Thursday, November 12, 2015

More on Nature's Palette

The previous post showed the photo below of a natural phenomena on the surface of the Elbow River. 

I returned to the site five days later. The pigments had dispersed and the water was covered with a thin layer of ice. I searched for and found the source of the pigments and the photo below shows the orange organic material on the ground beside the river.The organic pigments on the surface of the river included shades of red, orange, yellow, and green. The organic pigments on the shore were exclusively orange! 

How did this happen?

My sense is that the factors involved might include the very slow movement of the surface water (shallow rivulet with pigment restricted by beaver dam at one end and surface ice at the other), the incident light from the sun (south-exposed location), the temperature at the water-air interface (cold November mountain water but warmer air in sunlight), the chemical nature of the orange organic material, and time. These and likely other factors allowed the orange pigment to separate into the other colors. 

The photos below show close ups with water seeping over the organic material towards the river. Originally I considered the organic material to be from autumn leaves, berries, and lichen. I thought the colors fit well with the xanthines that are visible once the chlorophyll disappears. However, the organic material in the photos below look more like an algal growth? 

If any readers have other thoughts, please let me know. Thanks. 

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