Sustained North Atlantic warming drove anomalously intense MIS 11c interglacial.

The Marine Isotope Stage (MIS) 11c interglacial and its preceding glacial termination represent an enigmatically intense climate response to relatively weak insolation forcing. So far, a lack of radiometric age control has confounded a detailed assessment of the insolation-climate relationship during this period. Here, we present Th-dated speleothem proxy data from northern Italy and compare them with palaeoclimate records from the North Atlantic region.

Noble gases and nitrogen in samples of asteroid Ryugu record its volatile sources and recent surface evolution.

The near-Earth carbonaceous asteroid (162173) Ryugu is expected to contain volatile chemical species that could provide information on the origin of Earth's volatiles. Samples of Ryugu were retrieved by the Hayabusa2 spacecraft. We measured noble gas and nitrogen isotopes in Ryugu samples and found that they are dominated by presolar and primordial components, incorporated during Solar System formation.

Last glacial temperature reconstructions using coupled isotopic analyses of fossil snails and stalagmites from archaeological caves in Okinawa, Japan.

We applied a new geoarchaeological method with two carbonate archives, which are fossil snails from Sakitari Cave and stalagmites from Gyokusen Cave, on Okinawa Island, Japan, to reconstruct surface air temperature changes over the northwestern Pacific since the last glacial period. Oxygen isotope ratios (δO) of modern and fossil freshwater snail shells were determined to infer seasonal temperature variations. The observational and analytical data confirm that δO values of fluid inclusion waters in the stalagmite can be regarded as those of spring waters at the sites where snails lived.

Pulsed Terahertz Radiation for Sensitive Quantification of Carbonate Minerals.

Quantification of natural carbonate minerals, namely, aragonite, high- and low-Mg calcite, and dolomite provides essential information about biomineralization, carbon cycling on Earth, and the evolution of ocean chemistry, and is also useful in many other scientific, pharmaceutical, and industrial fields. However, X-ray diffractometer has previously been the only practical tool to identify and quantify carbonate minerals, including calcium carbonate (CaCO) polymorphs. We propose new fingerprint terahertz (THz) absorption and reflective index spectra in the 1-6 THz range that probe the lattice phonon modes and can be used for sensitive quantification of these four carbonate minerals, including polymorphs.

Cyanobacterial exopolymer properties differentiate microbial carbonate fabrics.

Although environmental changes and evolution of life are potentially recorded via microbial carbonates, including laminated stromatolites and clotted thrombolites, factors controlling their fabric are still a matter of controversy. Herein, we report that the exopolymer properties of different cyanobacterial taxa primarily control the microbial carbonates fabrics in modern examples. This study shows that the calcite encrustation of filamentous Phormidium sp.

Advanced maritime adaptation in the western Pacific coastal region extends back to 35,000-30,000 years before present.

Maritime adaptation was one of the essential factors that enabled modern humans to disperse all over the world. However, geographic distribution of early maritime technology during the Late Pleistocene remains unclear. At this time, the Indonesian Archipelago and eastern New Guinea stand as the sole, well-recognized area for secure Pleistocene evidence of repeated ocean crossings and advanced fishing technology.

Biogeochemical Cycle of Methanol in Anoxic Deep-Sea Sediments.

The biological flux and lifetime of methanol in anoxic marine sediments are largely unknown. We herein reported, for the first time, quantitative methanol removal rates in subsurface sediments. Anaerobic incubation experiments with radiotracers showed high rates of microbial methanol consumption.