Monday, November 23, 2009

Hurricane Fault and Coriolis Tectonics in 3D: Grass Valley, UT

On the distant skyline above, there is the scarp of the Hurricane Fault, Hf, where it is prominent at the location of the Divide vulcanism and adjoining basalt flow to the east (possibly related to the basalt to the west- the Grass Valley flow and basalt). Hurricane Fault- Grass Valley Vulcanism in 3D

Since a major criticism for my work with the crust- that the Mantle is the source of all Earth movements, with its much greater thickness and lower viscosity- I will now present a case for the Crust being acted on mostly alone by Tidal forces and Geo-magnetic cycling, for small cells, on the order of diameters approximating CRUSTAL THICKNESS. This will be for my local area, where we can easily check in the field for evidence one way or the other. The pertinent Diagram and Model for this case (above) are somewhat to scale- the horizontal and vertical presentations being as close to relative proportions as I can arrange with the circular drawings. They attempt to display the “Rest of the Traveler” for all to see, regarding the various movements occurring along Hf.
Although I didn’t intend to involve the 4th factor in Structural Geology- Magnetic cycling and striping- it fortuitously is staring at me right here in the town of Hurricane. Below is a picture of the Hurricane Cliffs- which are obviously displaying 3 cycles of uplift and erosion: Notice that there is limestone outcropping for the earlier uplifts (as compared to a basalt scarp for the youngest display), and that the scarps have risen west of previous displays- this will be important for determining the cyclicity and westward creep of the Colorado Plateau (similarly to the westward creep of the ocean bottom basalts west of the Mid-Atlantic Ridge).

Hurricane Fault- Grass Valley Vulcanism in 3D
The literature mainly reports on Geophysical researches from the standpoint of the Mantle dominating the Crust, when investigating the Structural Geology of the Globe. My pragmatic analyses indicates that the Crust is being directly affected by Coriolis Rotations, whenever the surface is used (from Google Earth maps) to relate photos to features found in the field. Overall, I believe that the crust, being more forcibly affected by TIDAL EFFECTS AND FRICTION SLOWING BY THE MOON, is somewhat independent of the Mantle. It has a greater viscosity and brittleness than the Mantle, hence is floating (and beng sheared by the rotation) on top of a ductile surface and rotating a bit more slowly than the Mantle or Core. However, the Mantle indirectly drags the Crust along its faster moving surface- gradually causing it to rotate in vertical cells, forcing the Colorado Plateau to rise vertically with time, for example.
We will explore this conjecture, using field data which I have found are remarkable in explaining most of the events related to Coriolis rotation and Reactionary Cells. I made the initial discovery using the 20-30 km cell surrounding the Grass Valley volcano (which is about the thickness of the Crust), and it is instructive to return to the field and to more closely examine Google Earth photos, to enlarge the analyses. The first photo shows the large cell extending from Virgin Town along the Virgin River to Washington City, UT, which was where I found that the combination of slickensides, grabens, monoclines, and movements along the hurricane fault presented a new paradigm for Structural Geology:
An introduction to this phenomenon is shown by the above photo, looking eastward towards Zion National Park and the town of Virgin, UT, which shows three levels of erosion.
Pulsing of the Hurricane Fault, Hf, in cliffs east of the Towns of Hurricane and Laverkin.
a. The present Hurricane Valley level (near Hurricane Town) has dropped about 100 meters from the present rim of the scarp, leaving a fairly sharp basaltic edge. This tough rock allows erosion to remain small, so that a good view of the basalts can be seen. The approximate age is 200 k.years, since this is the age of the start of the Pleistocene volcanic craters nearby. This area is anomalous, because of the rotation of both Hf and the 30 km Coriolis cell (from Laverkin to the AZ border). Hence, the 100 meters is not representative of scarp heights found away from the cell. And it is not eroded as slowly either, because the Laverkin graben and sink have accelerated loosening of the Crust.
b. At higher elevations above the youngest scarp is another one, which is somewhat more eroded. Notice the rounding of the limestone outcrops, and the wider drainage features.
c. The last one which is obvious is the oldest scarp, but it may be preceded by others which are older and fainter. Age dating of the oldest scarp may be approximated by the occurrence of Pine Valley Monzonite boulders north of the Virgin town, where there is a basalt-covered mesa which has been measured to be about 1 million years in age. Below this basalt is a Tertiary conglomerate containing the granite-like rocks which could only derive from PVM. These boulders rolled down from the Mountains when there was no scarp in their path- sometime before the million year basalt. This then was the start of the present series of scarps at Hf. Although this age of 1 m.y. is a minimum age (they may have rolled there at any time between Mesozoic and the age of the overlying basalt- but not before the age of PVM, which is 21 m.y.), we will use the minimum age as a precursor to the age of the oldest scarp shown at Hf at present. Consequently, the pulsing recurs near the elapsed time of 300 k.years, assuming that the creek through which the PVM boulders flowed was the same one which allowed the lava to flow in its most recent configuration.
Using all of these highly tentative ages and scarp developments, we can conjecture that vulcanism and Hf scarp renewals are simultaneously occurring- acting as pulses to a movement which is otherwise extremely slow. I have measured the rate of movement of Hf laterally, along with down drop of the local graben and find that the outer extremity of the shear along lateral striations in local canyons is about 5 mm/year, while Hf is forming on the edge of the Colorado Plateau, CP (which is moving CCW at a rate of 1/3 the vertical drop in the nearby graben). Vulcanism proceeds CW around the southern and southwestern CP- having moved from the Rio Grande rift since Oligocene time, to the St. George area now.

I anticipate that the pulsing is that of the magnetic reversal of the Earth’s field, creating vulcanism along the Mid Atlantic Ridge at fairly regular time intervals. The pulsing must create a renewal of magma emergence sufficient to shove the two parts of the Atlantic Ocean basin apart at intervals. This is all highly speculative, but I see the same pulsing occurring at intervals of less than a million years at a newly-forming transform found SE of the big island of Hawaii. Grid lines are formed parallel to each other and deviating regularly at intervals, about 8 nautical miles apart. This at the measured rate of movement of the apparent positioning of extrusion sites (volcanic islands) of 8.6 cm/year, yields a cyclicity of something less than a million years. This CONJECTURE is tying together Magnetic pulsing or striping, vulcanism at Hf, gridlines SE of Hawaii, uplift at Hf, and whatever institutes magnetic reversal.
Below is a magnification of the pertinent area near the Grass Valley volcano and Hf- showing how heat is produced by the counter-rotation of the Inner Cell with that movement near Hf. Now we have to go into the field to get the dip and strike of the rotated beds at the canyon near the AZ border.
Below is an analysis of the Grass Valley cell after fieldwork, looking at a "live portion". The feature is on an elevation high (in the valley west of Hf), and appears to have flowed to the west, after lapping over Hf. We will trek to the appropriate canyon on the east side, to find the rotational angle at which the cell is aligned. The question remains: What has initiated this action? Although the whole entity can be inside the Crust, the incipience can be in the Mantle! It is connected with the great fault Hf, which is moving independantly of the smaller cell. Note the black lava atop Hf on the following untouched photo:
Exploring further the possible relation of the Mantle to the Crust, as far as Coriolis cell emergence and rotation is concerned, consider the following:
1.The ATMOSPHERE is an excellent space to explore Coriolis cells and their rotation and configurations. It is only about 10 km in thickness, but its rotating cells and geometry can be followed across continents. Although there is drag and friction with the Earth's Surface, the cells remain coherent as they pass from west to east with time. They possess similarities with the cells shown on Google Earth, in that they have a fairly-straightline "FRONT" associated with them (it curves if you view the entity over a large enough distance), and they possess circulation which is easily viewed at Latitudes greater than 10N or 10S.
2. There are major changes in circulation upon traversing the space from Equator to the Poles: The doldrums exist mainly at the Equator, but consistent trade winds exist at the mid-latitudes. The division seems to occur at each 30 degrees latitude, where winds change direction, for 3 bands. At about 20N or 20S, deserts occur, due to compression as winds descend and heat the air, before returning to the Equator aloft.
3. There is drastic shear between coriolis cells, whenever the cells rotate in the same direcion- adjacent to each other. Weather develops at these intersections, and temperature and pressure change suddenly, simultaneous with shifts in wind direction.
4. There is a MAJOR difference when comparing oceanic weather with that over continents. Weather cells are huge with slight curvature, and weather "gathers" slowly. The TRADE WINDS remain steady, until Tropical covergences and Typhoons interject seasonal changes. Monsoons are fairly predictable, and precipitation is regular. There is litle interference from landmasses, and friction with the ocean surface is small, so that I could, as a "Dead Reckoning Navigator" fly from Guam to Okinawa without any Navigation Aids- similarly to the ancient Polynesian canoe-ers.
I maintain that the Crust is similar to the atmospshere in its reaction to Coriolis Force. It is only 40 km or so thick in the portion studied (Colorado Plateau), and I have mainly incorporated cases where the diameter of the cell studied is similar in magnitude. I will gradually enlarge my area of investigation, but for now the Divide and Grass Valley vulcanism and cell- adjoining CP- is sufficent to make some tentative conclusions about whether the Mantle may be mostly separated from events in the Crust, for small cells.
The MODELS we will use to determine the various movements along Hf, at the Divide and Grass Valley extrusions is shown in PLAN VIEW ABOVE, and in cross-section below:

Below is the first pass for determinatiion of the rotation of the CRUSTAL CELL- which is rotating both vertically (due to drag from the EASTWARD-MOVING MANTLE),and to horizontal drag of Hf (moving southward on the CP side):
Next we will incorporate the DIP AND STRIKE of outcrops on the southeast side of the cell, so that a calculation of rotational velocity of the small Crustal cell may be determined. I have already measured the southward NET MOVEMENT along Hf to be 155 meters for the greater than 200 k.year DIVIDE vulcanism, and this results in a southward shear of .4 mm/year (for the combination of CP southward and Grass Valley rotation NE-ward). But first, look on the west side of Hf, where a vent of greater age than 200 k.years has aligned with the spillover from the Divide flow (which flowed west across Hf and later fractured and slumped): This should be the NET MOVEMENT of both CP moving south and the arcuate dike moving NE.The distance between the arcuate dike and the extrapolation of the basalt spillover was measured along the gravel road, and found to be separated by 155 meters. NOTE: I am assuming that there is:
1. A subsurface connection between the Divide and Grass Valley extrusions;
2. That Grass Valley erupted first, and that Divide is a Rejuvenation phenomenon which will have a somewhat different composition to GV;
3. The rotations will tell the story of subsequent movements; and,
4. Extrapolations can be gauged from a consideration of spiralling geometry.

This goes into the hopper, to find the rotation velocity, both verticaly and horizontally, of the Divide Cell (which shold be thinner than the Crust, which is being dragged along the top of the Mantle toward the east).
The question remaining is: Are the large curvatures, on the order of continental size, due to Crustal movements or is the Mantle involved?
We will try to solve this problem, by looking at progressively larger cells- starting with local ones, such as the Grass Valley cell with a diameter of about 30 km. We will also attempt to discern why the Southern hemisphere presents very little to confirm the shearing of the Non-Bulge from the part near the Equator undergoing diminution. It is shown on the SA eastern coast, with breakup into islands on the west coast. This all indicates extension for Chile, below the 40S Latitude, where the Plate Tectonics theory would have only compression and subduction in that region (due to the presence of andesitic vulcanism). Altogether, it seems that upon closer inspection, the Plate Tectonics idea applies only to the deep ocean basins and that it only provides a start in understanding the movements of the Crust. Wherever there is a landmass (even islands), there is rotation induced by Coriolis Force and the subduction-wandering of continents idea does not apply.
Above photo shows basalt which has evidentally flowed from the Grass Valley crater, but which has now been sheared from the original location. We will research the literature, to determine whether the composition of the two separated mesa basalts are similar. This will be an important fact to support the idea of shear as a mechanism for rotating the mesa from its parent.
Below photo shows my interpretation of the shearing and rotation of the eastern part of the Divide vent and flow, faulted towards the south and spiraling to the SW: Putting this altogether, my interpretation is shown below This will be augmented as I get more information from the fieldwork for the Divide flow.

More to Come!

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