page_title: Giant current ripples
section_title: New hypotheses of the origin of the giant current ripple marks
hierarchical_section_title: Giant current ripples / History of the research / New hypotheses of the origin of the giant current ripple marks
caption_attribution_description: English: Giant current ripples on the left bank of Katun River, Altai Русский: Гигантская рябь течения на левом берегу р. Катунь, в районе с. Платово, Алтай
context_page_description: Giant current ripples are active channel topographic forms up to 20 m high, which develop within near-talweg areas of the main outflow valleys created by glacial lake outburst floods. Giant current ripple marks are morphologic and genetic macroanalogues of small current ripples formed in sandy stream sediments.
  The giant current ripple marks are important depositional forms in diluvial plain and mountain scablands.
context_section_description: The notice made by G.F. Lungershausen and O.A. Rakovets about the diluvial origin of giant ripple marks in Kuray was denied by E.V. Deviatkin, who referred to an oral conclusion made by E.V. Shantser and wrote that the large ripple marks in Kuray Basin were results of heavy erosional processing of a huge fluvioglacial fan. M.V. Petkevich expressed a similar opinion in her candidate thesis. She believed that the ridged relief on the right bank of the Tetio River in Kuray Basin was a washed proluvial fan.
  Every single diagnostic sign of the giant ripples given in the corresponding section contradict this theory, especially the cross-layered texture of the sediments in the ripple marks which correlates with their morphology and the regular asymmetry of their slopes at all the locations. The petrography composition of the coarse-fragmental material in the ripple marks witnesses also against this hypothesis, it is alien to the bed rock of the basins of the Tetio and the Aktru rivers.
  In addition, G.G. Rusanov found malachite, axinite, sillimanite and cinnabar in the schlichs of the ripple marks in Kuray Basin, which are characteristic of the Kuray Ridge but not found in the schlichs of the end moraines of the Tetio River, the latter adjoining the fields of the giant ripples. Cinnabar is a heavy, fragile and quickly worn mineral. That is why, as G.G. Rusanov remarks, it cannot be carried away from its original source farther than over first hundreds of metres. Over longer distances this mineral can be transported only in suspension state. At the same time, galena, which is very characteristic of the moraines of the Tetio and the Aktru Valleys, is not found in the ripple sediments. Hence, pebble deposits adjoining the end moraines of the Tetio cannot be fluvioglacial or proluvial formations of the meltwater from the glaciers of the Aktru and the Tetio.
  At that time P.A. Okishev flatly disagreed with his predecessors and contemporaries. He argued that the proofs of the erosional extension of a vast fluvioglacial fan here (in Kuray Basin) are unconvincing. In 1970 P.A. Okishev put forward the idea that the giant current ripple marks in Kuray depression are "inversional formations". "The ridges presently expressed in the relief used to accumulate as channel sediments within above-glacial floods of a vast flat glacial field and projected afterwards onto the substratum" (, p. 49).
  A. N. Rudoy shall point out in this quotation that 1) P.A. Okishev simply described, though superficially, the mechanism of the eskers, and 2) he emphasised the fluvial, channel origin of the ridges proceeding from their material composition and morphology.
  This investigator developed his theory later in his book and his doctoral thesis (1984), but practically at the same time he put forward another hypothesis, a "glacial" one, without explaining anything or mentioning the "inversional relief". P.A. Okishev wrote that the giant current ripples in Kuray Basin are "bedded, small-ridged, poly-ridged" moraines. The "inversional relief" was forgotten by the author for ever and has never been mentioned again.
  This author's unclear explanations of the essence of his second "moraine" hypothesis (he would have a third one as well) may be regarded in general as an attempt "to introduce something new" into the works by B.A. Borisov and E.A. Minina who, after many years of their geological surveys in the mountains of southern Siberia, discovered and described the relief of "a washing board" (the phase of the rogen moraine according to the classification by Yu. A. Lavrushin. B.A. Borisov and E.A. Minina ascribed the relief of giant current ripples of all the districts where it had been found, described and more or less studied to that relief of the ribbed moraine, the latter really exists in many ancient glacial mountainous valleys of Siberia, Middle Asia and in other mountains.
  The first investigator in Russia who not only correctly defined the genesis of the giant current ripples (we shall remind that this was done first by G.F. Lungershausen and O.A. Rakovets about 
caption: Giant current ripples on the left bank of Katun River, Altai Platovo Area.
exif: {"Image Orientation": "Horizontal (normal)", "Image XResolution": "400", "Image YResolution": "400", "Image ResolutionUnit": "Pixels/Inch", "Image Software": "ACD Systems Digital Imaging", "Image DateTime": "2010:06:22 03:53:00", "Image YCbCrPositioning": "Centered", "Image ExifOffset": "174", "EXIF SubSecTime": "468", "EXIF ExifImageWidth": "3360", "EXIF ExifImageLength": "1000"}