Stratigraphic boundaries identification from chemostratigraphic intervals in well logs based on first and second derivatives

An elemental analysis of rock samples from outcrop sections or wells is performed. Data quality checks, data analysis, and filtering are performed on the rock samples, including de-spiking of elemental profiles and elemental ratios. First and second derivatives for the elemental profiles and the elemental ratios are calculated. Samples and depths that exceed thresholds are determined. The process is repeated for the elemental profiles and the elemental ratios that are related with boundary determination and carbonate or siliciclastic sediments. Additional filters are applied to at least a subset of the elemental profiles and elemental ratios that are related with boundary determination and carbonate or siliciclastic sediments to enhance the boundary identification. Possible boundaries in depths of the outcrop sections or wells are determined by summarizing the additionally filtered elemental profiles and the additionally filtered elemental ratios.