Supplementary data to accompany Gernon, T.M., Hincks, T.K., Brune, S., Braun, J., Jones, S.M., Keir, D., Cunningham, A., & Glerum, A., Co-evolution of craton margins and interiors during continental breakup.

Supplementary data to accompany Gernon, T.M., Hincks, T.K., Brune, S., Braun, J., Jones, S.M., Keir, D., Cunningham, A., & Glerum, A., Co-evolution of craton margins and interiors during continental breakup. Nature (Accepted in Principle at time of writing, 3 June 2024).

Constraining thermochron uncertainty

We utilise published thermochron model data for 46 sites across southern Africa from Brown et al. (2002); Green et al. (2017); Kounov et al. (2013) and (2009); Stanley et al. (2020), (2015) and (2013); Tinker et al. (2008), and Wildman et al. (2017), (2016) and (2015). 

The above studies present model uncertainty in slightly different ways. However, we have attempted to provide equivalent estimates of uncertainty across the board in our analysis. 

Stanley and Flowers (2020) provide individual simulation runs for 15 sites, and we use these directly to estimate maximum temperature drop and associated timing for each simulation. For the 12 sites provided by Wildman et al. (2017, 2016, 2015), we use the best fit and 95 percentile envelope, and assume the 'good fit' envelopes of Kounov et al. (2009) to be broadly equivalent. For 15 sites (see MinMax.csv) we utilise the best fit curve together with an estimate of the minimum and maximum plausible timing of the point of maximum temperature drop.

Green et al. (2017) provides only a best fit curve, and in the absence of further data we cannot provide an uncertainty estimate here. 

Files provided

SourceData.csvSummary of each site, associated data source(s), coordinates and model uncertainty. Please see references listed within for complete thermochron model descriptions and original data.

MinMax.csvName/Location and references for thermochron source data for 15 sites with best fit curves, and estimates of the min/max time of maximum temperature drop.Tmin and Tmax (degrees C) are the minimum and maximum modelled temperatures for each location. t1_Ma and t2_Ma are the minimum and maximum times (Ma) where the model simulations (best, good or acceptable fit) reach the midpoint temperature Tmid= (Tmax -Tmin)/2The most likely timing is taken from the best fit curve. 

Files in Thermochron_bestfitBest fit thermochron curves (Age in Ma, and Temp in degrees C) for 31 sites digitized from the original publications. Names correspond to File Names in SourceData.csv, which also provides references.

Files in Thermochron_EnvelopesLower and Upper 95 percentile thermochron envelopes (denoted *_L95.csv or *_U95.csv) for 12 sites, digitized from Wildman et al. (2017, 2016, 2015).Lower and Upper good fit thermochron envelopes (denoted *_L.csv or *_U.csv) for three sites, digitized from Kounov et al. (2009)Age in Ma, and Temp in degrees C. Files in Stanley2020_model_runsIndividual model output directly from Stanley and Flowers 2020 for 15 sites (no modification of original published data). Note these files include modelled best fit curves.

If any of the thermochron model data/summaries given here are re-used, please cite the original source(s) as provided below.

Complete references

R. W. Brown, M. A. Summerfield, and A. J. W. Gleadow. Denudational history along a transect across the Drakensberg Escarpment of southern Africa derived from apatite fission track thermochronology. Journal of Geophysical Research: Solid Earth, 107(B12), 2002.

P. F. Green, I. R. Duddy, P. Japsen, J. M. Bonow, and J. A. Malan. Post-breakup burial and exhumation of the southern margin of Africa. Basin Research, 29(1):96–127, 2017.

A. Kounov, G. Viola, I. Dunkl, and H. E. Frimmel. Southern African perspectives on the long-term morpho-tectonic evolution of cratonic interiors. Tectonophysics, 601:177–191, 2013.

A. Kounov, G. Viola, M. deWit, and M. A. G. Andreoli. Denudation along the Atlantic passive margin: new insights from apatite fission-track analysis on the western coast of South Africa. Geological Society, London, Special Publications, 324(1):287–306, 2009.

J. R. Stanley and R. M. Flowers. Mesozoic denudation history of the lower Orange River and eastward migration of erosion across the southern African Plateau. Lithosphere, 12(1):74–87, 2020.

J. R. Stanley, R. M. Flowers, and D. R. Bell. Erosion patterns and mantle sources of topographic change across the southern African Plateau derived from the shallow and deep records of kimberlites. Geochemistry, Geophysics, Geosystems, 16(9):3235–3256, 2015.

J. R. Stanley, R. M. Flowers, and D. R. Bell. Kimberlite (U-Th)/He dating links surface erosion with lithospheric heating, thinning, andmetasomatism in the southern African Plateau. Geology, 41(12):1243–1246, 2013.

J. Tinker, M. de Wit, and R. Brown. Linking source and sink: Evaluating the balance between onshore erosion and offshore sediment accumulation since Gondwana break-up, South Africa. Tectonophysics, 455(1):94–103, 2008.

M. Wildman, R. Brown, C. Persano, R. Beucher, F. M. Stuart, V. Mackintosh, K. Gallagher, J. Schwanethal, and A. Carter. Contrasting Mesozoic evolution across the boundary between on and off craton regions of the South African plateau inferred from apatite fission track and (U-Th-Sm)/He thermochronology. Journal of Geophysical Research: Solid Earth, 122(2):1517–1547, 2017.

M. Wildman, R. Brown, R. Beucher, C. Persano, F. Stuart, K. Gallagher, J. Schwanethal, and A. Carter. The chronology and tectonic style of landscape evolution along the elevated Atlantic continental margin of South Africa resolved by joint apatite fission track and (U-Th-Sm)/He thermochronology. Tectonics, 35(3):511–545, 2016.

M. Wildman, R. Brown, R. Watkins, A. Carter, A. Gleadow, and M. A. Summerfield. Post break-up tectonic inversion across the southwestern cape of South Africa: New insights from apatite and zircon fission track thermochronometry. Tectonophysics, 654:30–55, 2015.