Search results for " Geology"
showing 10 items of 533 documents
Citizens’ perceptions in relation to transport systems and infrastructures: a nationwide study in the dominican republic
2021
One of the challenges currently faced by emerging countries is to get their citizens to decide to use sustainable transport for their regular trips, in order to reduce the current vehicular pollution rates. The objective of this descriptive research is to examine the perceptions of Dominicans regarding the state of the country’s transport systems and road infrastructure. For this purpose, a nationwide survey procedure was performed. This cross-sectional research used the data retrieved from a sample of 1260 citizens aged over 18, proportional in gender, age, habitat, and province of the Dominican Republic. The results showed how Dominicans believe that, compared to other road features, pede…
On the origin of the southern Permian Basin, Central Europe.
2000
A detailed study of the structural and stratigraphic evolution of the Southern Permian Basin during latest Carboniferous to Early Jurassic times, supported by quantitative subsidence analyses and forward basin modelling for 25 wells, leads us to modify the conventional model for the Rotliegend-Zechstein development of this basin. The Late Permian-Early Jurassic tectonic subsidence curves are typical for a Permian to Early Triassic extensional stage that is followed by thermal subsidence. However, a purely extensional model is extremely problematic because active faulting during this time is 'minor' and generally hard to document. Using inverse techniques to model the subsidence curves, we q…
Successes and failures in geodynamics
2001
Abstract The evolution of Earth models is reviewed and the open questions and problems are highlighted. Generally, evolution of science was not linear, but proceeded in “steps” of paradigms; where old ones remained within useful limits. “Geodynamic hypotheses”, while embedded into the general concepts of space and time, were often mutually exclusive and competing until the 1900s. Wegener's concept of continental drift was the first successful globally unifying view, but it was discarded by most Earth scientists. The “real” change of paradigms did not come before mid-century through geophysical observations in paleomagnetism, seismology, bathymetry, seafloor geology and dating, leading to th…
Fabric Development in Gneiss Terrains
1990
This chapter describes some aspects of the development of fabrics in gneiss terrains. It provides essential background information that should be read before attempting to map a gneiss terrain. Inevitably, the interpretations are ‘state of the art’ and not necessarily the absolute answer. Additional information can be found in the cited literature and various specialised journals such as the Journal of Structural Geology, the Journal of Metamorphic Geology, Tectonophysics, Tectonics and Precambrian Research.
Three-dimensional evolution of the Keuper of the Paris basin based on detailed isopach maps of the stratigraphic cycles: tectonic influences
1997
Detailed isopach maps of the stratigraphic cycles of the Keuper of the Paris basin are used to reconstruct the 3D evolution of the basin cycle by cycle and to investigate the influence of tectonic movements. The major base-level cycles record variations in the rate of subsidence in time and space. The area of greatest subsidence, which was confined to the east of the basin during the Scythian–Carnian cycle, shifted northwestwards during the Carnian–Liassic cycle. Within the “Marnes irisees inferieures”, the E–W faults abruptly limited the extent of salt deposits to the north and south by forming a “corridor” where subsidence was greater. The westward shift of areas of subsidence induced by …
Review of “Marine Hard Substrates: Colonization and Evolution,” a Thematic Session at the Geological Society of America Annual Meeting, Denver, USA, …
2005
A theme session, jointly sponsored by the Paleontological Society and the Geological Society of America Sedimentary Geology division, and entitled “Marine Hard Substrates: Colonization and Evolutio...
Análisis criptopaleontológico del lapidario de Teofrasto (s. III a.C.)
2013
The work “Perì líthon” or Teofrasto’s “Treatise of stones” has been considered the oldest text still available about minerals and rocks, even though it has remained incomplete. In this paper, the study of its contents shows that eleven of the stones called by geographic or cryptic names are either fossils from plants or vertebrates or chemical fossils. Therefore, the “Perì líthon” should also be considered as the oldest known treatise about palaeontology, because in addition to the fossils mentioned, it refers specifically to the fossilisation process.La obra “Perì líthon” o “Tratado de Piedras” de Teofrasto, es considerado el texto más antiguo conservado sobre minerales y rocas, aunque hay…
Land Surface Temperature Retrieval Methods From Landsat-8 Thermal Infrared Sensor Data
2014
The importance of land surface temperature (LST) retrieved from high to medium spatial resolution remote sensing data for many environmental studies, particularly the applications related to water resources management over agricultural sites, was a key factor for the final decision of including a thermal infrared (TIR) instrument on board the Landsat Data Continuity Mission or Landsat-8. This new TIR sensor (TIRS) includes two TIR bands in the atmospheric window between 10 and 12 $\mu\hbox{m}$ , thus allowing the application of split-window (SW) algorithms in addition to single-channel (SC) algorithms or direct inversions of the radiative transfer equation used in previous sensors on board …
Volume change characteristics of fine-grained soils due to sequential thermo-mechanical stresses
2019
Know-how of volume change characteristics, VCC, of the fine-grained soils, exposed to thermal stresses, is essential for design of various thermo-active structures. These stresses are known to induce excess pore-water pressure, Δu θ , in the saturated state of such soils, which in turn affects their compression and shear strength characteristics. In this context, through several experimental studies, the effect of thermo-mechanical stress-path, the over-consolidation ratio (OCR) and degree of saturation on VCC (viz., thermally induced volumetric strain, ε vθ , compression and re-compression indices, c c and c r ) of the fine-grained soils has been demonstrated by earlier researchers. Howeve…
Nonstationary flow surface theory for modeling the viscoplastic behaviors of soils
2016
Abstract This paper presents a three-dimensional elastic viscoplastic model that can describe the time-dependent behaviors of soft clays. The constitutive model is formulated based on the nonstationary flow surface theory and incorporates new developments, including (i) an improved definition of the nonstationary flow surface that is capable of capturing the stress–strain behaviors under different loading paths, (ii) a unique stress–strain—viscoplastic-strain-rate equation that is able to explicitly describe the nonstationary flow surface, and (iii) a final stable state concept that identifies the final equilibrium state at the end of creep and stress relaxation, which is also used to simpl…