3,132 research outputs found
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Macromolecular organic acids in the Murchison meteorite
This study has detected bound organic acids within the Murchison meteorite organic macromolecule. Benzoic acid was the most abundant compound; other abundant compounds include C1 and C2 benzoic acids. Their origin and significance will be discussed
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Scientific drilling of the Boltysh impact crater, Ukraine
Introduction: The Boltysh crater has been known for several decades and was first drilled in the 1960s as part of a study of economic oil shale deposits. Unfortunately, the cores were not curated and have been lost. We have re-drilled the impact crater and have recovered a near continuous record of ~400 m of organicrich sediments together with 15 m of suevite
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Organic geochemistry of the crater-fill sediments from Boltysh impact crater, Ukraine
The Boltysh impact crater, is a complex structure formed on the basement rocks of the Ukrainian shield which has been dated at 65.17┬▒0.64 Ma [1]. The Boltysh crater has been know for several decades and was originally drilled in the 1960s-1980s in a study of economic oil shale deposits. Unfortunately, the cores were not curated and have been lost. However we have recently re-drilled the impact crater and have recovered a near continuous record of ~400 m of organic rich sediments deposited in a deep isolated lake which overlie the basement rocks spanning a period ~10 Ma. At 24km diameter, Boltysh will not have contributed substantially to the worldwide devastation at the end of the
Cretaceous. However, the precise age of the Boltysh impact relative to the Chicxulub impact and its location on a stable low lying coastal plain which allowed formation of the postimpact crater lake make it a particularly important locality. After the impact, the crater quickly filled with water in a short marine phase but returned to fresh water which persisted for >10Ma [2]. These strata contain a valuable record of Paleogene environmental change in central Europe, and one of very few terrestrial records of the KT event. This pre-eminent record of the Paleogene can help us to answer several related scientific questions including the relative age of Boltysh compared with Chicxulub, recovery from the impact, and later climate signals. The organic geochemistry and playnology indicate main inputs to be algal and higher plant within most of the core although there are some marked changes in inputs in some sections. A number of carbon isotope excursions are also present within the core which are currently being further investigated
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Post-impact heating of a crater lake
Lacustrine sediments from the 24 km diameter Boltysh impact structure record the rapid formation of an intra-crater lake. Stable isotope compositions and organic maturity parameters from the lake sediments deposited post-impact show that they were heated by underlying impactites. This heating is attributed to the establishment of an impact- generated hydrothermal system. Estimates of the duration of heating are ~30 тАУ 40 k.y. consistent with the suggestion that crater lakes extend the longevity of impact-generated hydrothermal systems
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Alteration of the Nakhlite Lava Pile: was water on the surface, seeping down, or at depth, percolating up? Evidence (such as it is) from carbonates
We present carbon and oxygen isotope data on carbonates in five nakhlites and use the results to interpret the martian weathering processes
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