Dead Horse Point State Park, Canyonlands National Park, and Arches National Park
May 24, 2005
It is our last day of geology stops so this will be my last journal posting, but I will still check the page so that I can try to answer questions.
Our first stop of the day was at Dead Horse Point State Park. We observed incising meanders in the Colorado River. The best way to understand incising meanders is to understand the different stages of stream development. The first stage is an incising stream; streams incise when they are trying to reach base level, which is ultimately sea level. Once the streams approach base level they loose energy and down cutting power and the stream starts to erode laterally. An incised meander forms when a drop in sea level or an uplift of the river itself changes base level. The change in base level allows the stream to start to incise, but instead of just forming a V shaped valley like a normal incising stream the rejuvenated stream will follow the meanders while continuing to down cut.
We also stopped at Canyonlands National Park. Here we studied the Upheaval Dome that developed in the park. There are two different explanations of how the dome formed; one of the explanations is that a salt diapir below the rock domed up the rock and erosion removed the middle of the rock creating an eroded dome. The other explanation is that the dome formed because of a meteorite impact. If you would like to learn more about the Upheaval Dome in Canyonlands National Park visit there website at http://www.nps.gov/cany/nature/geology/upheaval.htm
Our last stop of the day, and our final stop of the trip was at Arches National Park. We looked at the different arches that formed in the park. Arches form in jointed rocks that have weak members below and strong members above. When the joints spread further apart erosion works on the lower rocks, which causes them to weaken and eventually gravity pulls the weak rocks down leaving the resistant rocks above. The diagram below shows a systematic process of how arches form, but if you have any questions I would be more than happy to answer them.
Formation of Arches
The image above was taken from: http://www.nps.gov/arch/student/geology.htm
It has been a fun trip, and I hope the people reading my journals have learned about geology. And again thanks for all of the questions.
It is our last day of geology stops so this will be my last journal posting, but I will still check the page so that I can try to answer questions.
Our first stop of the day was at Dead Horse Point State Park. We observed incising meanders in the Colorado River. The best way to understand incising meanders is to understand the different stages of stream development. The first stage is an incising stream; streams incise when they are trying to reach base level, which is ultimately sea level. Once the streams approach base level they loose energy and down cutting power and the stream starts to erode laterally. An incised meander forms when a drop in sea level or an uplift of the river itself changes base level. The change in base level allows the stream to start to incise, but instead of just forming a V shaped valley like a normal incising stream the rejuvenated stream will follow the meanders while continuing to down cut.
We also stopped at Canyonlands National Park. Here we studied the Upheaval Dome that developed in the park. There are two different explanations of how the dome formed; one of the explanations is that a salt diapir below the rock domed up the rock and erosion removed the middle of the rock creating an eroded dome. The other explanation is that the dome formed because of a meteorite impact. If you would like to learn more about the Upheaval Dome in Canyonlands National Park visit there website at http://www.nps.gov/cany/nature/geology/upheaval.htm
Our last stop of the day, and our final stop of the trip was at Arches National Park. We looked at the different arches that formed in the park. Arches form in jointed rocks that have weak members below and strong members above. When the joints spread further apart erosion works on the lower rocks, which causes them to weaken and eventually gravity pulls the weak rocks down leaving the resistant rocks above. The diagram below shows a systematic process of how arches form, but if you have any questions I would be more than happy to answer them.
Formation of Arches
The image above was taken from: http://www.nps.gov/arch/student/geology.htm
It has been a fun trip, and I hope the people reading my journals have learned about geology. And again thanks for all of the questions.