1200 years of decadal-scale variability of Mediterranean vegetation and climate at Pantelleria Island, Italy

A new sedimentary sequence from Lago di Venere on Pantelleria Island, located in the Strait of Sicily between Tunisia and Sicily was recovered. The lake is located in the coastal infra-Mediterranean vegetation belt at 2 m a.s.l. Pollen, charcoal and sedimentological analyses are used to explore linkages among vegetation, fire and climate at a decadal scale over the past 1200 years. A dry period from ad 800 to 1000 that corresponds to the ‘Medieval Warm Period’ (WMP) is inferred from sedimentological analysis. The high content of carbonate recorded in this period suggests a dry phase, when the ratio of evaporation/precipitation was high. During this period the island was dominated by thermophilous and drought-tolerant taxa, such as Quercus ilex, Olea, Pistacia and Juniperus. A marked shift in the sediment properties is recorded at ad 1000, when carbonate content became very low suggesting wetter conditions until ad 1850–1900. Broadly, this period coincides with the ‘Little Ice Age’ (LIA), which was characterized by wetter and colder conditions in Europe. During this time rather mesic conifers (i.e. Pinus pinaster), shrubs and herbs (e.g. Erica arborea and Selaginella denticulata) expanded, whereas more drought-adapted species (e.g. Q. ilex) declined. Charcoal data suggest enhanced fire activity during the LIA probably as a consequence of anthropogenic burning and/or more flammable fuel (e.g. resinous Pinus biomass). The last century was characterized by a shift to high carbonate content, indicating a change towards drier conditions, and re-expansion of Q. ilex and Olea. The post-LIA warming is in agreement with historical documents and meteorological time series. Vegetation dynamics were co-determined by agricultural activities on the island. Anthropogenic indicators (e.g. Cerealia-type, Sporormiella) reveal the importance of crops and grazing on the island. Our pollen data suggest that extensive logging caused the local extinction of deciduous Quercus pubescens around ad1750.

Wie über Wolken. Jüdische Lebens- und Denkwelten in Stadt und Region Bern, 1200 – 2000

Der bildhafte Titel dieses Buches ist einem Brief der Lyrikerin Else Lasker-Schüler aus den 1930er Jahren entnommen und schildert ihre hohe Stimmung beim Flanieren durch die ruhige Stadt Bern. «Solche Spaziergänge, schwebend, lassen das Leben ertragen», schreibt sie weiter. Dass das Leben zu ertragen sei, ja mitunter «stratosphärisch» leicht sich anfühle, verweist jedoch auch auf die Lasten und die Bedrängnis jener Jahre, die Anfechtungen, denen Juden und Jüdinnen vielerorts in Europa ausgesetzt waren. Der Titel verdeutlicht, dass hier Texte versammelt sind, die ein breites Spektrum an jüdischen Erfahrungen, Denkvorgängen und Erinnerungsfiguren aus verschiedenen Epochen dokumentieren: vom mittelalterlichen Privileg über die stigmatisierende Ausschliessung bis zur gewaltsamen Vertreibung, von der bürgerlichen Emanzipation im 19. Jahrhundert über die Ohnmacht während der Zeit der Schoah bis zur öffentlich-rechtlichen Anerkennung der jüdischen Religionsgemeinschaft. Durch die Verbindungen jüdischer Intellektueller mit Bern ergeben sich Einblicke in Sternstunden des europäischen Geisteslebens. Die jüdische künstlerische und politische Moderne war geprägt von Aufbruchstimmung und Exilerfahrung. Für viele wurde Bern zum Ort, wo ihr Traum vom Studium in Erfüllung ging. Und immer wieder spiegelt das Bild von der Wolkenstadt den Wechsel des Klimas: zwischen Judenhut und Alpenparadies, Schwermut und Traumhaftigkeit, Eigensinn und Höhenflug, Bangen und Bürgerlichkeit, liberalem Empfinden und Streben nach sozialer Beteiligung.

Melting of metasomatized peridotite at 4–6 GPa and up to 1200 °C: an experimental approach

The phase assemblages and compositions in a K-bearing lherzolite + H2O system are determined between 4 and 6 GPa and 850–1200 °C, and the melting reactions occurring at subarc depth in subduction zones are constrained. Experiments were performed on a rocking multi-anvil apparatus. The experiments had around 16 wt% water content, and hydrous melt or aqueous fluid was segregated and trapped in a diamond aggregate layer. The compositions of the aqueous fluid and hydrous melt phases were measured using the cryogenic LA-ICP-MS technique. The residual lherzolite consists of olivine, orthopyroxene, clinopyroxene, and garnet, while diamond (C) is assumed to be inert. Hydrous and alkali-rich minerals were absent from the run products due to preferred dissolution of K2O (and Na2O) to the aqueous fluid/hydrous melt phases. The role of phlogopite in melting relations is, thus, controlled by the water content in the system: at the water content of around 16 wt% used here, phlogopite is unstable and thus does not participate in melting reactions. The water-saturated solidus, i.e., the first appearance of hydrous melt in the K–lherzolite composition, is located between 900 and 1000 °C at 4 GPa and between 1000 and 1100 °C at 5 and 6 GPa. Compositional jumps between hydrous melt and aqueous fluid at the solidus include a significant increase in the total dissolved solids load. All melts/fluids are peralkaline and calcium-rich. The melting reactions at the solidus are peritectic, as olivine, clinopyroxene, garnet, and H2O are consumed to generate hydrous melt plus orthopyroxene. Our fluid/melt compositional data demonstrate that the water-saturated hybrid peridotite solidus lies above 1000 °C at depths greater than 150 km and that the second critical endpoint is not reached at 6 GPa for a K2O–Na2O–CaO–FeO–MgO–Al2O3–SiO2–H2O–Cr2O3(–TiO2) peridotite composition.