From extreme environments on Earth to space: Buttiauxella sp. MASE-IM-9 and Salinisphaera shabanensis as new model organisms in Astrobiology

Mars analogue environments are some of the most extreme locations on Earth. Their unique combination of multiples extremes (e.g. high salinity, anoxia, and low nutrient availability) make them a valuable source of new polyextremophilic microbes in general and for exploring the limits of life. These are seen as vital sources of information for Astrobiology, with implications for planetary protection and the search for life outside our planet. [...

Progressive environmental deterioration in northwestern Pangea leading to the latest Permian extinction

Stratigraphic records from northwestern Pangea provide unique insight into global processes that occurred during the latest Permian extinction (LPE). We examined a detailed geochemical record of the Festningen section, Spitsbergen. A stepwise extinction is noted as: starting with (1) loss of carbonate shelly macrofauna, followed by (2) loss of siliceous sponges in conjunction with an abrupt change in ichnofabrics as well as dramatic change in the terrestrial environment, and (3) final loss of all trace fossils. We interpret loss of carbonate producers as related to shoaling of the lysocline in higher latitudes, in relationship to building atmospheric CO2. The loss of siliceous sponges is coincident with the global LPE event and is related to onset of high loading rates of toxic metals (Hg, As, Co) that we suggest are derived from Siberian Trap eruptions. The final extinction stage is coincident with redox-sen- sitive trace metal and other proxy data that suggest onset of anoxia after the other extinction events. These results show a remarkable record of progressive environmental deterioration in northwestern Pangea during the extinction crises

Stratigraphy of the uppermost Old Red Sandstone of Svalbard (Mimerdalen Subgroup)

Between the fjords Dicksonfjorden and Billefjorden in central Spitsbergen, Svalbard’s youngest deposits (Early Givetian to Famennian in age) of the Old Red Sandstone—the Mimerdalen Subgroup—are exposed. They form a narrow outcrop area parallel to the Billefjorden Fault Zone and overlie unconformably the multicoloured sandstones of the Lower Devonian Wood Bay Formation. Stratigraphic rank and subdivision of the succession were changed repeatedly since its first mention in 1910. Based on student work in 1996, as well as regional mapping by the authors in 1993 and 2003, the present work formalizes the stratigraphic framework of the succession. This framework has already been applied in recent geological maps. At the same time it is a continuation of the lithostratigraphic standardization carried out by the Committee on the Stratigraphy of Svalbard (1999), where only post-Devonian rocks were considered. Except for some small-pebble conglomerate layers in the Wood Bay Formation, the upper part of the Mimerdalen Subgroup contains the first coarse-grained deposits in Svalbard’s Old Red since the lowermost Devonian Red Bay Group. Faulting between its formations as well as conglomerate pebbles derived from the Lower Devonian Wood Bay Formation indicate the onset of the Svalbardian Event after the tectonic stability during the deposition of the Wood Bay Formation. The Mimerdalen Subgroup is probably the detrital fill of a small foreland basin derived from erosion during the uplift of the Ny-Friesland Block to the east of the Billefjorden Fault Zone. It was later affected by compressional tectonic movements during the Svalbardian Event.Keywords: Svalbard; geology; stratigraphy; Mimerdalen Subgroup; Devonian; Old Red.To access the supplementary material for this article, please see supplementary files under Article Tools online.(Published: 30 October 2014)Citation: Polar Research 2014, 33, 19998, http://dx.doi.org/10.3402/polar.v33.1999