A transverse drainage on the southern flank of South Mountain in central Arizona

In the upper image, the drainage of interest flows along the center from top to bottom.  The "Gravel Capped..." criteria has an image associated with it, just click on that criteria to see it.  The lower image provides an oblique view looking to the west.   Notice that several criteria have been noted for you on the image.  Use this information to determine the mechanism responsible for this transverse drainage.  

Click on the criteria diagram above to go back to the previous page where this diagram has numerous helpful links!