Pyroclastic surges and base surges
Pyroclastic surges, are dilute, ground-hugging turbulent flows of hot, juvenile volcanic particles and a fluid phase of superheated steam and […]
Accretionary aggregates and accretionary lapilli
I have been under the (mistaken) impression that accretionary aggregates, including accretionary lapilli, are occasional odd-ball structures borne of explosive
Block and ash flows
Block and ash flows – a hot pyroclastic flows that transport big chunks of rock Block and ash flows (BAFs)
Ignimbrites in outcrop and thin section
Ignimbrite is a rock name. Ignimbrites form primarily from the collapse of eruption columns during explosive volcanism and are included
Glauconite in thin section
Glauconite – an important stratigraphic and paleoenvironmental indicator Glauconite is one of the most recognizable minerals in the entire sediment
Carbonates in thin section: Forams and sponges
Two important contributors to bioclastic limestones – foram tests and skeletal sponge spicules Foraminifera Foraminifera (forams) are single celled,
Carbonates in thin section: Bryozoans
Bryozoa – are a complex but important group of reef and non-reef invertebrates and contributors to bioclastic sediment. Bryozoa
Carbonates in thin section: Echinoderms and barnacles
Echinoderms and barnacles are important contributors to bioclastic limestones Echinoids are a diverse phylum with a geological history dating back
Carbonates in thin section: Molluscan bioclasts
Molluscan bioclasts are important components of tropical, and cool-temperate water limestones Bioclasts are probably the most important components of Phanerozoic
Volcanics in outcrop: Pyroclastic density currents
This post continues the series on volcanic and volcaniclastic rocks in outcrop, with a brief introduction to pyroclastic density currents