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 […]
How to do things
Fluid flow: Froude and Reynolds numbers
19th century experiments that helped quantify the nature of fluid flow, surface waves, and bedforms. It all depends on inertia,
Optical mineralogy: Some terminology
Petrographic (optical, polarizing) microscopes open doors to the architecture of rocks – crystals, grains, cements – a riot of colour
Beach microcosms as fan delta analogues
Natural analogues for full-sized fan deltas Walk any sandy beach at low water, negotiating flotsam, cusps, bedforms, and pools draining
Plotting a structural contour map
Structural contour maps are the subsurface equivalent of surface topography maps. They are widely used in exploration geology (regional mapping,
A submarine channel complex
Here is a brief description of a submarine channel complex in the Jurassic Bowser Basin (northern British Columbia), a major
Greywackes in thin section
Greywacke petrography On the outside, greywacke is generally presented in varying shades of grey commonly with greenish hues, hammer-ringing hard,
Sandstones in thin section
The selection of sandstones in plain polarized light (left) and crossed nicols (right) shown here illustrate common petrographic attributes. Abbreviations
Geohistory 2: Backstripping tectonic subsidence
Teasing the tectonic subsidence from total basin subsidence Sedimentary basins are defined as regions of long-term subsidence of the crust
Geohistory 1: Accounting for basin subsidence
Decompacting a stratigraphic column to determine basin subsidence The analysis of a sedimentary basin begins at the hand-sample and outcrop