A new optical method for automated pore analysis on benthic foraminifera

We developed a new automated procedure for measuring several pore parameters of benthic foraminiferal calcareous tests. Crushed test fragments are mounted on microscope slides and observed with an optical microscope under natural transmitted light, allowing the observation of pores and fragment outlines. Images are automatically acquired and processed using customised image acquisition and analysis software. Through a single analytical approach, several porosity indices can be directly and independently investigated, specifically pore density (PD) and pore surface area (PSA) of the whole test. Comparison with the classical scanning-electron microscope (SEM) method confirms the reliability of this new optical approach, including on fossil material. The main advantage of this new method is the quick generation and analysis of a large amount of data, which greatly increases the number of pores analysed per sample, thus ensuring statistically robust analyses. As such, the method appears well adapted for the extensive study of large sample sets, especially long sedimentary sequences.