Side
view of an alluvial fan
In the center of the picture is an alluvial fan. It's surface is fairly steeply dipping; we would actually call this a debris cone. Alluvial fans form when a stream changes slope - here, there is a tream coming out of the hills and reaching the flat valley floor. The stream loses energy and deposits most of the sediment it was carrying; this material spreads out in a fan from the end of the canyon. The steepness of the fan's surface depends on the rate at which the hills are being uplifted above the valley floor. In general the fans on this side of the valley are steeper than fans on the opposite valley wall - meaning that this side is being uplifted faster than the far side.
Front
view of an alluvial fan
This is the same fan as in the previous photo. The stream coming out of the canyon spreads out in all directions, splitting up. The darker material is sediment that was deposited a longer time ago than the lighter material - the darkening is desert varnish (which means the lighter sediment is more recent).
Coalesced
fans
This is the opposite side of the valley. The fans form an apron all along the sides of the valley; these coalesced fans are forming a surface called a bajada.
Lake
beds
This ridge of yellow and brown striped layers (in the middle ground) are lake beds that formed during the Tertiary. Since they formed, the lake dried up, and tectonic activity (e.g. faulting) has tilted the beds and broken them up. We saw the same lake beds at the Borax works and Zabriskie Point.
Faults
The walls of the valley here are ancient sedimentary units. If you follow the pair of prominent dark layers from left to right they are displaced in several places - these are fault planes. There are some clearly visible above the vegetation on the right hand side of the road. Ramapo Convoy for scale!
Common
critters
Just hangin' out. These guys were heard by the campers both nights.
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