H27: Honeymoon Canyon S22 T43S R13W 4/12/06

The Hurricane cliffs have remained a mystery to geologists. They have classified it, named it, noticed its peculiarities, and attempted to relate it to plate tectonics, but it is essentially an enigma. One does not increase understanding by using Taxonomy on a physical phenomenon; rather the procedure of classification merely places it in a category, such as would be used by archeologists, and lets it remain in a dusty file somewhere.

Firstly, it is noticed that the H cliffs are some 100 miles in length, where they trace an N-S path from southern Utah down to the Grand Canyon and a bit beyond. They monotonously rise some 200 meters for this last uplift- in the 40 km of our investigation- and continue this almost linear behavior, except for the occasional volcanic cone or extrusion along the path (some as distant as several miles perpendicular to the scarp).

Secondly, the H scarp generally exhibits Paleozoic rocks in the upthrown wall and Mesozoic in the valley below. It is only occasionally cut by a through-flowing creek; most of the time the creeks flow southwardly until they encounter a major break in the cliffs. The scarp does not exhibit properties as with a graben (two such scarps surrounding a down-dropped block);

Thirdly, the cliffs exhibit a youthful appearance, in terms of erosion of the limestone above the valley, but showing major erosion whenever a creek such as the Virgin allows it. The Virgin shows that there is a distinct flow pattern above the scarp (looking at a map), indicating that the river course east of the scarp makes right-angle turns, and then exhibits a different behavior after crossing the scarp. Geologists generally want to classify the scarp in terms which are used with rifts or basin and range mountain blocks- which is a mistake; and

Fourthly, the volcanic rocks (basalt) act as a dam to drainage, but this has always been overcome by the breaking of these dams by westward flowing creeks. Speaking in terms of Physics, the scarp is a discontinuity or separation of two completely different regimes, with no indication of a gradual change from one to the other.

We will try to determine whether my model for the Hurricane fault shows the same behavior at the AZ border Honeymoon canyon as it does at the Virgin canyon:

1. faulting along a N-S line (via the thinner crust at the edge of the Colorado Plateau), due to shrinkage of the ellipsoidal earth as the earth rotation rate (centrifugal force) decreases, whose deep fractures

2. allow deep magma to rise nearby, which

3. results in extrusion (volcanoes, which partly evacuate the magma chambers), which

4. causes shrinkage with cooling of the magma (after the volcanoes have belched) and downward settling, and then

5. rotation of a nearby sedimentary column CW (looking northward) into the fault zone- producing a monocline and resulting hogback up to the west, and finally resulting in N-S fissures, fractures, and faulting.

We will ask the following questions:

1. How close is a lava vent to either of the two rotated blocks located near the Honeymoon Canyon?

2. Do both sedimentary blocks rotate CW into the fault zone?

3. Since both of the large blocks are well developed and greatly eroded, indicating age larger than the one at Laverkin, is the concomitant lava flow equally old? and

4. Where there is no rotated block, along the path south from Hurricane town, is there also no lava vent nearby (this will help establish how close the two entities have to be)?

An alternative to question 4 is: If one entity depends on the other, are the two phenomena inter-related (that is can we have one feature without the other)?

Mesozoic beds' dip significance (as first observed by hiking group, in 2005):

The fact that the Mesozoic and Paleozoic strata dip up to the west on both sides of the Hurricane fault means that whatever created the fault had a thin zonal effect- not a regular uplift, as with an intrusion or anticline. Rather, the fault is a slice caused by a large region (edge of the C.P.) shearing away from another large region- that is, the transition from the Colorado Plateau CP to the basin and range B&R. This case has already been documented, for a dipping of the Eocene beds up to the west, while the underlying Mesozoic dipped oppositely in the Cedar City area. In our area, at Toquerville, and at Laverkin, the post-Laramide dip continues right across the Hurricane fault, even though the displacement is large at the fault. This means that entities south of the Pine Valley Mts. have been first subject to compression from the west (or below), and then later have been sliced by some simpler action.

We will check that this generally is the case, and if positive, this means that vulcanism, N-S faulting, and extensional faulting are operating together (but not necessarily at the same time), and have produced a lot of our geological anomalies fairly recently. The dynamics have proceeded through the following phases since Cretaceous time:

1. Compression from the Pacific plate moving eastward in Cretaceous times created anticlines, monoclines and folds oriented N-S here (as with the Kaibab plateau, as seen along the Lee's ferry to Cameron road, and several other features like Combs� Ridge;

2. These stresses died away in Oligocene times, as the Pacific plate moved northward (after the time of the dog-leg in the Hawaiian-Emperor seamount chain- of 41 my. time- after crossing a major transform, where the two separated regions slide horizontally at different rates);

3. Wrenching in Oligocene times was toward the NW- creating the omnipresent NW-SE fractures over most of the West US;

4. Some 2 m.y.ago, the original N-S weaknesses, created by the east-stressing Sevier and Laramide plate movement, were rejuvenated by extension (this is seen in the Verde ls. in Verde Valley- which is younger than 5 my, and in N-S rivers such as Rio Grande (older), Verde, and south Colorado Rivers);

5. Vulcanism started- first the basaltic type, as seen in our area as a clean contact of Mesozoic below basalt with rarely ash or gravels in the contact. The most recent extrusion has been of the ash fall type- in Hawaii, this is noticed as a rejuvenation phase, some 1-2 million years after the individual islands were isolated by eruptions further to the SE. The rejuvenated alkalic lavas tend to be on the SE side of islands (such as Diamond and Koko Heads);

6. The vulcanism has moved westward, in the transition zone- the youngest noticed is off hiway 18 near Snow Canyon and the older occurring in Zion Park. In AZ there has been a westward movement of extrusives also, but in this case over a 20 million year, mybp time span, and well off the C.P. into the basin and range, B&R;

7. Uplift along the Hurricane fault continues, and the fracture indications in Zion Park appear to have been re-oriented from NE-SW (as with the P.V. Mtns) to 160-340 degrees from north. One can see major canyons orienting in these two linear arrangements- older drainage tends toward the NE-SW or NW-SE (with the younger tending to be more N-S, as with Coal Pits Creek);

8. We will limit our remarks to the area near a 40 km strip running N-S from Toquerville to the AZ border, since it is readily seen that there are other discontinuities at the Pine Valley Mountains PV, at Fort Pierce Wash, and at distant places along the scarp as it traces a path to the Grand Canyon. I have chosen an area where there is a simpler presentation of the initial fault, not being disrupted by other weaknesses such as the NE-SW chain of mountains, or of tectonics known to occur earlier in the Tertiary or previously.

The author hiked westward of the large mesa at the Honeymoon canyon, trending 160-340 degrees along the Hurricane cliffs, to determine whether the beds dipping up to the west formed an anticline which had been breached and eroded at its central portion. This is mostly buried, but there is an exposure of Moenkopi to Chinle, dipping upward to the west still, at a dip angle of 45 degrees terminating (a Hogback) in the air- about 1 mile to the west of the Hurricane cliffs. To the south one can see a slight dip of beds down to the SW, and this may be a separate feature- this must be investigated further.

Conclusions formed during 2006:

1. There are two monoclines just north of the AZ border (indicating a bifurcation of the H-f) north of the Honeymoon wash, the largest one being closer to the H-f; the smaller some 2 km distant to the west has eroded more, and the closer has a lesser monocline angle (both dipping up to the west, as at Laverkin);

2. These two monoclines were investigated on April 12^th with the hiking group, and the fartherest north feature was associated with a basalt flow, which is just to the north of its termination (Grass Valley basalt). One can see how the dip of the Mesozoic is fairly flat west of the volcano to the north, but then drops down toward the H-f, with even the basalt flow dipping down into the fault. The whole zone is about 2 km wide, with the maximum dip down to the NE being 30 degrees. There is a later lava flow at the h-f cliff face which has spilled over into the fault zone, and which tapers off as it heads toward the larger flow to the west (this is reported independently as having an age of .41 mybp). The zone between is rubble-ized, so that the connection between the two cannot be made, But the basalt flow to the west is much the greater, and is not likely to be surface-associated with the smaller one to the east. Using sine of 30 degrees as the minimum distance dropped next to the fault face, or 1 km and at least .5 mybp, yields a drop rate of 2 mm/year, due to cooling and shrinking of the underlying magma;

3. The larger monocline should have an associated volcano; if the thesis is correct that the monocline is produced by the cooling and shrinking of the underlying magma, there should be an associated large volcano, and it would have to be on the eastern rim above unless it can be the one seen to the south some 5 miles distant. There were no significant basalt boulders in the wash, and even though the northern portion of the block does dip up to the west, it was concluded that the larger block of Mesozoic is an isolated fault block and not primarily a monocline associated with a quaternary volcano. It does portray faulting associated with the N-S Hurricane fault, which is vertical, and the block has been affected by the young faulting;

4. The major canyon (Honeymoon) is associated with both monoclines, and this could have created E-W faulting which allowed the creek to make a passage through the lipped-up-to-west cliffs. There are several small E-W and N-S faults, usually of only a few meters throw;

5. The larger monocline has some minor faulting which is interpreted to be quaternary, but its size and change of dip appears to indicate the presence of synclines and anticlines from the Laramide time. Rotation from the action of cooling magma below cannot be discounted, but the lack of vulcanism nearby and the absence of basalt in the adjacent wash connotes that this monocline cannot be used to prove or disprove the theory that cooling magma produces the monocline;

6. The 40 km strip from Laverkin to the AZ border is the simplest portion of the H-f, where generally a single fault trace is exhibited. Beyond this, the fault is complicated by older entities, such as the Pine Valley Mountain trend and multi-splays of the fault. These may have additional information which can yield added light upon the origin of the fault, but are outside of the region of investigation.

I have returned to the overlook on the Hurricane town side, to stand above the Virgin River, to look at the monocline associated with another block of Mesozoic rotating into the H-f. The dip of the indurated beds there is at least 10 degrees down to the east, which produces the young hogback. The width of the rotating zone (hogback to the H scarp) in the town of Laverkin is about 2 km. using a ten degree dip of the monocline, which is the same as a 20% grade, the drop of the block face fartherest to the east is 400 meters or 400,000 millimeters. Using my estimate of the age of the volcano, from erosion, of 100,000 years, this yields a drop rate at the fault face of 4 mm/year. There is a house built on the edge of the Laverkin canyon, which is suffering from having gotten too close to the dropping face and has had to build concrete bulwarks to delay the fate of the dwelling.

Looking north of the hogback in Laverkin, one can see that the dip of the monocline progressively increases to the north, finally becoming almost vertical. This continues almost to the town of Toquerville, forming the south boundary of the NW-SE weakened zone, which is associated with the anomaly of PV dikes, Wet Sandy Creek with its� linear SE orientation, Toquerville spring, and multi-faulting slivers east of Laverkin. This is the NW-SE trending anomalous boundary of our simple H-f system, where essentially the fault, vulcanism and rotation of Mesozoic blocks are all in 3-dimensional relationship as time proceeds.

We will attempt to use this same analytical procedure to predict the behavior of the Gould�s Wash- Sullivan�s Knoll- sinking of the Hurricane Valley farmlands with time. Sullivan�s volcano is estimated (by me) to be about 10,000 years of age, which would yield a total drop of about 20 meters (66 feet) at the fault scarp, in old town Hurricane, since incipience- this is in addition to the drop due to regional Hurricane faulting. The drainage of this valley is toward the north, as would be expected for a sink created by the dropping valley floor since the volcano has terminated its transfer of mass from the deep subsurface to the valley floor to the west. If the magma is now cooling (which is not yet proven), then the old town would be steadily dropping some 2 mm/year, at the far eastern face of the scarp. If this is the case, the following factors would be observed:

a. Gould�s Wash would be experiencing a net deposition on the east side of town, with a concomitant canyon formation on the west side. I notice that the depth of the wash is nearly constant, except for the confluence at the Virgin, where there is a 20 meter waterfall over basalt cliffs. There is a subtle sink on the east side of town, into which sediments are moving from the south (on the south side of Sullivan�s Knoll). Agriculture over the last century has masked any natural geological behavior, and it may not be possible to use this assessment. However, the slabs of newly-built houses can be used to assess the sinking or faulting near the airport. It is reported that the soils are unstable there, and this is a clue that there is sinking.

b. The east flank of Sullivan�s Knoll would become high with time, relative to the dropping portion in old town. This is difficult to assess, since this volcano has left resistant basalt around the flanks, while the Jn rock has been easily eroded to the east. A hogback would develop on the east side of the Knoll, as sinking near the main scarp occurs.

c. It is expected that drainage was to the south immediately after the H-f formed, because of the graben-like formation just west of the fault. This south-ward drainage channel is not observed, and I have traced the path to find if there are any river gravels which would have remained from this one million year history. They are not observed, and the drainage is regularly from the SW to the cliff face south and east of old town.

d. The 2 mm/year drop rate at the H-f is in addition to the drop occurring due to shrinkage of the Basin and Range, B&R, which has been measured as near 2/10-3/10 mm/year, for basalts above the town. This additional drop is due to the rotation of a block of crust, in reaction to the partial evacuation and cooling of the magma chambers which produced the nearby extrusions. This drop of 2 mm/year or less is a local sinking associated with the local volcanoes, and is independent of the regional sinking along the Hurricane fault. It is expected to be a continuous phenomenon- due to the continual cooling of the magma chamber, after extrusion.