In the field Archives

Glauconite filling of rotaliid foram chambers

Glauconite in thin section

January 31, 2022

Glauconite – an important stratigraphic and paleoenvironmental indicator Glauconite is one of the most recognizable minerals in the entire sediment […]

How to do things, In the field, Interpreting ancient environments, Under the microscope

Carbonates in thin section: Forams and sponges

January 19, 2022

Two important contributors to bioclastic limestones – foram tests and skeletal sponge spicules Foraminifera Foraminifera (forams) are single celled,

How to do things, In the field, Interpreting ancient environments, Under the microscope

Carbonates in thin section: Bryozoans

January 9, 2022

Bryozoa – are a complex but important group of reef and non-reef invertebrates and contributors to bioclastic sediment. Bryozoa

A community of grazing echinoderms have almost cleaned the bedrock surface of bryozoa and algae (depth 25 m). In the process they add fine bioclastic debris to the local sediment mass. Three Kings Islands, northernmost NZ. Image courtesy of Cam Nelson.

How to do things, In the field, Interpreting ancient environments, Under the microscope

Carbonates in thin section: Echinoderms and barnacles

January 8, 2022

Echinoderms and barnacles are important contributors to bioclastic limestones Echinoids are a diverse phylum with a geological history dating back

How to do things, In the field, Interpreting ancient environments, Under the microscope

Carbonates in thin section: Molluscan bioclasts

January 7, 2022

Molluscan bioclasts are important components of tropical, and cool-temperate water limestones Bioclasts are probably the most important components of Phanerozoic