196,091 research outputs found
VNIR spectral identification of Mars surface analogues: some problems related to basalt spectroscopy.
No full textAn attempt to determine densitimetric chracteristics of rock texture on aerial photographs
No full textDetermination of metamorphic grade in siliceous muscovite-bearing rocks in Madagascar using reflectance spectroscopy.
No full textVisible short-wave infrared laboratory reflectance spectra of quartzites and micaschists from the Precambrian basement of central-western Madagascar are dominated by the muscovite spectrum. The spectra were measured from rock samples collected along an E-W traverse across a metamorphic sequence recording progressively higher metamorphic grades. The wavelength of the AI-OH band around 2200 nm decreased westward and was inversely correlated with AI(VI) content of muscovite in rocks showing the same nonlimiting assemblage. This shift is correlated also with an increase of band intensity, which is attributed to the progressive increase of metamorphic grade. All of these variations in rock spectral properties can be detected by the high spectral resolution MIVIS and AVIRIS sensors, as well as by the lower resolution TM sensor
Tectonic and sedimentary evolution of the Gulf of Aden continental margins: new structural and stratigraphic data
No full textThe purpose of this work is to reconstruct the tectonic and stratigraphic evolution of the eastern sectors of these young margins. New structural and stratigraphic data were collected for the two continental margins facing the Gulf of Aden, in northern Somalia and southern Yemen, by integrating field work, aerial photo analysis and satellite multispectral data processing. A detailed stratigraphic correlation of pre-rift, Mesozoic to Eocene strata was constructed through north-eastern Somalia (Migiurtinia region), and selected sections were correlated between the two sides of the Gulf. The analysis of the deformation of these strata leads to the recognition of west-north-west-east-south-east trending half-graben and tectonic depressions, separated by structural highs interpreted as transfer zones. The transfer zones appear to be located on the landward extension of transform faults in the oceanic setting of the Gulf, and the tectonic depressions are approximately parallel to the oceanic ridge. Oligo-Miocene syn-tectonic basins developed within the depressions, and their patterns reflect their tectonic evolution of the eastern sector of the Gulf of Aden. The age of the deposits sealing the faults cutting Eocene strata confirm a early-middle Oligocene age for the beginning of rifting. The restoration of the pre-drift setting leads to a matching of the continental structures, such as basins and transfer zones, on the two sides of the Gulf. The comparison between the tectonic and stratigraphic features of both continental margins and the oceanic setting of the Gulf of Aden, indicates that a progressive crustal extension brought about the formation of oceanic spreading centres which correspond to the pre-existing syn-rift basins
Thematic Mapper multispectral facies in prevalent carbonate strata of an area of Migiurtinia (Northern Somalia): analysis and interpretation
No full text
Spectral classification of the rocks as a preliminary procedure for the lithologic interpretation of remote sensing multispectral data.
No full textDati spettroscopici e di laboratorio su sabbie litorali: le zone di foce adige e laguna Marano-Grado
No full textPrime considerazioni riassuntive sull'area appenninica dal F. Secchia al T. Nure
No full textCNR, P.F.GEODINAMICA-Sottoprogetto Neotettonic
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