An illustrated key and (palaeo)ecological primer for Postglacial to Recent Ostracoda (Crustacea) of the Baltic Sea

Frenzel, P., Keyser, D. & Viehberg, F.A. 2010: An illustrated key and (pala6e6o)ecological primer for Postglacial to Recent Ostracoda (Crustacea) of the Baltic Sea. Boreas, Vol. 39, pp. 567–575. 10.1111/j.1502‐3885.2009.00135.x. ISSN 0300‐9483 This synopsis of Baltic Sea brackish water Ostracoda gives an overview of all known Recent species for the first time. It also includes Holocene taxa now extinct in the area. There are 131 species, two of which are recorded only from Yoldia stage (Preboreal) sediments. The illustrated key is based exclusively on valve morphology, providing a taxonomical base for geoscience and biological studies using ostracods from the Baltic Sea area. A list of ecological tolerances and preferences as well as the latitudinal distribution of all species is intended as a reference for palaeoenvironmental analyses. Salinity, temperature and oxygen tolerance values as well as preferences for latitudinal distribution, water depth and energy, habitat and substrate are given. The data are based on quantitative sampling in the southern, central and western Baltic Sea and on information gained from literature.     

COLD,ALPINE ICE BODIES REVISITED: WHAT MAY WE LEARN FROM THEIR IMPURITY AND ISOTOPE CONTENT?

In the European Alps, ice core studies have been mainly performed in view of the recent man‐made influence on the atmospheric load of aerosol‐related species, while respective investigations on the pre‐industrial aerosol or on stable water isotope‐based climate records remained sparse. We address from a glaciological perspective the specific conditions of Alpine drilling sites and, in particular, the role of depositional noise. Thereby, we refer to two major drilling areas (located in the summit range of Monte Rosa and Mt Blanc massif, respectively) which largely differ in their snow accumulation rate and, hence, in their accessible time scale. A simple scheme considering the seasonality of both, the precipitation‐borne signal and the snow erosion‐controlled net accumulation rate is presented. It shows that water isotope trends are generally more sensitive to distortion by a seasonality effect than recent snow impurities trends, although the influence of a given seasonal accumulation rate cycle on the mean levels of water isotopes and impurities is similar. These findings are illustrated on the decadal and centennial time scale by the inter‐ and intra‐site variability of major ion and water isotope records. The intra‐site comparison includes the discussion of strong water isotope depletions seen some meters above bedrock at low accumulation drilling sites.     

40Ar/39Ar Geochronology of the Rajmahal Basalts, India, and their Relationship to the Kerguelen Plateau

During the mid-Cretaceous, extensive magmatism occurred in theIndian Ocean to form volcanic portions of the southern and centralKerguelen Plateau, Elan Bank and Broken Ridge. Basalt was eruptedalso along the rifted margin of eastern India (Rajmahal). Weinvestigated the ages of these Indian basalts using ⁴⁰Ar/³⁹Arincremental-heating experiments on whole rocks. Our resultsare consistent with the hypothesis that the lava pile of