1,721,093 research outputs found
Tree-induced changes in a Terra Rossa soil under olive. Observation from an integrated field study
No full textSoil micromorphology for construction science: the mortar archaeometry
Full text linkMicromorphology revealed in depth evaluation of materials particularly soil micromorphology yielded numerous data on processes such as formation, neoformation and transformation of minerals and microstructure in soils, pottery and construction materials. Mortars, one of the first human made materials for construction of Byzantine and the Ottoman worlds were compared in terms of micromorphology and mineralogy
Güney Doğu Anadolu Bölgesinde Yaygın Olarak Bulunan Smektitik Toprakların Makro-Mikro Yapı Dayanımlarını Etkileyen Faktörler
No full textŞanlıurfa ilinden seçilen ve Güney Doğu Anadolu bölgesinde yaygın olan, ve yüksek düzeyde smektit içeren Entisol, Aridisol ve iki Vertisolden bozulmuş ve bozulmamış toprak örnekleri alınmıştır. Bu örneklerin detaylı fiziksel, kimyasal, mineralojik ve mikromorfolojik özellikleri saptanarak, toprak makro-mikro yapı dayanımlarını etkileyen etmenlerin etki düzeylerinin belirlenmesi amaçlanmıştır. Araştırma sonuçları, kültür altına alınmayan profil 1’de yapı dayanımlarını organik maddenin, profil 2, 3 ve 4’te ise gerilim kütanları başta olmak üzere sırasıyla Fe-Al oksitleri, kil, karbonatlı minerallerin agregatları bir arada tutulmasını sağlayan etmenler olduğu ortaya koymuştur. Profil 4’te saptanan yüksek düzeydeki agregasyon indeksinin gerilim kütanlarıyla birlikte belirlenen kalsit kütanları ile ilişkili olduğu belirlenmiştir. Çalışma topraklarındaki başat kil mineralinin smektit olması ve agregatları bir arada tutan etmenlerin başında gerilim kütanları ile yüksek kil içeriğinin bulunması, çalışılan alanda sulamayla birlikte tuzlulaşma-alkalileşme ve toprak makro-mikro yapısındaki bozulma risklerini arttırmaktadır
Polygenetic evolution and bioturbation: micromorphological study of a Terra Rossa soil in a traditional olive crop (Sardinia, Italy)
Full text linkThe origin of Mediterranean red soils has been the subject of numerous studies. Complex genetic processes, and massive inputs of allochtonous materials such as wind-blown Saharan dust and volcanic ashes, have been advocated to interpret their genesis. The present study was carried out in a traditional olive grove nearby Sassari (Sardinia, Italy), where the land use remained unchanged for the last 150 years, on Terra Rossa developed on Miocene marine limestone
A tribute to Ewart A. FitzPatrick (1926-2018), a life for Pedology and Morphology of Soils
No full textWOS: 000437053000001
Colour origin of Tortonian red mudstones within the Mersin area, southern Turkey
No full textFluvial red mudstones of Tortonian age (overbank deposits) are widespread in the Mersin area in southern Turkey. The XRD analysis reveals that the mudstones consist predominantly of smectite, containing 3.0 to 6.6 wt.% Fe2O3, of which ≤ 1% is present as hematite. However this is evidently sufficient hematite to yield a red colour to the whole rock. SEM images show that very fine hematite crystals are disseminated in the mudstones as pore-filling cement between smectite flakes. After reddening, some of the clay and hematite were most likely leached and accumulated with smectite in the shrink–swell fractures as infill. Reddening in the mudstone took place in a terrestrial environment and the hematite pigment formed from intrastratal water by inorganic precipitation at the initial stage of diagenesis. The free Fe2+ was most likely released from the Fe-bearing minerals in an aqueous reducing environment, with hematite being precipitated as cement during the dry periods
Tree-induced changes in a terra rossa soil under olive. Observations from an integrated field study
No full textA range of indicators including chemical, physical, morphological, and clay mineral properties were investigated to support an integrated evaluation of the changes induced by a long established olive grove on a red Mediterranean soil. The study area was located in Sardinia (Italy). Two soil profiles were studied in a site where land use had remained unchanged for the previous 150 years: one under the canopy and around the trunk of an olive tree and one between the trees. Chemical analyses including organic matter fractions were performed by horizon. Undisturbed soil samples were collected from aggregates for thin section and scanning electron microscopy (SEM) analyses, complemented by clay mineralogy. Relative compaction was observed in tree topsoil due to the pressure of the anchoring roots. Lower compaction, higher porosity, and less developed micro-aggregates were observed in deeper horizons in relation with the loosening action induced by roots. Sharper vertical chemical gradients were determined under the tree. Stress features were observed in thin sections from all the horizons. Traces of smectite were determined as indicator of past shrink-swell processes suggesting that the present-day dominance of illite-like minerals might be explained by transformation of smectite induced by pedogenesis and by the long-lasting K-enriching action of the plants. Our findings indicate the need to undertake more systematic, integrated, and comparative future research on this subject
Application of Soil Analyses as Markers to Characterize a Middle Eastern Chalcolithic - Late Bronze Age Mounds
No full textTell El-Ghassil in Lebanon's Beka'a Valley is typical of mounds, in Syria, Turkey, and Iraq. While stratigraphy and human artefacts are used in archaeological investigations of such sites, soil analysis is a less frequently used. This study involved sampling to a depth of about 6 to 7 meters on exposed surfaces of a vertical transect, as well as away from the mound. The data show that parameters such as organic matter, total and available phosphorus, and the proportion of iron oxides are potentially useful indicators of soil weathering and the intensity of human occupation of the site, as well as periods of abandonment, and thus in charting the human evolution of the mound. The diffuse archaeological layers, i.e., the stratigraphy of the mound, which is difficult to distinguish, may also be elucidated with soil analysis
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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