The Turbidite Problem

Abstract

The turbidity current hypothesis has met with much support as well as severe criticism. Dogmatic statements in support of this hypothesis are not uncommon in the literature and a clear distinction between fact and inference is not always made. First developed as an explanation for the origin of submarine canyons, the turbidity current hypothesis was later applied to explain the deposition of ancient flysch-type sediments as well as recent deep-sea deposits of alternating coarse and fine layers. Though a turbidity current origin for these two facies has not yet been demonstrated beyond reasonable doubt, diagnostic features of the one are commonly used to prove such an origin for the other. Such circular reasoning is unwarranted and data from both facies should be kept strictly separated. Evidence to support the turbidity current hypothesis comes from three areas: ancient flysch-type sediments; Recent deep-sea deposits; and experimental turbidity currents. Careful study of this evidence shows so many exceptions, irregularities, and inconsistencies in the general turbidity current concept, that serious doubt as to its general validity must be expressed. More consideration should be given to alternative theories, such as ocean bottom currents and tectonically controlled sedimentation. The ocean bottom current theory provides a good explanation for Recent deep-sea sedimentation, but cannot explain flysch-type deposits. Tectonically controlled sedimentation under relatively shallow water conditions provides a promising working hypothesis for the origin of flysch-type sediments.

Geology ofMonotis-bearing Torlesse rocks in Temple Basin near Arthur's Pass, South Island, New Zealand

“…1969 to present). In contrast, sediment gravity flow deposits that occur in shallow water, such as in lakes or on delta fronts (not to be confused with delta fronts that extend into deep water), are uncommon, and no one has demonstrated that thick areally extensive sediment gravity flow deposits are forming today in shallow water, as suggested by Van der Lingen (1969). Thus, by comparison with the modern record, the very presence of voluminous sediment gravity flow successions in the geologic record is, in itself, strong evidence for deep-water deposition.…”

Ordovician and Silurian Stratigraphy of Northeastern Aroostook County, Maine

“…In areas I, II, and III discussed above, the Lower Silurian (Llandoverian and early Wenlockian) units are overlain conformably by a thin-bedded "flysch-type" on June 22, 2015 memoirs.gsapubs.org Downloaded from (Van Der Lingen, 1969) sequence, the Jemtland Formation (late Wenlockian-early Ludlovian) that is in turn overlain conformably by the "flysch-like" Fogelin Hill Formation (early Ludlovian-Siegenian(?)). These two formations are best exposed in the Stockholm Mountain syncline, a relatively simple structure that lies along the western margin of the Ashland synclinorium in the vicinity of Jemtland, Maine (area IV, Fig.…”

Sedimentary evidence relating to the tectonic evolution of the Lau Basin, SW Pacific, from ODP Sites 834–839 (ODP Leg 135)

“…Kuenen (1964) divided the e division into e (turbidite mud) and e (pelagic/ t p hemipelagic mud) to distinguish between mud deposited by the turbidity current and the overlying mud deposited by pelagic and hemipelagic processes. Van der Lingen (1969) and Hesse (1975) used the letter e for turbidite mud and f for pelagic/ hemipelagic mud. Piper (1978) subdivided turbidite mud (e) into three structural divisions: e 1 (laminated mud), e 2 (graded mud) and e 3 (ungraded mud), and retained the f notation for overlying hemipelagic or pelagic sediment.…”