Featured Research

from universities, journals, and other organizations

History Of Quaternary Volcanism And Lava Dams In Western Grand Canyon

Date:
February 11, 2008
Source:
Geological Society of America
Summary:
John Wesley Powell wrote in 1895: "...what a conflict of water and fire there must have been [in western Grand Canyon]! Just imagine a river of molten rock running down over a river of melted snow." Over 110 years later, a synthesis of new and existing dates on these lava flows shows that many are significantly younger than initially thought and all are less than 725 thousand years old. The geochronology data indicates four major episodes when lava flows either erupted into the canyon or flowed over the rim into it. These flows formed lava dams in western Grand Canyon that had dramatic impact on the Colorado River.

Toroweap Point in Grand Canyon national park.
Credit: iStockphoto/Natalia Bratslavsky

John Wesley Powell wrote in 1895: “...what a conflict of water and fire there must have been [in western Grand Canyon]! Just imagine a river of molten rock running down over a river of melted snow.”

Over 110 years later, a synthesis of new and existing dates on these lava flows shows that many are significantly younger than initially thought and all are less than 725 thousand years old. The geochronology data indicates four major episodes when lava flows either erupted into the canyon or flowed over the rim into it: 725-475 thousand years ago (ka), 400-275 ka, 225-150 ka, and 150-75 ka.

These flows formed lava dams in western Grand Canyon that had dramatic impact on the Colorado River.

This paper* presents light detection and ranging (lidar) data to establish the elevations of the tops and bottoms of basalt flow remnants along the river corridor. These data show the original extent of now-dissected intra-canyon flows and aid in correlation of flow remnants.

From 725 to 475 ka, volcanism built a high edifice within Grand Canyon in the area of the Toroweap fault, with dike-cored cinder cones on both rims and within the canyon itself. These large-volume eruptions helped drive the far-traveled basalt flows which flowed down-canyon over 120 km. A second episode of volcanism, from 400 to 275 ka, built a 215-m-high dam along the Hurricane fault, about 15 km downstream.

The ca. 200 and 100 ka flows (previously mapped as Gray Ledge) were smaller flows and lava cascades that entered the canyon from the north rim between the Toroweap and Hurricane faults.

The combined results suggest a new model for the spatial and temporal distribution of volcanism in Grand Canyon in which composite lava dams and edifices were generally leaky in proximal areas.

Available data suggest that the demise of volcanic edifices may have involved either large outburst-flood events or normal fluvial deposition at times when the river was established on top of basalt flows. These data highlight complex interactions of volcanism and fluvial processes in this classic locality.

This research, authored by Ryan Crow (University of New Mexico) et al. was published in the February issue of Geosphere, published by the Geological Society of America.


Story Source:

The above story is based on materials provided by Geological Society of America. Note: Materials may be edited for content and length.


Cite This Page:

Geological Society of America. "History Of Quaternary Volcanism And Lava Dams In Western Grand Canyon." ScienceDaily. ScienceDaily, 11 February 2008. <www.sciencedaily.com/releases/2008/02/080205100014.htm>.
Geological Society of America. (2008, February 11). History Of Quaternary Volcanism And Lava Dams In Western Grand Canyon. ScienceDaily. Retrieved July 29, 2014 from www.sciencedaily.com/releases/2008/02/080205100014.htm
Geological Society of America. "History Of Quaternary Volcanism And Lava Dams In Western Grand Canyon." ScienceDaily. www.sciencedaily.com/releases/2008/02/080205100014.htm (accessed July 29, 2014).

Share This




More Earth & Climate News

Tuesday, July 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Climate Change Could Cost Billions According To White House

Climate Change Could Cost Billions According To White House

Newsy (July 29, 2014) A report from the White House warns not curbing greenhouse gas emissions could cost the U.S. billions. Video provided by Newsy
Powered by NewsLook.com
Baluchistan Mining Eyes an Uncertain Future

Baluchistan Mining Eyes an Uncertain Future

AFP (July 29, 2014) Coal mining is one of the major industries in Baluchistan but a lack of infrastructure and frequent accidents mean that the area has yet to hit its potential. Duration: 01:58 Video provided by AFP
Powered by NewsLook.com
$50bn Yukos Case Latest Russia Cost

$50bn Yukos Case Latest Russia Cost

Reuters - Business Video Online (July 28, 2014) A Hague court has ordered Russia to pay $50 billion to a group of shareholders in defunct oil giant Yukos for expropriating its assets. Russian Foreign Minister Lavrov says Moscow will most likely appeal. As Joel Flynn reports, the ruling hits Russia as it's facing more international sanctions about its role in Ukraine. Video provided by Reuters
Powered by NewsLook.com
Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Asteroid's Timing Was 'Colossal Bad Luck' For The Dinosaurs

Newsy (July 28, 2014) The asteroid that killed the dinosaurs struck at the worst time for them. A new study says that if it hit earlier or later, they might've survived. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins