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Establishing a 14.6 ± 0.2 Ma age for the Nördlinger Ries impact (Germany)—A prime example for concordant isotopic ages from various dating materials
Author(s) -
BUCHNER Elmar,
SCHWARZ Winfried H.,
SCHMIEDER Martin,
TRIELOFF Mario
Publication year - 2010
Publication title -
meteoritics and planetary science
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.09
H-Index - 100
eISSN - 1945-5100
pISSN - 1086-9379
DOI - 10.1111/j.1945-5100.2010.01046.x
Subject(s) - geology , impact structure , biotite , impact crater , plateau (mathematics) , geochemistry , fission track dating , radiometric dating , lithology , mineralogy , zircon , paleontology , quartz , mathematics , mathematical analysis , physics , astronomy
– 40 Ar/ 39 Ar dating of recrystallized K‐feldspar melt particles separated from partially molten biotite granite in impact melt rocks from the approximately 24 km Nördlinger Ries crater (southern Germany) yielded a plateau age of 14.37 ± 0.30 (0.32) Ma (2σ). This new age for the Nördlinger Ries is the first age obtained from (1) monomineralic melt (2) separated from an impact‐metamorphosed target rock clast within (3) Ries melt rocks and therewith extends the extensive isotopic age data set for this long time studied impact structure. The new age goes very well with the 40 Ar/ 39 Ar step‐heating and laser probe dating results achieved from mixed‐glass samples (suevite glass and tektites) and is slightly younger than the previously obtained fission track and K/Ar and ages of about 15 Ma, as well as the K/Ar and 40 Ar/ 39 Ar age data obtained in the early 1990s. Taking all the 40 Ar/ 39 Ar age data obtained from Ries impact melt lithologies into account (data from the literature and this study), we suggest an age of 14.59 ± 0.20 Ma (2σ) as best value for the Ries impact event.