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《Gondwana Research》2013,24(4):1656-1658
The abundant and diverse assemblage of filamentous microbial fossils permineralized in the ~ 3465 Ma Apex chert of northwestern Australia — among the oldest records of life — are arguably the “best studied,” by the most workers using the most advanced techniques, in the history of science. Despite the extensive body of data establishing the biogenicity of the demonstrably cellular carbonaceous Apex fossils, Pinti et al. (2013) and Marshall and Marshall (2013) have raised issues regarding the interpretation of their studies of the Apex chert presented in our recent review article (Schopf and Kudryavtsev, 2012). We agree with the assessment of both of the relevant papers by Pinti et al. (2009, 2013): the observations they report do not apply to the bona fide microscopic fossils of the Apex chert. Similarly, like the minute objects reported by Pinti et al. (2009, 2013), the “quartz and haematite-filled fractures” discussed by Marshall and Marshall (2013) are mineralic pseudofossils that are not relevant to interpretation of the Apex fossil microbes and their suggestion that “multiple populations of carbonaceous material may be a wide-spread issue through out the Precambrian” is without merit. 相似文献
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《International Geology Review》2012,54(1):123-125
The authors by their own statement do not intend to make a general criticism of the work but which only to point out these specific errors: 1) There is no justification in assigning all the massifs to the junction zone of East and West Sayans. It is incomprehensible to include such dissimilar massifs as the gabbros of Kazyr and the granitic Kryzhin range, both because of age and form; 2) There are no chromite deposits in the West Sayans; 3) The use of an effusive-schist formation in the Upper Proterozoic is incorrect; it should read series; 4) What do Ordovician faults have to do with the Lysansk massifs? 5) There are serious errors and omissions in the petrography of the Lysansk complex, on which the authors elaborate; 6) The TiO2 deposits in gabbros were discovered not in 1956, as claimed, but in 1954 by two other geologists; 7) The sequence of the emergence of secondary minerals from a magmatic melt “can only be visualized;” 8) They object to “superimposing” an autometamorphic phase on the mineralization; 9) They object to the concepts of the origin of Lysansk intrusions, as being “in the dogmatic form of an article of faith.” — M.A. Klugman 相似文献
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W.J.Kennedy I.Walaszczyk W.A.Cobban 《《幕》》2005,28(2):93-104
Following the recommendation of the International Commission on Stratigraphy (16 votes Yes [94%], 1 abstention, 2 votes not received), the Global boundary Stratotype Section and Point (GSSP) for the base of the Turonian Stage of the Cretaceous System is defined as the base of bed 86 of the Bridge Creek Limestone Member of the Greenhorn Limestone Formation at the western end of the Denver and Rio Grande Railroad cut near the north boundary of the Pueblo Reservoir State Park Recreation Area, west of Pueblo, Colorado, USA. This GSSP horizon is also exposed and protected in the adjacent state recreation area. It coincides with the first occurrence of the ammonite Watinoceras devonense, is in the middle of a global positive excursion in Carbon-13 isotopes, and is bracketed by widespread bentonites that have yield edages of 93 to 93.5 Ma. 相似文献
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S. I. Sherman 《Geotectonics》2009,43(2):100-114
The further development of Peyve’s concept of deep faults in the Earth’s crust and brittle part of the lithosphere is discussed. Three aspects are accentuated in this paper: (1) the modern definition of the term deep fault; (2) the parameters of deep faults as ruptures of the geological medium and three-dimensional, often boundary, geological bodies; and (3) reactivation of deep faults, including the development of this process in real time. Peyve’s idea of deep faults readily fitted into the concept of new global tectonics (plate tectonics). This was facilitated, first of all, by the extensive efforts made to elaborate Peyve’s ideas by a large group of researchers at the Geological Institute of the Russian Academy of Sciences (GIN RAS) and other scientists. At present, the term deep fault has been extended and transformed to cover three-dimensional geological bodies; the geological and geophysical properties and parameters of these bodies, as well as their reactivation (recurrent activation) in real time, have been studied. 相似文献
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Doklady Earth Sciences - Highly accurate observations of the Earth’s total magnetic field vector promptly derived from the data recorded at the “St. Petersburg” (Leningrad oblast)... 相似文献
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We focus on Swiss earthquakes in antiquity and the early medieval period before A.D. 1000. We have information on less than
half a dozen earthquakes within this era, since written records for the first half of the first millennium A.D. are minimal,
and there is little hope of finding more written evidence for earthquakes. Furthermore, interpreting the documents at hand
is somewhat complex. For the 6th century Gregory of Tours in Historia Francorum gives hints of a rockslide near the castle Tauredunum (Le Grammont) in the Swiss canton Valais, an event that has been considered in the literature as caused by an earthquake. The Carolingian period (ca. 750–950) included the rise of some very important cultural centers in various parts of today’s Switzerland. For
instance, the ecclesiastical culture in St. Gallen generated a remarkable number of written records, which survived for our
use in a unique manner. From the 9th and 10th centuries, we have evidence for earthquakes in the years 849, 867, 902, and
944. However, information on them remains so scarce that their location and intensity are generally difficult to assess. Nevertheless,
the finding of a new document - a memoir written by the abbot of Reichenau - offers some insight into the A.D. 849 event and
its reportedly aftershocks.
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| Monika GislerEmail: |
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A.Yu. Guzhikov 《Russian Geology and Geophysics》2013,54(3):349-354
In this study we analyze the importance of new magnetostratigraphic data on the Nordvik section for solving the problem of detailed Tethyan–Boreal correlation around the Jurassic–Cretaceous boundary with a special emphasis on the aspects of interpretation of the paleomagnetic data in magnetostratigraphic studies and the need for the integrated (paleontological and paleomagnetic) approach to recognition of the base of the Berriasian. 相似文献
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A metamorphic rock complex, strongly resembling the so-called “Granulitgebirge” of Saxony, occurs in the Spanish region Galicia. Stratigraphically, these rocks are overlain by migmatites, supracrustal metamorphites and finally by early palaeozoic strata cropping out in Western Asturias and Northern Portugal. Structurally the complex constitutes a mushroom-shaped dome which has been raised through a thin mantle of schists and gneisses along blastomylonitic borderzones containing tectonic “fish”. Petrologically it consists predominantly of rather coarsely banded, lenticular or massive rocks belonging for the greater part to the hornblende-clinozoisite granulite subfacies ofEskola's granulite facies, closely associated with eclogites, serpentinites, amphibolites and gneisses. Indications of progressive metamorphism and migmatization (especially that of a pegmatoid nature) are of strictly local occurrence, but on the other hand there is abundant evidence of one or more stages of retrograde metamorphism, particularly in the blastomylonitic horizons. The chemistry of granulites and eclogites and of their typomorphic minerals is briefly mentioned together with their metamorphic facies relations. Finally, petrogenesis and tectogenesis of the rock complex are discussed. 相似文献