The term ''calcareous nannofossils'' includes both fossil coccoliths and nannoliths. '''Coccoliths''' are minute (<25μm) calcite objects produced by unicellular marine plants (golden-brown algae). The origin of nannoliths is uncertain, but these calcite bodies are associated with fossil coccoliths assemblages in marine sediments and are also organically derived. | The term ''calcareous nannofossils'' includes both fossil coccoliths and nannoliths. '''Coccoliths''' are minute (<25μm) calcite objects produced by unicellular marine plants (golden-brown algae). The origin of nannoliths is uncertain, but these calcite bodies are associated with fossil coccoliths assemblages in marine sediments and are also organically derived. |