Surface analysis of agglutinated benthic foraminifera through ESEM–EDS and Raman analyses: An expeditious approach for tracing mineral diversity

• Minerals of agglutinated foraminiferal tests are characterised.
• Mineral diversity was shown as very large.
• Hypotheses about the sources of the mineral have been advanced.

The use of an ESEM–EDS (Environmental Scanning Electron Microscope coupled with an Energy Dispersive X-ray Spectrometer), refined and corrected by point Raman micro-analyses, enables a rapid and representative overview of the mineral diversity of agglutinated foraminiferal tests. Statistical analyses of chemical data for ca. 180 tests and ca. 720 grains are used to evaluate environmental influences on test formation. While some species of the genus Textularia are known to select specific grains for their test, no statistically significant differences in grain selection are observed, at the genus level. The test chemistry is controlled by the availability of minerals and, therefore by the area's geological setting. Due to the active tectonic setting of the Aegean and Marmara Seas, the agglutinated tests of this area are characterised by a high content of fresh mafic feldspar and amphibole.