Table 26.1 U-Pb and Re-Os geochronological constraints on Cryogenian glacial onsets and terminations
Paleocontinent
Age (Ma)
Method
a
Reference
Marinoan deglaciation/cap carbonate: 636.0–634.7 Ma
Laurentia
>632.3 ± 5.9
Re-Os
(63)
South China
635.2 ± 0.5
U-Pb ID-TIMS
(57)
Southern Australia
636.41 ± 0.45
U-Pb CA-ID-TIMS
(59)
Swakop
635.21 ± 0.59/0.61/0.92
U-Pb CA-ID-TIMS
(56, 83)
Marinoan glacial onset: 649.9–639.0 Ma
Congo
>639.29 ± 0.26/0.31/0.75
U-Pb CA-ID-TIMS
(83)
Southern Australia
<645.1 ± 4.3
Re-Os
(137)
South China
<654.2 ± 2.7
U-Pb SIMS
(134)
South China
<654.5 ± 3.8
U-Pb SIMS
(58)
Sturtian deglaciation/cap carbonate: 659.3–658.5 Ma
Southern Australia
>657.2 ± 2.4
Re-Os
(137)
Tuva-Mongol ia
659.0 ± 4.5
Re-Os
(63)
Southern Australia
<659.7 ± 5.3
U-Pb SIMS
(366)
Laurentia
662.4 ± 3.9
Re-Os
(60)
South China
>662.7 ± 6.2
U-Pb SIMS
(65)
Sturtian glacial onset: 717.5–716.3 Ma
Oman
>713.7 ± 0.5
U-Pb ID-TIMS
(365)
South China
<714.6 ± 5.2
U-Pb SIMS
(64)
South China
<715.9 ± 2.3
U-Pb SIMS
(62)
South China
<716.1 ± 3.4
U-Pb SIMS
(62)
Laurentia
>716.5 ± 0.2
U-Pb CA-ID-TIMS
(32)
Laurentia
<717.4 ± 0.1
U-Pb CA-ID-TIMs
(32)
Laurentia
<719.47 ± 0.29
U-Pb CA-ID-TIMS
(61)
Re-Os isochron ages from sedimentary organic matter. Errors are quoted at the 2r level of uncertainty. Where multiple uncertainties are given,
they represent analytical/analytical + tracer solution/analytical + tracer solution + decay-constant uncertainties
Ca chemical abrasion; ID6TIMS isotope-dilution and termal-ionization mass spectrometry; SIMS secondary-ion mass spectrometry
Table from Hoffman et al., Sci. Adv. (2017)
Fig. 26.1 The d
18 O of the
Precambrian ocean measured in
the cherts
344
Y. Goddéris et al.