Overturned mega boulders on coastal cliff-tops and in bedrock river channels : can cosmogenic nuclides constrain tsunami and palaeo-flood

Simple item page
dc.contributor.authorFink, Den_AU
dc.contributor.authorFujioka, Ten_AU
dc.contributor.authorMifsud, Cen_AU
dc.contributor.authorNanson, GCen_AU
dc.contributor.authorFelton, Aen_AU
dc.date.accessioned2012-05-16T05:50:31Zen_AU
dc.date.available2012-05-16T05:50:31Zen_AU
dc.date.issued2011-03-23en_AU
dc.date.statistics2012-05-16en_AU
dc.description.abstractJacks Waterhole at the Durack River in the Kimberley region of north west Australia is an exposed bedrock paleo-channel, excavated by hydraulic plucking of well-jointed bedrock. This section of the channel consist of arc-shaped disconnected stacks of imbricated meter-sized slabs dislodged from bedrock steps immediately upstream of the boulder-filled channel. The semi-arid climate is punctuated by summer tropical storms/cyclones causing occasional violent floods. High magnitude floods with high flow velocities are required to erode and transport such large rock slabs. Along the south-eastern Australian coastline, at Little Beecroft Head, large detached sandstone boulders are found unconformably on horizontal cliff top escarpments and benches of identical lithology some 20-35 meters above present day sea-level. For some boulders, local stratigraphy indicates transport from the nearby cliff face, implicating tsunami or exceptional storm events. In other cases, an interpretation of differential erodibility along bedding strata, slow emergence and preservation from the contemporary platform is applicable. For both locations, detailed geomorphic mapping, cross-bedding orientation and tracing from the identified detachment site clearly indicates that boulders have experienced at least one flipping event. Consequently, previously buried surfaces are instantaneously exposed to an enhanced production rate of cosmogenic nuclides. The possibility of dating the ‘flipping’ event depends largely on a comparison of measured cosmogenic concentrations from 4 surfaces (upper and lower boulder, shielded and exposed bedrock) to that predicted on the boulder as a function of boulder thickness. In this paper, we describe our model and its sensitivity to boulder thickness, inheritance and postflipping time. Preliminary results of 10Be and 26Al analysis from flipped and non-flipped boulders at Jack’s Waterhole and Little Beecroft Head are given.Copyright (c) 2011 AMS12.en_AU
dc.identifier.citationFink, D., Fujioka, T., Mifsud, C., Nanson, G., & Felton, A. (2011). Overturned mega boulders on coastal cliff-tops and in bedrock river channels: can cosmogenic nuclides constrain tsunami and palaeo-flood? Presentation to the 12th International Conference on Accelerator Mass Spectrometry (AMS 12), 20th - 25th March 2011. Museum of New Zealand: Te Papa Tongarewa, Wellington, New Zealand, (pp. 143).en_AU
dc.identifier.conferenceenddate25 March 2011en_AU
dc.identifier.conferencename12th International Conference on Accelerator Mass Spectrometry (AMS 12)en_AU
dc.identifier.conferenceplaceWellington, New Zealanden_AU
dc.identifier.conferencestartdate20 March 2011en_AU
dc.identifier.govdoc4386en_AU
dc.identifier.pagination143en_AU
dc.identifier.urihttp://www.gns.cri.nz/ams12/en_AU
dc.identifier.urihttp://apo.ansto.gov.au/dspace/handle/10238/4254en_AU
dc.language.isoenen_AU
dc.publisher12th International Conference on Accelerator Mass Spectrometry (AMS-12)en_AU
dc.subjectAustraliaen_AU
dc.subjectTsunamisen_AU
dc.subjectIsotopesen_AU
dc.subjectRock bedsen_AU
dc.subjectFloodsen_AU
dc.subjectHydraulicsen_AU
dc.titleOverturned mega boulders on coastal cliff-tops and in bedrock river channels : can cosmogenic nuclides constrain tsunami and palaeo-flooden_AU
dc.typeConference Abstracten_AU
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
AMS-12_Abstracts_Book_Final(5).pdf
Size:
5.14 MB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.63 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Conference Publications