Physics and Chemistry of Dykes

G. Baer, A. Heimann, both Geological Survey of Israel.

• 1 Dyke physics 1.1 Dyke swarms: Geometry and characteristics. Giant dyke swarms: Characteristics, distribution and geotectonic applications. The geometry and growth of dykes. Congruent dyke-widths in large basaltic volcanoes. Emplacement of the Meugueur-Meugueur cone-sheet (Niger, West Africa), one of the world’s largest igneous ring-structures. 1.2 Emplacement mechanics and host rock deformation. Why geologists should avoid using ‘fracture toughness’ (at least for dykes). Damage distribution and localization during dyke intrusion. Dyke propagation and arrest in Proterozoic tholeiitic dyke swarms, Vestfold Hills, East Antarctica. Deformation bands associated with dyke propagation in porous sandstone, Makhtesh Ramon, Israel. 1.3 Magma flow Fluid-mechanical models of the interaction between solidification and flow in dykes. Fracture propagation and magma flow in segmented dykes: Field evidence and fabric analyses, Makhtesh Ramon, Israel. The significance of phenocryst distributions in chilled margins of dykes and sills for the interpretation of tip processes. Anisotropy of magnetic susceptibility results from the Mashonaland dolerite sills and dykes of northeast Zimbabwe. 1. 4 Paleomagnetism and rock magnetism. Magnetic polarity domains in the early Proterozoic Matachewan dyke swarm, Canada: A novel method for mapping major faults. The origin and age of feldspar clouding in the Matachewan dyke swarm, Canada 2 Dyke chemistry. 2.1 Geochemistry. Palaeoproterozoic mafic dyke swarms in the Eastern Fennoscandian Shield, Finland: A review. The Tony Ridge zoned ultramafic dyke, Wyoming, USA: Preliminary geochemical results. The Precambrian Lavras mafic dykes, southern Sao Francisco Craton, Brazil: Preliminary geochemical and geochronological results. Major and trace element geochemistry of Early Proterozoic mafic dykes of northern Minnesota and southwestern Ontario 2.2 Petro gene sis. Nd isotopic constraints on mantle and crustal contributions to Early Proterozoic dykes of the southern Superior Province. Records of deep seated magma chamber processes from plagioclase and amphibole phenocrysts in Pan-African dyke rocks of Bir Safsaf, SW-Egypt. Dykes and sills from Eastern Paraguay: Sr and Nd isotope systematics. 2.3 Geochronology. Thermal events and low temperature alteration in the Precambrian Schistose Dykes and their host rocks in the Elat area, southern Israel: 40A r/39Ar geochronology. Palaeomagnetic and geochronological results from Proterozoic mafic intrusions in southern Zimbabwe. Isotopic and chronological constraints on dyke emplacement, Makhtesh Ramon, southern Israel. 2.4 Alteration processes. Low temperature alteration of a basaltic dyke in Makhtesh Ramon, Israel. Raman micro-spectrometry and infrared spectroscopy study of the alteration products of trachyte sills and dykes in Makhtesh Ramon area, Israel.