When you buy through links on our internet site , we may bring in an affiliate perpetration . Here ’s how it works .
A provocative new surmisal suggest that Yosemite Valley was carved by an ancient volcano and a disappearing river , both of which have long since eat at away .
geologist have long debated why Yosemite Valley is so deep , with walls that tower up to 4,000 feet ( 1,219 meters ) above the valley floor . The prevailing explanation is that in the last 10 million years , the Sierra Nevada mountains of California have a menstruation of upheaval , steepen their incline and get the rivers to flow more quickly and erode more quickly into the granite around them .
Researchers have suggested a new hypothesis for how Yosemite Valley formed.
But a Modern cogitation , print April 3 in the journalGeosphere , suggests uplift was n’t the tangible reason Yosemite exist . or else , allege study co - authorManny Gabet , a geomorphologist at San Jose State University , the landscape of Yosemite and the surrounding Sierras is considerably explained by a long - fly river .
jillion of eld ago , this river would have increased the catamenia to the modern day Merced River and Tenaya Creek , which would have then had enough power to slit through the Sierras to make Yosemite Valley and nearby Tenaya Canyon .
" At some point in meter , " Gabet told Live Science , " there was a with child river here . And now that river is gone . "
Yosemite mysteries
geologist agree that in the last 2 to 3 million year , Yosemite was under a glacier that helped deepen the vale . But they also conceive that this glacier filled a pre - existing deep vale , saidKurt Cuffey , a geologist at the University of California , Berkeley , who was not require in the new inquiry .
" So why did the canyon form in the first place ? " Cuffey say .
There are a caboodle of faults on the east side of the Sierra Nevada that belike would have induce the pile to rise up and get steeper , Cuffey told Live Science . But geologists ca n’t say how much higher the passel range got , or if it was gamey enough to well increase the erosive mogul of the river . It ’s a controversial topic , he say .
Uplift also does n’t explain three odd observations , Cuffey said . The first is that Tenaya Canyon , a outrageous and treacherous canyon that runs from Tenaya Lake into Yosemite Valley , is way too cryptic to have been thin by the stream that run through it today , Tenaya Creek . " It ’s just a really small river , " Gabet say . " you could derail across it . The mystery is , how did this tiny brook cut through thousands of feet of very resistant , very monolithic granite ? "
The 2nd mystery story is that in California ’s Central Valley , where the Merced River pour forth out of Yosemite and produce a devotee - shaped layer of deposit it has carried from the hatful , there are Brobdingnagian deposits of volcanic careen that should n’t be there . " You ’ve get 8 cubic miles [ 33.3 cubic kilometer ] of volcanic sediment deposit in the Central Valley by the Merced River , but you ca n’t find a scrap of these volcanic rocks , " in the area around the river , Gabet enounce .
The third mystery has to do with the uneven shape of the vale cut by the Tuolumne River just northward of the Merced , Cuffey read . This valley is much large on one side than the other . It ’s a relatively insidious point to a non - geologist , but " that need an explanation , " he enounce .
Lost river
Gabet ’s hypothesis harkens back to 5 to 10 million years ago , when a chain of volcanoes had buried the northern Sierra Nevada in huge mudflows , produce a gently sloping volcanic plain with only a few passel peaks poking out of it . These deposits are still visualize northerly of Yosemite , but not in the surface area around the Merced River .
" I realized these volcanic rocks that had been transported by the Merced River must have come from this chain of volcanoes , " Gabet enunciate .
The peaks of such a volcanic chain of mountains would have been enfeeble by a big , now lost river , he said . This river would have flowed from now - vanished volcanic slopes north of where the National Park is today and then gush into the ancient Merced and Tenaya Creek , enabling them to carve out Yosemite Valley and Tenaya Canyon .
— Flowing flame ? Yosemite ’s burning waterfall explained
— Photos : Take a spell of spectacular Yosemite
— Earth ’s crust is peeling aside under California
The influence of this river would have made both the Merced and Tenaya Creek much big than today ’s relative trickle — so great that they could have trend down the canon . The drain normal from this touch river would also excuse the lopsided topography around the Tuolumne River , Cuffey say . Finally , the river would have carry the volcanic tilt now bump in the Central Valley down from the northerly Sierra Nevada , a journey that is strong to explain otherwise .
The river and vent would have themselves eventually erode to nothing , so there is no way of life to see if they ever existed . One of Gabet ’s pupil is now working on a project to endeavor to recreate the ancient topography of the Sierra Nevada to better sympathize how the geology of the lot evolve and perhaps shed more light on the possibility .
" He ’s got a really interesting thing going , " Cuffey said of Gabet . " I really do n’t know if it ’s true or not at this point , but it ’s a expectant speculation that we should think about . "
You must confirm your public display name before commenting
Please logout and then login again , you will then be prompt to participate your video display name .
