Friday, October 17, 2008
Photos below and above were submitted by Karen Hughes- our skilled Photographer
A Laramide Fold Has been levelled and topped with Tertiary gravels, off the shoulder of Hiway 9
This unconformity (older tilted sediments covered by younger gravels) may be seen off the shoulder of Hiway 9, near the Virgin River.
Return to Dixie
Several Debacles have prevented my weekly Blog for Earth Sciences from appearing during summer 2008- the financial crisis, my negotiations into now-appealing real estate, some health issues such as sciatica, and more importantly the attempt to duplicate my salmon catch of 2007 (49 big ones- see Link in 07 photos). Since my catch of a single 15 pound Coho has impacted my outlook on everything, I extrapolated this total catch to imply that everything is going down the tank (what with 30 séances at my ol’fishing hole proving to be futile- plus one). In the words of Winston Churchill, when corrected for using a preposition for terminating a sentence “This is a matter up with which we must not Put”.
I finally forcibly packed my fishing gear in Cosmoline, to prevent my fishing “one more time” to catch that 2nd big one. My gear is now languishing in the shade of my cellar, encrusted in salt spray, un-oiled, disheveled, and lonely. I’ll wait for the pink salmon (humpies) to return during the odd-numbered year 2009, to bring the much-desired Coho along in their tow.
So here I am back in Color Country- that land of active Geology, passionately stimulating scenery, Geography which you can’t resist touching, home to hopefully-dying volcanoes, my resident roadrunner, and lastly the place where all city-dwellers would remain until the grave (if only they knew about it).
Goals for 2009:
Life is nothing if uninspired, and everything else is arbitrary. The present economic and social scene should make this personal observation obvious. With the President of Destruction on his way out, into the dust bin of history, we have a chance to enliven ourselves with a less-materialistic way of life. Where else could one launch toward a new direction than in Color Country, where Nature reveals her beauty and mysteries?
My goal must be to stimulate myself to reach out to the outdoors, away from the armchair and slippers, continuing my observations of the Earth and its intentions. Nature is waiting for us, and it would be sacrilegious to ignore her for the comforts of arbitrary Society
Quail Creek put the WA salmon catch to shame (although these are small rainbows, they outnumber everything I caught on Whidbey Island, for each of 2 canoe trips taken in Utah)
What’s the result of your four years of Hiking in Color Country? Similarly to people who are stimulated by living where they can see and feel the power of moving water, such as near a beach or creek, there are those of us who feel the power of the moving Earth’s Surface. At the edge of the Colorado Plateau (CP), this is the place where it happens!
1. Here is the uplifting CP, with its great Hurricane fault (Hf) and Rebound caused by unloading (Lightening or removing mass) of CP by wind and water erosion, across the local elevation differences;
2. Loosely connected with Hf are the dying Volcanoes;
3. Hot Springs and Thermal areas are part of the St. George Geothermal zone;
4. Reactions to the local changes in Heating are entities such as the Laverkin Sink and land subsidence;
5. Uplifts increase the tendency of cliffs and elevated areas to erode and spall;
6. Shear or Rotation (Torsion) of the Earth’s Crust causes lengthy fractures and lateral faulting of the land surface; and
7. Stretching and extension of the land just west of CP allows intrusion of magmas which never reach the surface until erosion uncovers them- such as the Pine Valley Mountains, PVM.
One can see and measure all of these Features, while hiking near the boundary of CP, shown along Hf.
The numbers on Photographs below refer to the entities listed above:1. A linear expression of cliffs or sudden change in elevation of the land surface is called a Scarp (from escarpment). Below is a photo of the world-famous Hurricane Fault or scarp:
2. Sullivan’s Knoll (Volcano) is a Pleistocene cone from a 200k year to recent eruption. It still exudes a rotten egg smell (as from Hydrogen Sulfide- H2S), especially since the eastern flank has been subject to excavation and mechanical shock, with the new golf estates being initiated there):
3. Pah Tempe Hot Springs represents the released heat from volcanic magma which is cooling just below the area. It releases foul gases, in addition to supersaturated lime in solution which cements gravels downstream in the Virgin River, as the pressure is released upon traveling down the stream:
4. The Laverkin Sink exists under the town of Laverkin, causing local fracturing and sinking of the surface, noticeable especially on the cliffs above the Laverkin Creek. It is caused by the cooling and shrinking experienced whenever the local seeps and hot springs release heat to the emerging water:
5. Toquerville sits near a large block of the earth’s crust, which has uplifted relative to the lands to the west. It is tilted, probably caused by Hf as it shoves the lands to the east upward relative to the sinking lands to the west of town:
6. Shear of the surface laterally produces Fractures, which are noticeable as large-scale linears or straight-line cracks in the exposed rock. These are very pronounced near the linear trace of Hf, and tend to orient northwest-southeast (NE-SE) or north-south (N-S). Perpendicular to these are the Orthogonals which orient NE-SW or E-W:
7. Pine Valley Mountains (PVM) are an exposed granite-like rock, which rose to just near the surface in Miocene time (21 million years, approximately). It has since been exposed by erosion which wore away the sedimentary cover of one kilometer or less thickness. It is oriented NE-SW, which was the orthogonal alignment of the fractures dominant in Miocene times until the late Pliocene of about 2 million years: