ABSTRACT. The two medial moraines of the Glacier de Tsidjiore Nouve a re nourished by rock de bris revealed a t the surface by progressive a bla tion down-glacier. The sources of th e moraine appear to be rock outcrops ma rgina l to or above the Pigne d'Arolla ice fall , much of the d etri tus entering the glacier via c revasses either at the summit or the base of the ice fall. The role of differential a blation in the emergence of the moraines as relief features is illuminated by measurements made in the late summ ers of 197 1 and 1972. The eventua l decl ine of the moraines down-glacier is related to factors of reducing d ebris supply, lateral sliding and accelerated abla ti on due to attenuation of the de trita l cover to a mean thickness of 1 cm or less. A model of moraine development, different in several respects from that proposed by Loomis ( 1970) for the Kaskawulsh Glacier, Alaska, is outlined. RESUME. us moraines medianes de la par/ie inferieure du glacier de Tsidjiore Nouve dans le Valais, Suisse. Les deux moraines medianes du glacier de Tsidjiore Nouve sont nourries par des debris de roe qui a ppara issent a la surface en raison de l'ablation progressive a u bas du glacier. Les sources d e la mora ine semblent ctre un affieurement rocheux, marginal a la cascade d e seracs d e la Pigne d'Arolla, beaucoup de de tritus pene trant dans le glacier pa r les crevasses form ees a la base d e la cascade. Le role de l'ablation differentielle dans l'emergence des moraines comme des reliefs, est illustre par les mesures faites en fin d 'ete 1971 et 1972. L'eve ntuel abaissement d es moraines a u bas du glacier es t en relation avec les facteurs d e reduction de l'approvisionnement en debris, avec le glissement la teral , et avec l'accelera tion de l'ablation en raison de l'amincissement de la couche d e debris jusqu'a une epaisseur moyenne de 1 cm ou moins. On evoq ue un modele de developpement de moraine, different a plusieurs egards de celui propose par Loomis ( 1970) pour le K aska wulsh Glacier, Alaska. (Fig. I ). The glacier is notable for its considerable burden of supragla cial moraine, largely composed of blocks and finer fragments of light grey gneiss of the Arolla Series of the D ent Blanche Nappe and highly fractured darker schists of the Schistes Lustres Series. This material forms two well-defined m edial moraines, ea ch approximately I km in length, which at their downglacier ends spread to m erge with marginal morainic d ebris. Of the two moraines that to the south (right) is markedly broader and higher (rea ching a width of 101 m and a maximum elevation of 22.25 m above nearby bare ice, comp a red with corresponding figures of 59 m and 6 m for the northern m oraine), a nd will accordingly be referred to throughout this paper as the main moraine; that to the north (left) is termed th e subsidiary moraine.

ABSTRACT. The Haut Glacier d' Arolla displays three medial moraines: an ablation-dominant moraine east of the glacier centre line, an ice-stream interaction moraine west of the glacier centre line, and a medial-lateral supraglacial moraine complex along the western margin of the glacier. The eastern moraine is formed by the emergence of coarse angular clasts from a series of short longitudinal debris bands 1 km from the glacier terminus; this debris is derived from rock falls at the glacier head-wall, and follows a low-level transport path through the glacier. The western moraine is formed partly by the direct fall of weathered debris on to the ice surface at a point 2.6 km from the snout, but it receives further increments of sediment from extensive longitudinal en glacial debris bands developed from the convergence of two ice streams with lateral englacial debris septa. The medial-lateral moraine complex is formed largely by rock falls from the western valley wall, but is also nourished by a debris layer developed at the base of the small tributary Glacier de la Mitre. This layer crops out at the eastern margin of the re-sultant inset ice stream, and releases more rounded, abraded and comminuted rock fragments to supplement the surface debris cover of supraglacial origin. RESUME.

The relationship between supraglacia l latcral moraines and lateral dump mora in es at Arolla. Switzerland. is discussed. A detailed stud y of the lateral moraines of glacier de Tsidjiore Nouve reveals their com pl ex form (as superimposed a nd nested ridges) and th e current mode of devel o pm ent (possi bl y relat ed to th e passage of a kinematic wave). Sedimentological ana lysis indicates that much of the constituent debris is of supraglacial origin ; it is transported either directly from the base of slopes flanking the Pi gne d'Aro ll a ice-fall or via englac ial sepIa comprisin g marginal sediment incorporated in the accumu lati o n zone. A calc ul at io n of the volume of debris in th e lateral morain es suggests that glacier de Tsidjiore Nouve has recently bcen more active in transporting and depos itin g supr aglacia l debris th an in glaci al erosion sellS/./ slriclO. RESUME. Morailles lalerales du g lacier de Tsidjio r e Nouve:!orllle, deve loppemelll el cOllclusiolls. On di scu te les rapports entre les morain es laterales de surface et les mo raines laterales de depot a Arolla en Sui sse. Unc etude de detail des moraines laterales du glac ier de Tsidji ore No uve revele leur forme complexe (avec des ondul ati ons en serics surimposees) et leur mode normal de developpement (peut-et re lie au passage d'une on de cin ematiqu e). Une analyse indiquc q ue beauco up des sediments constitutifs sont d'origine supra -glac iaire; ils son t transportes soit directement depuis le pied des pentes bordant les chutes de serac de Pi gne d'Arolla ou par I"intermediaire d'impuretes intraglaciaires comprenant des sedim ent s margin aux incorpores da ns la zone d·accumulation. Un calcul du volu mc de sediment dans Ics moraines laterales porte a conciure que le glac ier de Tsidjiorc Nouvc a ete recemment plus actif pour le tra nspo rt et le depot de sedi ments supraglaciaires qu e pour I"erosio n glac iaire sellsu slriclO.

Fatty material from a Thule Eskimo site on Herschel Island, Yukon Territory, Canada was analysed by gas chromatography and thin layer chromatography. The fatty acid composition of the samples was then compared with published data for a number of marine species which could have been food sources for the Thule peoples. The samples appear to be derived from seal or whale, or a mixture of these, but what is more surprising is that the fats have changed so little over the 1000 year period of their burial.

The relationship between supraglacial lateral moraines and lateral dump moraines at Arolla. Switzerland, is discussed. A detailed study of the lateral moraines of glacier de Tsidjiore Nouve reveals their complex form (as superimposed and nested ridges) and the current mode of development (possibly related to the passage of a kinematic wave). Sedimentological analysis indicates that much of the constituent debris is of supraglacial origin; it is transported either directly from the base of slopes flanking the Pigne d’Arolla ice-fall or via englacial septa comprising marginal sediment incorporated in the accumulation zone. A calculation of the volume of debris in the lateral moraines suggests that glacier de Tsidjiore Nouve has recently been more active in transporting and depositing supraglacial debris than in glacial erosion sensu stricto.