%0 Journal Article
%T Analysis and Interpretation of the Field and Laboratory Geophysical Measurements of Black-Sand Beach Deposits, East Rosetta, Egypt
%A Mohamed A. El-Sadek
%A Ahmed A. Ammar
%A Sayed A. Elkhateeb
%J International Journal of Geophysics
%D 2012
%I Hindawi Publishing Corporation
%R 10.1155/2012/435216
%X The present study deals with the analysis and interpretation of the results of field geophysical survey and laboratory geophysical measurements. The study of the magnetic and electrical methods was selected because the beach sands contain many minerals that have magnetic and electric properties. Analysis and interpretation of the field and laboratory magnetic and geoelectric maps demonstrated that the investigated beach-alluvial deposits can be subdivided according to their magnetic and geoelectric properties into three main zones striking nearly parallel to the shoreline of the Mediterranean Sea at the study area. The northern zone is more enriched in black sands than the central or southern zones. Field and laboratory magnetic susceptibility measurements provided very useful maps for the concentration of heavy minerals. The deep-seated magnetic response was calculated at an average depth of 239.6£¿m, while the near-surface magnetic responses were computed at average depths of 9.1, 57.9, and 81.8£¿m, respectively. The correlation between the geophysical features, recorded on the total magnetic field intensity, the electric resistivity, the IP chargeability, and the calculated metal factor, was found to agree to a great extent. The heavymineral concentration was found to decrease with depth. However, the heavyminerals show parallel zones below the surface, suggesting similar sedimentation environments. 1. Introduction The alluvial-beach placer deposits, East Rosetta, Mediterranean Sea Coast, Northern Egypt, are known for their enhanced natural radiation environment, due to the presence of radiogenic heavy minerals, such as monazite and zircon, which contain Th and U in their chemical composition [1]. The placer deposits are well known as sources for economic heavy minerals and nuclear raw materials, in addition to their importance in many of the strategic, metallurgical, and engineering industries. The mineralogical analyses identified six main heavy mineral sands accompanied by traces of cassiterite and gold as well as some minerals of rare earth elements (REEs). According to their relative frequencies, the six heavy minerals include ilmenite, magnetite, zircon, monazite, garnet, and rutile. The study area (30¡ã32¡ä10¡ä¡äE and 30¡ã34¡ä08¡ä¡äE long.; 31¡ã26¡ä59¡ä¡äN and 31¡ã27¡ä59¡ä¡äN lat.) extends over a length of 3.0£¿km, trending in an E-W direction along the Mediterranean Sea Coast, with an average width of more than 1.8£¿km (Figure 1). Figure 1: Map of Northern Egypt showing the location of the study area. The main objectives of the present study are(1)evaluation of
%U http://www.hindawi.com/journals/ijge/2012/435216/