock magnetic variability constrained, through analysis of 109 u-channel samples and 56 discrete samples. Downcore variations in sediment lithology reflect climate and hydrological processes over glacial-interglacial time frames and these changes are strongly reflected in the bulk magnetic properties. Glacial sediments are characterized by higher detrital silt content, higher magnetic susceptibility and magnetic remanence values, and a magnetic coercivity that is characteristic of ferrimagnetic (titano)magnetite and/or maghemite. Interglacial sediments and low lake-level facies are dominated by carbonate lithologies and/or peat horizons that result in lower magnetic concentration values. Sediments with moderately high Natural Remanent Magnetization (NRM) intensity (>1 × 10–3 A/m) have well resolved component directions and inclination values that vary around geocentric axial dipole expectations. This remanence value can be used as a threshold to filter the lowest quality paleomagnetic data from the record. Normalized NRM intensity values are also sensitive to lithologic variability, but following NRM remanence filtering, only the highest quality ferrimagnetic dominated data are retained which then show no coherence with bulk magnetic properties. Constrained by the existing radiocarbon based chronology over the last 50 kyrs and 18 U-Th age constraints that are restricted to five interglacial sediment packages, filtered normalized remanence parameters compare well with global relative paleointensity stacks, suggesting relative variations in geomagnetic intensity are preserved. By adjusting the existing age-depth model we improve the correlation between the Junín normalized intensity record and a well-dated RPI stack and RPI model. We then incorporate these paleomagnetic tie points with the existing radiometric dates using a modeling approach to assess uncertainty and refine the age-depth model for Lake Junín. In combining relative and radiometric dating, the new age-depth model captures glacial-interglacial variations in sedimentation rate and improves the orbital-scale age model for the sediments accumulated in Lake Junín basin over most of the Brunhes. © Copyright © 2020 Hatfield, Stoner, Solada, Morey, Woods, Chen, McGee, Abbott and Rodbell. 2020 English 22966463 10.3389/feart.2020.00147 Frontiers in Earth Science 8 Frontiers Media S.A. Department of Geological Sciences, University of Florida, Gainesville, FL, United States; College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR, United States; Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, United States; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Geology, Union College, Schenectady, NY, United States Binary alloys; Ferrimagnetism; Geomagnetism; Glacial geology; Lakes; Lithology; Magnetic susceptibility; Magnetite; Natural resources management; Radiometry; Remanence; Stratigraphy; Thorium alloys; Uncertainty analysis; Uranium alloys, Continental scientific drillings; Geomagnetic intensity; Hydrological process; Interglacial sediments; Magnetic coercivities; Magnetic concentration; Natural remanent magnetization; Relative paleointensity, Sediments, age determination; Brunhes chron; chronology; geomagnetism; lacustrine deposit; paleointensity; paleomagnetism; remanent magnetization; stratigraphy, Junin; Lake Junin; Peru https://www.scopus.com/inward/record.uri?eid=2-s2.0-85086510575&doi=10.3389%2ffeart.2020.00147&partnerID=40&md5=0297c6b1814dc403b33bb2f013e82327 cited By 7 R.G. Hatfield J.S. Stoner K.E. Solada A.E. Morey A. Woods C.Y. Chen D. McGee M.B. Abbott D.T. Rodbell article Hatfield202083 Sediment records from deep-drilling projects such as those carried out by the International Continental Scientific Drilling Program are often tens to hundreds of meters in length. To ensure the complete recovery of a stratigraphic section, a basin is usually cored multiple times in adjacent holes so that gaps between sequential cores, poorly recovered sections, or intervals affected by disturbance can be bridged or replaced with sediments from another hole. Stratigraphic correlation, the alignment of stratigraphically-equivalent horizons in cores from different holes in a common-depth scale, and splice generation, the integration of the most-representative core sections into a composite-stratigraphic section, are essential steps in this process to both evaluate and synthesize the recovered-sediment record and focus the scientific analyses. However, these undertakings can be complex and are inherently subjective, making the need for the development of a single robust stratigraphic section early in the project critical to its success. Despite this, the steps between core recovery and on-splice data generation are rarely published in sufficient detail to allow reconstruction, or refinement, of the composited record at a later date. To increase the transparency of how the composite record is created, and to provide a template for future projects, we detail the step-by-step approaches and decisions involved in generating the composite-depth scale and complete-stratigraphic splice following recovery of sediments from Lake Junín, Peru. We first explain the details and nuances of different drilling-depth scales before describing how we integrated different physical property records to generate the composite-depth scale and complete-stratigraphic splice. Here, we show that due to the complex stratigraphy in the Lake Junín sediments, high-resolution line-scan images of the cores offer millimeter-scale precision for construction of the primary-stratigraphic splice at a resolution not afforded by other physical property data. Finally, through comparison of the spliced record to physical-property records acquired in situ on the borehole, we demonstrate that the stratigraphic splice is an accurate representation of the sediment accumulated in the Lake Junín basin. © 2019, Springer Nature B.V. 2020 English 09212728 10.1007/s10933-019-00098-w Journal of Paleolimnology 63 Springer 83-100 College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, OR 97330, United States; Department of Geological Sciences, University of Florida, Gainesville, FL 32611, United States; Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA 15260, United States; Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States; Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum GFZ, Potsdam, Germany; Department of Geology, Union College, Schenectady, NY 12308, United States 1 deep drilling; historical record; lacustrine deposit; physical property; project assessment; reconstruction; recovery; scale effect; sediment core; stratigraphic correlation, Junin; Lake Junin; Peru https://www.scopus.com/inward/record.uri?eid=2-s2.0-85075369507&doi=10.1007%2fs10933-019-00098-w&partnerID=40&md5=fc4915b3e04a5b213b7a99d877d576df cited By 9 R.G. Hatfield A. Woods S.B. Lehmann N. Weidhaas C.Y. Chen S. Pierdominici J.S. Stoner M.B. Abbott D.T. Rodbell article Chen2020 Deep sediment cores from long-lived lake basins are fundamental records of paleoenvironmental history, but the power of these reconstructions has been often limited by poor age control. Uranium-thorium (U-Th) dating has the potential to fill a gap in current geochronological tools available for such sediment archives. We present our systematic approach to U-Th date carbonate-rich sediments from the ∼100m drill core from Lake Junín, Peru. The results form the foundation of an age-depth model spanning ∼700 kyrs. High uranium concentrations (0.3–4 ppm) of these sediments allow us to date smaller amounts of material, giving us the opportunity to improve sample selection by avoiding detrital contamination, the greatest factor limiting the success of previous U-Th dating efforts in other lake basins. Despite this advantage, the dates from 174 analyses on 55 bulk carbonate samples reveal significant scatter that cannot be resolved with traditional isochrons, suggesting that at least some of the sediments have not remained closed systems. To understand the source of noise in the geochronological data, we first apply threshold criteria that screen samples by their U/Th ratio, reproducibility, and δ234Uinitial value. We then compare these results with facies types, trace element concentrations, carbonate and total organic carbon content, color reflectance, mineralogy, and ostracode shell color to investigate the causes of open system behavior. Alongside simulations of the isotopic evolution of our samples, we find that the greatest impediment to U-Th dating of these sediments is not detrital contamination, but rather post-depositional remobilization of uranium. Examining U-Th data in these contexts, we identify samples that have likely experienced the least amount of alteration, and use dates from those samples as constraints for the age-depth model. Our work has several lessons for future attempts to U-Th date lake sediments, namely that geologic context is equally as important as the accuracy and precision of analytical measurements. In addition, we caution that significant geologic scatter may remain undetected if not for labor intensive tests of reproducibility achieved through replication. As a result of this work, the deep sediment core from Lake Junín is the only continuous record in the tropical Andes spanning multiple glacial cycles that is constrained entirely by independent radiometric dates. © 2020 Elsevier Ltd 2020 English 02773791 10.1016/j.quascirev.2020.106422 Quaternary Science Reviews 244 Elsevier Ltd Massachusetts Institute of Technology-Woods Hole Oceanographic Institution Joint Program in Oceanography, Cambridge, MA, United States; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA, United States; Department of Geology and Environmental Science, University of Pittsburgh, Pittsburgh, PA, United States; Institut für Geosysteme und Bioindikation, Technische Universität Braunschweig, Braunschweig, Germany; Department of Geological Sciences, University of Florida, Gainesville, FL, United States; College of Earth, Ocean, and Atmospheric Science, Oregon State University, Corvallis, OR, United States; Department of Earth and Environmental Sciences, University of Minnesota Twin Cities, Minneapolis, MN, United States; Institute of Global Environmental Change, Xi'an Jiaotong University, Xi'an, China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; Pyrenean Institute of Ecology, CSIC, Avda Montañana 1005, Zaragoza, 50059, Spain; Laboratorio Internacional en Cambio Global, CSIC-PUC-UFRJ, Zaragoza, Spain; Department of Earth Sciences, Syracuse University, Syracuse, NY, United States; Instituto Nacional de Investigación en Glaciares y Ecosistemas de Montañas, Huaraz, Ancash, Peru; Department of Geology, Union College, Schenectady, NY, United States Binary alloys; Carbonation; Core drilling; Geochronology; Lake pollution; Lakes; Minerals; Organic carbon; Sediments; Thorium compounds; Trace elements; Uranium alloys, Accuracy and precision; Color reflectance; Radiometric dates; Reproducibilities; System behaviors; Total organic carbon content; Trace element concentrations; Uranium concentration, Thorium alloys, biostratigraphy; color; core analysis; facies analysis; geochronology; lacustrine deposit; ostracod; paleoenvironment; remobilization; shell; total organic carbon; trace element; uranium series dating, Junin; Lake Junin; Peru, Ostracoda https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089419593&doi=10.1016%2fj.quascirev.2020.106422&partnerID=40&md5=03bf80d83c88dc3d445e71e2602bd88d cited By 7 C.Y. Chen D. McGee A. Woods L. Pérez R.G. Hatfield R.L. Edwards H. Cheng B.L. Valero-Garcés S.B. Lehmann J.S. Stoner A. Schwalb I. Tal G.O. Seltzer P.M. Tapia M.B. Abbott D.T. Rodbell article Rodbell201258 2012 English 18168957 10.2204/iodp.sd.13.10.2011 Scientific Drilling 58-60 Union College, Schenectady, NY 12308, United States; Department of Geology and Planetary Science, University of Pittsburgh, 4107 O'Hara Street, SRCC Building, Pittsburgh, PA 15260-3332, United States 13 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84865356790&doi=10.2204%2fiodp.sd.13.10.2011&partnerID=40&md5=c1119654b49b1a30209d15a306ba2a18 cited By 4 D.T. Rodbell M.B. Abbott