Could the Colorado River once have flowed into the Labrador Sea?

Oct 24, 2013
A figure stands on Esplanade surface opposite Vulcan's Throne volcano, Grand Canyon, USA. Photo by J.W. Sears. Credit: James W. Sears

In the November issue of GSA Today, James W. Sears of the University of Montana in Missoula advocates a possible Canadian connection for the early Miocene Grand Canyon by arguing for the existence of a "super-river" traceable from headwaters in the southern Colorado Plateau through a proto–Grand Canyon to a delta in the Labrador Sea.

Sears proposes that the river flowed first toward the southwest corner of the Colorado Plateau, and then, in a shift initiated by uplift of the Rio Grande Rift, turned north into Paleogene rifts in the vicinity of Lake Mead. He posits that it then followed northeast-trending grabens across the Idaho and Montana Rockies to the Great Plains and joined the pre-ice age "Bell River" of Canada, which discharged into a massive delta in the Saglek basin of the Labrador Sea.

In this scenario, tectonic faulting beginning 16 million years ago dammed the Miocene Grand Canyon, creating a large lake that existed up to six million years ago. Then volcanism, including the action of the Yellowstone hotspot, cut the river off in Idaho about six million years ago, leading to the eventual capture of the Colorado River by the Gulf of California.

Explore further: First evidence that dust and sand deposits in China are controlled by rivers

More information: Late Oligocene–early Miocene Grand Canyon: A Canadian connection? James W. Sears, DOI: 10.1130/GSATG178A.1

add to favorites email to friend print save as pdf

Related Stories

Ancient Colorado river flowed backwards

Oct 04, 2010

(PhysOrg.com) -- Geologists have found evidence that some 55 million years ago a river as big as the modern Colorado flowed through Arizona into Utah in the opposite direction from the present-day river. Writing in the October ...

Recommended for you

Aging Africa

14 hours ago

In the September issue of GSA Today, Paul Bierman of the University of Vermont–Burlington and colleagues present a cosmogenic view of erosion, relief generation, and the age of faulting in southernmost Africa ...

NASA animation shows Hurricane Marie winding down

15 hours ago

NOAA's GOES-West satellite keeps a continuous eye on the Eastern Pacific and has been covering Hurricane Marie since birth. NASA's GOES Project uses NOAA data and creates animations and did so to show the end of Hurricane ...

EU project sails off to study Arctic sea ice

20 hours ago

A one-of-a-kind scientific expedition is currently heading to the Arctic, aboard the South Korean icebreaker Araon. This joint initiative of the US and Korea will measure atmospheric, sea ice and ocean properties with technology ...

User comments : 0