Preprints
Filtering by Subject: Tectonics and Structure
Precision and Accuracy in Geochronology
Published: 2017-11-05
Subjects: Earth Sciences, Geochemistry, Geology, Paleontology, Physical Sciences and Mathematics, Stratigraphy, Tectonics and Structure, Volcanology
Geochronology in Earth and Solar System science is increasingly in demand, and this demand is not only for more results, but for more precise, more accurate, and more easily interpreted temporal constraints. Because modern research often requires multiple dating methods, scrupulous inter- and intramethod calibration in absolute time is required. However, improved precision has highlighted [...]
Geological applications of digital terrain analysis
Published: 2017-11-01
Subjects: Earth Sciences, Geochemistry, Geographic Information Sciences, Geography, Geology, Geomorphology, Geophysics and Seismology, Physical Sciences and Mathematics, Remote Sensing, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure, Volcanology
Editorial to the IJGIS Special Issue on "Geological applications of digital terrain analysis". In this volume, the modern advances in the field of geological terrain analysis are presented, while emphasis is given to the quantitative analysis of modern datasets.
Reactivation of intrabasement structures during rifting - A case study from offshore southern Norway
Published: 2017-11-01
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Pre-existing structures within crystalline basement may exert a significant influence over the evolution of rifts. However, the exact manner in which these structures reactivate and thus their degree of influence over the overlying rift is poorly understood. Using borehole-constrained 2D and 3D seismic reflection data from offshore southern Norway we identify and constrain the three-dimensional [...]
Multi-scale Analysis of Topographic Surface Roughness in the Midland Valley, Scotland
Published: 2017-10-31
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Remote Sensing, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
Surface roughness is an important geomorphological variable which has been used in the earth and planetary sciences to infer material properties, current/past processes and the time elapsed since formation. No single definition exists, however within the context of geomorphometry we use surface roughness as a expression of the variability of a topographic surface at a given scale, where the scale [...]
Análise digital de terreno e evolução de longo-termo de relevo do centro-leste brasileiro
Published: 2017-10-31
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
Geomorphological theories for long-term relief evolution postulate the existence of planation surfaces, created by the con- tinuous work of erosion/deposition during periods of tectonic quiescence and recognized as extensive areas of very gentle relief disturbed only locally by residual elevations, or by the apparent leveling of summit heights in a given region. After decades since the [...]
Quantificação da Deformação Finita nos Metagranitoides Cariris Velhos na Região de Alagoa Grande (PB)
Published: 2017-10-31
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure
The Cariris Velhos Metagranitoids are considered an important geological unit of the Transversal Zone (Borborema Province – NE Brazil). We evaluated the use of raw and processed digital images to obtain the deformation ellipsoid for the Cariris Velhos Metagranitoids using the Inertia Tensor and Intercepts methods. The ellipsoid symmetry of the deformed fabric was very similar for both methods, [...]
SRTM resample with short distance-low nugget kriging
Published: 2017-10-31
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
The Shuttle Radar Topography Mission (SRTM), was flow on Space Shuttle Endeavour in February 2000, with the objective of acquire a digital elevation model of all land between 60º north latitude and 56º south latitude, using Interferometric Synthetic Aperture Radar (InSAR) techniques. SRTM data is distributed at horizontal resolution of 1 arc-second (aprox. 30m) for areas within the USA and at 3 [...]
SRTM-based morphotectonic analysis of the Poços de Caldas Alkaline Massif, southeastern Brazil
Published: 2017-10-30
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
An evaluation of SRTM 03” data applicability in geomorphology and morphotectonics analysis is proposed, considering the morphometric parameters slope, aspect, surface roughness and isobase surface. The study area, in southeastern Brazil, comprises the Poços de Caldas Alkaline Massif, a 33km-diameter Late Cretaceous collapsed volcanic caldera. Morphometric indices evaluated showed the correlation [...]
Trend-surfaces analysis of morphometric parameters: A case-study in southearstern Brazil
Published: 2017-10-30
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
Trend-surface analysis was carried out on data from morphometric parameters isobase and hydraulic gradient. The study area, located in the eastern border of Quadrilátero Ferrífero, southeastern Brazil, presents four main geomorphological units, one characterized by fluvial dissection, two of mountainous relief, with a scarp of hundreds of meters of fall between them, and a flat plateau in the [...]
Morphometric analysis in Geographic Information Systems: applications of free software GRASS and R
Published: 2017-10-30
Subjects: Earth Sciences, Geographic Information Sciences, Geography, Geomorphology, Other Earth Sciences, Physical Sciences and Mathematics, Social and Behavioral Sciences, Spatial Science, Tectonics and Structure
Development and interpretation of morphometric maps are important tools in studies related to neotectonics and geomorphology; Geographic Information Systems (GIS) allows speed and precision to this process, but applied methodology will vary according to available tools and degree of knowledge of each researcher about involved software. A methodology to integrate GIS and statistics in morphometric [...]
Normal fault growth in layered basaltic rocks: the role of strain rate in fault evolution
Published: 2017-10-30
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Conceptual models for the evolution of dilatant faults in volcanic rift settings involve a step-wise growth pattern, involving upward propagation of subsurface faults, surface monocline formation, which are breached by subvertical, open faults. Immature, discontinuous normal faults are considered representative of the early stages of mature, linked faults that accommodate extensional strains. We [...]
Igneous sills record far-field and near-field stress interactions during volcano construction: Isle of Mull, Scotland
Published: 2017-10-28
Subjects: Earth Sciences, Physical Sciences and Mathematics, Tectonics and Structure, Volcanology
Sill emplacement is typically associated with horizontally mechanically layered host rocks in a near-hydrostatic far-field stress state, where contrasting mechanical properties across the layers promote transitions from dykes, or inclined sheets, to sills. We used detailed field observations from the Loch Scridain Sill Complex (Isle of Mull, UK), and mechanical models to show that layering is not [...]
Influence of fault reactivation during multiphase rifting: the Oseberg area, Northern North Sea rift
Published: 2017-10-28
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Multiphase rifts tend to produce fault populations that evolve by the formation of new faults and reactivation of earlier faults. The resulting fault patterns tend to be complex and difficult to decipher. In this work we use seismic reflection data to examine the evolution of a normal fault network in the Oseberg Fault Block in the northern North Sea Rift System – a rift system that experienced [...]
Pre-existing normal faults have limited control on the rift geometry of the northern North Sea
Published: 2017-10-28
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
Many rifts develop in response to multiphase extension with numerical and physical models suggesting that reactivation of first-phase normal faults and rift-related variations in bulk crustal rheology control the evolution and final geometry of subsequent rifts. However, many natural multiphase rifts are deeply buried and thus poorly exposed in the field and poorly imaged in seismic reflection [...]
Balancing sub- and supra-salt strain in salt-influenced rifts: Implications for extension estimates
Published: 2017-10-28
Subjects: Earth Sciences, Geology, Physical Sciences and Mathematics, Tectonics and Structure
The structural style of salt-influenced rifts may differ from those formed in predominantly brittle crust. Salt can decouple sub- and supra-salt strain, causing sub-salt faults to be geometrically decoupled from, but kinematically coupled to and responsible for, supra-salt forced folding. Salt-influenced rifts thus contain more folds than their brittle counterparts, an observation often ignored [...]