Search results for "feature"
showing 10 items of 4091 documents
2003
We expose the preliminary results of the archaeological excavations developed between 2000-2002 in Sidron's Cave, according to the three main objectives that concern the human fossil record: the anthropological characteristics, how and when they arrived there and the relation between fossils and culture. We conclude preliminarily that the record belongs to Horno Neanderthalensis, archeological remains to the Middle Paleolithic techno-complex, and they are in a secondary position.
Morphology, internal structure and genesis of the Burtnieks drumlin field, Northern Vidzeme, Latvia
1997
Abstract The Burtnieks drumlin field is one of the largest in the Baltic countries. It occupies a broad and uneven bedrock macrodepression. The uneven distribution of drumlins is related to the relief of the bedrock surface. Needle-shaped drumlinoids occur in the proximal part of the drumlin field, and they gradually merge into typical drumlin forms downglacier. This morphologic change reflects the differences in their genesis as suggested by internal structure. The cores of drumlins consist mainly of glaciotectonically deformed Pleistocene sediment and, in some places, also weakly cemented, dislocated Middle Devonian sandstone. All of them are folded into linear anticlines trending paralle…
StalAge – an algorithm especially designed for construction of speleothem age models
2012
The Devonian Stratigraphic Succession and Evolution of the Baltic Sedimentary Basin
2014
Facies analysis, biostratigraphic and taphonomic studies, a re-evaluation of signatures of worldwide events, and a new mathematical model of the Baltic sedimentary basin (BSB) have together enabled a better understanding to be gained of the development of the Devonian basins in the Baltic area. We have established four stages of basin evolution: (a) remnant basin stage (Lochkovian); (b) shallow epeiric basin stage, with mainly siliciclastic sedimentation (Pragian–early Frasnian); (c) shallow epeiric basin stage, with mainly carbonate sedimentation (Frasnian); and (d) infilling stage of the progressively narrowing shallow epeiric basin, with mixed sedimentation (Famennian).
Volcanic and anthropogenic contribution to heavy metal content in lichens from Mt. Etna and Vulcano island (Sicily)
1998
Major and trace element concentrations were determined in two lichen species (Parmelia conspersa and Xanthoria calcicola) from the island of Vulcano and all around Mt. Etna. In both areas, the average concentrations of Al, Ca, Mg, Fe, Na, K, P and Ti are substantially greater than those of other elements. Several elements (Br, Pb, Sb, Au, Zn, Cu) resulted enriched with respect to the local substrates. The Br and Pb enrichment factors turned out to be the highest among those calculated in both areas. Data indicate that mixing between volcanic and automotive-produced particles clearly explains the range of Pb/Br shown by lichen samples. Sb is also enriched, revealing a geogenic origin at Vulc…
Responses of taxonomic distinctness and species diversity indices to anthropogenic impacts and natural environmental gradients in stream macroinverte…
2007
SUMMARY 1. Many studies have shown traditional species diversity indices to perform poorly in discriminating anthropogenic influences on biodiversity. By contrast, in marine systems, taxonomic distinctness indices that take into account the taxonomic relatedness of species have been shown to discriminate anthropogenic effects. However, few studies have examined the performance of taxonomic distinctness indices in freshwater systems. 2. We studied the performance of four species diversity indices and four taxonomic distinctness indices for detecting anthropogenic effects on stream macroinvertebrate assemblages. Further, we examined the effects of catchment type and area, as well as two varia…
Substrate quality of drained organic soils—Implications for carbon dioxide fluxes
2021
Complex-forming properties of peat humic acids from a raised bog profiles
2013
Abstract Humic substances (HS) belong to the most powerful complex-forming agents, significantly affecting major and trace element speciation in natural environment. Several authors have focused on humic–metal interactions, using differing methods and comparing humic substances on different sources. However, the intrinsic differences among the HS of different origin and the impact of humification degree on the complex formation between humic substances and metals have not received the necessary attention until now. The aim of this study is to determine the Cu(II) complexing capacity and stability constants of Cu(II) complexes of humic acids (HA) isolated from two well-characterized raised b…
Parasitoids (Hymenoptera) of leaf-spinning moths (Lepidoptera) feeding on Vaccinium uliginosum L. along an ecological gradient in central European pe…
2011
Parasitoids of leaf-spinning Lepidoptera associated with two isolated central European peat bogs were investigated. Five families of parasitoid Hymenoptera (Braconidae, lchneumonidae, Eulophidae, Pteromalidae and Encyrtidae) were recorded. Three categories were recognised: (1) primary parasitoids, (2) facultative hyperparasitoids and (3) obligatory hyperparasitoids. Ten species of Braconidae, five species and seven marked morphospecies among lchneumonidae, and three species of Chalcidoidea were identified. Despite of some niche-specific (but less host-specific) parasitoids, all these hymenopterans are likely to be generalists and none of them were confirmed to be habitat and/or host special…
Acoustic detection of neutrinos in bedrock
2019
We propose to utilize bedrock as a medium for acoustic detection of particle showers following interactions of ultra-high energy neutrinos. With the density of rock three-times larger and the speed of sound four-times larger compared to water, the amplitude of the generated bipolar pressure pulse in rock should be larger by an order of magnitude. Our preliminary simulations confirm that prediction. Higher density of rock also guarantees higher interaction rate for neutrinos. A noticeably longer attenuation length in rock reduces signal dissipation. The Pyh\"asalmi mine has a unique infrastructure and rock conditions to test this idea and, if successful, extend it to a full-size experiment.