Description: Much of our understanding of Earth’s past climate comes from the measurement of oxygen and carbon isotope variations in deep-sea benthic foraminifera. Yet, long intervals in existing records lack the temporal resolution and age control needed to thoroughly categorize climate states of the Cenozoic era and to study their dynamics. Here, we present a new, highly resolved, astronomically dated, continuous composite of benthic foraminifer isotope records developed in our laboratories. Four climate states—Hothouse, Warmhouse, Coolhouse, Icehouse—are identified on the basis of their distinctive response to astronomical forcing depending on greenhouse gas concentrations and polar ice sheet volume. Statistical analysis of the nonlinear behavior encoded in our record reveals the key role that polar ice volume plays in the predictability of Cenozoic climate dynamics.

Description: Constraining the long‐term variability and average of the Earth’s magnetic field strength is fundamental to understanding the characteristics and behavior of the geomagnetic field. Questions remain about the strength of the average field, and the relationship between strength and reversal frequency, due to the dispersion of data from key time intervals. Here, we focus on the Cretaceous Normal Superchron (CNS; 121‐84 Ma), during which there were no reversals. We present new intensity results from 41 submarine basaltic glass (SBG) sites collected on the Nicoya Peninsula and Murcièlago Islands, Costa Rica. New and revised 40Ar/39Ar and biostratigraphic age constraints from previous studies indicate ages from 141 to 65 Ma. One site with an age of 135.1 ± 1.5 Ma (2σ) gave a reliable intensity result of 34 ± 8 µT (equivalent to a virtual axial dipole moment, VADM, value of 88 ± 20 ZAm2), three sites from 121 to 112 Ma, spanning the onset of the CNS, vary from 21 ± 1 to 34 ± 4 µT (53 ± 3 to 87 ± 10 ZAm2). These results from the CNS are all higher than the long‐term average of ∼42 ZAm2 and data from Suhongtu, Mongolia (46‐53 ZAm2) and are similar to the Troodos Ophiolite, Cyprus (81 ZAm2, reinterpreted in this study). Together with the reinterpreted data, the new Costa Rica results suggest that the strength of the geomagnetic field was approximately the same both before and after the onset of the CNS. Therefore, the data do not support a strict correlation between polarity interval length and the strength of the magnetic field.

Description: Since its first field season (2006–2007), the ANDRILL (Antarctic Geological Drilling) program has implemented an innovative educational and public outreach (EPO) program known as ARISE (ANDRILL Research Immersion for Science Educators), which has actively involved a group of selected educators in every phase of the research, from participation in field activities to discussion of the scientific results. This method of research immersion has led to an impressive list of achievements, including the development of quality outreach initiatives and diverse educational materials, the involvement of a large number of schools using these resources, the creation of an international network of strongly motivated polar geoscience educators, and the realization of new and unexpected professional opportunities for educators. In Italy this program initiated a specific project (progettosmilla.it), in accordance with the objectives of the ARISE Program. Thanks to the use of both a wide range of instruments (online and material) and the network of personal relationships provided by teachers involved in the program, ARISE has resulted in many short-term accomplishments. The development of new partnerships with local and national institutions has led to a number of middle- and long-term processes, rarely seen in similar EPO projects, resulting in the attainment of other goals. Research immersion experiences promote close interactions between teachers and scientists, and provide the potential for accomplishing other long-term educational outcomes. The shared development of educational resources by scientists and educators through ARISE has created an opportunity to advance scientific education within schools and, through outreach, in the general populace.

Description: Paleoenvironmental and paleoclimate changes that occurred during the late postevaporitic stage of the Mediterranean Basin in the Messinian foreland domain of the Adriatic region offer a new perspective on the relationship between orbital forcing and climate response. The magnetic susceptibility record of the Fonte dei Pulcini A section (Maiella Mountains, Italy) allows us to orbitally tune the record between 5.394 and 5.336 Ma and to temporally constrain the paleoenvironmental and paleoclimate changes evidenced by quantitative paleontological (palynomorphs, ostracods, and calcareous nannofossils), stable isotope (d18O and d13C), and X-ray diffraction (XRD) analyses. The base of the Fonte dei Pulcini A section is characterized by Paratethyan ostracods and dinocysts, which point to the late Messinian Lago-Mare biofacies (Loxocorniculina djafarovi zone) of the Mediterranean Messinian stratigraphy. From paleontological and geochemical (d18O) analyses, there is no evidence of a marine incursion in the Fonte dei Pulcini A section. The major changes in terms of paleodepth, paleosalinity, evaporation versus precipitation, aridity versus humidity, and reworking processes occurred in the upper part of the Fonte dei Pulcini A section, during the last Messinian insolation cycle (i-cycle 511/512), which is characterized by high-amplitude oscillations. In contrast, the lower part of the Fonte dei Pulcini A section, which was deposited during relatively low-amplitude insolation cycles, is characterized by more stable environmental conditions. Comparing summer insolation with the paleoenvironmental changes at the Fonte dei Pulcini A section, we identify delays of several thousands of years between orbital forcing and climate response.

Description: We present ten 40Ar/39Ar age determinations, both on primary volcanic deposits and on detrital sanidine, which provide geochronologic control on the MIS 5.5 and MIS 5.3 sea-level indicators that occur at three coastal caves in the central Tyrrhenian Sea of Italy. Samples dated for the present work are as follows: - Two pumice clasts (MOSC-22, MOSC-37) extracted from the sand layers constituting the sedimentary fill of Moscerini Cave, recovered during the original archaeological excavations performed in the year 1949, stored at the IIPU (Istituto Italiano di Paleontolgia Umana) repository in Anagni (Frosinone, italy). These two samples were processed at the rare Gas Laboratory of the University of Wisconsin Madison in March, 2019. - One tephra layer (sample GDC-10) intercalated in the sedimentary fill of Capre Cave collected in June, 2021. - Seven sedimentary sand samples collected at Guattari Cave (GU-1, GU-5, GU-105, GU-116) in June, 2020, and at Capre Cave (GDC-6, GDC-8, GDC-0) in June, 2021 . These dates constrain the age of a Strombus-bearing biodetritic conglomerate associated with a tidal notch occurring at 9.5 m a.s.l. at Cape Circeo between 121.5±5.8 and 116.2±1.2 ka. Moreover, deposition of backbeach deposits intercalated in the sedimentary filling of Guattari and Capre coastal caves is bracketed in the interval 110.4±1.4 ka to 104.9±0.9 ka. Such deposits are directly correlated with a tidal notch at ~2.5 m associated with another biodetritic conglomerate at Cape Circeo. The latter is correlated with the adjacent marine terrace, occurring at 3-5 m in the coast between Capes Circeo and Anzio, for which a maximum age of 100.7±6.6 ka was previously reported. These data provide evidence for a maximum sea level around 9.5 m above the present sea level and a duration of MIS 5.5 highstand until 116 ka, in line with estimation from other regions in the world. In contrast, they suggest a maximum sea level during MIS 5.3 highstand that is similar to the present level, and only ~7 m lower than the MIS 5.5 highstand, challenging the reconstructions of the MIS 5 ice-sheet volumes and derived global sea levels that are based on the benthic oxygen isotope records.

Description: The AND-1B drill core recovered a 13.57 million year Miocene through Pleistocene record from beneath the McMurdo Ice Shelf in Antarctica (77.9°S, 167.1°E). Varying sedimentary facies in the 1285 m core indicate glacial-interglacial cyclicity with the proximity of ice at the site ranging from grounding of ice in 917 m of water to ice free marine conditions. Broader interpretation of climatic conditions of the wider Ross Sea Embayment is deduced from provenance studies. Here we present an analysis of the iron oxide assemblages in the AND-1B core and interpret their variability with respect to wider paleoclimatic conditions. The core is naturally divided into an upper and lower succession by an expanded 170 m thick volcanic interval between 590 and 760 m. Above 590 m the Plio-Pleistocene glacial cycles are diatom rich and below 760 m late Miocene glacial cycles are terrigenous. Electron microscopy and rock magnetic parameters confirm the subdivision with biogenic silica diluting the terrigenous input (fine pseudo-single domain and stable single domain titanomagnetite from the McMurdo Volcanic Group with a variety of textures and compositions) above 590 m. Below 760 m, the Miocene section consists of coarse-grained ilmenite and multidomain magnetite derived from Transantarctic Mountain lithologies. This may reflect ice flow patterns and the absence of McMurdo Volcanic Group volcanic centers or indicate that volcanic centers had not yet grown to a significant size. The combined rock magnetic and electron microscopy signatures of magnetic minerals serve as provenance tracers in both ice proximal and distal sedimentary units, aiding in the study of ice sheet extent and dynamics, and the identification of ice rafted debris sources and dispersal patterns in the Ross Sea sector of Antarctica.