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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
Correlation of diagenetic data from organic and inorganic studies in the Apenninic-Maghrebian fold-and-thrust belt: a case study from Eastern Sicily
No full textTemperature-dependent clay mineral assemblages and vitrinite reflectance data have been used to investigate levels of diagenesis from the Apenninic-Maghrebian fold-and-thrust belt in eastern Sicily at the footwall of the Peloritani-Calabride Arc. Data are from units sampled along a regional transect between the Nebrodi Mountains to the north and Mount Judica to the south. These units developed in very different tectonic settings from those of oceanic to passive continental margin domains deformed during the Cenozoic mountain building and related active margin deposits. The integration of organic and inorganic thermal indicators allowed us to distinguish among different tectonic settings, with thermal maturity generally decreasing from hinterland to foreland as a result of progressively less severe thermal evolution and/or tectonic loading during the mountain building. Specifically, the highest vitrinite reflectance (VR0%) values (ca. 0.60%-0.75%) and percentages of illite layers in illite-smectite (I-S; 60%-80%) are found in trench-involved and accreted passive margin units. Lower VR0% values (0.20%-0.47%) and percentages of illite layers in IS (30%-60%) are found in thrust-top and foredeep basin deposits and far-traveled Sicilide units that have escaped involvement in trench evolution. Furthermore, either sedimentary or long-lived tectonic burial (at least more than 5 m.yr.) seem to have affected levels of diagenesis of the studied successions. The correlation between organic and inorganic thermal indicators is satisfactory for most of the samples derived from hemipelagic and siliciclastic deposits, whereas it is poor for some proximal siliciclastics. A tentative calculation of paleotemperatures is also proposed for the studied tectonostratigraphic units
Correlation of diagenetic data from organic and inorganic studies in the Apenninic-Maghrebian fold-and-thrust belt: a case study from Eastern Sicily.
No full textTemperature-dependent clay mineral assemblages and vitrinite reflectance data have been used to investigate levels of diagenesis from the Apenninic-Maghrebian fold-and-thrust belt in eastern Sicily at the footwall of the Peloritani-Calabride Arc. Data are from units sampled along a regional transect between the Nebrodi Mountains to the north and Mount Judica to the south. These units developed in very different tectonic settings from those of oceanic to passive continental margin domains deformed during the Cenozoic mountain building and related active margin
deposits. The integration of organic and inorganic thermal indicators allowed us to distinguish among different tectonic
settings, with thermal maturity generally decreasing from hinterland to foreland as a result of progressively less severe
thermal evolution and/or tectonic loading during the mountain building. Specifically, the highest vitrinite reflectance
(VRo%) values (ca. 0.60%–0.75%) and percentages of illite layers in illite-smectite (I-S; 60%–80%) are found in trench-involved and accreted passive margin units. Lower VRo% values (0.20%–0.47%) and percentages of illite layers in I-S (30%–60%) are found in thrust-top and foredeep basin deposits and far-traveled Sicilide units that have escaped involvement in trench evolution. Furthermore, either sedimentary or long-lived tectonic burial (at least more than 5 m.yr.) seem to have affected levels of diagenesis of the studied successions. The correlation between organic and inorganic thermal indicators is satisfactory for most of the samples derived from hemipelagic and siliciclastic deposits,
whereas it is poor for some proximal siliciclastics. A tentative calculation of paleotemperatures is also proposed for the studied tectonostratigraphic units
Correlation of inorganic and organic thermal indicators in the eastern Sicily fold-and-thrust belt
No full textCorrelation of organic and inorganic thermal indicators in the Apenninic-Maghrebian fold-and-thrust belt: a case study from Eastern Sicily
No full textA thermal and thermo-chronological approach to study the evolution of the Eastern Sicily fold-and-thrust belt (Italy)
No full textThe Monte Carrubba Formation (Messinian, Sicily) and its correlatives: new light on basin-wide processes controlling sediment and biota distributions during the Palaeomediterranean-Mediterranean transition.
No full textA little known marine Miocene (Messinian) succession in the Hyblean region of south eastern Sicily preserves a carbonate ramp sequence which developed on the tectonically stable foreland margins of the African Plate (Pelagian Block). The ramp (Monte
Carrubba Formation) was distally steepened and contained a shoalwater barrier and lagoonal inner ramp complex. The outer ramp
is poorly preserved though distal deep water ramp facies (Tellaro Formation) in the south Hyblean region preserve a full
Globorotalia mediterranea Subzone and major part of the Globigerina multiloba Subzone succession. This ramp sequence
faithfully records the subtle interplay between the global eustatic curve and internal Palaeomediterranean base-level signatures for the Late Miocene. The earliest second order Palaeomediterranean lowstand occurred in the Late Tortonian at about 7.3 Ma and a second occurred at about 6.75 Ma within the Early Messinian G. mediterranea Subzone. Although the overriding control at the time was the global eustatic curve, harmonic discrepencies between it and the Palaeomediterranean curve resulted from constriction of the Atlantic connection during the latest Tortonian. From about 6.4 Ma until about 5.96 Ma increasingly restricted conditions developed across the Monte Carrubba inner ramp. These faithfully reflect many second order, constriction-driven Palaeomediterranean sea-level oscillations which were superimposed on to the falling global signal as the connecting Atlantic seaways became constricted. These oscillations resulted in major reductions in planktonic faunal diversity within the outer ramp, followed by total emergence of the inner ramp by about 6.05 Ma. Marine deposition continued until about 5.96 Ma in the southern part of the Hyblean region. However, between 6.05 Ma and about 5.6 Ma the amplitude of successive Palaeomediterranean sealevel
oscillations increased to over 100 m, causing prolonged periods of total Palaeomediterranean isolation. The Hyblean
carbonate suite also contains post-Messinian Salinity Crisis (post-MSC) ‘Lago Mare’ highstand deposits which are developed
unconformably above the Monte Carrubba Formation. The widespread distribution of hyposaline to near-marine Congeria faunas within the Lago Mare episode argues for high post-MSC Mediterranean water levels in the Central Mediterranean Late Messinian
Thermal and thermo-chronological evolution of the eastern Sicily fold-and-thrust belt (Italy): constraints from organic and inorganic parameters and fission track data
No full textCorrelation of organic and inorganic thermal indicators in the Apenninic-Maghrebian fold-and-thrust belt: a case study from Eastern Sicily
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