CHEMICAL DEMAGNETIZATION - METHODS, PROCEDURES, AND APPLICATIONS THROUGH VECTOR ANALYSIS

A total of 75 samples from the Freda sandstone (1050 Ma old) have been drilled from the same slab in order to investigate the best method of sample preparation and to optimize procedures for chemical demagnetization of red sandstones. Expanding on the chemical demagnetization procedures used by Park, several variables have been tested. Visual inspection of cores sectioned during progressive chemical demagnetization has allowed the comparison of the solubility spectra to the blocking temperature spectra of thermal demagnetizations. This comparison has linked the coarser-grained specularite to the highest blocking temperatures, and the fine-grained hematitic cement to intermediate blocking temperatures. There exists a component of magnetization which appears to be insoluble to the leaching process. It has been shown to be carried by detrital titanomagnetite. Through the combined use of chemical, thermal, and alternating field demagnetization of magnetic history involving deposition, lithification, and later overprinting has been unraveled from this slab of Freda.-Author