Datation par résonance de spin électronique (ESR) de carbonates marins quaternaires (Coraux et coquilles de mollusques) [ Electron spin resonance (ESR ) dating of quaternary marine carbonates (corals and mollusc shells).]

Quaternaire ◽  
1995 ◽  
Vol 6 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Jean Jacques Bahain ◽  
Yuji Yokoyama ◽  
Christophe Falguères ◽  
Roland Bibron
2018 ◽  
Vol 163 ◽  
pp. 142-151
Author(s):  
Dengfeng Qiu ◽  
Quanyou Liu ◽  
Jinbiao Yun ◽  
Zhijun Jin ◽  
Dongya Zhu ◽  
...  

1988 ◽  
Vol 25 (2) ◽  
pp. 235-245 ◽  
Author(s):  
Steve Zymela ◽  
Henry P. Schwarcz ◽  
Rainer Grün ◽  
A. MacS. Stalker ◽  
C. S. Churcher

Teeth collected from Pleistocene surficial sediments in southeastern Alberta and western Saskatchewan have been dated by electron spin resonance (ESR). The dates generally agree with the previously determined temporal sequence of the deposits, largely based on studies of fossil vertebrates and supplemented by some absolute ages, but the absolute ages of the oldest deposits appear to be much younger than previously estimated. Absolute ages (ESR) have been compared with faunal ages (using nomenclature of Stalker and Churcher): the age of Aftonian – early Kansan deposits at the Maser–Frisch site is 450 ± 30 ka; Kansan deposits in the Medicine Hat region range from 410 to 250 ka; Sangamon deposits at Mitchell Bluff are 67 ± 12 ka; middle Wisconsinan deposits at Empress, Alberta, are 34 ± 4 ka; postglacial beds near Medicine Hat give ages of 11 ± 2 ka (in agreement with 14C ages). At Wellsch Valley, however, ESR dates (280 ± 35 ka) are much younger than the age of about 1.5 Ma obtained from fauna, fission track, and paleomagnetics. This discrepancy may be due to late introduction of U into the teeth.


1988 ◽  
Vol 29 (3) ◽  
pp. 197-215 ◽  
Author(s):  
Ulrich Radtke ◽  
Rainer Grün ◽  
Henry P. Schwarcz

The reef tracts of Barbados have been investigated by electron spin resonance dating; all parameters necessary for ESR dating (including effective α-efficiency and thermal stability) were determined without cross checking with another independent dating method. In addition, some U-series analyses were carried out in order to test the reliability of ESR. In most cases, the results show a satisfactory agreement between ESR and both these and previously published U-series dates (M. L. Bender, R. G. Fairbanks, F. W. Taylor, R. K. Matthews, J. G. Goddard, and W. S. Broecker (1979). Geological Society of America. Bulletin 90 , 577–594). For the oldest samples, ESR dates tend to exceed He/U dates, suggesting that there might have been He loss from aragonite. Raised reef tracts are assigned to high sea stands from successive interglacial stages 5, 7, 9, 11, 13, and 15. ESR and U-series (230Th/234U) dates for corals and molluses in North Barbados do not support the suggestion of N. P. James ((1971). Unpublished Thesis, McGill University, Montreal) that this region has subsided during part of the past 125,000 yr. Whereas the experimentally determined mean life (τ) of trapped electrons is only 500,000 yr for the ambient temperature in Barbados, there is no evidence from the comparison between ESR and other dates for thermal fading. This emphasizes the difficulty of experimental measurement of τ.


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