Sun Haloes at Morrow Mountain State Park in Central North Carolina

Under propitious conditions, at sunset you might see something amazing. These images were captured from Morrow Mountain State Park in the central Piedmont of North Carolina. This is a rhyolite ridge in the Uwharrie Mountains. The volcanic rocks formed several hundred million years ago as part of a volcanic arc on the other side of an ocean from ancestral North America.

Ice crystals in cirrus clouds refract light from the setting sun. When the sun is near the horizon, a bright halo often showing red-to-violet spectra appears. You can see this halo as a bright semi-circle here.

sun halo with sundogs

Sun halo, sundogs, and top of a light pillar from Morrow Mountain State Park. This is a three-image HDR photograph made with a Canon 5D Mark II.

Along a line parallel to the horizon and at 22° left and right of Sol there are two bright spots. These are sundogs or perihelia. In this image, the sundogs also show a refraction spectrum.

Another bright spot is directly above the sun. It’s not so obvious here, but sometimes a vertical light pillar connects this part of the halo to the sun, the result of falling ice crystals in the atmosphere.

Panorama compiled from eight images of sunset, Morrow Mountain State Park, North Carolina.

All images ©Andy Bobyarchick.


Meander and Point Bar in Flat Creek, SC

Flat Creek southeasterly through Lancaster County, South Carolina. The stream feeds into Lynches River, that farther southeast joins the Great Pee Dee River. The Pee Dee joins the Waccama River at Georgetown on the SC Atlantic Coast.

Flat Creek carries a heavy load of sediment. Where this image was made, the stream crosses the Pageland granite, a pluton that is about 300 million years old. The granite is coarse-grained and sheds considerable quartz and feldspar grains as it weathers and erodes.

This image is a 180° panorama around a meander bend in Flat Creek. Lower water velocity on the inside of the meander causes the coarser sediment load to drop out to form a sandy point bar. The near bank of the river is being undercut by erosion on the outside of the meander where water velocity is greater. In time, the stream channel will migrate toward this cut bank.

It’s difficult to see in the shadows, but in the lower left corner of the photograph a tributary trickles into the main channel, and there are abundant beaver tracks there. Beavers use the tributary mouth as a slide.

In the lower right corner of the photograph you can see a boulder of Pageland granite. It’s rounded shape is characteristic of spheroidal weathering of a larger mass of granite bedrock.

Not far to the southeast, Flat Creek crosses from Piedmont igneous and metamorphic rocks into sedimentary rocks of the Sandhills.

This image was made late on a Spring afternoon under a brilliant blue sky reflecting off the water’s surface and under the long shadows of hardwood trees yet to put out theire leaves.

This image is ©Andy R. Bobyarchick

meander and point bar

A meander bend and point bar in Flat Creek near Taxahaw, SC.