Construção de perfis compostos de teor de carbonato de cálcio e de susceptibilidade magnética para o Quaternário da Bacia de Santos

Abstract

The establishment of chronology is essential in paleoceanographic and paleoclimatic studies. Over the years, different chronological methods have been developed, however, most existing tools require a lot of time and/or have a high financial cost. The objective of this study was to construct composite profiles of calcium carbonate content and magnetic susceptibility for the last 1650 ka (Quaternary) that can be used as an auxiliary tool to obtain relative ages for samples of unknown ages, through the correlation of calcium carbonate content and magnetic susceptibility with the composite profile of the target parameters. For the construction of composite profiles, seven piston cores were used, located in the Santos Basin, which cover different age ranges but which together comprise the last 1650 ka. Two methods were developed TO construct composite profiles (Methods 1 and 2). The composite profile generated by Method 1 was the one that preserved the variations of the base profiles of the seven cores used and the one that presented the least possible errors. Throughout the results and the discussions some limitations were observed in relation to the composite profiles of calcium carbonate content and magnetic susceptibility, mainly related to the data resolution. However, the applicability of the generated composite profiles was tested and, in general, the profiles were able to efficiently determine ages of additional piston cores in Santos Basin. therefore, is still necessary to improve the data resolution of composite profiles, through the use of a larger number of cores, as well as cores that cover the same age range.