The metamorphic basement of Romanian Carpathians: a discussion of K-Ar and 40Ar/39Ar ages

More than 600 radiometric K-Ar ages on rocks from the metamorphic basement of the Romanian Carpathians are statistically treated and discussed. The data suggest that the most pervasive Alpine rejuvenation occurred in a belt of about 100-120 km width, within which crystalline rocks were intensely reworked, undergoing a metamorphic remobilisation of Barrovian type before Middle – Late Cretaceous. This Eo-Alpine metamorphic belt outcrops on the flanks of the Mureş Zone, i.e., in the Rodna massif to the NE, and in the Northern Apuseni to the west. Away from it, ages get progressively older and outline a broad Variscan metamorphic province. In the most external part of the South Carpathians preserved pre-Variscan ages point to the former extension of the Moesian Plate. Within the study area radiometric K-Ar ages, as well as recently reported fission-track data, do not support reheating above 300°C and corresponding regional metamorphic events during meso- and neo-Alpine times

Utilization of wetland ecosystem through fish-crop diversification for enhanced productivity and economic stability for fish-farm community of Indian sub-continent

This paper deals with a number of case studies that were undertaken during the last 8- 10 years in utilizing divergent æTalÆ wetland ecosystems (deep, semi-deep, temporary in a range of agro-ecological zones like NAZ, OAZ and Coastal Zone of the region) for the development of integrated management programmes using a range of approaches. These included (i) system approach (excavation & renovation, methodological approach), (ii) management (fish-crop management, inter & post-harvest care & processing, marketing), (iii) integrated natural resource management utilizing organic as well inorganic sources, and (iv) low-cost fish-feeds, based on fish-crop diversification. This paper also deals with some endangered indigenous fish species. The unique approach of watershed plans (bherri system), which were formulated for upright production systems, was economically successful. Economic indicators reveal there were comparative advantages of mixed farming systems compared to monoculture, exhibiting less than 2.5 fold gains even for resource poor fish farming families.Fishery management, Resource management

Growth and yield of summer groundnut (Arachis hypogaea L.) as influenced by foliar application of water soluble fertilizer

The field experiment was undertaken at the District Seed Farm, Kalyani at Bidhan Chandra Krishi Viswavidyalaya, Nadia, West Bengal during summer season of 2012 and 2013 to study the growth and yield of summer groundnut as influenced by application of water soluble foliar grade fertilizer. Application of liquid grade fertilizerat early growth stage up to 45 DAE did not influence the plant height and dry matter production significantly, but towards maturity varied significantly (P ? 0.05). Crop growth rate was faster at early part of the crop age and gradually slows at later part towards maturity. Foliar application of water soluble fertilizer along with RDF 85% had the significant (P ? 0.05) influence to increase the number of pods per plant, but shelling percentage and hundred kernel weight did not vary significantly. Liquid grade fertilizer either starter dose or booster dose or in both had the positive response to increased the groundnut pod yield up to 4-6 % over RDF only. The crop was equally responsive in increasing the pod yield, when RDF was reduced by 15% along with foliar application of liquid grade fertilizer. The foliar application of water soluble fertilizer was not the substitute to soil applied inorganic fertilizer. Instead, foliar supplementation of nutrients showed positive response to increase the pod yield, in addition to the fertilizers added to soil. Gross return decreased with reduction in amount of RDF applied for the crop, but gross return increased, when water soluble foliar grade inorganic fertilizer was supplemented with RDF. The maximum gross return of `150399 was obtained. The results obtained from correlation analysis carried out to examine the linear relationship between pod yields with different plant characters. Data obtained in case of dry matter of the plant was 0.995 and 0.997 in the respective years at 1% level of significance. Thus, it was concluded that dry matter content of plant is solely responsible over the yield increase in groundnut and foliar application of inorganic fertilizers in addition to that in soil has helped in better adsorption of nutrients in adequate amount by the crop

Along-strike shearing instead of orthogonal compression: A different viewpoint on Orogeny and Regional Metamorphism

Orogeny has been regarded for over a century as a compressional phenomenon due either to contraction or to lithospheric collision. However, generation of linear structures like orogens can hardly be explained by variation over large areas of stress gradients, as is to be expected in the rigid-plate convergence assumption. Lateral escape - implied by newer plate-tectonics interpretations to overcome this difficulty - might apply to some degree, but should by no means be more important than up and outward escape, i.e. in the direction of minimum principal stress. Movement indicators in regional metamorphic rocks have shown that tectonic transport along the orogens is a matter beyond question but also that this transport begins at a very early stage, a situation that contradicts the lateral escape model. Therefore it is assumed that the lateral movement is not due to compression, but to transcurrency, which has both the maximum and minimum principal stresses in the horizontal plane. This agrees particularly well with the observed belt-like distribution of deformation. Two models are advanced, the corridor and the gliding-blocks model, which are not mutually exclusive even if each of them relates to a specific geotectonic setting.Published191-1983.3. Geodinamica e struttura dell'interno della TerraN/A or not JCRope

Along-strike shearing instead of orthogonal compression: A different viewpoint on Orogeny and Regional Metamorphism

Orogeny has been regarded for over a century as a compressional phenomenon due either to contraction or to lithospheric collision. However, generation of linear structures like orogens can hardly be explained by variation over large areas of stress gradients, as is to be expected in the rigid-plate convergence assumption. Lateral escape - implied by newer plate-tectonics interpretations to overcome this difficulty - might apply to some degree, but should by no means be more important than up and outward escape, i.e. in the direction of minimum principal stress. Movement indicators in regional metamorphic rocks have shown that tectonic transport along the orogens is a matter beyond question but also that this transport begins at a very early stage, a situation that contradicts the lateral escape model. Therefore it is assumed that the lateral movement is not due to compression, but to transcurrency, which has both the maximum and minimum principal stresses in the horizontal plane. This agrees particularly well with the observed belt-like distribution of deformation. Two models are advanced, the corridor and the gliding-blocks model, which are not mutually exclusive even if each of them relates to a specific geotectonic setting

Geotectonic hypotheses at the beginning of the 21st century

In this contribution to the volume honouring Ott Ch. Hilgenberg the main directions of thought in the field of geotectonics at the beginning of the 21st century are reviewed. However, because of its seminal importance for the geological thinking during most of the last century, the Wegener (continental drift) hypothesis is also included and opens the review. It is followed by the critical presentation of Plate tectonics and the hypotheses of Earth expansion, Surge tectonics and Wrench tectonics. Finally the authors present their own view, which may best be described as shear-belt tectonics or tectonics above asthenocurrents. In their opinion, to expand knowledge on crust and mantle, terms like plate, slab, sliver a.o., that imply rigidity, should be abandoned and replaced by terms used in fluid dynamics (e.g. currents, laminar and turbulent flow, vortices).Published259-2733.3. Geodinamica e struttura dell'interno della Terraope

Geotectonic hypotheses at the beginning of the 21st century

In this contribution to the volume honouring Ott Ch. Hilgenberg the main directions of thought in the field of geotectonics at the beginning of the 21st century are reviewed. However, because of its seminal importance for the geological thinking during most of the last century, the Wegener (continental drift) hypothesis is also included and opens the review. It is followed by the critical presentation of Plate tectonics and the hypotheses of Earth expansion, Surge tectonics and Wrench tectonics. Finally the authors present their own view, which may best be described as shear-belt tectonics or tectonics above asthenocurrents. In their opinion, to expand knowledge on crust and mantle, terms like plate, slab, sliver a.o., that imply rigidity, should be abandoned and replaced by terms used in fluid dynamics (e.g. currents, laminar and turbulent flow, vortices)