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Evaporites through space and time
No full textEvaporites are fascinating deposits not only becauseof their hydrocarbon potential and usually excellentpreservation of depositional structures but alsofrom their important role in the interpretation of basinevolution and palaeogeography. They have an unusualpotential to record in detail the final stage of developmentof many sedimentary basins. For these reasons,there was widespread research on evaporites in thesecond half of the 20th century, which resulted in severalkey books and special volumes that outlined thegeological conditions and processes controlling theformation of these deposits. It is worth stressing herethe outstanding efforts in this field of the first of the coeditorsof the volume. It is now clear, for example, thatevaporites are unusually differentiated with regard totheir lithology, petrography and mineralogy, sedimentologyand diagenesis, composition, origin and evolutionin space and time.As a result of this expansion inresearch many fundamental questions relating to thegeology of evaporites have been identified. Some ofthese, however, such as diagenetic conversion, theprocesses leading finally to the evaporitic rocks and thegeochemistry of these rocks, to mention only a few;have received little attention from researchers so farand remain for future investigation. In this context, theorigin of evaporites, their sedimentology and diagenesis,and their economic potential are still at the descriptivestage, as exemplified by the book under review.The volume documents evaporites of different agesand regions around the world, attributed to variousmodels and processes of origin, composition and diagenetictransformations, and occurring essentially inthe ancient record. There is first a critical overview bythe editors of the results of the papers comprising thevolume, placing these into the context of the state-ofthe-art of current research. The compilation is dividedinto five parts of unequal length, each comprising fromtwo to six contributions. The first part of the volume isrelatively long and deals with Tectonics, basin evolutionand evaporites (five papers). Then follow twovery short parts devoted to Working depositional models(two papers) and Post-depositional evolution ofsediments (two papers). The fourth part is the largestand deals with Ancient basins (seven papers). Thebook finishes with two examples of Regional reviews(two papers). In my view it is the first and fourth partsof the volume that are the most interesting.The volume covers a great range of evaporite topics.In their selection of papers, the editors have tendedto concentrate on those describing gypsum and salt deposits,but there is one paper on clastic deposits predatingtheMioceneMediterranean evaporites and twopapers on carbonates supposedly associated with theAlpine Triassic and Neoarchaean evaporites respectively.With regard to evaporite mineralogy, the topicscovered range from gypsum, through anhydrite, KMgsulphate to halite, potash salts and sylvite. The volumepresents evaporites from South Africa, northAfrica, through theMediterranean and eastAsia, fromthe European Alpine systems to South Atlantic saltsettings and the Permian Basin of Texas and NewMexico; the evaporites described were deposited in intracratonic,through orogenic, foreland and platform tosyn- and post rift evaporitic basins, and range in agefrom Precambrian to modern saline brines. The methodsused by the authors range from classic field and regionalinvestigations, through seismic to geochemical(fluid inclusions and stable isotopes) and even experimentalstudies. The reader will find in this volume regionalsyntheses, discussions of local phenomena(“pseudocarniole”, sylvite), short and long contributions,standard research papers and overviews, newideas and repetitions of old hypotheses. Taking into accountthe great range of geological questions and methodscovered, and the different types of paper (both analyticand synthetic) presented, this is a well plannedand well organized book with up-to date references, auseful index, and excellent photos and illustrations. Theindividual papers are written by active researchers whoare well recognized in their respective field of researchat least at least in their own region. In general, everybodymay find something of interest to enhance theirknowledge of evaporites. In particular, I would like todraw the reader’s attention to how much we can learnfrom seismic analyses with regard to the geometry ofevaporites and basin evolution (papers by KERNER &GAMBÔA and BERTONI & CARTWRIGHT). Similarly,some new ideas with regard to the Badenian gypsumpalaeoenvironments may come from the highly sophisticateddepositional models for gypsum suggestedby M. BĄBEL. However, this extensive conceptualmodelling does not help to account for the gypsumsubfacies present across the whole Carpathian Foredeep,especially when the interpretations of these faciesare often based by that author on very local, essentiallycarbonate settings, which are nonrepresentativefor this regionally large gypsum basin.An unusual assemblage of evaporitic structures, aswell as possible, albeit unproven, examples of true calcitereplacement after selenites are found in Neoarchaeancarbonates of South Africa (GANDIN &WRIGHT). Certainly worth reading is the use of the arrayof evaporite sedimentary fabrics in the interpretationof the palaeowater depth of the Permian Basin ofTexas and NewMexico (HOVORKA & al.), which mayprove helpful in palaeoenvironmental reconstructionsof other evaporite basins.Finally, to what extent does the book achieve itsaim?As may be inferred from this extremely short reviewof the contents it would be difficult to find a sophisticatedcommon theme or idea linking this collectionof papers. This is understandable in that the editorswere limited in their choice of papers by the presentationsat the International Geological Union conferencein Florence in 2004. Possibly for the same reason,the papers included in the volume are uneven in length,content and quality.Although the editors have assembledthe papers on a wide range of topics in a satisfactorymanner, the contents and presentation of thevolume are not well balanced. Nevertheless, the volumemay help to complete or refresh our knowledge of“Evaporites Through Space and Time”. Although theeditors at the end of their overview aim to “...the futureMartian evaporites”, it is clear from the volumeunder review that there is still a lot of work to be doneon the evaporites of our own planet. In my opinion, astriking example of this is a common lack of considerationof carbonates in a wider palaeogeographic contextand their relationship to evaporites (e.g. papers byBĄBEL, BĄBEL& BOGUCKIJ and BUKOWSKI & al.). Becauseof this, the palaeoenvironmental reconstructionsare often hindered by the lack of relevant information.Perhaps it is a personal view, but some of the papersare overloaded with glossaries of concepts and definitionswhich make the texts too long and very heavy toread (e.g. BĄBEL). It is also usual for authors of scientificinvestigations to provide evidence in support oftheir interpretations and not merely state their own beliefs(e.g. HRYNIV & al., p. 320).In spite of these faults, I sincerely hope that thebook will be appreciated by students, researchers andprofessionals alike who wish to further their knowledgeof evaporites. It will certainly be a welcome additionto the libraries of both research and academic institutesand therefore can be recommended.ANDRZEJ GĄSIEWICZ Państwowy Instytut Geologiczny, Rakowiecka 4, 00-975 Warszawa, Poland. E-mail: [email protected]
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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