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

Tropical Storm Dolly forms, threatens Mexico

6 hours ago

Tropical Storm Dolly formed off Mexico's northeastern coast on Tuesday and headed toward landfall in Tamaulipas state, threatening to spark floods and mudslides, forecasters said.

Giant garbage patches help redefine ocean boundaries

9 hours ago

The Great Pacific Garbage Patch is an area of environmental concern between Hawaii and California where the ocean surface is marred by scattered pieces of plastic, which outweigh plankton in that part of ...

New satellite maps out Napa Valley earthquake

10 hours ago

Scientists have used a new Earth-observation satellite called Sentinel-1A to map the ground movements caused by the earthquake that shook up California's wine-producing Napa Valley on 24 August 2014.

User comments : 0