Afternoon drive to the Jurassic
Where
Warner Valley Dinosaur track site, south of Hurricane, UT.
In the
Springdale Sandstone Member of the Kayenta Formation. Signage at the sight lists the Springdale as part of the Kayenta, but the NPS geology page lists it as part of the Moenave. The Utah Geological society in paper M-250 lists it as part of the Kayenta.Springdale Sandstone Member (Lower Jurassic) – Mostly pale-reddish-brown to pale-grayish-yellow, moderately sorted, fine- to medium-grained, medium- to very thick bedded, ledge- to small-cliff-forming sandstone, and minor, thin, discontinuous lenses of intraformational conglomerate and thin interbeds of moderate-red-dish-brown or greenish-gray mudstone and siltstone; has large lenticular and wedge-shaped,low-angle, medium-to large-scale cross-bedding; secondary color banding that varies from concordant to discordant to cross-beds is common in the sandstone; contains locally abundant petrified and carbonized fossil plant remains; theropod tracks common in upper horizon known as the Springdale megatracksite.
The Springdale Sandstone Member of the Moenave Formation is equivalent to the basal Kayenta Formation to the northeast. Marzolf (1993, 1994) removed theSpringdale Sandstone from the Moenave Formation and included it as the basal member of the overlying Kayenta Formation. This stratigraphic revision has been applied to new geological maps of the area published by UGS. Seems like just semantics, but it's all a matter of time. The Moenave is Triassic, the Kayenta Jurassic. The diagonal stripe in the next photo may reveal the Trias/Juras boundary; or just some old tracks.
Track site is the diagonal lighter rocks in the center of the picture. The black line is a steel wall to force the wash off the tracksite. Tracks start at the left edge of the wall and continue around the right hand bend. The white is a limey layer above bed containing the tracks.
Site is easily accessible from Hurricane in 2wd in good weather. Contact
St George BLM office for further details.
What
Spectrum Tracksite
from
Making Tracks Across the Southwest 2006, California State University, Desert Studies Consortium and LSA Associates
25.3 (2.9) EXIT at Washington Parkway (Utah Exit 13).
25.4 (0.1) Stop, TURN RIGHT (east) onto Washington
Parkway.
25.5 (0.1) Pass the traffic circle/round-about, and move to
left lane....
Watch for breaking updates
Entrance described in the road log is marked NO TRESPASSING. But there is another possible entrance nearby that isn't posted, just a barbed wire fence.
