Geochemical and mineralogical related magnetic characteristics of the tertiary-quaternary (Umm Al-Qutein) basaltic flows from the basaltic field of Harra El-Jabban, Northeast Jordan

摘要

Several basaltic samples from the Tertiary-Quaternary field of Harra El-Jabban, specifically from (Umm Al-Qutein) area, underwent geochemical, mineralogical, and magnetic investigations. Geochemically, the flow is of silica-undersaturated types, and belongs to sodic, mildly alkaline magma series. The modal analysis shows higher magnetite (Titanomagnetite) up to 11 wt%, with TiO2 content ranging between 25 and 27 wt%, besides the olivine, clinopyroxine, and plagioclase. The magnetization was measured by using the superconducting quantum interference device Magnetometer. By doing zero-field cooling (ZFC), we can classify the magnetic anisotropy of the three samples studied, and these observations were assured again by doing magnetic isothermal curves. It seems that the critical temperature is above 400 K. A mixture of two magnetic phases (ferromagnet and ferrimagnet) was present in the samples. These were attributed to the presence of high total Fe2O3. The ferrimagnetic phase in these rocks was confirmed by the tendency of the magnetization toward zero value (compensation temperature) as we warm up the samples in ZFC and field-cooling methods. (C) 2002 Elsevier Science B.V. All rights reserved. [References: 15]