Plagioclase crystal fragments and a block of anorthosite occur in small basaltic dykes on the Jos Plateau. The anorthosite is unusual, for the feldspar is labradoritic, but the interstitial mineralogy is granitic rather than basic, displaying granophyric intergrowths in places. The anorthosite is probably not an intermediate stage in fractionation from a basic parent magma towards granite, sinc...

Magmatic sheet intrusions (dykes) constitute the main form of magma transport in the Earth's crust. The size distribution of dykes is a crucial parameter that controls volcanic surface deformation and eruption rates and is required to realistically model volcano deformation for eruption forecasting. Here we present statistical analyses of 3,676 dyke thickness measurements from different tectoni...

The goal of geovisualization is discovery and this can be hindered by a number of factors, including inadequate tools, that represent significant obstacles to the geovisualization thought process and require considerable effort to overcome (Dykes, forthcoming). Good software design using methods to support interaction can reduce these, but impediments are increasingly likely as geovisualization...

in taleghan, olivine basalt-basaltic andesite dykes as part of tertiary mamgmatic activities in central and western alborz zone, intruded into both karaj formation and late eocene-oligocene volcanic rocks. these dykes have similar geochemical characteristic which suggest that they are originated from a common source. on the primitive mantle normalized spider diagram, the dykes are characterized...

Observations from 145 submersible dives are used to create a database of mid-ocean ridge scarp topography and lithology. Seafloor lithologies are classified into extrusives, basaltic talus, dykes, gabbros and serpentinites, and the dive locations are broadly classified according to whether they are close to transform valleys and as a function of ridge spreading rate. The database is used to det...

Nep tu nian dykes were re cently re corded within the Mid dle Mio cene (Up per Badenian and Lower Sarmatian) Medobory reef com plex of the Carpathian Fore land in west ern Ukraine. The Up per Badenian reefs are cut by a reg u lar, semi-per pen dic u lar net work of in ter sect ing fis sures that pen e trate the Badenian reef lime stone down for more than 10 m. The dykes are filled by sev eral g...

The analysis of Anisotropy of Magnetic Susceptibility (AMS) is a powerful and rapid technique to examine the preferred orientations of mineral (magnetic) fabrics and can indicate the nature of a magma transport (vertical or lateral). The relationship between magnetic fabric and geometry of a dyke swarm enables us to understand magma emplacement processes. Depending on the mutual relationship of...