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One of the key-principles of the iron-sulphur world theory is to bring organic molecules close enough to interact with each other, using the surface of pyrite as a substrate in a hydrothermal setting. The present paper explores the relationship of pyrite and organic matter in a hydrothermal setting from the geological record; in hydrothermal calcite veins from Carboniferous limestones in central I
In the 23-km-diameter Haughton impact structure, Canadian High Arctic, in sulfate-rich bedrock, widespread hydrothermal sulfide mineralization occurred in breccias formed during the impact. The sulfides exhibit extreme sulfur isotopic fractionation relative to the original sulfate, requiring microbial sulfate reduction by thermophiles throughout the crater. This evidence of widespread microbial ac
Limestone samples from the Cambro-Ordovician Durness Group were crushed, aciddigested and searched for evidence of micrometeorites. Eleven melted micrometeorites were extracted from the magnetic fraction of samples from the Balnakeil and Croisaphuill formations near the top of the group. Other formations in the Durness Group did not yield micrometeorites. Only melted spherules with a distinctive d
Impact-generated hydrothermal systems are commonly proposed as good candidates for hosting primitive life on early Earth and Mars. However, evidence of fossil microbial colonization in impact-generated hydrothermal systems is rarely reported in the literature. Here we present the occurrence of putative fossil microorganisms in a hydrothermal system of the 89 Ma Dellen impact structure, Sweden. We
On Earth, the deep subsurface biosphere of both the oceanic and the continental crust is well known for surviving harsh conditions and environments characterized by high temperatures, high pressures, extreme pHs, and the absence of sunlight. The microorganisms of the terrestrial deep biosphere have an excellent capacity for adapting to changing geochemistry, as the alteration of the crust proceeds
A Devonian siltstone from Orkney, Scotland, shows survival of biomarkers in high-velocity impact experiments. The biomarkers were detected in ejecta fragments from experiments involving normal incidence of steel projectiles at 5-6 km s-1, and in projectile fragments from impact experiments into sand and water at 2-5 km s-1. The associated peak shock pressures were calculated to be in the range of
The 39-2Ma Haughton impact structure on Devon Island comprises a thick target succession of sedimentary rocks, mainly carbonates. The carbonates contain pre-impact organic matter, including fossil biological markers. Haughton is located in an area where no major thermal event has affected the sedimentary succession after heating caused by impact. This makes Haughton uniquely suitable for studies c
In a series of experiments the pyrolytic effects of the heating induced during the hypervelocity impact (HVI) of small projectiles of high TOC mudrock were observed. Impacts at these high speeds (km s-1) release sufficient energy to vaporise metal projectiles, and the temperatures created greatly exceed the pyrolysis temperatures typically employed during laboratory studies of the thermal alterati
The Ordovician Lockne impact structure is located in central Sweden. The target lithology consisted of limestone and black unconsolidated shale overlaying a Precambrian crystalline basement. The Precambrian basement is uranium-rich, and the black shale is both uranium- and organic-rich. This circumstance makes Lockne a good candidate for testing the occurrence of U-Th-rich bitumen nodules in an im
Melt fragments in melt breccias from the Gardnos impact crater, Norway, contain abundant carbon. A high proportion of the carbon present in the original melt was preserved. The stripping of hydrogen from carbon during melting prevents later hydrocarbon formation, hence the carbon is fixed in place rather than volatilized. Underlying lithic breccias that were not melted record hydrocarbon generatio
The response of organic matter to high-temperature events is important to astrobiology, as it governs the survival of carbon during several processes that may be critical to the origin and spread of life. Impact cratering is a widespread high-temperature process. The behaviour of carbon during impact events is not well understood. But there is the potential to examine other examples of the respons
Graphitic carbon is a widespread precipitate in terrestrial and extraterrestrial samples. However it has a range of possible origins, which can be difficult to distinguish, including the in situ alteration of organic matter, thermal alteration of hydrocarbons, and precipitation from C-O-H fluids. Petrographic characteristics help to understand the origin of the graphite, including relationships wi
The release of methane from crater sites following meteorite impact is a possible consequence of the thermal alteration of organic matter, or tapping of reservoired gas of biogenic or abiogenic origin. At least the latter is feasible on Mars. Methane and higher hydrocarbons are susceptible to polymerization and precipitation by radioactive minerals. Where such minerals are present in impact target
Owing to its diagenetic instability, aragonite is rare in the geological record and almost entirely absent from pre-carboniferous sedimentary rocks. The former presence of this mineral in older deposits has to be inferred from petrographic, chemical or isotopic proxies. Crystals of aragonite that formed around 4563 million years ago occur in carbonaceous chondrite meteorites, showing that under ce
The dating of terrestrial impact craters and impact glasses that exhibit high degrees of mineralogical complexity can be problematic. However, if the maximum potential of the terrestrial impact crater record is to be realized, accurate and precise ages for crater-forming events are critical. Here we report a high-precision 40Ar/39Ar age for the Dellen impact structure, Sweden. Previous radio-isoto
Mark Burchell and the organizers of an RAS Specialist Discussion Meeting in May 2012 argue, on the basis of the Stardust and Hayabusa missions, that collecting samples from asteroids and comets offers a potentially rich scientific return – and one that can be exploited for many years to come.
A novel approach to the synthesis of Mn-doped InSb nanowires is demonstrated in this work. We first report on the preparation of InSb nanowires without high temperature treatment. Indium nanowires are grown by glance angle deposition and then coated with a layer of Sb. Single crystalline InSb nanowires are obtained by annealing In/Sb nanostructures at 200 °C. Triple-layer In/Mn/Sb nanostructures a
Weather and climate conditions can have large impacts on the outcome of forest management operations: Suboptimal conditions can increase the amount of driving damage to forest ground caused by the heavy machines used for harvesting, forwarding and soil scarification. Planting of tree seedlings is commonly practised after clear cutting, and drought in summer or soil frost uplifting in autumn reduce
