Parking: This cache location has a small parking area suitable for cars, trucks, and motorcycles. There is an additional parking waypoint for vehicles pulling a trailer, RV's, Motorhomes, and Busses. Please use caution as the road is narrow in the mountains, and can be very busy during summer time with tourists.
The Cache: From the viewing spot coordinates you will need to be looking in the Southwest direction, you will see a nice example of preserved ripple marks in the Uncompahgre Formation. This section of a former water bed was once horizontal, and because of uplift this section of preserved ripples is now an almost verticle wall in the canyon. Erosion on the now Uncomphagre River has exposed this layer of rock and ripple marks for us to see today. The ripplemarks are found in a quartzite layer of the Uncomphagre Formation. This is hard light gray rock in which quartz grains are firmly interlocked or cemented together by quartz or other minerals. It forms by the metamorphism of sandstone under heat and pressure.
Ripple Marks
Ripple marks are ridges of sediment that form in response to water moving or wind blowing along a layer of sediment. Ripple marks form perpendicular to the water/wind direction in almost all cases.
The troughs and crests of fossilized ripple marks in sandstone and siltstones are hardened versions of the short-lived ripples in the loose sand of a modern-day stream, lake, sea, or sand dune. Ripples may be made by water or, in sand dunes, by wind. The symmetry of water-current ripple marks indicate whether they were formed by gentle waves or faster water currents. Ripple marks are catigorized in two different planes, meaning they are catigorized by what they look like when viewed from above, and then again when viewed in a cross section from the side. Geologists study the orientation of the ripple marks to determine the original position of the layers.
Ripple Forms (When viewed from above)
Straight
Straight ripples generate cross-laminae that all dip in the same direction, and lay in the same plane. These forms of ripples are constructed by unidirectional flow of the current.
Sinuous (wavy)
Sinuous ripples generate cross-laminae that are curvy. They show a pattern of curving up and down as shown in picture. Sinuous ripples produce trough cross lamination. All laminae formed under this type of ripple dip at an angle to the flow as well as downstream. These laminae are also formed by the unidirectional current found in rivers and streams.
Catenary
Catenary ripples generate cross-laminae that are curvy but have a unidirectional swoop. They show a pattern similar to what a repeated "W" would look like. Like the sinuous ripples, this form of ripple is created by unidirectional flow with the dip at an angle to the flow as well as downstream.
Linguoid
Linguoid ripples have lee slope surfaces that are curved generating a laminae similar to caternary and sinuous ripples. Linguoid ripples generate an angle to the flow as well as downstream. Linguoid ripples have a crecent shape, usually made/assoiciated with water flow as the tide moved out.
Ripple Types (when viewed from the side in a cross section)
The ripple marks can provide information about the wind or water that created them.
Symmetrical
Symmetrical ripples are created in environments where there is a steady back and forth movement of the water (a two way current with swash and backwash). This creates ripple marks with pointed crests and rounded troughs, which aren't inclined more to a certain direction.
Asymmetrical
These are created by a one way current, for example in a river, or the wind in a desert.
This creates ripple marks with still pointed crests and rounded troughs, but which are inclined more strongly in the direction of the current. Therefor they are asymmetric in shape, with the steep (lee) face in the down-current direction.
Asymmetrical ripple marks can give an indication of current direction when formed in water, and when formed by wind, give wind direction.
Questions
To get credit for finding this earthcache you must answer the following questions:
1. What kind of ripple marks can you see looking at the ripple wall across the canyon from your viewing point? Are they straight, sinuous, catenary or linguoid?
2. Are the ripple marks asymmetrical or symmetrical?
3. Can you tell in what direction the water flowed that created these ripples? Why or Why not?
4. If your answer to #3 was yes, in which direction was the water flowing? Up the wall, or down the wall as it currently sits?
5. REQUIRED Post a picture with your found log of yourself (Face picture not required) or a personal item at the site with an identifiable part of the highway pullout, waterfalls, or mountains in the background that shows you visited the site.
NOTE: If you post ANY answers to the questions above in your log (encrypted or not) it will be deleted. If you fail to send an e-mail within 7 days of your 'found' log, your log will be deleted. The photo in task 5 is required and is a viable logging task (click on the work "required" at the start of task 5 to go to acceptable logging requirements for earthcaches). If you are caching as a group, only one e-mail needs to be sent with answers, please list the members you are caching with by caching name. Every account claiming a find must have a photo.
Sources:
1. some photos taken, and used with permission from Dr. Jessica Winder
2. US Forest Service, Ouray Ranger District information board
3. My personal knowledge gained from my geology classes at Stephen F. Austin State University in Texas.