Controversy
The origin of the geological landscapes of the park have been under debate since 1865. At that time, Josiah Whitney, then chief geologist of California, proposed that Yosemite Valley is a graben: a downdropped block of land surrounded by faults. John Muir proposed that Yosemite Valley and Hetch Hetchy Valley were formed purely by glacial action. In 1930, Francois Matthes proposed a hybrid hypothesis, where most of the depth of the valley was gouged by water erosion, the rest by glacial action. The glacial action also claimed to have widened the valley.
More recently, the debate has been reopened by Jeffrey Schaffer, who suggests that the role of glaciers and other erosion processes has been dramatically overstated. Schaffer states that Yosemite Valley above 5600 feet (1700 m), for example, has changed relatively little in the past 30 million years. Other than being slightly larger, if one could look back in time and see them, the major features would be recognizable to the modern eye. Schaffer believes that the numerous joint planes have had the greatest impact on the geomorphology of the Park's major features. This is in contradiction to the consensus view that huge highly abrasive glaciers acting on joint planes combined with a great deal of uplift over just the past couple million years was the primary shaping force of the features (such rapid uplift would have greatly accelerated all types of erosion).
Read more about this topic: Geology Of The Yosemite Area
Famous quotes containing the word controversy:
“Ours was a highly activist administration, with a lot of controversy involved ... but I’m not sure that it would be inconsistent with my own political nature to do it differently if I had it to do all over again.”
—Jimmy Carter (James Earl Carter, Jr.)
“And therefore, as when there is a controversy in an account, the parties must by their own accord, set up for right Reason, the Reason of some Arbitrator, or Judge, to whose sentence, they will both stand, or their controversy must either come to blows, or be undecided, for want of a right Reason constituted by Nature; so is it also in all debates of what kind soever.”
—Thomas Hobbes (1579–1688)