Abstract To investigate the influence of local climate and transboundary circulation of moisture on the stable isotope of precipitation in Ramnicu Valcea, Romania, monthly values of δ 2 H, δ 18 O, deuterium excess (d excess ), temperature, relative humidity and precipitation were determined between January 2012 and December 2018. Monthly analysis showed differences in d excess varying between 24.2‰ (October 2015) and −23.7‰ (July 2013) with a multi-annual average of 6.1 ± 5.9‰, suggesting an Atlantic origin of moisture with episodic Mediterranean transport. Also a significant correlation between the North Atlantic Oscillation on the local temperature during winter season was noticed. The local meteoric water line (LMWL) for the entire period showed slope and intercept values similar to those for neighbouring localities with the same altitude. When the analysis was extended to summer (April–October) and winter (November–March) seasons, the LMWL slope and intercept were different, reflecting the summer–winter difference in temperatures and air circulation. The monthly values of all parameters formed equal-spaced time series whose detailed analysis confirmed at p < 0.01 that δ 2 H, δ 18 O, temperature and relative humidity show a well-evidenced one-year periodicity. In contrast, precipitation and d excess seasonality were almost unrecognizable, most probably owing to the reduced number of observations.

ABSTRACT Extensive glaciers covered the High Atlas mountains in Morocco during the late Pleistocene. On the northern escarpments of the Marrakech High Atlas, a series of cirques perched at ~3000–3500 m above sea level (asl) fed their valley glaciers that, in some cases, extended to as low as 2000 m asl. Cosmogenic exposure dating with 10 Be and 36 Cl has shown that at least three phases of glaciation are preserved in glacial deposits over the last glacial cycle at 50, 22, and 12 ka, which appear to correlate with marine isotope stage (MIS) 3, the global Last Glacial Maximum (LGM), and the Younger Dryas chronozone. This geochronological framework is sufficiently robust to allow for time-constrained glacier-climate reconstructions. The glaciers associated with these three phases of advance had equilibrium line altitudes (ELAs) of 2761 m asl (ca. 50 ka), 2919 m asl (ca. 22 ka), and 3213 m asl (ca. 12 ka). Glacier-climate modeling suggests that all of these phases were driven by both colder temperatures and wetter conditions than today. The dominant moisture supply to these glaciers in all phases would have been sourced from Atlantic depressions. The influence of an extended and enhanced West African monsoon on glacier development during African Humid Periods is unlikely to have been a significant influence on glacier dynamics. The climate conditions associated with the three glacier phases indicate sustained moisture supply to the highest mountain areas when records from other areas, such as the Middle Atlas lakes and marine sediment cores offshore, indicate marked aridity.

ABSTRACT The earliest Pleistocene fossil forest of Dunarobba (Umbria, Italy) consists of a set of more than 70 tree trunks of an extinct species of sequoia or cypress with original cellulose still preserved. Spectral analyses of tree-ring series (325 and 448 yr in duration) combined with oxygen isotope analyses of the cellulose provide a glimpse into the mean annual temperature and the interannual climate variability that characterized this region at the beginning of the Pleistocene, when the concentration of atmospheric CO 2 was ~400 ppm. The high-frequency variability of the ring width time series shows significant spectral components that are consistent with the influence from the North Atlantic Oscillation, and to a lesser extent, solar cycles and El Niño–Southern Oscillation. The mean annual temperature estimate of ~19 °C, based on a model that combines ring widths and oxygen isotope values, is a full 6 °C warmer than the present-day value for this region. These elevated temperatures are consistent with estimates from pollen analyses and with estimates from higher latitudes.

ABSTRACT In this paper, we review ~140 yr of investigations about pelagosite, a usually black aragonitic encrustation with a vitreous luster that forms in the splash zone of Mediterranean rocky coasts. Prior to the mid-1920s, the geologic community considered pelagosite to be a separate mineral of uncertain composition, but then in 1926, Italian mineralogist Ettore Onorato determined that pelagosite has the same structure as aragonite (orthorhombic CaCO 3 ), and also that it contained cells of blue-green algae (i.e., cyanobacteria). Once pelagosite was declassed from the status of a mineral, and its name was eliminated from catalogues and textbooks, Onorato’s documentation of the cyanobacterial cells contained in this encrustation seems to have fallen into almost total oblivion during the rest of the twentieth century. We revisited pelagosite in its original type locality, the remote southern Adriatic island of Pelagosa (today’s Croatian island of Palagruža), as well as in the Dalmatian island of Hvar. Using modern analytical methods and techniques, we redefined the mineralogical and geochemical composition of pelagosite, the nature and significance of its microbial content, and the origin of its pisolitic “tree-ring” internal structure, which probably reflects cyclic climate changes.