1) La descarga del recurso depende de la página de origen
2) Para poder descargar el recurso, es necesario ser usuario registrado en Universia


Opción 1: Descargar recurso

Detalles del recurso

Descripción

Stable cosmogenic isotopes such as ^3He and ^(21)Ne are useful for dating of diverse lithologies, quantifying erosion rates and ages of ancient surfaces and sediments, and for assessing complex burial histories. Although many minerals are potentially suitable targets for ^3He and ^(21)Ne dating, complex production systematics require calibration of each mineral–isotope pair. We present new results from a drill core in a high-elevation ignimbrite surface, which demonstrates that cosmogenic ^3He and ^(21)Ne can be readily measured in biotite and hornblende. ^(21)Ne production rates in hornblende and biotite are similar, and are higher than that in quartz due to production from light elements such as Mg and Al. We measure ^(21)Ne_(hbl)/^(21)Ne_(qtz) = 1.35 ± 0.03 and ^(21)Ne_(bio)/^(21)Ne_(qtz) = 1.3 ± 0.02, which yield production rates of 25.6 ± 3.0 and 24.7 ± 2.9 at g^(−1) yr^(−1) relative to a ^(21)Ne_(qtz) production rate of 19.0 ± 1.8 at g^(−1) yr^(−1). We show that nucleogenic ^(21)Ne concentrations produced via the reaction ^(18)O(α,n)^(21)Ne are manageably small in this setting, and we present a new approach to deconvolve nucleogenic ^(21)Ne by comparison to nucleogenic ^(22)Ne produced from the reaction ^(19)F(α,n)^(22)Ne in F-rich phases such as biotite. Our results show that hornblende is a suitable target phase for cosmogenic ^3He dating, but that ^3He is lost from biotite at Earth surface temperatures. Comparison of ^3He concentrations in hornblende with previously measured mineral phases such as apatite and zircon provides unambiguous evidence for ^3He production via the reaction ^6Li(n,α)^3H → ^3He. Due to the atypically high Li content in the hornblende (~ 160 ppm) we estimate that Li-produced ^3He represents ~ 40% of total ^3He production in our samples, and must be considered on a sample-specific basis if 3He dating in hornblende is to be widely implemented.

Pertenece a

Caltech Authors  

Autor(es)

Amidon, William H. -  Farley, Kenneth A. - 

Id.: 55202810

Versión: 1.0

Estado: Final

Tipo de recurso: Article  -  PeerReviewed  - 

Tipo de Interactividad: Expositivo

Nivel de Interactividad: muy bajo

Audiencia: Estudiante  -  Profesor  -  Autor  - 

Estructura: Atomic

Coste: no

Copyright: sí

Requerimientos técnicos:  Browser: Any - 

Relación: [References] http://resolver.caltech.edu/CaltechAUTHORS:20120416-090156503
[References] http://authors.library.caltech.edu/30094/

Fecha de contribución: 24-ago-2016

Contacto:

Localización:

Otros recursos del mismo autor(es)

  1. Response to comment on “A reporting protocol for thermochronologic modeling illustrated with data from the Grand Canyon” We suggested a reporting protocol for thermochronologic modeling with which to arrange and explain t...
  2. Eocene activity on the Western Sierra Fault System and its role incising Kings Canyon, California Combining new and published apatite (U–Th)/He and apatite ^4He/^3He data from along the Kings River ...
  3. A reporting protocol for thermochronologic modeling illustrated with data from the Grand Canyon Apatite (U–Th)/He and fission-track dates, as well as ^4He/^3He and fission-track length data, provi...
  4. Evidence for indigenous nitrogen in sedimentary and aeolian deposits from the Curiosity rover investigations at Gale crater, Mars We present data supporting the presence of an indigenous source of fixed nitrogen on the surface of ...
  5. Combined ^(40)Ar/^(39)Ar and (U–Th)/He geochronological constraints on long-term landscape evolution of the Second Paraná Plateau and its ruiniform surface features, Paraná, Brazil Regional correlation of dated weathered land surfaces provides the necessary constraints to test lon...

Otros recursos de la misma colección

  1. A Tight Relation between N/O Ratio and Galaxy Stellar Mass Can Explain the Evolution of Strong Emission Line Ratios with Redshift The offset of high-redshift star-forming galaxies in the [O III]/Hβ versus [N II]/Hα (O3N2) diagram ...
  2. Enabling high confidence detections of gravitational-wave bursts Extracting astrophysical information from gravitational-wave detections is a well-posed problem and ...
  3. Metalloproteins : theory, calculations, and experiments Preface: Metalloproteins play essential critical functional roles in enzymatically catalyzing reacti...
  4. Systematic U(1)_(B-L) extensions of loop-induced neutrino mass models with dark matter We study the gauged U(1)_(B–L) extensions of the models for neutrino masses and dark matter. In this...
  5. High-resolution and simultaneous measurement along the depth direction using virtual phase conjugation for optical tomography To improve the measurement speed of optical tomography based on the virtual phase conjugation, a vir...

Aviso de cookies: Usamos cookies propias y de terceros para mejorar nuestros servicios, para análisis estadístico y para mostrarle publicidad. Si continua navegando consideramos que acepta su uso en los términos establecidos en la Política de cookies.