Clast orientations of the 1985 lahars of the Nevado del Ruiz, Colombia and implications for depositional processes

Contribution of lateral processes to stone pavement formation in deserts inferred from clast orientation patterns

“…This is in agreement with reported results from other authors (e.g. Kohlbeck et al, 1994;Major, 1998). With our approach we present a comprehensive method for assessing quantitative characterisation of circular data.…”

Neogene fjordal sedimentation on the western margin of the Lambert Graben, East Antarctica

“…Observations in modern glacier settings show: (a) for lodgement till, a fabric strongly clustered and parallel to the direction of local ow; (b) for deformation till, a preferred orienta-tion fabric broadly, but not always, parallel to the cumulative strain ellipse; and (c) for glacigenic sediment¯ows (¯ow tills), strongly clustered to polymodal and random fabrics, depending on the position in the¯ow. Highly variable fabrics, including strongly directional ones, have also been noted in debris¯ows of non-glacial origin, such as those in low-latitude alluvial fans (Hubert & Filipov, 1989), in lahars (Kohlbeck et al, 1994;Vallance & Scott, 1997) and in experimental¯ows (Major, 1998). However, the marine context rules out any of these non-glacial mechanisms.…”

Complex internal architecture of a debris‐flow deposit revealed using ground‐penetrating radar, Cass, New Zealand

“…An earlier hypothesis for debris‐flow deposition related the poorly sorted, massive character of the deposits to an en masse emplacement process (Pierson ; Costa ; Kohlbeck et al . ). Support for this hypothesis waned as an increasing body of experimental and observational evidence demonstrated that deposits frequently formed by vertical and horizontal accretion of sediment (Major ; Vallance & Scott ; Major & Iverson ; Kim & Lowe ; Johnson et al .…”

“…Whereas previous research on debris-flow deposit structure typically described massive beds of matrix-supported sediments with little or no internal stratigraphy (Costa 1984;VanDine 1985;Jackson et al 1989;Major 1997;Jakob et al 2000), the present study offers preliminary evidence of a more complex subsurface architecture in a small alpine debris-flow deposit. An earlier hypothesis for debris-flow deposition related the poorly sorted, massive character of the deposits to an en masse emplacement process (Pierson 1981;Costa 1984;Kohlbeck et al 1994). Support for this hypothesis waned as an increasing body of experimental and observational evidence demonstrated that deposits frequently formed by vertical and horizontal accretion of sediment (Major 1997;Vallance & Scott 1997;Major & Iverson 1999;Kim & Lowe 2004;Johnson et al 2012).…”