Showing papers by "Geological Survey of Sweden published in 1983"
TL;DR: In this article, the authors used multivariate statistical analysis to discriminate between the different populations in the analyzed samples, and obtained chemical haloes which have an extension of more than one kilometer in all directions around the various ore types in the area.
16 citations
TL;DR: In this article, a theoretical solution to the problem where a VLF anomaly is generated by a conducting halfplane or a perfectly conducting wedge below a stratified overburden is presented.
Abstract: A theoretical solution is presented to the problem where a VLF anomaly is generated by a conducting half-plane or a perfectly conducting wedge below a stratified overburden. The solution is obtained by the use of a scattering matrix for plane-wave eigenfunctions. VLF anomalies have been computed for different values of the conductance and dip of the halfplane. The phase of the VLF anomaly due to a conducting half-plane depends on the conductance and the distance to the half-plane. Close to the half-plane the tilt angle and ellipticity are of opposite sign for a perfect conductor, but the ellipticity will change sign for a poor conductor. The VLF anomaly for a perfectly conducting wedge is essentially determined by the position of the upper surface of the wedge, i.e. the anomaly will closely resemble the anomaly of a perfectly conducting half-plane in the same position as the upper surface of the wedge.
15 citations
01 Jan 1983
TL;DR: In this paper, the authors show that in the upper part of the Middle Allochthon and in the higher nappes, they are preserved relics of pre-Iapetus rifting with oceanic crust, lapetus closing with subduction-related arc volcanics and even late extentional magmatism developed on newly sutured crust.
Abstract: Caledonian igneous rocks are concentrated in the upper part of the Middle Allochthon and in the higher nappes. Within these tectonically bounded stratigraphic packages there are preserved relics of pre-Iapetus rifting, lapetus opening with oceanic crust, lapetus closing with subduction-related arc volcanics and even late extentional magmatism developed on newly sutured crust. Different environments are characteristic of successively higher groups of nappes:-l) Rifting related dolerites and amphibolites occur in the Middle (Sarv Nappe and equivalents) and Upper (Seve Nappes and equivalents) Allochthons respectively, intruded or extruded in an ensialic environment. 2) Arc-related (probably ensimatic) volcanic and sub-volcanic rocks occur within the Upper Allochthon (Koli Nappes and equivalents). 3) Fragmentary ophiolite slices and associated within-plate basalts occur in the Upper Allochthon (including the Staren Nappe) and possibly even the Uppermost Allochthon.
1 citations
01 Jan 1983
TL;DR: The Caledonian fold belt of western Scandinavia outcrops over a strike length of some 1800 km with a maximum transverse width of 30 km in the central and southern parts as discussed by the authors.
Abstract: The Caledonian fold belt of western Scandinavia outcrops over a strike length of some 1800 km with a maximum transverse width of 30 km in the central and southern parts. The structure is characterized by a series of nappes, remarkable for their great areal extent in relation to their limited vertical thicknesses, that have all been displaced southeast-wards onto the Baltoscandian Platform.
1 citations