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Summary Further instances of A‐tents in unglaciated granite terrain do not require fresh explanation. Three cases in glaciated country in a variety of rocks demonstrate an origin through pressure release as a result of glacial erosion and ice retreat. A‐tents in limestone on the unglaciated Cooleman Plain, N.S.W., are attributed to solutional offloading, though residual compressive stresses were probably released. In some cases the amount of apparent expansion calls for further explanation, certainly including dilatancy resulting from intergranular stress, itself a product of calcite anisotropies. Expansion of the confining sheet as well as the A‐tent may contribute to the measured expansion.

Summary Differential erosion over a long subaerial history has resulted in a wide range of Australian structural landforms, commonly emphasized under the dry prevailing climate. They include Appalachian relief on ancient orogenic structures, more compact or even circular landforms associated with astroblemes and igneous intrusions, and linear features.

Detection of anomalies in measurements of low rates of limestone surface lowering with a traversing micro-erosion meter (MEM) led to temperature-controlled laboratory and field investigations of some sources of error in the method. Regressions for the correction of temperature change in the instrument and in the stud-rock interface were obtained. Probe erosion tests permitted a correction to be devised and also provided information whereby a measure of operational irregularity was adopted. Corrections and error terms were applied to field measurements from two southern New South Wales karsts and a collection of Australian limestone slabs exposed at one site. Examination of these results and of published MEM rates from other parts of the world validated the MEM method. Marine platforms are lowered at such gross rates that these error sources may be neglected there. However limestone lowering in terrestrial environments cannot be assumed to proceed at rates which permit this and recommendations are made about procedures to ensure that investigations are prosecuted within the limitations of the method.

Summary Four years of air and soil temperatures from two sites, on the grassland Cooleman Plain and the surrounding forested ridge respectively, amplify evidence that the Plain frequently acts as a frost hollow. Excess of mean soil temperatures over mean air temperatures is probably partly due to the increasingly favourable net radiation balance at ground surface with elevation but aerodynamic factors such as cold air drainage from the forest to the grassland and differences in soil moisture content may be contributory. Mean groundwater temperature exceeds mean air temperature at mean catchment elevation, presumably due to the influence of soil temperatures and the unrepresentativeness of temperature at mean catchment elevation where this coincides with frequent temperature inversion and underground flow.

Summary The degradational and aggradational features of the valleys of the Cooleman Plain fluviokarst are discussed in relation to karst development, rejuvenation through uplift and climatic change. Aggradation, including mudflow action, as a result of a cold climatic phase, probably that between 30 000 and 15 000 B.P. in the Late Pleistocene, led to blockage of caves and temporary restoration of surface drainage.

On the backwall of Twynam East Cirque selected stones moving through snow creep were marked and their movements from 1963 to 1975 measured. Their annual movements varied markedly between 1963 and 1970 but thereafter little. The percentage of stones failing to move varied reciprocally with snow thickness over a snow course in a comparable site near Spencers Creek. The annual mean movement, ranging from 7·6 to 36·3 cm, correlated strongly with Spencers Creek snow thickness. Frequent occurrence of annual movements of intermediate value characterise the process. Snow surface maps with 2m contours for 1964, 1974 and 1975 permitted determination of snow slope at the stone positions and of snow thickness by subtraction of ground heights. A 2 m contour ground surface map was also the basis for hillslope angles at stone positions. Basal area and area transverse to snow movement were calculated from measurements of the three principal axes of the stones. The vertical angles and directions of their abrasion tracks were measured. Rank correlation of stone movements with hillslope and snow slope was usually not significant but with track angle was so in most years. Track angle and direction are controlled partly by hillslope and partly by local rock geometry. Movements correlated inversely with stone basal area on which frictional drag depends. Correlation with stone transverse area was weak and inverse; this may be due to snow tending to move round larger stones. In most years there was significant correlation with snow thickness and basal stress (calculated from snow thickness and snow slope). However, the amount of ‘explanation’ associated with all the independent variables was small and the experiments revealed an importance of surface roughness at various scales in controlling stone movement which was much greater than expected from direct observation.

Summary London Bridge spans Burra Creek in the Southern Tablelands. It was formed by the development of an underground cut‐off through a limestone lens in the waist of a meander spur and controlled by the strike of the limestone and dip and unloading joints. The meander loop is occupied by a tributary alluvial fan, which may have been a dynamic factor in forming the cut‐off, not simply a consequence of it. Abandoned caves along the strike at higher level represent earlier cut‐offs. Descending profiles in these caves were caused by a rejuvenation head, held at the meander by resistant greywacke. London Bridge combines scientific interest and natural beauty to such a degree that it should be preserved as a geologic monument.

A dot map of karst cave areas in Australia is presented together with a similar one redrawn from the National Atlas of the United States of America. The limitations of the map are described. The geographical circumstances behind Australia's poverty in these resources and the risks to which they are exposed are outlined.

AUSTRALIA — A GEOGRAPHY edited by D. N. Jeans. 19 by 25 cm, vii and 571 pages, text figures, plates. Sydney University Press, Sydney 1977 (ISBN 0 424 00036 9) A$20 limp BRISBANE AT THE CENSUS, 1971: A SOCIAL ATLAS by G. T. McDonald et al. 40 by 30 cm, 116 pages, text figures, tables. Cities Commission, Canberra 1976 (ISBN 0642 938 4) NEW TOWNS IN ISOLATED SETTINGS edited by O. E. Oeser. 17 by 25 cm, xv and 304 pages, text figures, tables, plates. Australian Government, Canberra 1976 (ISBN 0 642 01083 8) A$7.50 limp ALTERNATIVES OF ETHNICITY: Immigrants and Aborigines in Anglo‐Saxon Australia by W. W. Bostock. 14 by 21 cm, iii and 190 pages. Cat and Fiddle Press, Hobart 1977. A$4.95 limp CAPITALISM, SOCIALISM AND THE ENVIRONMENT by H. Stretton. 13 by 22 cm, vi and 332 pages, text figures. Cambridge University Press, Cambridge 1976 (ISBN 0 521 29025 2) A$7.30 limp ENVIRONMENTAL MANAGEMENT IN AUSTRALIA, 1788–1914 by J. M. Powell. 16 by 25 cm, xii and 191 pages, text figures, tables. Oxford University Press, ...

(1953). On the origin of certain Lochans in Glen Iorsa, Arran. Scottish Geographical Magazine: Vol. 69, No. 2, pp. 67-78.

Introduction The importance of topographical maps to the geomorphologist scarcely needs demonstration since he is concerned with the nature and distribution of landforms. He attempts to unravel their origin and history by a variety of approaches, including the study of the processes fashioning them today. Therefore the portrayal on topographical maps of the relief of the land (more particularly by mensural methods rather than by impressionistic means), of drainage systems and of coastal features is vital to his studies.

(1967). Two maps of rainfall intensity in Australia. Australian Geographer: Vol. 10, No. 4, pp. 256-262.

(1955). The influence of wave action on coastal outline in plan. Australian Geographer: Vol. 6, No. 4, pp. 36-44.

as Schweinfurth (1961) has demonstrated very well in this journal. Perhaps the geographical facet of the natural history of these birds which has most signi ficance is that of their migrations (fig. 1). This is best documented in the case of the Bass Strait muttonbird or Short-tailed Shearwater, Puffinus tenuirostris (Ser venty, 1953 & 1956; Marshall & Serventy, 1956). Preceded by their parents, the fledglings in their hunger leave their rookeries in late April and early May. Shortly afterwards casualties are picked up along New Zealand beaches. By May the birds are found in numbers in Japanese seas; in July-Septem ber, they are over Bering Straits, Alaskan coastal waters and even reach into the Arctic Ocean. The

(1966). Solution doline and subjacent karst doline. Australian Geographer: Vol. 10, No. 2, pp. 132-133.

(1970). Ingrown meander and Meander Cave. Australian Geographer: Vol. 11, No. 4, pp. 401-402.