Tag Archives: Mississippi Alluvial Valley

Geo-pic of the week: Aerial Photography

Aerial Photo-Central Arkansas

Sometimes the best way to see what’s on the ground is to get as far away from it as possible.  Geologists use a variety of tools to do just that.  One of those tools is aerial photography.

The picture above shows the Arkansas River where it leaves the mountainous western uplands and enters the bottomlands of the Mississippi Alluvial Plain, east of Little Rock (upper left).  Driving east across that boundary, it’s easy to get the impression that the Mississippi Alluvial Plain is a broad flat expanse of land with little to no distinguishing features.  That’s far from the case as this photo reveals.  

From high-altitude imagery, subtle relic features created by the Arkansas River can be easily recognized.  Note the swirling landforms that characterize the lowlands on the right side of the picture.  Over time the Arkansas River has meandered through the valley carving new channel courses and abandoning old reaches of channel.  The continually changing river has left a mosaic of oxbow lakes (water-filled abandoned channels) and arc-shaped river deposits known as point bars.