Regional and Local Trends in helium isotopes, basin and rangeprovince, western North America: Evidence for deep permeablepathways

PDF Version Also Available for Download.

Description

Fluids from the western margin of the Basin and Range have helium isotope ratios as high as {approx}6-7 Ra, indicating a strong mantle melt influence and consistent with recent and current volcanic activity. Moving away from these areas, helium isotope ratios decrease rapidly to ''background'' values of around 0.6 Ra, and then gradually decrease toward the east to low values of {approx}0.1 Ra at the eastern margin of the Basin and Range. Superimposed on this general regional trend are isolated features with elevated helium isotope ratios (0.8-2.1 Ra) compared to the local background. Spring geochemistry and local geology indicate that ... continued below

Creation Information

Kennedy, B. Mack & van Soest, Matthijs C. July 15, 2005.

Context

This article is part of the collection entitled: Office of Scientific & Technical Information Technical Reports and was provided by UNT Libraries Government Documents Department to Digital Library, a digital repository hosted by the UNT Libraries. More information about this article can be viewed below.

Who

People and organizations associated with either the creation of this article or its content.

Publisher

Provided By

UNT Libraries Government Documents Department

Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.

Contact Us

What

Descriptive information to help identify this article. Follow the links below to find similar items on the Digital Library.

Description

Fluids from the western margin of the Basin and Range have helium isotope ratios as high as {approx}6-7 Ra, indicating a strong mantle melt influence and consistent with recent and current volcanic activity. Moving away from these areas, helium isotope ratios decrease rapidly to ''background'' values of around 0.6 Ra, and then gradually decrease toward the east to low values of {approx}0.1 Ra at the eastern margin of the Basin and Range. Superimposed on this general regional trend are isolated features with elevated helium isotope ratios (0.8-2.1 Ra) compared to the local background. Spring geochemistry and local geology indicate that these ''He-spikes'' are not related to current or recent magmatic activity, suggesting that the spikes may reflect either localized zones deep mantle melting or deep permeable pathways (faults) with high vertical fluid flowrates. A detailed study of one of the He-spikes (Dixie Valley and the Stillwater Range Front Fault system), indicates that features with high 3He/4He ratios are confined to the range front normal faults characteristic of the extensional regime in the Basin and Range, suggesting that these faults are deep permeable pathways. However, not all range front fault systems transmit fluids with a mantle signature, implying that not all have deep permeable pathways.

Source

  • Annual Meeting of the Geothermal ResearchCouncil, Reno, Nevada, 25-28 September 2005

Language

Item Type

Identifier

Unique identifying numbers for this article in the Digital Library or other systems.

  • Report No.: LBNL--59811
  • Grant Number: DE-AC02-05CH11231
  • Office of Scientific & Technical Information Report Number: 888972
  • Archival Resource Key: ark:/67531/metadc875118

Collections

This article is part of the following collection of related materials.

Office of Scientific & Technical Information Technical Reports

What responsibilities do I have when using this article?

When

Dates and time periods associated with this article.

Creation Date

  • July 15, 2005

Added to The UNT Digital Library

  • Sept. 21, 2016, 2:29 a.m.

Description Last Updated

  • Sept. 30, 2016, 2:31 p.m.

Usage Statistics

When was this article last used?

Yesterday: 0
Past 30 days: 0
Total Uses: 1

Interact With This Article

Here are some suggestions for what to do next.

Start Reading

PDF Version Also Available for Download.

Citations, Rights, Re-Use

Kennedy, B. Mack & van Soest, Matthijs C. Regional and Local Trends in helium isotopes, basin and rangeprovince, western North America: Evidence for deep permeablepathways, article, July 15, 2005; Berkeley, California. (digital.library.unt.edu/ark:/67531/metadc875118/: accessed August 19, 2017), University of North Texas Libraries, Digital Library, digital.library.unt.edu; crediting UNT Libraries Government Documents Department.