scholarly journals Colorado River chronostratigraphy at Lee's Ferry, Arizona, and the Colorado Plateau bull's-eye of incision: COMMENT

Geology ◽  
2013 ◽  
Vol 41 (12) ◽  
pp. e303-e303 ◽  
Author(s):  
K. Karlstrom ◽  
A. Darling ◽  
R. Crow ◽  
G. Lazear ◽  
A. Aslan ◽  
...  
Geology ◽  
2013 ◽  
Vol 41 (4) ◽  
pp. 427-430 ◽  
Author(s):  
J. L. Pederson ◽  
W. S. Cragun ◽  
A. J. Hidy ◽  
T. M. Rittenour ◽  
J. C. Gosse

Geology ◽  
2013 ◽  
Vol 41 (12) ◽  
pp. e304-e304 ◽  
Author(s):  
J. L. Pederson ◽  
A. J. Hidy ◽  
J. C. Gosse ◽  
T. M. Rittenour

Geosphere ◽  
2015 ◽  
Vol 11 (6) ◽  
pp. 1719-1748 ◽  
Author(s):  
David L. Kimbrough ◽  
Marty Grove ◽  
George E. Gehrels ◽  
Rebecca J. Dorsey ◽  
Keith A. Howard ◽  
...  

Arts ◽  
2016 ◽  
Vol 5 (4) ◽  
pp. 7
Author(s):  
Polly Schaafsma

Dating the late 1000s to the mid-1200s CE, petroglyphs of sandal images are among others that distinguish ancient Pueblo rock art in the San Juan and Little Colorado River drainages on the Colorado Plateau from Ancestral Pueblo rock art elsewhere across the Southwest. The sandal “track” also has counterparts as effigies in stone and wood often found in ceremonial contexts in Pueblo sites. These representations reflect the sandal styles of the times, both plain in contour and the jog-toed variety, the latter characterized by a projection where the little toe is positioned. These representations are both plain and patterned, as are their material sandal counterparts. Their significance as symbolic icons is their dominant aspect, and a ritual meaning is implicit. As a component of a symbol system that was radically altered after 1300 CE, however, there is no ethnographic information that provides clues as to the sandal icon’s meaning. While there is no significant pattern of its associations with other symbolic content in the petroglyph panels, in some western San Juan sites cases a relationship to the hunt can be inferred. It is suggested that the track itself could refer to a deity, a mythological hero, or the carver ’s social identity. In conclusion, however, no clear meaning of the images themselves is forthcoming, and further research beckons.


Geosites ◽  
2020 ◽  
Vol 1 ◽  
pp. 1-17
Author(s):  
Thomas Chidsey ◽  
Hellmut Doelling

The Dead Horse Point geosite, within the state park by the same name, is located in the heart of the Canyonlands region of Utah between Canyonlands and Arches National Parks. The views are spectacular, sublime, awe-inspiring, and majestic, and hard to surpass anywhere on the Colorado Plateau. The mood of the vistas changes by season and time of day. Here, one of nature’s engineers, in this instance the Colorado River and its tributaries, has carved and exposed strata of Late Pennsylvanian (307 million years ago [Ma]) to Early Jurassic (200 Ma) age within just the past 5 million years (figures 2 and 3).


Geosphere ◽  
2021 ◽  
Author(s):  
A.T. Steelquist ◽  
G.E. Hilley ◽  
I. Lucchitta ◽  
R.A. Young

The timing of integration of the Colorado River system is central to understanding the landscape evolution of much of the southwestern United States. However, the time at which the Colorado River started incising the westernmost Grand Canyon (Arizona) is still an unsettled question, with conflicting interpretations of both geologic and thermochronologic data from western Grand Canyon. Fluvial gravels on the Shivwits Plateau, north of the canyon, have been reported to contain clasts derived from south of the modern canyon, suggesting the absence of western Grand Canyon at the time of their deposition. In this study, we reassess these deposits using modern geochronologic measurements to determine the age of the deposits and the presence or absence of clasts from south of the Grand Canyon. We could not identify southerly derived clasts, so cannot rule out the existence of a major topographic barrier such as Grand Canyon prior to the age of deposition of the gravels. 40Ar/39Ar analysis of a basalt clast entrained in the upper deposit (in combination with prior data) supports a maximum age of deposition of ca. 5.4 Ma, limiting deposition to post-Miocene, a period from which very few diagnostic and dated fluvial deposits remain in the western Colorado Plateau. Analysis of detrital zircon composition of the sand matrix supports interpretation of the deposit as being locally derived and not part of a major throughgoing river. We suggest that the published constraint of <6 Ma timing of Grand Canyon incision may be removed, given that no clasts that must be sourced from south of Grand Canyon were found in the only known outcrop of gravels under the Shivwits Plateau basalts at Grassy Mountain north of Grand Canyon.


Sign in / Sign up

Export Citation Format

Share Document