Bow River shoreline gravel
The parameters of a fluvial system (i.e., a river) fluctuate: when the water level is higher and this gravel is submerged, this would be the riverbed rather than the exposed shoreline shown here.
Note the well developed rounding of the gravel stones (clasts), the result of repeated abrasion during transport (rolling forward, downstream) by strong water currents. The composition of the clasts, grey limestone and well layered sandstone (or quartzite), reflects the source area to the west, the Rocky Mountains, where Paleozoic carbonate rocks (limestones, dolomites) and Late Proterozoic to Paleozoic sandstone/quartzite are abundantly exposed.
(I worked as a geologist for decades and have known this sort of sedimentary subject matter for 40 years - to write this caption I did not have to look anything up on Wikipedia or other info sources.)
C. J.R. Devaney
Bow River shoreline gravel
The parameters of a fluvial system (i.e., a river) fluctuate: when the water level is higher and this gravel is submerged, this would be the riverbed rather than the exposed shoreline shown here.
Note the well developed rounding of the gravel stones (clasts), the result of repeated abrasion during transport (rolling forward, downstream) by strong water currents. The composition of the clasts, grey limestone and well layered sandstone (or quartzite), reflects the source area to the west, the Rocky Mountains, where Paleozoic carbonate rocks (limestones, dolomites) and Late Proterozoic to Paleozoic sandstone/quartzite are abundantly exposed.
(I worked as a geologist for decades and have known this sort of sedimentary subject matter for 40 years - to write this caption I did not have to look anything up on Wikipedia or other info sources.)
C. J.R. Devaney