228 research outputs found
Solar system chaos and the Paleocene-Eocene boundary age constrained by geology and astronomy
Astronomical calculations reveal the solar system's dynamical evolution,
including its chaoticity, and represent the backbone of cyclostratigraphy and
astrochronology. An absolute, fully calibrated astronomical time scale has
hitherto been hampered beyond 50 Ma, because orbital calculations
disagree before that age. Here we present geologic data and a new astronomical
solution (ZB18a), showing exceptional agreement from 58 to 53 Ma. We
provide a new absolute astrochronology up to 58 Ma and a new Paleocene-Eocene
boundary age (56.01 0.05 Ma). We show that the Paleocene-Eocene Thermal
Maximum (PETM) onset occurred near a 405-kyr eccentricity maximum, suggesting
an orbital trigger. We also provide an independent PETM duration (170 30
kyr) from onset to recovery inflection. Our astronomical solution requires a
chaotic resonance transition at 50 Ma in the solar system's fundamental
frequencies.Comment: Supplementary materials available at this URL:
www2.hawaii.edu/~zeebe/Astro.htm
Державно-приватне партнерство у вугільній галузі України: господарсько-правовий аспект
Розглянуто аспекти застосування правових механізмів Закону України «Про державно-приватне партнерство» стосовно пошуку, розвідки родовищ корисних копалин та їх видобування, зокрема кам’яного вугілля. Обґрунтовано пропозиції щодо виключення зазначених видів господарської діяльності із Закону України «Про державно-приватне партнерство».Рассмотрены аспекты применения механизмов Закона Украины «О государственно-частном партнерстве» относительно разведки месторождений полезных ископаемых и их добычи, в частности каменного угля. Обоснованы предложения об исключении названых видов хозяйственной деятельности из Закона Украины «О государственно-частном партнерстве».The paper deals with aspects of applying the mechanisms of the Law of Ukraine «On Public Private Partnership» as for exploration of minerals and their extraction, in particular coal. The grounds are given in favour of the proposals which concern the deletion of the above types of activity from the Law of Ukraine «On Public Private Partnership»
About the age and depositional depth of the sediments with reported bipedal footprints at Trachilos (NW Crete, Greece)
New data on the foraminifers and the regional geological setting of the Trachilos sediments (NW Crete, Greece) from which Gierlinski et al. (Proc Geol Assoc 128: 697–710, 2017) described hominin-like footprints show that the published 6.05 Ma-shallow marine interpretation is incorrect. In our new interpretation, the Trachilos succession is Late Pliocene and part of a shallowing marine series that became subaerially exposed some 3 millions of years ago. Placed in a larger geological context, Crete was an island during the Late Pliocene and separated by ~ 100 km of open sea from the nearest European mainland, and therefore out of reach of Late Pliocene hominins
Поліваріантний вплив біоактивної води Нафтуся на секрецію шлунка і пошкодження його слизової за умов перев’язки воротаря у щурів
Употребление крысами-самцами в течении 10-11 дней биоактивной воды Нафтуся вызывает в 72% случаев увеличение секреции кислоты желудком в условиях лигирования привратника. У 17% крыс кислотообразование не отличается от такового у контрольных животных, употреблявших водопроводную воду, а у 11% крыс констатирован кислотоингибиторный эффект биоактивной воды Нафтуся. Обнаружена инверсная связь между ацидогенезом и выделением гастрина в кровь и полость желудка, а также выраженностью язвенных повреждений его слизистой.The use rats-males in a flow 10-11 days of bioactive water Naftussya cause in 72% cases increase of secretion of acid by stomach in the conditions of ligating of pylorus. For 17% rats acid secretion does not differ from such for control animals, using a tapwater, and for 11% rats the inhibiting effect is established. Found out inverse relationship between acid secretion and secretion of gastrin in blood and cavity of stomach, and also expressed of ulcerous damages to his mucous membrane
Вулиця Басейна у Києві
Challenges and pitfalls for developing age models for long lacustrine sedimentary records are discussed and a comparison is made between radiocarbon dating, visual curve matching, and frequency analysis in the depth domain in combination with cyclostratigraphy. A core section of the high resolution 284-ka long temperature record developed from Lake Fuquene in the Northern Andes is used to explore four different age models (a-d). (a) A model based on 46 AMS C-14 dates of bulk sediment is hampered by low concentrations of organic carbon. (b) A model based on the comparison of the radiocarbon dated pollen record to the well-established record from Cariaco Basin using curve matching and visual tie points. For the upper 26 m of the core this approach yields an age interval of 28-59.5 ka. (c) Another age model is based on curve matching and the Intcal09 radiocarbon calibration curve, yielding an age range of 22.5-80.4 ka for the same core interval. (d) Finally, a model is developed based on spectral analysis in the depth domain of the temperature-related altitudinal migrations of the upper forest line. This method identifies periodicities without a pre-conceived idea of age. The main frequency of 9.07 m appears to reflect the 41-kyr orbital signal of obliquity, which is tuned to the filtered 41-kyr temperature signal from the well-constrained LRO4 marine benthic delta O-18 stack record (Lisiecki and Raymo, 2005). Using this last age-modelling approach, the upper 26 m of core Fq-9C yields a temporal interval of 27-133 ka. Problems arising from radiocarbon dating carbon poor sediments from a large lake are addressed and the visual curve matching approach is compared to the analysis of cyclic changes in sediment records in developing an age model. We conclude that the frequency analysis and cyclostratigraphy model is the most reliable one of the four approaches. These results show that cyclostratigraphy may provide a useful method for developing an age model for long terrestrial records including multiple orbital cycles. (C) 2014 Elsevier B.V. Al! rights reserved
On the duration of magnetochrons C24r and C25n and the timing of early Eocene global warming events: Implications from the Ocean Drilling Program Leg 208 Walvis Ridge depth transect
Five sections drilled in multiple holes over a depth transect of more than 2200 m at the Walvis Ridge (SE Atlantic) during Ocean Drilling Program (ODP) Leg 208 resulted in the first complete early Paleogene deep-sea record. Here we present high-resolution stratigraphic records spanning a ~4.3 million yearlong interval of the late Paleocene to early Eocene. This interval includes the Paleocene-Eocene thermal maximum (PETM) as well as the Eocene thermal maximum (ETM) 2 event. A detailed chronology was developed with nondestructive X-ray fluorescence (XRF) core scanning records and shipboard color data. These records were used to refine the shipboard-derived spliced composite depth for each site and with a record from ODP Site 1051 were then used to establish a continuous time series over this interval. Extensive spectral analysis reveals that the early Paleogene sedimentary cyclicity is dominated by precession modulated by the short (100 kyr) and long (405 kyr) eccentricity cycles. Counting of precession-related cycles at multiple sites results in revised estimates for the duration of magnetochrons C24r and C25n. Direct comparison between the amplitude modulation of the precession component derived from XRF data and recent models of Earth’s orbital eccentricity suggests that the onset of the PETM and ETM2 are related to a 100-kyr eccentricity maximum. Both events are approximately a quarter of a period offset from a maximum in the 405-kyr eccentricity cycle, with the major difference that the PETM is lagging and ETM2 is leading a 405-kyr eccentricity maximum. Absolute age estimates for the PETM, ETM2, and the magnetochron boundaries that are consistent with recalibrated radiometric ages and recent models of Earth’s orbital eccentricity cannot be precisely determined at present because of too large uncertainties in these methods. Nevertheless, we provide two possible tuning options, which demonstrate the potential for the development of a cyclostratigraphic framework based on the stable 405-kyr eccentricity cycle for the entire Paleogene
Bromine counts from XRF scanning as an estimate of the marine organic carbon content of sediment cores
XRF sediment core scanning technology is increasingly used to quantify sediment composition. The overall good correlation between biophilic halogen bromine (Br) and sedimentary total organic carbon (TOC) potentially allows the fast estimation of down core TOC profiles by XRF scanning. In order to test this approach we present data from the Arabian Sea and a Mediterranean brine basin, comparing XRF core scanning Br data with discrete sample TOC analyses. Overall, Br counts and TOC show a clear correlation, except when stable carbon isotope and C/N data indicate intervals characterized by enhanced input of terrestrial organic matter. Hence, solid phase Br is exclusively associated with marine organic matter (MOC) and can be used as a direct estimate of this parameter after a calibration is established. High pore water Br in the brine core steepens the Br/TOC correlation but after salt correction shows a nearly identical gradient to that of the Arabian Sea cor
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What, if anything, is Quaternary?
The formal recognition of Quaternary as a Period/ System was approved by IUGS in June 2009, in accordance with a proposal originated by INQUA. There are reasons to believe that this will have destabilizing consequences for the geological time scale. Until now, the primary divisions of the stratigraphic record, at the Period level and above, have been based on the progressive change of Earth’s biota. The Quaternary, on the other hand, is a paleoclimatic concept based on glacial-interglacial variability, expressed in lithological change. The IUGS vote holds that this paradigm now supersedes the biochronological identity of the Neogene Period/System. Furthermore, to accommodate the most recent INQUA opinion about “when the Ice Ages began”, the ICS agreed to relocate the base of the Pleistocene to 2.59 Ma from 1.81 Ma, enlarging the epoch by 43% and again without regard for its original paleontological definition, or for the vast literature in other fields of Pleistocene research. If history is a guide, the resulting disruption in late Cenozoic marine and vertebrate paleontology, human evolution, paleoceanography and paleoclimatology will be widely resisted, with potential impact on the authority of IUGS. The consequence of abandoning basic principles in order to satisfy the interest of a special group deserves a wider consideration than it has so far received
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