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John Strong Newberry (1822-1892) and Lake-Overflow proposed 1861:

Newberry performed as the doctor and scientist for several early exploratory efforts into the western United States.  He grew up in Ohio and trained as a scientist.  After graduating from med school, he spent several years in France studying medicine.  His most remembered endeavor was probably  his appointment to the Ives Expedition.  The expedition, put together by Lt. Ives, determined once and for all whether a trade route along the Colorado River exists from the Gulf of California to several mining claims and military outposts in the interior of Utah, Wyoming, and Colorado.  The expedition crew dismantled a steamboat into several movable pieces outside New York, shipped them around the horn of South America and up to the Gulf of California.  They then reassembled their steamboat, and headed up the Colorado River in 1857.

Figure 1. A portrait of John Strong Newberry and the steamboat and crew of the Ives Expedition heading up the Colorado River, 1857.

The expedition made short headway before running aground on large boulders in (hence the name) Boulder Canyon, near the present site of Hoover Dam.  The trip had yet to approach the fabled Grand Canyon rumored to exist somewhere upstream.  So they abandoned their broken vessel and headed afoot westward from Boulder Canyon paralleling the course of the Colorado River.




Figure 2. The steamboat heading into Boulder Canyon. 

The Ives expedition's greatest adventure must have been their decent into Grand Canyon from the south rim.  They ventured down Diamond Creek in the western portion of the canyon.  Their journey to the bottom of Grand Canyon was the first by any westerners.  John Strong Newberry, the scientist for the Ives expedition, was the first investigate the Grand Canyon's geology.  While spending over a week at the bottom, Newberry described and sketched for the first time the famous rocks making up the walls of Grand Canyon--not a bad first.  After exploring the Canyon, they headed out on foot again.  They roughly paralleled the modern route of interstate 40 that passes through Williams, Flagstaff, and Winslow in northern Arizona .  Newberry noted geologic units  along the way and defined their basic characteristics, again a first in the region.  The Bidahochi Formation, one of these rock units, represents an old lake basin at times dry and at other times held a fresh to brackish lake.  These lake deposits led Newberry to propose the first hypothesis to explain Grand Canyon incision.




Figure 3. A map of the Grand Canyon region drawn by a member of the Ives expedition. 




Figure 4.  The Bidahohi Formation in northern Arizona.  

Newberry never provided very many details, but he essentially thought a lake ponded behind  some structure (he didn't know about the Kaibab Plateau) and overspilled a low divide incising Grand Canyon.  For the canyon to cut, there needed to be a significant difference in elevation between the Kaibab Plateau and the downstream region (what is today Lake Mead).  Newberry argued against a dominant hypothesis of his day to explain landforms like Grand Canyon (termed transverse drainages).  Many thought transverse drainages result from rivers that follow paths through mountains by following huge fissures or fractures.  These paths of "least resistance" would have developed during Earth's early formation, an now stands as an outdated idea.  Newberry's hypothesis, termed "lake-overflow", represented a new idea to explain transverse drainages and his work was the first of many to scrutinize Grand Canyon's history. 




Figure 5.  A physical model that illustrates a "Lake Bidahochi" overspilling the "Kaibab Plateau".  

 


 For a lake to generate a transverse drainage, it must simply spill over the low point of the basin rim and drain across a sufficiently steep slope to instigate incision.  If steep enough (and it doesn't have to be, numerous lakes in Minnesota occupy depressions across a relatively level plain where there isn't enough energy in the draining waters to cause erosion), then a canyon cuts via a series of retreating waterfalls similar to Niagara Falls (termed knickpoints) across the topographic high / basin rim and forming a transverse drainage.  The image above illustrates a "lake" flowing across a modeled "Kaibab Plateau" and cutting a "Grand Canyon".  However, if you go to Grand Canyon National Park today and find yourself a friendly ranger to ask how Grand Canyon formed, they will not likely explain to you the lake-overflow hypothesis.  Instead, they'll likely explain the next hypothesis we explore--antecedence.
 

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