Geochemical Study of Radioactive Elements (Uranium, Thorium, and Potassium) in the Rocks of Latakia Sheet

This paper deals with a geochemical study of radioactive elements (uranium, thorium, and potassium) in rocks of different composition within the Latakia sheet, where the concentration of radioactive isotopes 238U, 232 Th, 40K was determined using a high-purity germanium detector, and an X-ray diffraction method-was (XRD) used to determine the mineral phases. The study showed a variation in the concentration of 238U, 232 Th, and 40K in the rocks of the study area, and it was observed that the radioactivity is mainly related to the element thorium, due to the presence of metals carrying thorium. The low concentration of potassium in most samples is due to the low percentage of mica and feldspar metals, or their corruption to elite and montmorillonite. The ratio Th/U indicated a suitable reference environment for deposition of uranium in most sedimentary samples, and this high percentage in the ophiolitic complex samples (with the exception of serpentinite rocks) is due to the oxidation and migration of uranium from these rocks towards rocks of sedimentary formations, and the stability of thorium and is not affected by oxidative conditions. The ratio Th/K indicated the predominance of elite and montmorillonite in most samples, with the presence of weather-resistant thorium-bearing metals in the basalt sample, and the sediments of Lake 16 October. The mineralogical study revealed the existence of mineral phases of uranium and thorium, in addition minerals carrying radioactive elements such as monazite and zircon

Study of Palaeomagnetism and Magnetic and Some Physical Properties of Tertiary Igneous Rocks of Sana’a Region (Republic of Yemen)

Palaeomagnetism and some magnetic and physical properties (magnetic susceptibility, intensity of remanent magnetization, ac current electrical conductivity and density) of 115 samples from 18 sites of the Yemen Volcanic Group TKY (Tertiary and (or) Cretaceous) from igneous rock exposures from Sana’a region were studied. One palaeomagnetic pole position was determined and a magneto-strigraphy of the area was suggested. The different properties were measured in order to use them as characteristic factors in discriminating the neighboring igneous flows. The measurement of the in situ magnetic susceptibility of 80 points, distributed on 4 sub-areas, in the area helped to calculate the mean value of the magnetic susceptibility of each sub-area, which may be used in any magnetic interpretation of aeromagnetic or magnetic anomalies. Also, the density of 115 samples were measured and a mean value of the density of each sub-area and an overall mean density of each rock age, were calculated in order to be used in any future interpretation of any gravity anomaly in the area.

Study of Palaeomagnetism and Some Magnetic and Physical Properties of Some Tertiary Igneous Rocks between Sana’a and Al-Hudyadah Region (Republic of Yemen)

Palaeomagnetism and some magnetic and physical properties (magnetic susceptibility, intensity of the Natural Remnant Magnetization (NRM), ac current electrical conductivity and density) of 136 samples from 22 sites of the Yemen Volcanic Group TKY (Tertiary and (or) Cretaceous) from igneous rock exposures along the road from Sana’a – west towards Al-Hudyadah were studied. A single population consists of seven Virtual Geomagnetic Poles (VGP), of the Upper Oligocene, was accepted and a mean at 182.81° E, 77.44° N with α95= 12.5° was calculated. The different properties were measured in order to use these properties as characteristic factors to discriminate the neighboring igneous flows. The measurement of the in situ magnetic susceptibility of 140 points, distributed on 7 sub-areas, in the region helped to calculate the mean value of the magnetic susceptibility of each sub-area, which might be used in any magnetic interpretation of aeromagnetic or magnetic anomalies. Also, the density of 132 samples were measured and a mean value of the density of each sub-area was calculated in order to be used in any future interpretation of any gravity anomaly in the area.