Mineralogical and geochemical features of colored benthic foraminifers from Aegean and southwestern coasts of Turkey

Abstract

We studied a total of 24 genera and 41 species of modern benthic foraminifers with colored shells from 49 samples collected from the Gokceada region. Southwestern Bozeaada, eastern Mitilini in the northeast Aegean Sea and from different points along the shores of southwest Antalya. d((104)) reflection and MgCO3 content of shell calcite vary between 2.979-3.035 angstrom and 0.33-19.00 mole%, respectively. Mg/Ca and Sr/Ca ratios of whole shells range between 2.95-51.51 and 1.45-10.44 [mmol/mol]. These values are normalized to maximum and minimum concentrations in chemical analyses from whole shells and shell surfaces in colored and colorless foraminifers. Enrichments in metallic elements seem to be related to absorption depending on qualitative and quantitative measurements of shell structures, although variations are also related to mineralogical composition of shells. Hypothetically ions transferred with hot waters from active faults on the sea-floorand/or the ions transported with cold water runoff from land may cause abnormal enrichment of some metals within foraminifer shells and/or secondary metabolic enrichment of foraminifer shells during life.