1,720,981 research outputs found
The Silurian of Sardinia: facies development and palaeoecology
No full textMain features of the Silurian sequences exposed in Sardinia (Italy) are here described. Oldest sediments are represented by black shales, rich in graptolites, grading into a calcareous facies throughout the middle Silurian; however, the sequences exposed in the southeast and in the southwest are different, even if some similitude is evident. The spectacular variety of invertebrate fossils is briefly outlined and their environmental settings are discussed in the attempt of giving a contribution to the global picture of Silurian events
Wenlockian graptolites and the Lower Graptolitic Shales-Ockerkalk transition East of Lantini Tunnel near Ballao (SE Sardinia)
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Silurian Palaeogeography of northern Gondwana: where was Sardinia at that time?
No full textAn unambiguous collocation of the actual European sectors in Silurian times is still far from accepted. The most recently published data appear to contradict and disprove current models. The position of Sardinia within this ill-defined scenario is still unclear
The Silurian of Sardinia: introduction to the field trip
No full textThe general features of the Silurian of Sardinia are briefly outlined, with special respect to the two main facies suites exposed in the southeastern and southwestern parts of theisland, respectively. An integrated biostratigraphical scheme with graptolite, conodont and chitinozoan zonations applied in the island is presented
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
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