Sunday, March 14, 2010

Sand Mountain and Sand Hollow Fracture Patterns

EARTH SCIENCE postings from www.googleearth.com are reported in blogsites in: www.PorOgle.blogspot.com for other locations.


Why the sand spills onto the South side of Sand Hollow Lake

By now all are familiar with the circular paths of rivers, for some portion of their course (the circular portion indicating an opening, created by Coriolis rotation). The same feature can be visualized with the sand flow from Sand Mountain, south of the lake- sand flow instead of water flow. This is due to Coriolis rotation WHICH CREATES THE PATH of the two separating cells (indicating a path created by lateral faulting) or hills there- one clockwise and the other CCW. Between the two there is an opening where there occurs divergence. This DIVERGENCE ALLOWS SEPARATION OR STRETCHING OF THE SPACE BETWEEN THE TWO FEATURES, AND SUBSEQUENT LOOSENING OF THE SAND IN THIS JURASSICC SANDSTONE (which is otherwise very indurated and tough to shear). THE FEATURE IS THE SAME- FLOW DENOTING A PREFERRED EROSIONAL PATH CREATED BY LATERAL FAULTING. THINK OF THE FLOW OF SAND AS SEDIMENT WHICH CAN BE USED TO FOLLOW A FAULT PATH, RATHER THAN WATER WHICH THE GEOLOGY CULTURE CONSIDERS ONLY A MEDIUM AND NOT AN INDICATOR OF A FAULT PATH (WHICH HAS BEEN OBSCURED BY THE WATER PRESENCE)
If you are not convinced by now, you never will be, but look at the accompanying photos anyway:

NOTE THE SMALL CUT OR WATERWAY ON TH SOUTH SIDE OF THE LAKE, WHICH INDICATES A RECENT SLICING OR FRACTURING OF THE COASTLINE:
THE SOUTH SIDE IS ENLARGED TO SHOW A CANYON WHICH I JUST RE-TREKKED LAST WEEK. THIS CANYON NW OF THE DINOSAUR DISPLAY IS A ZONE OF CONVERGENCE- THE OPPOSITE OF THE DIVERGENCE ZONE:

THE "BIG PICTURE" SHOWS HOW THE ROTATION FITS WITH THE OVERALL MOVEMENT OF THE CRUST AROUND THE GRASS VALLEY CORIOLIS CELL, BUT THIS IS MORE COMPLICATED THAN I HAVE PREVIOUSLY PUBLISHED. TO ELIMINATE HEATING FROM TWO CELLS ROTATING IN THE SAME DIRECTION (CW VS. CW) THERE IS A BUFFER CELL OF SMALLER DIAMETER WHICH ABSORBS THE SHOCK OF FRICTIONAL HEATING. IF YOU LOOK CLOSELY YOU CAN SEE SEVERAL OF THESE IN THE PHOTO BELOW. THIS PHOTO PROBABLY SOLVES THE DILEMMA OF THE N60E STRESS CRACKS' PATTERN- WHERE THEY ARE SUBJECT TO A TORQUE BETWEEN THE TWO SEPARATELY-ROTATING LARGE CELLS. WE'LL LOOK AT THIS AGAIN, BUT FIRST DETERMINE WHETHER THE N60E LINEARS RELATE TO ANYTHING OUTSIDE OF THE GRASS VALLEY CELL:

Sand Mountain and Sand Hollow Fracture Patterns
Sand Mountain- a mainly Jurassic Navajo surface expression- fits in the circular arrangement of the Grass Valley Coriolis rotation ABOUT the Hurricane Cliffs near Hurricane, Utah.
This is a 30 km diameter feature, which has arcuate canyons, monoclines and hogbacks, and compressional features near its southern border- near the Ft. Pierce wash. The compressional entities appear to become larger, the further they occur from the Grass Valley center and drainage divide (located at the basalt spill over Hurricane fault, Hf). Consequently, there is a small rise at the divide, a larger monocline and hogback north of the AZ border, and the Sand Mountain uplift which is the largest appearing related to the general rotation of the Coriolis cell north of the AZ border.



The intent of this writing is to show that there are compressional features, on the south and east side of the Grass Valley Coriolis cell, compared to extensional features on the north, such as the Laverkin sink, Ash Creek rotating hogback-like block tilted up to the west, and the Hiway 9 graben. Photos and analyses are shown below, which document the compressional nature of Sand Mountain- similar to the monocline at the AZ border (see photo above).
GRASS VALLEY IS SHOWN BELOW, AS THE AREA NEAR THE SKY RANCH AIRPORT, WHICH IS TO THE NORTH OF THE GRASS VALLEY EXTRUSION (BASALT). THIS BASALT HAS BEEN SHEARED AND ROTATED BY THE DRAG OF THE HURRICANE FAULT- WHICH HAS THE COLORADO PLATEAU, CP, MOVING CCW (SOUTH) ON THE EAST SIDE:

ANOTHER VIEW OF THE GRASS VALLEY FLOW IS SHOWN FROM THE NORTH, FROM SULLIVAN KNOLL, SO THAT THE SADDLES- REPRESENTING LATERAL FAULTING- MAY BE SEEN:
BELOW ARE PHOTOS OF SAND MOUNTAIN, SHOWING HOW IT IS MONOCLINE-LIKE, VIEWED FROM THE NORTH:

A "CLINCHER" FOR A COMPRESSIONAL REGIME IS THE DOME OF Jn CROSS-BEDS, LOCATED BY THE EDGE OF THE SAND HOLLOW GOLF COURSE. THE AREA HAS MANY PROTRUSIONS OF SANDSTONE:
PHOTO BELOW SHOWS A GOOGLE PHOTO OF SAND MOUNTAIN AND THE LAKE, AND NOW THERE IS AN ADDED PIECE OF INFORMATION- THE UPLIFTED MONOCLINE HAS STRIATIONS SIMILAR TO GROOVES ON A LARGE SCALE (N60E ORIENTATIONS, PARALLEL TO EACH OTHER IN A CONSISTENT MANNER). THESE ARE IN SUCH A PATTERN, THAT THEY REPRESENT A REGIONAL PHENOMENON. WE WILL HAVE TO TREK INTO THE MOUNTAIN TO DETERMINE IF THERE IS A RELATION TO OTHER FEATURES OF SUCH A SCALE:
A LARGER VIEW SHOWS THAT THE N60E GRIDS OCCUR AT THE Hf FAULT, AT THE GRASS VALLEY EXTRUSION, AND AT SLICES IN Hf, AND THAT THE SPACING IS VARIABLE, BUT NEAR .33 KM APART. REMEMBER THAT THE SPACING ABOVE Hf NEAR HIWAY 59 AT THE SWITCHBACKS IS ABOUT .22 KM (HINTING THAT THE SPACING IS DUE TO THE TOPOGRAPHIC MOVEMENT WESTWARD OF THE GROUND SURFACE RELATIVE TO THE BASE OF THE CRUST JUST ABOVE THE MANTLE (WHICH IS MOVING RELATIVELY EASTWARD AND TILTING Hf DOWN TO THE EAST):


EVIDENTLY WE HAVE STUMBLED ON ANOTHER FEATURE, WHICH WILL HAVE TO BE EXPLORED, SINCE THE PHOTO BELOW SHOWS THAT THE N60E GRIDS INFLUENCE NOT ONLY Hf, BUT ALSO SANDSTONE FROM SNOW CANYON TO ZION- A DISTANCE OF ALMOST 100 KM:
The photo of the lineaments indicates that the DIMNESS is of an age greater than the fractures, which are re-delivering the sand down the mountain into the lake. However, if you assume that the pattern has produced the lineaments in Hf (which is more doubtful, because they have a curvature), then the age must be less than 200 k.years (because of the measured age of the vulcanism, which was simultaneous with them). Hence we must look elsewhere, to obtain the relative age. The place to start for this is in the Zion highlands, where the N60E pattern also occurs. If we find that the age of the N60E canyons is greater than those tracing NW-SE, then we can conclude that the grids are older than the present dominant pattern (tracing NW-SE). Below is a blowup of the appropriate part of Zion:

Evidently we have stumbled on fossil traces of linears, which are related to stresses PRE-LATEST CYCLE Hf. THE FAINT N60E TRACES ARE OLDER IN ZION THAN THE DOMINANT ONES- INDICATING THAT THEY MAY BE OLDER ELSEWHERE. THIS DOESN'T PROVE THAT THEY ARE OF THE SAME AGE, BUT IS A TENTATIVE CONCLUSION WHICH CAN BE CHECKED IN MY OTHER WORK IN THE REGION. The sandstone has retained the ancient grooves left after erosion has filled in the older fractures or faulting. This N60E pattern does not show up in most of my work, and I have canvassed most of the outcrops near my hometown of Hurricane. It will be interesting to find what minerals were precipitated in these older gulches, compared to those whose age has been determined. I will fit this in my present research on the IRON DEPOSITS of Miocene age, near Cedar City. This pattern does help to clarify the various fracture and stream orientations in the park, and we will store it for reference to other anomalies. It does seem important that the grids remain in sandstones, which would be supposed to easily re-arrange with time of sorting, compaction, and weak calcareous cementation (compared to limestone, which has little original porosity, and which is ductile, easily made resistant to shear, and which re-cements with calcite- except for dolomitization).

VIEWING THE FRACTURE PATTERNS IN ZION, VERSUS THOSE FOUND ON A HIKE ONTO SAND MOUNTAIN, NOTICE THAT THERE ARE BLOCKS OF Jn WHICH APPEAR RELATIVELY FRESHLY UNCOVERED YIELDING FLAT SURFACES POINTING TO THOSE IN ZION:


THE DIFFICULTY SHOWN HERE IS THAT THE AREA ROTATED CCW, WHEN RISING AND HEATING FROM THE MAGMA CHAMBER, AND THOSE FRACTURES ARE PRESERVED (WRITTEN IN STONE, SO TO SPEAK), AND NOW WITH A COOLING AND SHRINKING SUBSURFACE, THE AREA IS ROTATING CW. THERE IS A WELL NEAR VIRGIN TOWN, WHICH PRODUCES WARM DRINKING WATER- INDICATING THAT BRITTLE FRICTION IS PRODUCING HEAT TODAY, SIMILAR TO PAH TEMPE (THIS IS CALLED FAULT REVERSAL BY GEOLOGISTS, AND NOW WE HAVE DRAINAGE SHIFT DUE TO THE SAME ENTITY):

Sand Hollow fracture patterns, and Jn rotation in Zion NP
These grid lines represent fossil stresses, in the Miocene age- by my calculation of rotation movements in the Park. This is valuable, from the standpoint of determining relative age of stress systems, especially since I haven’t found this N60E pattern in the area (except for fossil Jurassic dunes being investigated). FINDING THE ORDER OF STRESS-FRACTURE REGIMES IS AS VALUABLE AS FINDING PALEONTOLOGICAL AND STRATIGRAPHIC SUCCCESSION, OR SUPERPOSITION! I will re-analyze this occurrence, since it is not always obvious which rotation movement is happening. The clues as to which direction is ambient is not always straight-forward. Below are the important features, which I have seen in the field and which bear on this analysis:
1. Crater Hill above Coal Pits Wash is of the order of 1 million years of age, and should be rotating CW (cooling and shrinking);
2. The Virgin River nearby has a lateral fault, which is rotating CW (affirmed by slickensides), so that there must be a buffer cell between the two features (there is a warm well just to the west of it- near the town of Virgin);
3. There are no active warm springs or volcanic activity in Zion, so that even though it is uplifting, it should rotate CCW and create HEAT OF FRICTION AT THE BORDER OF CRATER HILL, should it NOT BE ROTATING IN HARMONY with it (harmony means that adjoining cells rotate opposite to each other, so that there is no brittle friction to create heat, e.g. CW next to CCW):


4. Above photo shows that there is a buffer cell between Crater hill and the Virgin river, so that Crater Hill cell is rotating CW. This allows the Zion cell immediately to the east to rotate CCW without creating vulcanism;
5. Continuing to question whether the east part of Zion is rotating in harmony with the west part (CW vs. CCW), we will look again at the confluence of the canyons, to see whether the west section is older than the east. The canyons which are truncated by the present deeper gorges appear to be fainter and more meandering than the linear canyons of the beautiful part of Zion Park:
6. The canyons are down-cutting so drastically, that it seems intuitive that the whole area is rapidly rising and therefore rotating CCW; and,
7. There are indeed multiple fracture patterns, as is obvious just by driving along the fossil dunes and noting the grid-like checkerboards in the cone-shaped dunes. ABOVE IS THE "BIG PICTURE" OF ZION AS IT IS RELATED TO IRON COUNTY AND THE B&R LATERAL FAULT (WHICH IS DRAGGING AGAINST THE CP (BOTH GOING SOUTHWARD AT THE COMMON BORDER).

The sand mountain south of the Sand Hollow State Park has some excellent views and geological features similar to those in the wave, AZ wilderness area. There are slot canyons (some of which are not negotiable for all but climbers), three sets of fracture patterns- in addition to the drainage along a N-S axis- and a few springs or seeps. This is an area which has been ignored by all except the ORV addicts. Below is the “Big Picture” of the area which can easily be accessed from the State Park:

There are major grids of fractures, as seen above and below in detail- the rise to the south accentuating them:

When hiking the crags and outcrops, there are several features which become apparent:
1. The dominant N60E grids, although freshly-appearing, are eroded by drainage with N-S trends, relating that the N-S Hurricane fault orientation is a younger feature. This one million year fault is the latest in a cycle of several, which has formed a scarp and vulcanism associated with it. Previous to that the fault had little vulcanism apparent, although there are significant vents to the east- such as Mt. Trumbull, crater Hill, and vents near Diamond Ranch;
2. The displacement on the fractures is only on the order of inches for each step (fracture segment), but consistently up to the south- indicating an uplift north of Ft. Pierce Wash, which we have already affirmed from the lateral rotation there;
3. LATEST Drainage cuts the N60E fractures, although there is activity indicated from seeps at the fracture faces. This relates that the stream capture is younger and associated with the Hf N-S stress system; and,
4. The steepness and sharp edges of the fractures faces of both N60E and N-S traces indicates that both are much younger than the Jurassic rock (and not Pre-Tertiary). Although the Hf traces are younger than the N60E fractures, it seems evident that the age is close. Measuring the Coriolis rotation of the N60E traces in Zion NP indicates that they are of Miocene or later age.


The south side of SAND MOUNTAIN, approached near the DINOSAUR DISPLAY AND NEARBY CANYONS SHOWS THRUSTING FROM THE EAST (CW ROTATION ALONG THE WASH TRENDING TOWARD THE WA CITY FAULT, WHICH MOVES UP TO THE NORTH ON THE EAST SIDE- A LEFT LATERAL FAULT).

THE SOUTH SIDE OF THE SAND MOUNTAIN HAS SOME INTERESTING COMPRESSIVE FEATURES, INDICATING THAT LATERAL FORCE FROM THE DIRECTION OF THE CANYON TO THE EAST IS INFLUENCING THE SCARP OF THE MOUNTAIN FOR SEVERAL MILES TO THE WEST:


:
Shown below is some of the movement, from rotations and southward lateral displacement along Hf, that is occurring near the canyon on the Utah side:
MOST IMPORTANT CONCLUSIONS:
1. GRASS VALLEY CELL IS COMPOSED OF SEVERAL CONCENTRIC CIRCLES, AND ALL MAJOR ONES ARE ROTATING CW (COOLING AND SHRINKING OF THE CRUST, BUT THIS DOES NOT INCLUDE MINOR CELLS, WHICH ACT AS BUFFERS TO THE MAJOR ROTATIONS);
2. THERE IS COMPRESSIVE STRESS ON THE SOUTH SIDE OF THE CELL AT THE AZ BORDER AND THE CANYON TO THE NORTH (PRODUCING THE MONOCLINE AND HOGBACK);
3. THE ONLY HINTS OF RESURGENCE OF VULCANISM ARE THE H2S SMELL ON THE EAST SIDE OF SULLIVAN KNOLL AND THE PAH TEMPE HOT SPRING- BOTH OF WHICH CAN BE PRODUCED FROM BRITTLE-FRICTION DUE TO LATERAL MOVEMENT, EITHER CW OR CCW;
4. THE CONCENTRIC CELLS ARE PRODUCED BY MOVEMENT CREATED BY CCW (SOUTH) MOVEMENT ON THE CP SIDE OF Hf, AS COMPARED TO RELATIVE OPPOSITE MOVEMENT ON THE B&R SIDE (THIS FORMS A TORQUE AROUND A BLOCK OF CRUST); AND,
5. VULCANISM IS PRODUCED NEAR A MOVING ENTITY, SUCH AS Hf, AND IT CAN BE DUE TO DIVERGENCE OF TWO FAULT SYSTEMS (CAUSING EXTENSION AT THE "Y") OR BY CONTINUAL SHEAR ALONG ONE MOVING FAULT SYSTEM.
CAVEATS FOR THE CONCLUSIONS:
A. Should I be wrong in my analysis of the rotation direction of the two major cells in Sand Mountain (CW vs. CCW) and they be rotating such as to generate heat of friction, then the uplift will be that of an incipient geothermal event. The south convergence will then be a divergence zone, where the uplift is definitely occurring. This will be a cause for further investigation. I have measured a seep at the dead-end BOX CANYON at this zone, and find only a few degrees rise above normal 40F, for this time of the year. I concluded that the analysis was correct, but there are some buffer cells, which don’t quite agree. The overall rotation of the Grass Valley cell is CW, but there are many small cells which are rotating in the opposite direction (from analysis of thrust direction, drag of crustal segments, and orientation of beds).
B. Should I be wrong, then the UGS is derelict in either failing to read this missive (sent to the practicing geo-community) or in following up on the conclusions. I will return to do field work this week, and make more careful measurements. This is a known geothermal area, and it is just a matter of time (HOW MUCH?) before there is another vent extruding. There is no cause for alarm, even is there is an uplift, since there will be sufficient warning of H2S gas, earthquakes, and more rapid movement near the Sand Mountain rise.
C. The analysis of involvement of areas outside the Grass Valley cell is now suspect- Zion and Snow Canyon should have no connection with the feature, being separated from them by significant faulting (on a large scale, such as the WA and Hurricane faults.) However, I did find similar N60E striations in the Delta north of the Overton Arm and Muddy Creek, and I will re-visit this young Pleistocene and Pliocene sedimentary deposit for more specific analysis.

LOOKING AT DETAILS OF SMALL ROTATIONS ON THE EDGE OF SAND MOUNTAIN, WE FIND THAT THIS IS SUBJECT TO A LOT OF LOCAL MOVEMENTS. THE CARDINAL RULE: HIGHER ELEVATION AREAS INCUR MORE CORIOLIS INFLUENCE THAN LOWER (THEY PROTRUDE INTO THE ATMOSPHERE, WHERE THEY ARE SUBJECT TO MORE WRENCHING OR TORQUE)- HENCE IT IS NECESSARY TO INVOLVE ELEVATION OF FEATURES, WHEN IN THE FIELD. BELOW ARE SHOWN FEATURES, WHICH HAVE BEEN CONFIRMED BY HIKING THE TERRAIN. SINKS OR HOLLOWS ROTATE CW, WHILE RISES OR MOUNTAINS ROTATE CCW:



THIS WILL BE CONTINUED, AFTER ADDED FIELD WORK- AN ANALYST'S WORK IS NEVER DONE! I JUST TOOK A FORAY, AS PART OF A SUNDAY DRIVE, AND THE VIEW WAS TREE-MEND-US.

1 comment:

Amy said...

I appreciate your PO very much the picture with the article. Continues to refuel!!