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Preliminary geochemical characterization of gas manifestations in North Macedonia
Full text linkL ike most of the Balkan Peninsula, North Macedonia is a geodynamically active area. As such it has
many hydrothermal features and gas manifestations. Until now, no systematic study about the
geochemical characterization of the geogenic gases was made before in this country. In August
2019, 24 gas samples were collected in the study area. All, except one collected at Duvalo (soil gas),
are gases bubbling or dissolved in thermomineral waters (temperatures from 12 to 66 °C). They
were analysed in the laboratory for their chemical (He, Ne, Ar, O2 , N2 , H2 , H2S, CH4 and CO2) and
isotopic composition (δ13C-CO2, δ13C-CH4, δ2H-CH4 and R/RA). Most of the gases have CO2 as the
main component (400-998,000 ppm) while the remaining are enriched in N2 (1300-950,000 ppm).
Helium ranges from 0.3 to 2560 ppm while CH4 from 1.6 to 20,200 ppm. R/RA and 4He/20Ne ratios
indicate a generally low atmospheric contamination, a prevailing crustal contribution and mantle
contributions between 1 and 20% considering a MORB endmember. The highest mantle
contributions are found in the SE part of the country very close to the sites that show the highest
R/RA values in continental Greece [1]. This area is characterised by extensional tectonics and Plio-
Pleistocene volcanism. A quite high mantle contribution (about 15%) is also found in two
manifestations in the NW part of the country along a main normal fault system. With the exception
of the sample of Smokvica, which has very low CO2 (1400 ppm) and δ13C-CO2 (-15.7 ‰ V-PDB), all
free gases show a relatively narrow range in δ13C-CO2 values (-4.6 to +1.0 ‰ V-PDB) indicating the
mixing between a mantle and a carbonate rock source. The isotope composition allows us to
assign the CH4 origin to three sources. The largest group can be attributed to a hydrothermal
origin (δ13C-CH4 around -20 ‰ V-PDB and δ2H-CH4 around -100‰). Three samples collected in the
SW part of the country have a thermogenic origin (δ13C-CH4 around -35 ‰ V-PDB and δ2H-CH4
around -160‰ V-SMOW). Finally, one sample (Smokvica) with the highest values (δ13C-CH4 -7.2 ‰
V-PDB and δ2H-CH4 -80‰ V-SMOW) may be attributed to abiotic processes in a continental
serpentinization environment or to methane oxidation
Duvalo (North Macedonia): A "volcano" without volcanic activity
Full text linkT he Duvalo locality is located in the SW of the Republic of North Macedonia, in the Ohrid region,
near the village of Kosel. It is an area of strong soil degassing, called “volcano” by the local people
despite volcanic activity has never been documented in the recent geologic history of the area [1].
A large area (thousands of sqm) shows signs of strong alteration and is devoid of vegetation. Until
the 19thcentury sulphur was mined from this area [1].
In August 2019, a campaign of soil CO2 flux measurements and soil gas sampling was made.
Duvalo is sometimes referred to as an active geothermal feature but no signs of enhanced
geothermal gradient were found and the soil temperatures at 50 cm depth in this campaign were
always within the range of local mean air temperatures. Soil CO2 flux values ranged from 1.3 to
59,000 g/m2/d and can be modelled with the overlapping of 3 or 4 flux populations. A possible
biological background is estimated in 6.8±1.8 g/m2/d while the other populations are characterized
by an anomalous average flux ranging from 180 to 33,000 g/m2/d. The CO2 total emission,
estimated both with a statistical and geostatistical approach, provided similar values in the order
of 50 t/d. This has to be considered as a minimum value because only areas with evident signs of
alteration have been investigated. Nevertheless, the estimated output is quite high for an area
unrelated with recent volcanism or geothermal activity.
The chemical composition of soil gases shows: CO2 (96.6%), N2 (1.8%), H2S (0.6%) and CH4 (0.3%) as
the main gases. The present composition is almost indistinguishable from previous analyses made
in 1957 and 1977 [1] pointing to a stability of the system in last decades. The isotope compositions
indicate for CO2 (δ13C -0.2 ‰) a pure carbonate rock origin, for CH4 (δ13C -34.4 ‰ and δ2H -166 ‰)
a thermogenic origin and for He (R/RA 0.10) a pure crustal origin.
The H2S released at Duvalo may be produced by either microbial or thermochemical sulphate
reduction favoured by hydrocarbons whose presence can be inferred by the uprise of
thermogenic methane. Partial oxidation of H2S during its upflow, producing sulphuric acid, may be
responsible of the production of abundant CO2 through dissolution of carbonate rocks. Similar processes have been evidenced also in other parts of North Macedonia [2]. These gases rise up
through the N–S trending normal faults bordering the seismically active Ohrid basin graben [3]
being released to the atmosphere through the soils of Duvalo “volcano”
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
Variations on the Author
Full text link“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
Full text linkWe 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
Geomorphological heritage and geoconservaton in the Republic of Macedonia
No full textRegardless of its relatively small area (25,713 km2), Republic of Macedonia
has a rich and diverse geomorphological heritage. The reason is primarily due
to the turbulent geotectonic activity and dynamics of this part of the Balkan
Peninsula, in the zone of collision of the African and European (Eurasian)
continental plates and their sub-segments. Also, a high impact on the
geodiversity was imposed by the significant climate changes of the past.
Therefore, almost all genetic types of relief are present, with the exception
of the typical aeolian forms. In terms of geodiversity, from the 38 mountains
in the country, 12 are higher than 2,000 m and characterized with fossil
glacial and periglacial landscape. There are several mountains with typical
karst landscape, while some have unique weathering landforms. There are about
30 volcanic cones and few calderas, a number of deep valleys and canyons,
etc. However, regardless of the abundant geodiversity, their protection and
promotion (as geo-values) was not sufficiently addressed. Generally, more
attention has been paid to biodiversity, assuming that threats to the
geodiversity are not as dramatic and irreversible as to the biosphere.
However, this course is drastically changed in the latest years, especially
with the preparation and adoption of the National Strategy for Nature
Protection, where geodiversity and geoheritage have very significant place.
Within the Strategy, 79 new geomorphological sites are proposed for
protection, reaching almost 180 protected geosites up to the year of 2027.
Thus, the results from this paper represent an important step in completing
the European geoheritage database by including the data from the Republic of
Macedonia
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
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