A Short History of Ideas on the Origin of the Grand Canyon Wayne Ranney, 2013, Pp
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New Mexico Geological Society Downloaded from: http://nmgs.nmt.edu/publications/guidebooks/64 A short history of ideas on the origin of the Grand Canyon Wayne Ranney, 2013, pp. 167-174 in: Geology of Route 66 Region: Flagstaff to Grants, Zeigler, Kate; Timmons, J. Michael; Timmons, Stacy; Semken, Steve, New Mexico Geological Society 64th Annual Fall Field Conference Guidebook, 237 p. This is one of many related papers that were included in the 2013 NMGS Fall Field Conference Guidebook. Annual NMGS Fall Field Conference Guidebooks Every fall since 1950, the New Mexico Geological Society (NMGS) has held an annual Fall Field Conference that explores some region of New Mexico (or surrounding states). Always well attended, these conferences provide a guidebook to participants. Besides detailed road logs, the guidebooks contain many well written, edited, and peer-reviewed geoscience papers. 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Hutcheson Dr. Flagstaff, AZ 86001, [email protected] ABSTRACT—For as well known and highly regarded as the Grand Canyon is, its precise age and the specific processes involved in its formation remain somewhat elusive to the geologist. This is not due to a lack of trying, for the great gorge has been the subject of passionate inquiry since John Strong Newberry first laid eyes on it over 155 years ago. Research into the canyon’s origin has accelerated greatly since the turn of the millennium and a survey of the ever evolving ideas related to its development can serve to frame the foundations of many modern proposals. Historic ideas on the canyon’s origin gener- ally sought to relate the deeply dissected modern landscape (that continues to captivate practically anyone who encounters it), with the possible evolution of the Colorado River. The earliest geologists however, could not perceive of the dynamism that can be involved in a rivers’ history, nor could they benefit from a larger understanding of the tectonic evolution of the American Cordillera. It took nearly seventy years of research before definitive evidence was found that showed that the modern Colorado River, one that begins in the Rocky Mountains and drains across the elevated Colorado Plateau to the foundered Basin and Range and the Gulf of California, might actually be one of the younger geologic features found upon the southwestern landscape. Since this relative youthfulness of the river has been detected, myriad searches for prior ancestors, cut-off chan- nels, past configurations, or flow reversals have been postulated, presented, debated upon and accepted or rejected. Ideas that the river and canyon might be as old as the Laramide Orogeny have never gone away but consensus points to younger dates. A familiarity with historic theories for how the Grand Canyon and Colorado River evolved is presented below to help to frame modern debate. THE 19TH CENTURY locality. It seems intended by nature, that the Colorado River, along the greater portion of its lonely and majestic It is interesting to note how important geology has been in way, shall be forever unvisited and undisturbed. the development of a worldwide appreciation of Grand Canyons’ significance. People of European descent first saw the canyon in Newberry fortunately was not swayed by the views of his com- 1541 when members of the Coronado Expedition sought a resup- mander on the perceived shortcomings of this parched landscape. ply route from the sea to the interior. With nothing of its kind Rather, he made the first seminal observation about its geologic found on the European landscape, these conquistadors had no nature - that it was “the exclusive action of water” (Newberry, reference in which to comprehend the spectacle before them – no 1861, p. 46) that led to the formation of the great chasm. The Spaniard returned for 235 years. In fact, as far as we know, not emerging visage of the American West, the Colorado Plateau, one of the numerous explorers, mountain men, or trappers who and Grand Canyon in particular, led to the important concept that saw the canyon during the period of exploration (from 1541 to rivers could play a dominant role in the shaping of landscapes. 1858) ever returned for a second time. Yet when the first geolo- Old World geologists, where the science was born, were gist laid eyes on it in April 1858, he and every geoscientist that hindered perhaps by the reality that much of northern Europe was followed sounded a siren call for the display of earth history and shaped by recent glacial action and they at first seemed to resist the extravagant exposure of strata that could be read like a book. this new American fluvialism. At Grand Canyon, an untrained or From the first geologist to all who followed in the 19th century, more casual observer might surmise that it could have formed each returned for at least a second look, as the profound meaning as the result of a of the landscape was never lost on scientists trained to see earth giant rift in Earth’s history so acutely. In a very real way, geologists told the world crust that was only how to appreciate Grand Canyon’s unique and endearing land- later occupied by the scape (Ranney, 2013). Colorado River. With his geologic training John Strong Newberry Newberry observed that, “opposite sides John Strong Newberry is credited as the first geologist to of the deepest chasm view the Grand Canyon. He was part of the Ives Expedition showed perfect cor- (1857-58), led by Lt. Joseph Christmas Ives, who made what is respondence of strati- considered by many to be the least prophetic statement about the fication,” (Newberry, Grand Canyon: 1861, p. 46) meaning that the river was not The region ... is, of course, altogether valueless. It can be placed here merely approached only from the south, and after entering it there along a pre-existing is nothing to do but leave. Ours has been the first, and will fault or fissure. How doubtless be the last party of whites to visit this profitless instructive are the Photo courtesy of Wikimedia 168 RANNEY opposed reactions to the landscape by Newberry and Ives. present site, but . cleared away the obstruction by cut- Ives saw it as a profitless locality, while Newberry later ting a cañon, [as] the walls were thus elevated on either penned on a subsequent expedition that ”to the geologist the side. The river preserved its level [as] the mountains were Colorado Plateau is a paradise” (Macomb, 1876, Part III, lifted up. p. 56). The first theory about the canyon’s origin had been proposed and showed a vital relationship between the Colorado At this early stage in American geology the relative age of River and the Grand Canyon. Newberry’s initial idea that the the Laramide uplifts were not known and based on the field rela- Colorado River carved Grand Canyon has never seriously been tionships he saw, Powell invoked river antecedence as the major challenged, although some workers have recently invoked landscape forming process (Powell, 1875). His ideas would significant excavating by ancient predecessors of the Colorado later prove untenable but Powell’s growing reputation and his River (Flowers et. al., 2008; Wernicke, 2011). later directorship of the U.S. Geological Survey meant that most criticism of his idea would be muted at most. As an exception, John Wesley Powell S.F. Emmons (1897) strongly sought to challenge antecedence when he published a paper in the journal Science. But Powell Powell needs little could only respond that his own line of reasoning for antecedence introduction since his was too far in the past to recall precisely why he settled on that two river trips down idea. And although antecedence is rarely, if ever, associated with the Colorado River modern ideas on Grand Canyon’s formation, Powell neverthe- became widely publi- less inspired many generations of future geologists. Powell set cized, and his status as the stage for future work and recruited and introduced the next explorer “par excel- two geologists to the wonders of the Grand Canyon. lence” was assured. But first and foremost, Clarence Dutton Powell was trained in geology and always The first of Pow- concerned himself ell’s protégés in the with the origin of the Southwest was Army landscape he traveled officer and Yale through.