Below is the model we are trying to confirm or disprove, for the uplift of 
the Colorado Plateau (C.P.) in the transition zone:
 
 How the Tbb (Tertiary Beavertail Butte sands and gravels) conglomerates, 
containing extrusives, and what I call Kg (gravels
moving under the influence of tectonic wedging), show episodes of uplift and
downdropping in the transition zone.
1. Outside the Verde graben, as well as I can tell- since one is never sure
exactly when the faulting is from another entity- the pre-extrusive
conglomerates (those with no Miocene basaltic clasts) are near 4000 feet; 
this is at 3900 feet at Rattlesnake
canyon (near the Stoneman interchange on I-17), and at 4000 feet east of
Dugas Road (between the freeway and the Verde River). Further, in Gaddis 
Canyon (north of I-17 just north of Camp Verde) they are again near
4000 feet. Proceeding up the Black Hills, they are found at progressively
higher elevations, occurring at 6300 feet near 89A above Jerome. How is it possible that
the gravels flowed down to the NE, when they are found outside the graben at
about the same elevation (a gradient must occur, in order for gravels to
move downhill)?
 One part of the explanation is that the graben has dropped down more on the
west side at least 100 feet than on the east side- this would erase part of
the presently-seen dip.
This doesn't help much, since the graben is younger than the gravels.
 The more likely explanation is that the  Kg gravels moved east much like
soil
falling off a plow, as the subducting tectonic wedge moved eastward. After passage of
the wedge, the land becomes nearly level again.
 We have measured the dip of the gravels- it is near 2 degrees now (dip in
degrees can be converted to uplift, by remembering that angle in radians is
equal to sin and to tan angle, where 1 radian is 57.3 degrees- hence 2
degrees over 22 miles from Stoneman to Black Hills is .03 radians is also
the tan of the angle, or 3500 feet uplift), and
imbrication shows that indeed the gravels moved eastward in Laramide time.
This is
understandable, under the impetus of the wedge, where the Plateau is tilted
to the east. After the wedge moved through, the land is higher, but nearly
level again. What makes this confusing is that the dip of about 2 degrees
can still be seen- probably large blocks maintain the old dips, while the
blocks themselves drop down into the faulting at other angles.
2. The highest level of Tbb is at 6300 feet off hiway 89A, below Mingus-
this tells us that Mingus has uplifted at least 2400 feet, relative to 
gravels found outside the graben and not in the Black Hills.
Using 2 degrees of dip to the east, the change of elevation between Black
Hills and Rattlesnake Canyon would be at least 3000 feet, for the gravels
to flow under the impetus of the 2 degree dip. But with the plow effect,this
could be unnecessary. In any case, the gravels indicate a relative uplift of
2400 feet, for Black Hills (post-gravels and post basalts). I like 
the horst containing the gravels found at a 4900 foot
elevation (by I-17 feeder at 169 intersection), being 1000 feet 
higher than Rattlesnake outcrop of Tbb-
4900 compared to 3900 feet.
This indicates that the dip was more like 1/2 degree for the original flow
of Tbb gravels to the NE. But we have to account for the other dips seen-
3-5 degrees at the freeway, and 2-3 degrees elsewhere, as an average.
2. The first uplift (of the C.P.) indication outside the general wedging of the Colorado
P. is that Hickey Mt. (volcano) is now some 1000 feet lower in elevation
than the lava flows on Mingus and Woodchute. This indicates that the Black
Hills have risen relative to Hickey, since Hickey time.
3. Tbb is found in canyon deposits north of Mingus Mt, not in sheet flows
as to the south; this indicates that Mingus was high and hilly in Tbb time-
but the gravels still flowed through. This would happen with the Kg gravels
moving under the influence of the tectonic wedge. To get movement with
extrusive clasts, there must have been at least two movements (the common 
one without extrusive clasts is older, the ones with extrusive clasts is much younger).
 Tbb with basaltic clasts at the top of the formation are either thin or
rare, indicating that most of the gravels traveled by tilting of C.P.,
before the
vulcanism started. At the I-17 & hiway 169 feeder, there are abundant basaltic
clasts at the top of the outcrop, and the dip is down to the east at 5
degrees. This says that the horst there had
Tbb gravels flowing simultaneous with vulcanism. Not only that, but there are
Mr (redwall) clasts present, which says that there were Paleozoics west of
I-17 in Tbb time. Bradshaws were being stripped of Paleozoic sediments at about the 20
m.y. time, and the terrain was almost level between
Bradshaws and Black Hills (not a basin, as it is now). So, the Black Hills
had to rise sometime after 20 m.y.
This could still be in Hickey time, as shown by the high Woodchute & Mingus
basalts, with the Woodchute rise occurring shortly after Hickey erupted.
3. The I-17 & hiway 169 horst had to rise later than the Hickey (since it has
Hickey clasts in it), it is uplifted separately an unknown amount; but the
fact that it is a horst makes it yield a smaller uplift than would be
calculated if it were in original position- the uplift of Mingus (relative
to Tbb, shown on 89A, just below Mingus) is 6300 feet - 4900 feet measured
at the freeway = 1400 feet of uplift after the horst was in place. This
makes a portion of Black Hills rise for a third time. This must be by some
thermal mechanism- I like the idea (mine) that buried radioactive elements,
put in place by tectonic wedging, begin to show significant heat after 50
m.y. (half lives of K, U, Th are on the order of 1 b.y.- 50 million m.y.
represents a 5% decay). Others speculate that wedge absorption or
interference  by the asthenosphere allows the heat to move upwardly. This
assumption is key, and any means to measure crystal changes or phase
boundaries must take into account that the thermal gradient under the C.P. is
almost twice that of basins far away- such as the Gulf Coast, except for
salt domes and some other anomalies. I have measured the gradient from well
logs, and find it to be near 1.7 degrees/ hundred feet in the C.P., compared to
1.0 in the Gulf Coast. Reviewing:
1. A subduction wedge lifts the C.P. a few thousand feet- the amount of the
Arkosic redbeds (I label them Kg) underneath Chalk Canyon subtracted from
the normal Tbb elevation? (about 2000 feet difference?). 
Chalk Canyon doesn't rise later with thermal
expansion, because the heat is released at the C.P. edge through vulcanism;
C.P. rises  because most of the heat is not released through vulcanism, but
is used for thermal expansion of the plateau. This is responsible for the
difference of el. between B&R and C.P.
3. A third intrusion (dike) uplifts part of the
Black Hills- this is not explained yet, and is made somewhat problematic
because the Paleozoic on top of the dike (midway up the cliffs on the east
 side of B.H.) remains at a fairly similar elevation (not
irregular) all along the B.H. But there is a 1400 feet uplift not accounted
for by other visual means. I am filing this under Black Hills Uplift.
                    Harold L. Overton