An Upland Bog in North Carolina

This upland bog lays on the top of a mountain ridge in Uwharrie National Forest, NC. The ridge top is unusually flat, possibly caused by the weathering and erosion characteristics of underlying metamorphosed volcanic rocks or it is an old terrace created by the Pee Dee River, that is west of this location. The only drainage outlet is a small low-order ephemeral stream and the stream's head is elevated above the level of the bog. There is also a geomorphic barrier on one side of the ridge created by a resistant rhyolite layer. Two deer ran across the bog as I approached.
This upland bog lays on the top of a mountain ridge in Uwharrie National Forest, NC. The ridge top is unusually flat, possibly caused by the weathering and erosion characteristics of underlying metamorphosed volcanic rocks or it is an old terrace created by the Pee Dee River, that is west of this location. The only drainage outlet is a small low-order ephemeral stream and the stream’s head is elevated above the level of the bog. There is also a geomorphic barrier on one side of the ridge created by a resistant rhyolite layer. Two deer ran across the bog as I approached.

Sediment Mixing in Moccasin Creek

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Sediment plumes and mixing during rainfall.

This is Moccasin Creek in Uwharrie National Forest, North Carolina after an extended period of rainfall. At least three sediment trails are visible. The light orange and tan in the thalweg of the stream is the result of sediment influx upstream some distance. (The stream is flowing away from you.)

A tributary on the right side of the channel is transporting bright orange suspended sediment derived mostly from runoff on a gravel road to the right. The tributary is fairly shallow, so most of the suspended load is still near the trunk stream’s surface. On the left, fine particles are being lifted from a recent excavation in the low-velocity margin of the larger stream.

Although the sediment plumes, especially in the central channel, show turbulent and convoluted flow, there is little mixing in this fairly straight channel. The margin of the bright orange plume shows evidence of eddies and vortices.

Image © Andy R. Bobyarchick.

Ripples over Bedrock № 1

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Shallow water ripples over jointed bedrock with algae.

Water ripples are forming in very shallow water of a Piedmont stream as it flows over orange bedrock. The rock is a metamorphosed argillite (fine-grained sedimentary rock) whose present color is the result of weathering in an oxygen-rich environment. Algae has grown preferentially in planar, nearly vertical fractures in the rock called joints.

The stream is in Uwharrie National Forest, North Carolina.

Image © Andy R. Bobyarchick.