Interpretation of discordant 40Ar/39Ar age-spectra of mesozoic tholeiites from antarctica

Fleck, Robert J.; Sutter, John F.; Elliot, David H.

doi:10.1016/0016-7037(77)90184-3

Cited by 605 publications

(245 citation statements)

References 28 publications

Supporting

Mentioning

228

Contrasting

Unclassified

Order By: Relevance

“…The older age obtained for the hightemperature step may represent a small amount of excess argon (e.g., contained in olivine/pyroxene phenocrysts or disaggregated xenoliths) although the low amount of Ar released and occurrence in only one step make this possibility difficult to evaluate. All samples confirm with the plateau definitions of Fleck et al (1977) and McDougall & Harrison (1999), namely three or more contiguous steps that represent more than 50% of the 39 Ar released that overlap within 95% confidence.…”

Section: Resultssupporting

confidence: 81%

Holocene-Neogene volcanism in northeastern Australia: Chronology and eruption history

Cohen

Mark

Fallon

et al. 2017

Quaternary Geochronology

View full text Add to dashboard Cite

Quaternary and late Neogene volcanism is widespread in northeastern Australia, producing at least 397 eruptions covering more than 20,000 km 2 , including at least 20 flows over 50 km long. Despite this abundance of young volcanism, before this study numerous eruptions had tentative ages or were undated, and the area requires a comprehensive evaluation of eruption patterns through time. To help address these issues we applied multi-collector ARGUS-V 40 Ar/ 39 Ar geochronology to determine the age of four of the younger extensive flows: Undara (160 km long, 189 ± 4/4 ka; 2σ, with full analytical/external uncertainties), Murronga (40 km long, 153 ± 5/5 ka), Toomba (120 km long, 21 ± 3/3 ka), and Kinrara (55 km long, 7 ± 2/2 ka). Verbal traditions of the Gugu Badhun Aboriginal people contain features that may potentially describe the eruption of Kinrara. If the traditions do record this eruption, they would have been passed down for 230 ± 70 generations -a period of time exceeding the earliest written historical records. To further examine north Queensland volcanism through time we compiled a database of 337 ages, including 179 previously unpublished K-Ar and radiocarbon results. The compiled ages demonstrate that volcanic activity has occurred without major time breaks since at least 9 Ma. The greatest frequency of eruptions occurred in the last 2 Ma, with an average recurrence interval of <10-22 ka between eruptions. Activity was at at times likely more frequent than these calculations indicate, as the geochronologic dataset is incomplete, with undated eruptions, and intraplate volcanism is often episodic. The duration, frequency, and youthfulness of activity indicate that north Queensland volcanism should be considered as potentially still active, and there are now two confirmed areas of Holocene volcanism in eastern Australia -one at each end of the continent. More broadly, our data provides another example of 40 Ar/ 39 Ar geochronology applied to Holocene and latest Pleistocene mafic eruptions, further demonstrating that this method has the ability to examine eruptions and hazards at the youngest volcanoes on Earth.

show abstract

Section: Resultssupporting

confidence: 81%

Holocene-Neogene volcanism in northeastern Australia: Chronology and eruption history

Cohen

Mark

Fallon

et al. 2017

Quaternary Geochronology

View full text Add to dashboard Cite

show abstract

“…Ar-Ar датирование проведено в Институте гео-логии и минералогии СО РАН (г. Новосибирск) по биотиту по методике, изложенной в работе [Travin et al, 2009]. При расчете 39 Ar/ 40 Ar возраста по плато использовались критерии [Fleck et al, 1977].…”

Section: методы исследованийunclassified

Numerical modeling of the development of small-scale magmatic emulsions by Korteweg stress driven flow

Valentini

Moore

2009

Journal of Volcanology and Geothermal Research

View full text Add to dashboard Cite

Our study of aplite dykes cross-cutting the Oshurkov basite massif revealed drop-shaped inclusions of the monzonite composition. These are crystallized drops of basite melts, which show traces of the interaction with the host acidic melt. The Ar-Ar method was applied to determine the age of the aplites (114.9 Ma for biotite) and the monzonite inclusions (123.3 Ma for amphibole). Геологический институт СО РАН, Улан-Удэ, РоссияАннотация: Статья посвящена вещественному исследованию даек аплитов, секущих Ошурковский базито-вый массив. В нескольких телах аплитов обнаружены каплевидные включения монцонитового состава. Уста-новлено, что они являются закристаллизованными каплями базитового расплава и имеют следы взаимодей-ствия с вмещающим кислым расплавом. Ar-Ar методом определен возраст аплитов (по биотиту -114.9 млн лет) и монцонитовых включений (по амфиболу -123.3 млн лет).

show abstract

“…No analytical precision is calculated for total gas ages. Plateau ages were determined using the definition of Fleck et al (1977) as modified by Haugerud and Kunk (1988). Average ages are calculated in the same manner as a plateau age but fail the definition of Fleck et (1977).…”

Section: Isotopic Data Reductionmentioning

confidence: 99%

“…Plateau ages were determined using the definition of Fleck et al (1977) as modified by Haugerud and Kunk (1988). Average ages are calculated in the same manner as a plateau age but fail the definition of Fleck et (1977). Inverse isotope correlation analysis of the analytical data to assess if non-atmospheric argon components were trapped in any samples and to calculate an inverse isochron age was done using the method of York (1969).…”

Section: Isotopic Data Reductionmentioning

confidence: 99%

40Ar/39Ar dating studies of minerals and rocks in various areas in Mexico : USGS/CRM scientific collaboration. Part 1

Iriondo¹,

Kunk²,

Winick³

2003

Open-File Report

View full text Add to dashboard Cite

Interpretation of discordant 40Ar/39Ar age-spectra of mesozoic tholeiites from antarctica

Cited by 605 publications

References 28 publications

Holocene-Neogene volcanism in northeastern Australia: Chronology and eruption history

Holocene-Neogene volcanism in northeastern Australia: Chronology and eruption history

Numerical modeling of the development of small-scale magmatic emulsions by Korteweg stress driven flow

40Ar/39Ar dating studies of minerals and rocks in various areas in Mexico : USGS/CRM scientific collaboration. Part 1

Contact Info

Product

Resources

About