ALBERT

Description: This paper introduces an integrated Neogene microfossil biostratigraphic chart developed within post-merger BP for the Gulf of Mexico Basin and is the first published industrial framework "fully-tuned" to orbital periodicities. Astronomical-tuning was accomplished through a 15-year research program on ODP Leg 154 sediments (offshore NE Brazil) with sampling resolution for calcareous nannofossils and planktonic foraminifera about 20 k.y. and 40 k.y. (thousand year), respectively. This framework extends from the Late Oligocene (25.05 Ma) to Recent at an average Chart Horizon resolution for the Neogene of 144 k.y., approximately double that of published Gulf of Mexico biostratigraphic charts and a five-fold increase over the highest resolution global calcareous microfossil biozonation. Such resolution approximates that of 4th to 5th order parasequences and is a critical component in the verification of seismic correlations between mini-basins in the deep-water Gulf of Mexico. Its utility in global time-scale construction and correlation has been proven, in part, by application of the scheme in full to internal research for the Oligocene-Miocene boundary interval on the Global Boundary Stratotype Section and Point (GSSP) in northern Italy and offshore wells in the eastern Mediterranean Sea. This step change in Neogene resolution, now at the level of cyclostratigraphy (the orbital periodicity of eccentricity) and the magnetostratigraphic chron, demonstrates the potential for calcareous microfossil biostratigraphy to more consistently reinforce correlations of these time scale parameters. The integration of microfossil disciplines, consistent taxonomies, and rigorous analytical methodologies are all critical to obtaining and reproducing this new level of biostratigraphic resolution.

Description: Ocean acidification causes corals to calcify at reduced rates, but current understanding of the underlying processes is limited. Here, we conduct a mechanistic study into how seawater acidification alters skeletal growth of the coral Stylophora pistillata. Reductions in colony calcification rates are manifested as increases in skeletal porosity at lower pH, while linear extension of skeletons remains unchanged. Inspection of the microstructure of skeletons and measurements of pH at the site of calcification indicate that dissolution is not responsible for changes in skeletal porosity. Instead, changes occur by enlargement of corallite-calyxes and thinning of associated skeletal elements, constituting a modification in skeleton architecture. We also detect increases in the organic matrix protein content of skeletons formed under lower pH. Overall, our study reveals that seawater acidification not only causes decreases in calcification, but can also cause morphological change of the coral skeleton to a more porous and potentially fragile phenotype.

Description: Changes in the life cycle of organisms (i.e. phenology) are one of the most widely used early-warning indicators of climate change, yet this remains poorly understood throughout the tropics. We exhaustively reviewed any published and unpublished study on fruiting phenology carried out at the community level in the American tropics and subtropics (latitudinal range: 26°N?26°S) to (1) provide a comprehensive overview of the current status of fruiting phenology research throughout the Neotropics; (2) unravel the climatic factors that have been widely reported as drivers of fruiting phenology; and (3) provide a preliminary assessment of the potential phenological responses of plants under future climatic scenarios. Despite the large number of phenological datasets uncovered (218), our review shows that their geographic distribution is very uneven and insufficient for the large surface of the Neotropics (~ 1 dataset per ~ 78,000 km2). Phenological research is concentrated in few areas with many studies (state of São Paulo, Brazil, and Costa Rica), whereas vast regions elsewhere are entirely unstudied. Sampling effort in fruiting phenology studies was generally low: the majority of datasets targeted fewer than 100 plant species (71%), lasted 2 years or less (72%), and only 10.4% monitored 〉 15 individuals per species. We uncovered only 10 sites with ten or more years of phenological monitoring. The ratio of numbers of species sampled to overall estimates of plant species richness was wholly insufficient for highly diverse vegetation types such as tropical rainforests, seasonal forest and cerrado, and only slightly more robust for less diverse vegetation types, such as deserts, arid shrublands and open grassy savannas. Most plausible drivers of phenology extracted from these datasets were environmental (78.5%), whereas biotic drivers were rare (6%). Among climatic factors, rainfall was explicitly included in 73.4% of cases, followed by air temperature (19.3%). Other environmental cues such as water level (6%), solar radiation or photoperiod (3.2%), and ENSO events (1.4%) were rarely addressed. In addition, drivers were analyzed statistically in only 38% of datasets and techniques were basically correlative, with only 4.8% of studies including any consideration of the inherently autocorrelated character of phenological time series. Fruiting peaks were significantly more often reported during the rainy season both in rainforests and cerrado woodlands, which is at odds with the relatively aseasonal character of the former vegetation type. Given that climatic models predict harsh future conditions for the tropics, we urgently need to determine the magnitude of changes in plant reproductive phenology and distinguish those from cyclical oscillations. Long-term monitoring and herbarium data are therefore key for detecting these trends. Our review shows that the unevenness in geographic distribution of studies, and diversity of sampling methods, vegetation types, and research motivation hinder the emergence of clear general phenological patterns and drivers for the Neotropics. We therefore call for prioritizing research in unexplored areas, and improving the quantitative component and statistical design of reproductive phenology studies to enhance our predictions of climate change impacts on tropical plants and animals.

Description: Stratigraphy, sedimentology and paleoecology of Mesozoic continental sequences in the Depressao periferica, Rio Grande do Sui, Brazil, are subject of a DFG (German Research Foundation) research project. Results of the first two years period of activities in which the Geologicai-Paleontological Institutes of the Universities of Kiel and Frankfurt/M. in collaboration with the Departamento de Geociencias, University of Santa Maria in Camobi, RS, were involved are reported here. A second phase of field activities is planned for the time period from fall 1993 to the spring of 1995. The stratigraphic boundaries of the investigation are the underlying sediments of the Permian Passa Dais-Series and the overlying basalts of the Serra Geral Formation, covering the time span of 235 Ma to 133 Ma. A subordinate, chronostratigraphic system encompassing the sediments of this time period has yet to be established and extensive hiatuses are to be expected. Correlations with the lschigualasto Formation in NW-Argentina support the assumption that the upper Santa Maria Formation (Aiemoa member) falls in the mid Carnian. This is the only reasonable certain chronostratigraphic date from the Mesozoic of the Depressao periferica established at the present time. The classical tetrapod sites of the Triassic Santa Maria Formation all fall within the Alemoa-Member, the sediments of which were deposited under in part evaporitic conditions on playa mud flats. Evidence points to isochronic sedimentation and discounts the possibility of a diachronic genesis. The Santa Maria Formation and the underlying Sanga do Cabral Formation are placed together in the Rio do Rasta Subgroup as a genetic unit in accordance with the original definition, which conflicts with present day usage of the names. The Rio do Rasto Subgroup pinches out west of Sao Francisco do Assis and east of the Taquarl river. The entire Rio do Rasto Formation is enclosed in eolic sediments, indicating an extensive sedimentation complex arising from a persistently subsiding playa areal within the Botucatu desert. Beyond the range of the Rio do Rasto Subgroup, it is difficult or impossible to distinguish between the eolic sediments of the older, underlying Rosario do Sui Formation and the overlying, younger Botucatu Sandstone Member. As such, the entire paleogeographically and genetically uniform sedimentation complex is compiled together under the term Botucatu Group. The Sanga do Cabral Formation is characterized by an abundance of detritic micas (muscovite and biotite). K/ Ar dating have indicated a preliminary age for muscovite of 418 ± 8 Ma and 423.5 ± 9.7 Ma. Presumably, they originated from volcanites, subvolcanites and pyroclastics of the Camaqua Group (Brasiliano molasse). As such, the Precambrian/ lower Paleozoic Escudo Sui in Rio Grande do Sui was exposed and eroded to the level found today at the time of deposition of the Sanga do Cabral Formation.

Description: Due to the remoteness and di culty to access the snow covered polar regions, ski-equipped aircraft are an indispensable tool for polar research. The Alfred Wegener Institute has a long tradition in airborne polar science – starting with the aircraft Polar1 and Polar2 in 1983. In 2007 the rst Basler BT-67 (Polar5) and in 2011 the second Basler BT-67 (Polar6) were brought into service and replaced Polar2 and Polar4. They carry a variety of scienti c equipment for investigation of the lithosphere, atmosphere and cryosphere and all their interactions. Beside being deployed for science missions, the aircraft are also part of the Dronning Maud Land Air Network (DROMLAN), a logistical partnership to transport equipment and personnel to various stations in Dronning Maud Land, Antarctica.