Flood-flipped boulders: in-situ cosmogenic nuclide modeling of flood deposits in the monsoon tropics of Australia

Simple item page
dc.contributor.authorFujioka, Ten_AU
dc.contributor.authorFink, Den_AU
dc.contributor.authorNanson, GCen_AU
dc.contributor.authorMifsud, Cen_AU
dc.contributor.authorWende, Ren_AU
dc.date.accessioned2015-09-11T05:59:45Zen_AU
dc.date.available2015-09-11T05:59:45Zen_AU
dc.date.issued2014-12-04en_AU
dc.date.statistics2015-09-04en_AU
dc.description.abstractDuring the Quaternary, extreme floods along the Durack River, in the Kimberley, northern Australia, dislodged, transported, and stacked massive meter-sized boulders from the underlying bedrock channel floor. Field evidence identified a population of the boulders to have been overturned after detachment. We measured in situ cosmogenic 10Be and 26Al concentrations in six imbricated boulders to constrain the timing of flood events. We present a simple numerical model that simultaneously solves the expressions for the predicted nuclide concentrations from the exposed and hidden surfaces of a flipped boulder to calculate the time since it was overturned. The ability of the model to unequivocally discern whether a boulder was overturned depends on boulder thickness and the site-specific steady-state erosion rate. Of the six boulders sampled, our model successfully determined four finite flip ages, whereas the other two boulders indicated steady state and were either not flipped or flipped sufficiently long ago for the nuclide profile to have returned to steady state. While the two older model ages (ca. 150 ka and ca. 260 ka) are strongly sensitive to assumptions made for the local erosion rate correction, the two younger flip ages, 5.6 ± 1.0 ka and 10.3 ± 1.9 ka, are robust against such corrections. Early to mid-Holocene major floods have been recorded in other parts of northern Australia. We suggest that similar Holocene floods occurred in the Kimberley and that such extreme events may have been widespread in northern Australia in the late Quaternary. Our boulder-flip model can be applicable to similar deposits associated with other extreme events such as paleo-tsunamis. © 2014, Geological Society of America.en_AU
dc.identifier.citationFujioka, T., Fink, D., Nanson, G., Mifsud, C., & Wende, R. (2015). Flood-flipped boulders: In-situ cosmogenic nuclide modeling of flood deposits in the monsoon tropics of Australia. Geology, 43(1), 43-46. doi:10.1130/G35856.1en_AU
dc.identifier.govdoc6001en_AU
dc.identifier.issn0091-7613en_AU
dc.identifier.issue1en_AU
dc.identifier.journaltitleGeologyen_AU
dc.identifier.pagination43-46en_AU
dc.identifier.urihttp://dx.doi.org/10.1130/G35856.1en_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/6198en_AU
dc.identifier.volume43en_AU
dc.language.isoenen_AU
dc.publisherGeological Society of Americaen_AU
dc.subjectGeologic depositsen_AU
dc.subjectNumerical solutionen_AU
dc.subjectFloodsen_AU
dc.subjectTropical regionsen_AU
dc.subjectAustraliaen_AU
dc.subjectErosionen_AU
dc.titleFlood-flipped boulders: in-situ cosmogenic nuclide modeling of flood deposits in the monsoon tropics of Australiaen_AU
dc.typeJournal Articleen_AU
Files
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.71 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Journal Articles