Evidence for aeolian origins of heuweltjies from buried gravel layers

Simple item page
dc.contributor.authorCRAMER, MICHAEL D
dc.contributor.authorvon Holdt, Johanna
dc.contributor.authorKhomo, Lesego
dc.contributor.authorMidgley, Jeremy J
dc.date.accessioned2021-10-08T07:16:12Z
dc.date.available2021-10-08T07:16:12Z
dc.date.issued2016
dc.description.abstractAbstract Although heuweltjies (19–32 m diameter) dominate the surface of much of the southwestern Cape of South Africa, their origins, distribution and age remain controversial. Current hypotheses are that the heuweltjies are (1) constructed by the excavation and mounding habits of burrowing animals; (2) the result of erosion by water of areas between patches protected from fluvial action by denser vegetation or (3) the product of localised aeolian sediment accumulation beneath denser vegetation associated with termitaria. At a site where quartz-containing gravels occur on the soil surface in areas between heuweltjies, these gravels were found to extend as a relatively intact layer of uniform concentration from the inter-mound area into the mound at the same plane as the surrounding soil surface. This buried layer suggests that heuweltjies were either built-up by deposition on a previous soil surface layer or eroded from sediment accumulated above the buried gravel layer. Mounds contain a relatively large proportion of silt consistent with sediment deposition. Mound sediment elemental composition was strongly correlated with that of local shale, indicating a local source of sediment. Pedogenesis was considerably more advanced off- than on-mound. There was no evidence of extensive regional aeolian sediment mantling over the vast area in which the heuweltjies occur. These findings and observations support the aeolian deposition hypothesis of heuweltjie origins combined with a degree of erosion, rather than a termite bioturbation hypothesis or a predominantly erosion-based hypothesis.
dc.identifier.apacitationCRAMER, M. D., von Holdt, J., Khomo, L., & Midgley, J. J. (2016). Evidence for aeolian origins of heuweltjies from buried gravel layers. <i>South African Journal of Science</i>, Volume 112(Number 1/2), 174 - 177. http://hdl.handle.net/11427/34792en_ZA
dc.identifier.chicagocitationCRAMER, MICHAEL D, Johanna von Holdt, Lesego Khomo, and Jeremy J Midgley "Evidence for aeolian origins of heuweltjies from buried gravel layers." <i>South African Journal of Science</i> Volume 112, Number 1/2. (2016): 174 - 177. http://hdl.handle.net/11427/34792en_ZA
dc.identifier.citationCRAMER, M.D., von Holdt, J., Khomo, L. & Midgley, J.J. 2016. Evidence for aeolian origins of heuweltjies from buried gravel layers. <i>South African Journal of Science.</i> Volume 112(Number 1/2):174 - 177. http://hdl.handle.net/11427/34792en_ZA
dc.identifier.issn0038-2353
dc.identifier.issn1996-7489
dc.identifier.ris TY - Journal Article AU - CRAMER, MICHAEL D AU - von Holdt, Johanna AU - Khomo, Lesego AU - Midgley, Jeremy J AB - Abstract Although heuweltjies (19–32 m diameter) dominate the surface of much of the southwestern Cape of South Africa, their origins, distribution and age remain controversial. Current hypotheses are that the heuweltjies are (1) constructed by the excavation and mounding habits of burrowing animals; (2) the result of erosion by water of areas between patches protected from fluvial action by denser vegetation or (3) the product of localised aeolian sediment accumulation beneath denser vegetation associated with termitaria. At a site where quartz-containing gravels occur on the soil surface in areas between heuweltjies, these gravels were found to extend as a relatively intact layer of uniform concentration from the inter-mound area into the mound at the same plane as the surrounding soil surface. This buried layer suggests that heuweltjies were either built-up by deposition on a previous soil surface layer or eroded from sediment accumulated above the buried gravel layer. Mounds contain a relatively large proportion of silt consistent with sediment deposition. Mound sediment elemental composition was strongly correlated with that of local shale, indicating a local source of sediment. Pedogenesis was considerably more advanced off- than on-mound. There was no evidence of extensive regional aeolian sediment mantling over the vast area in which the heuweltjies occur. These findings and observations support the aeolian deposition hypothesis of heuweltjie origins combined with a degree of erosion, rather than a termite bioturbation hypothesis or a predominantly erosion-based hypothesis. DA - 2016 DB - OpenUCT DP - University of Cape Town IS - Number 1/2 J1 - South African Journal of Science LK - https://open.uct.ac.za PY - 2016 SM - 0038-2353 SM - 1996-7489 T1 - Evidence for aeolian origins of heuweltjies from buried gravel layers TI - Evidence for aeolian origins of heuweltjies from buried gravel layers UR - http://hdl.handle.net/11427/34792 ER - en_ZA
dc.identifier.urihttp://hdl.handle.net/11427/34792
dc.identifier.vancouvercitationCRAMER MD, von Holdt J, Khomo L, Midgley JJ. Evidence for aeolian origins of heuweltjies from buried gravel layers. South African Journal of Science. 2016;Volume 112(Number 1/2):174 - 177. http://hdl.handle.net/11427/34792.en_ZA
dc.language.isoeng
dc.publisher.departmentDepartment of Biological Sciences
dc.publisher.facultyFaculty of Science
dc.sourceSouth African Journal of Science
dc.source.journalissueNumber 1/2
dc.source.journalvolumeVolume 112
dc.source.pagination174 - 177
dc.source.urihttps://dx.doi.org/10.17159/sajs.2016/20150025
dc.subject.othermima-mounds
dc.subject.othertermite
dc.subject.othererosion
dc.subject.othervegetation pattern
dc.subject.othercalcrete
dc.titleEvidence for aeolian origins of heuweltjies from buried gravel layers
dc.typeJournal Article
uct.type.publicationResearch
uct.type.resourceJournal Article
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
CRAMERMICHAELD_Evidence_for_ae_2016.pdf
Size:
2.86 MB
Format:
Adobe Portable Document Format
Description:
Download
Collections
Journal Articles