skip to main content
US FlagAn official website of the United States government
dot gov icon
Official websites use .gov
A .gov website belongs to an official government organization in the United States.
https lock icon
Secure .gov websites use HTTPS
A lock ( lock ) or https:// means you've safely connected to the .gov website. Share sensitive information only on official, secure websites.

Explore Research Products in the PAR
It may take a few hours for recently added research products to appear in PAR search results.


  • NSF Public Access
  • Search Results
  • Paleomagnetism and40Ar/39Ar ages from volcanics extruded during the Matuyama and Brunhes Chrons near McMurdo Sound, Antarctica (Dataset)
Title: Paleomagnetism and40Ar/39Ar ages from volcanics extruded during the Matuyama and Brunhes Chrons near McMurdo Sound, Antarctica (Dataset)
Paleomagnetic, rock magnetic, or geomagnetic data found in the MagIC data repository from a paper titled: Paleomagnetism and40Ar/39Ar ages from volcanics extruded during the Matuyama and Brunhes Chrons near McMurdo Sound, Antarctica  more » « less
Award ID(s):
2126298
PAR ID:
10558631
Author(s) / Creator(s):
; ;
Publisher / Repository:
Magnetics Information Consortium (MagIC)
Date Published:
Subject(s) / Keyword(s):
Igneous Extrusive Lava Flow Basalt 55000 4470000 Years BP
Format(s):
Medium: X
Location:
(East Bound Longitude:169.38; North Bound Latitude:-78.4; South Bound Latitude:-77.46; West Bound Longitude:163.22); (Latitude:-77.46; Longitude:169.23); (Latitude:-77.47; Longitude:169.23); (Latitude:-77.51; Longitude:169.38); (Latitude:-77.55; Longitude:166.2); (Latitude:-77.55; Longitude:166.2); (Latitude:-77.57; Longitude:166.23); (Latitude:-77.57; Longitude:166.23); (Latitude:-77.58; Longitude:166.23); (Latitude:-77.64; Longitude:166.41); (Latitude:-77.64; Longitude:166.41); (Latitude:-77.83; Longitude:166.67); (Latitude:-77.84; Longitude:166.76); (Latitude:-77.84; Longitude:166.7); (Latitude:-77.85; Longitude:166.64); (Latitude:-77.85; Longitude:166.69); (Latitude:-77.86; Longitude:165.23); (Latitude:-77.88; Longitude:165.02); (Latitude:-77.8; Longitude:166.72); (Latitude:-77.8; Longitude:166.83); (Latitude:-77.8; Longitude:166.83); (Latitude:-78.21; Longitude:166.49); (Latitude:-78.21; Longitude:166.57); (Latitude:-78.24; Longitude:163.36); (Latitude:-78.24; Longitude:163.36); (Latitude:-78.25; Longitude:163.22); (Latitude:-78.29; Longitude:164.73); (Latitude:-78.2; Longitude:166.54); (Latitude:-78.31; Longitude:164.8); (Latitude:-78.34; Longitude:164.28); (Latitude:-78.34; Longitude:164.87); (Latitude:-78.36; Longitude:164.26); (Latitude:-78.36; Longitude:164.3); (Latitude:-78.37; Longitude:164.12); (Latitude:-78.37; Longitude:164.24); (Latitude:-78.38; Longitude:164.34); (Latitude:-78.38; Longitude:164.34); (Latitude:-78.39; Longitude:164.12); (Latitude:-78.39; Longitude:164.21); (Latitude:-78.39; Longitude:164.21); (Latitude:-78.39; Longitude:164.23); (Latitude:-78.39; Longitude:164.27); (Latitude:-78.39; Longitude:164.27); (Latitude:-78.39; Longitude:164.2); (Latitude:-78.4; Longitude:164.21); (Latitude:-78.4; Longitude:164.27); (Latitude:-78.4; Longitude:164.27)
Right(s):
Creative Commons Attribution 4.0 International
Institution:
Paleomagnetic Lab Scripps Institution Of Oceanography, UCSD, USA
Sponsoring Org:
National Science Foundation
More Like this
  1. ; ; ; ; ; ; ; ; ; ; et al (, EPJ Web of Conferences)
    Mattoon, C.M.; Vogt, R.; Escher, J.; Thompson, I. (Ed.)
    The cross-section of the thermal neutron capture41Ar(n,γ)42Ar(t1/2=32.9 y) reaction was measured by irradiating a40Ar sample at the high-flux reactor of Institut Laue-Langevin (ILL) Grenoble, France. The signature of the two-neutron capture has been observed by measuring the growth curve and identifying the 1524.6 keV γ-lines of the shorter-lived42K(12.4 h) β−daughter of42Ar. Our preliminary value of the41Ar(n,γ)42Ar thermal cross section is 240(80) mb at 25.3 meV. For the first time, direct counting of42Ar was performed using the ultra-high sensitivity technique of noble gas accelerator mass spectrometry (NOGAMS) at Argonne National Laboratory, USA. 
    more » « less
  2. ; ; ; ; (, Geophysical Research Letters)
    Abstract We report40Ar‐39Ar step‐heating ages of Paleocene‐Eocene (P‐E) boundary impact spherules from Atlantic Margin coastal plain and open ocean sites. We test the hypothesis that the P‐E spherules are reworked from an earlier event (e.g., K‐Pg impact at ~66 Ma), which predicts a cooling age discordant from their depositional age of 55.93 ± 0.05 Ma at the P‐E boundary. Isochrons from the step‐heating analysis yield40Ar‐36Ar intercepts in excess of the modern in most cases, indicating that the spherules have excess radiogenic Ar (40Ar*), typical of impact glasses incompletely degassed before solidification. The weighted mean of the isochron‐corrected plateau age is 54.2 ± 2.5 Ma (1σ), and their isochron age is 55.4 ± 4.0 Ma, both indistinguishable from their P‐E depositional age, not supporting the K‐Pg reworking hypothesis. This is consistent with all other stratigraphic and geochemical evidence for an impact at the P‐E boundary and ejecta distribution by air fall. 
    more » « less
  3. ; (, The Astrophysical Journal)
    Abstract We calculate cross sections for fine-structure transitions of Ne+, Ar+, Ne2+, and Ar2+in collisions with atomic hydrogen by using quantum-mechanical methods. Relaxation rate coefficients are calculated for temperatures up to 10,000 K. The temperature-dependent critical densities for the relaxation of Ne+, Ar+, Ne2+, and Ar2+in collisions with H have been determined and compared to the critical densities for collisions with electrons. The present calculations will be useful for studies utilizing the infrared lines [Neii] 12.8, [Neiii] 15.6, [Neiii] 36.0, [Arii] 6.99, [Ariii] 8.99, and [Ariii] 21.8μm as diagnostics of, for example, planetary nebulae and star formation. 
    more » « less
  4. ; ; ; ; ; ; (, Geological Society, London, Special Publications)
    Abstract Improvements in analytical procedures in parallel with intercalibration of40Ar/39Ar and U–Pb methods and laboratories, spurred since 2003 by the EarthTime geochronology community initiative, have led to ±2σuncertainties of the order of 50–100 ka, or better, for Cretaceous ash beds. Assembled here are 5740Ar/39Ar ages and 17238U–206Pb ages of volcanic ash beds in strata of the Western Interior Basin of North America determined during the last 15 years since these improvements have been made. These age determinations span from 108 Ma in the middle Albian to 66 Ma in the latest Maastrichtian. Five of the40Ar/39Ar ages from Campanian and Maastrichtian strata are newly reported here, whereas the remainder are from the literature. Building on the pioneering work of John Obradovich and Bill Cobban, where possible these age determinations are tied to ammonite and inoceramid biostratigraphy. For most ash beds, the temporal uncertainties, unlike earlier timescales for the Western Interior Basin, are much shorter than the duration of fossil biozones. Proposed ages for stage boundaries based on this review of the radioisotopic ages include: Maastrichtian–Danian, 66.02 ± 0.08 Ma; Campanian–Maastrichtian, 72.20 ± 0.20 Ma; Santonian–Campanian, 84.19 ± 0.38 Ma; Coniacian–Santonian, 86.49 ± 0.44 Ma; Turonian–Coniacian, 89.75 ± 0.38 Ma; Cenomanian–Turonian, 93.95 ± 0.05 Ma; Albian–Cenomanian, 100.00 ± 0.40 Ma. Six bentonites that occur within theVascoceras diartianum, Neocardiocerus juddi, Prionocylus macombi, Scaphites preventricosus, Scaphites depressusandDesmoscaphites bassleriammonite zones, dated using both40Ar/39Ar and U–Pb methods, yield ages in agreement to within 150 ka and form the backbone of the Western Interior Basin timescale. In parallel, improvements in the taxonomy of ammonites, inoceramids and foraminifera, and recent field work, are better establishing the biostratigraphic framework for these age determinations. Each of these efforts contributes to the progressive refinement of the chronostratigraphic framework of the Western Interior Basin, and enhances its utility for global correlation. 
    more » « less
  5. ; ; ; (, The Planetary Science Journal)
    Abstract The bulk of Uranus consists of a rock–ice core, but the relative proportions of rock and ice are unknown. Radioactive decay of potassium in the silicates produces40Ar. If transport of argon from the core to the gaseous envelope is efficient, a measurement of40Ar in the envelope will provide a direct constraint on the rock mass present (assuming a chondritic rock composition). The expected40Ar concentrations in this case would be readily detectable by a mass spectrometer carried by a future atmospheric probe. For a given envelope concentration there is a trade-off between the rock mass present and the transport efficiency; this degeneracy could be overcome by making independent determinations of the rock mass (e.g., by gravity and seismology). Primordial40Ar is a potential confounding factor, especially if Ar/H2is significantly enhanced above solar or if degassing of radiogenic40Ar were inefficient. Unfortunately, the primordial40Ar/36Ar ratio is very uncertain; better constraints on this ratio through measurement or theory would be very helpful. Pollution of the envelope by silicates is another confounding factor but can be overcome by a measurement of the alkali metals in the envelope. 
    more » « less
  • Citation Formats
  • MLA
  • APA
  • Chicago
  • BibTeX
  • Save / Share this Record
  • Send to Email