Revisiting the Late Jurassic-Early Cretaceous of the NW South Iberian Basin: new ages and sedimentary environments

The study of the Upper Jurassic-Lower Cretaceous deposits (Higueruelas, Villar del Arzobispo and Aldea de Cortés Formations) of the South Iberian Basin (NW Valencia, Spain) reveals new stratigraphic and sedimentological data, which have significant implications on the stratigraphic framework, depositional environments and age of these units. Moreover, these new data encourage revising the previously proposed stratigraphic correlations between the studied units and those deposited in adjacent areas of the Iberian Basin. The Higueruelas Fm was deposited in a mid-inner carbonate platform where oncolitic bars migrated by the action of storms and where oncoid production progressively decreased towards the uppermost part of the unit. The overlying Villar del Arzobispo Fm has been traditionally interpreted as an inner platform-lagoon evolving into a tidal-flat. Here it is interpreted as an inner-carbonate platform affected by storms, where oolitic shoals protected a lagoon, which had siliciclastic inputs from the continent. The Aldea de Cortés Fm has been previously interpreted as a lagoon surrounded by tidal-flats and fluvial-deltaic plains. Here it is reinterpreted as a coastal wetland where siliciclastic muddy deposits interacted with shallow fresh to marine water bodies, aeolian dunes and continental siliciclastic inputs. The contact between the Higueruelas and Villar del Arzobispo Fms, classically defined as gradual, is interpreted here as gradual and rapid, because the transition between both units comprises few meters. More importantly, the contact between the Villar del Arzobispo and Aldea de Cortés Fms, previously considered as unconformable, is here interpreted as gradual. The presence of Alveosepta in the Villar del Arzobispo Fm suggests that at least part of this unit is Kimmeridgian, unlike the previously assigned Late Tithonian-Middle Berriasian age. Consequently, the underlying Higueruelas Fm, previously considered Tithonian, should not be younger than Kimmeridgian. Accordingly, sedimentation of the Aldea de Cortés Fm, previously considered Valanginian-Hauterivian, probably started during the Tithonian and it may be considered part of the regressive trend of the Late Jurassic-Early Cretaceous cycle. This is consistent with the dinosaur faunas, typically Jurassic, described in the Villar del Arzobispo and Aldea de Cortés Fms.

Building International CSR on Solid Foundations: Location and Network Aspects of Nonmarket Environments in Europe and Non-Europe Markets. ACES Working Papers, 2011

Multinational companies' (MNCs) corporate social responsibility (CSR) programs frequently comprise a portfolio of disconnected country-level programs or, alternatively, consist of blanket corporate policies that apply in the same way across the geographies where the company operates. Yet, the international nonmarket environment in which CSR programs operate is neither a completely fragmented nor a perfectly homogeneous one. Building on the concept of stakeholder-issue-networks, we develop a model that explicitly takes into consideration the role of geography in the characterization of a firm's nonmarket environment. This allows us to develop a taxonomy of nonmarket environments on the basis of their geographic spread and their degree of cross-border connectedness. We then explore the strategic and organizational implications that different ideal types of (cross-border) nonmarket environments have for the development of international CSR policies.

Geochemical and Microbiological Studies of Nitrous Oxide Variations within the New NEEM Greenland Ice Core During the Last Glacial Period

Deep polar ice cores provide atmospheric records of nitrous oxide (N₂O) and other trace gases reflecting climate history along with a parallel archive of microbial cells transported with mineral dust, marine and volcanic aerosols from around the globe. Our interdisciplinary study of 32 samples from different depths of the recently drilled NEEM Greenland ice core addressed the question whether the identified microorganisms were capable of post-depositional biological production of N₂O in situ. We used high-resolution geochemical and microbiological approaches to examine the N₂O concentrations, the quantitative distributions of dust, Ca⁺², NH₄⁺ and NO₃⁻ ¡ons related to N cycle pathways, the microbial abundance and diversity at specific NEEM core depths from 1758 m to 1867.8 m. Results showed varying concentrations of N₂O (220 –271.5 ppb). Microbial abundance fluctuated between 3.3 x 10⁴ and 3.3 x 10⁶ cells mL⁻¹ in direct correlation with dust and Ca²⁺ concentrations with higher cell numbers deposited during colder periods. The average values of NH₄⁺ and NO₃⁻ indicated that substrates were available for the microorganisms capable of utilizing them. PCR amplification of selected functional genes involved in bacterial and archaeal nitrification and denitrification was not successful. Sanger and Illumina MiSeq sequence analyses of SSU rRNA genes showed variable representation of Alpha-, Beta- and Gammaproteobacteria, Firmicutes, Actinobacteria, chloroplasts and fungi. The metabolic potential of the dominant genera of Proteobacteria and Firmicutes as possible N₂O producers suggested that denitrification activity may have led to in-situ production and accumulation of N₂O.

(Table 1) Age determination and isotopic signature of last glacial Patagonian caly/silt

Ice cores provide a record of changes in dust flux to Antarctica, which is thought to reflect changes in atmospheric circulation and environmental conditions in dust source areas (Forster et al., 2007; Diekmann et al. 2000, doi:10.1016/S0031-0182(00)00138-3; Winckler et al., 2008, doi:10.1126/science.1150595; Reader et al., 1999, doi:10.1029/1999JD900033; Mahowald et al., 1999, doi:10.1029/1999JD900084; Petit et al., 1999, doi:10.1038/20859; 1990, doi:10.1038/343056a0 Delmonte et al., 2009, doi:10.1029/2008GL033382; Lambert et al., 2008, doi:10.1038/nature06763). Isotopic tracers suggest that South America is the dominant source of the dust (Grousset et al., 1992, doi:10.1016/0012-821X(92)90177-W; Basile et al., 1997, doi:10.1016/S0012-821X(96)00255-5; Gaiero et al., 2007, doi:10.1016/j.chemgeo.2006.11.003), but it is unclear what led to the variable deposition of dust at concentrations 20-50 times higher than present in glacial-aged ice (Petit et al., 1990, doi:10.1038/343056a0; Lambert et al., 2008, doi:10.1038/nature06763). Here we characterize the age and composition of Patagonian glacial outwash sediments, to assess the relationship between the Antarctic dust record from Dome C (refs Lambert et al., 2008, doi:10.1038/nature06763; Wolff et al., 2006, doi:10.1038/nature04614) and Patagonian glacial fluctuations (Sugden et al., 2005; McCulloch et al., 2005, doi:10.1111/j.0435-3676.2005.00260.x; Kaplan et al., 2008, doi:10.1016/j.quascirev.2007.09.013) for the past 80,000 years. We show that dust peaks in Antarctica coincide with periods in Patagonia when rivers of glacial meltwater deposited sediment directly onto easily mobilized outwash plains. No dust peaks were noted when the glaciers instead terminated directly into pro-glacial lakes. We thus propose that the variable sediment supply resulting from Patagonian glacial fluctuations may have acted as an on/off switch for Antarctic dust deposition. At the last glacial termination, Patagonian glaciers quickly retreated into lakes, which may help explain why the deglacial decline in Antarctic dust concentrations preceded the main phase of warming, sea-level rise and reduction in Southern Hemisphere sea-ice extent (Wolff et al., 2006, doi:10.1038/nature04614).

Behavior and physiological correlates of varying noise environments /

Mode of access: Internet.

Exploring Mars and beyond : what's next for U.S. planetary science : hearing before the Subcommittee on Space and Aeronautics, Committee on Science, Space, and Technology, House of Representatives, One Hundred Twelfth Congress, first session, Tuesday, November 15, 2011.

Mode of access: Internet.