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B. Salt Studies

1. Sampling in Kennar Valley and around Taylor Glacier completes a programme of sampling from the coast to the Lashly Mountains 90 km to the west, at the edge of the polar plateau.
2. Microscopic examinations of various salt samples were undertaken in the field and at Scott Base to help elucidate the patterns of salt crystal growth. The examinations indicate that wind erosion of surface salt deposits is extensive in some deposits.
3. Surface and soil temperatures and frozen level depths were measured on several basalt cones on the slopes of Mt. Discovery. These show that sunnier slopes tend to have shallower frozen levels indicating that more moisture is present in such soils for salt dissolution and distribution.

4. The area of mineral discharge (Black et al, 1965) at the snout of Taylor Glacier was closely examined. Another saline discharge has occurred since the summer of 1975/76, mainly on the lateral stream delta. A cold (min. temp. − 7.8°C) saline spring was found flowing in late November, near the source of the lateral discharge. Such a spring does not appear to have been observed previously although Hamilton et al (1962) describe a saline "ice platform" at this location which was probably similar to the saline ice build-up from this most recent discharge. Estimated spring flow rates show some diurnal variation and possibly a relationship with spring temperature. No simple relationship exists between flow and air temperature and/or pressure.

   The orange coloured layers in the glacier around the glacier discharge site were mapped. They do not outcrop more than 200 m from the site. Other englacial dirt layers on the surface further up Taylor Glacier appear to be mainly diffuse, low concentration rock debris layers, although one sharp high concentration layer containing mainly (basaltic?) tephra was found. These layers were previously believed to be extensions of the orange layers at the snout.

5. The volume percentage of tephra in englacial layers was measured for layers in the glacier between Mts. Morning and Discovery and in the Fang Glacier windscoop. Volume percentage is a useful parameter for distinguishing direct airfall deposits from wind deposited tephra and for describing englacial debris layers generally.
6. Snow free areas around the summits of Mts. Morning and Discovery were examined for traces of 'volcanic' salts such as are found on Mt. Erebus and the Fang. None were found.
7. The large (up to 20 m high) snow and ice features around the summits of Mt. Morning and Discovery were examined and ice sample densities measured. Their external and internal structures indicate that they are snow depositional features modified by strong mainly southerly winds. Direct condensation from clouds appears to be an important accumulation process. Although some of the "towers" on Mt. Discovery resemble the fumarole towers of Mt. Erebus, present day geothermal activity is not the cause of the Mt. Discovery and Mt. Morning structures. Structures similar to the latter are found on certain Marie Byrd Land volcanoes and were considered by Le Masurier and Wade (1968) to indicate fumarolic activity there. In the light of this season's work such a conclusion may be unsoundly based.

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References:

Black, R.F., Jackson, M.L. and Berg, T.E. (1965). Saline Discharge from Taylor Glacier, Victoria Land, Antarctica. J. Geol. v.73(1), p. 175-81.

Hamilton, W., Frost, I.C., and Hayes, P.T. (1962). Saline Features of a Small Ice Platform in Taylor Valley, Antarctica. U.S. Geol. Survey Prof. Paper 450-B, p. 73-75.

Le Masurier, W.E. and Wade, F.A. (1968). Fumarolic activity in Marie Byrd Land, Antarctica. Science v.162, p. 352.