Journal of Botany

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Changes in geomorphic environments in Canterbury during the Aranuian

Jane M. Soons

To cite this article: Jane M. Soons (1994) Changes in geomorphic environments in Canterbury during the Aranuian, New Zealand Journal of Botany, 32:3, 365-372, DOI: 10.1080/0028825X.1994.10410479 To link to this article: https://doi.org/10.1080/0028825X.1994.10410479

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Full Terms & Conditions of access and use can be found at http://www.tandfonline.com/action/journalInformation?journalCode=tnzb20 New Zealand Journal of Botany, 1994, Vol. 32:365-372 365 0028-825X/94/3203-0365 $2.50/0 9The Royal Society of New Zealand 1994

Changes in geomorphic environments in Canterbury during the Aranuian

JANE M. SOONS in climatic conditions, with associated changes in Department of Geography vegetation cover, has been the subject of interest to University of Canterbury botanists who have identified fluctuations in the Private Bag 4800 generally warming trend of the Aranuian. In very , New Zealand recent years, this period of warming has become of wider interest as a possible analogue of global warm- ing. McGlone (1988) has demonstrated, however, Abstract Changes in landforms in Canterbury that climate change alone does not provide a compre- consequent on the change from glacial to non-glacial hensive explanation for the known vegetation conditions during the Aranuian are examined. Land- changes. form evidence may supplement that provided in the Sea level at the beginning of the Aranuian was vegetation record and suggest that the montane low--probably some 60-70 m below that of today environments of Canterbury were more sensitive to (Carter et al. 1986), giving a somewhat higher climate change than the lower, including coastal, effective altitude to the land mass. Inland parts of the environments. On the whole, however, it appears that country would have been more continental than they landforms record only the broad change from glacial are today; the Canterbury coast lay some 40 km east environments to those of the present. Alternations of its present position (Herzer 1983), and the North of erosion and deposition in any given valley may and South Islands were joined somewhere along the reflect a variety of causes, including seismic events, line of Farewell Spit (Stevens 1980). Nevertheless, fire, and intense local storms, as well as longer term even during glacial periods, New Zealand was open and regional climate change. It is concluded that the to air masses from a relatively warm Pacific Ocean, vegetation record will provide a more sensitive and and to high insolation values. Thus, recession of detailed record of climatic variation than will the glaciers and recovery of vegetation at a somewhat geomorphological record. earlier date than the internationally defined Holocene boundary (10 000 yr B.P.) is not surprising. This Keywords Aranuian; geomorphology; landform paper examines geomorphic change during the sensitivity; Canterbury mountains; coastal regions; Aranuian, both for its intrinsic interest and to assess Banks Peninsula whether it can be related to, and perhaps supplement, the botanic record.

INTRODUCTION EXTENT OF GLACIERS The Aranuian was a time of environmental change during which conditions shifted from almost fully One component of the geomorphic record during the glacial to those of the present day. The period began Aranuian is information provided by glaciers, but c. 14 000 years ago, when the glaciers of the peak fluvial erosion and deposition, and mass movement of the late Otiran had receded significantly, but when forms, often closely associated with the glacial most of the valleys of the Southern Alps were still history, also provide evidence for environmental partly occupied by ice (Suggate 1965). The change change, and are part of it. The rapidity of change during the early Aranuian in Canterbury is demon- strated by changes in the extent of ice. Dating of glacier terminal positions is poor and has led to a B93079 number of assumptions and extensions of infor- Received 7 December 1993; accepted 4 May 1994 mation from one valley to others that may or may 366 New Zealand Journal of Botany, 1994, Vol. 32 not have similar controls. There is, however, little Thereafter, glaciers were confined to the narrow, doubt that at the beginning of the Aranuian ice still upper reaches of the valleys, and receded steadily, extended well down the major Canterbury valleys. with some interruption by relatively minor re- In the Valley, the glacier terminus may have advances (Burrows 1989; Burrows et al. 1990). For been close to the upstream end of the gorge, which the most part, the newly exposed surfaces in these was probably barely in existence (Soons & headwater valleys were steep and limited, or were Gullentops 1973). In the Waimakariri Valley, the valley bottom sites constantly subject to inundation Cass Basin was partially ice filled (Gage 1958), and and/or burial by gravel. Lake Speight had not yet come into existence. Ice In parts of the Northern Hemisphere, there is occupied most of the Ashburton and Rangitata evidence that the beginning of the Holocene was Valleys above their respective gorges (Mabin 1984). accompanied by a spectacular collapse of glaciers, In North Canterbury, the Humnui and Walau Valleys which may have lost their sources of snow in a rapid still held major glaciers (Powers 1962; Clayton rise of regional snowlines. This does not seem to 1968), while in the Mackenzie Basin, ice occupied have been the case in New Zealand. Glacier mass much of the trenches now filled by Lakes Pukaki and balance is a function of both precipitation and temp- Tekapo (Speight, J. 1963; Fitzharris et al. 1992). erature, and the elevation of most of the catchment Meltwater from the glaciers spread out as braided areas, on or close to the Main Divide, would have streams, probably wider and more vigorous even ensured a constant replenishment of the n6v6 fields than their counterparts today, pushing their load of to maintain glacier flow. gravel out beyond the present coast to the lowered Considerable effort has been put into identifying shore. Rising sea level to some extent countered the Aranuian fluctuations of glaciers, especially in the effect of this, reworking the gravels into barrier Mount Cook region. Burrows and others have identi- structures, which were backed by lagoons and topped fied fluctuations of glaciers within the Rakaia by sand dunes, much like the coast of today (Herzer catchment, with the Cameron Valley providing a 1983). particularly useful contribution, while Chinn has produced a similar record for the Waimakariri Warming climate and receding ice glaciers. (For a useful summary see Gellatly et al. Figure 1 shows the probable extent of ice in the 1988.) A significant part of the exercise has been to Rakaia Valley at three not very widely separated try to relate such fluctuations to those of neighbour- periods. In the / Acheron River valley, ing glaciers, and in the case of Gellatly et al. (1985) the last phase of the major late Otiran Advance, to variations over greater distances. By doing so, it Bayfield 3, is dated at some time after 19 200 yr B.P. is hoped to demonstrate synchroneity, and therefore (Soons & Burrows 1978). By comparison with dates control by large scale regional and global influences. from the West Coast (Burrows 1988), this can be Major glacier fluctuations, such as occurred refined to c. 18 000-17 000 yr B.P. At this time, the during the Pleistocene, were the result of global Rakaia and its tributary valleys were occupied by a atmospheric circulation changes. Consequently it large glacier system, as were the adjacent Ashburton, can be argued that major glacier fluctuations should Rangitata, and Waimakariri Valleys. By c. 11 000 be synchronous in both hemispheres, even though years ago the Rakaia Glacier had shrunk until its when detailed and reliable dates are available there snout lay somewhere near the entrar, ce to the Lake are frequently discrepancies (Salinger 1984). How- Stream Valley (Burrows & Russell 1990). This ever, as we move closer to the present day, the recession ofc. 45 km in some 6000 years must reflect evidence for synchroneity is less compelling. The a significant change in global atmospheric and uncertainty in dating becomes a more important oceanic circulation. The rate of recession cannot, proportion of the age of a dated feature as the present however, be estimated by simple division. In the time is approached. Differences in regional and local between these two ice limits, a substantial readvance, topography and the geometry of n6v6 fields and the triple Acheron Advance, took place. This was mountain valley systems become increasingly paralleled by the Poulter Advances in the Waima- important as glaciers diminish in size. Increasingly, kariri Valley, and by comparable events elsewhere. adjacent glaciers behave in very different ways, and Its peak was probably reached c. 14 000 years ago confidence in their ability to reflect other than local but cannot be dated with confidence. fluctuations of climate must diminish in proportion. This rapid recession exposed extensive and varied The contrasts in behaviour between the Canterbury new surfaces for colonisation by plants and animals. glaciers and the Fox and Franz Josef Glaciers on the Soons--Aranuian geomorphic environments in Canterbury 367

Fig. 1 Successive late-glacial and Aranuian ice marginal positions in the Rakaia Valley.

West Coast have demonstrated this on several Non-glacial geomorphic changes in the occasions this century. montane regions Thus, while the record of glacier behaviour is important in recording a sequence of change from The early Aranuian recession of glaciers was one of full glacial to present day during the Aranuian, and significant landscape disequilibrium. Major readjust- is provided essentially by the landforms produced by ments of stream channels and slopes took place. Ice- the glaciers themselves, the interpretation of that marginal drainage systems were entirely or in part record has its problems. Glaciers respond to two abandoned, leaving sometimes spectacular channels. controls--temperature and precipitation--and there Streams which had previously flowed into proglacial is no incontrovertible geomorphological evidence as lakes incised their channels into former deltas and to which of these changed in order to produce a given across former lake shore terraces as they adjusted to advance or retreat. Clarification must depend on new base levels. Incision frequently continued into other indicators, one of which may well be the rock floors of valleys, and the detritus formed vegetation change. alluvial fans where the streams emerged onto the 368 New Zealand Journal of Botany, 1994, Vol. 32 floors of formerly glacier-filled basins. Some the frequency of high magnitude events, or with changes of course were inevitable as casual accidents more subtle but persistent shifts of climatic of erosion and deposition switched streams from one parameters. side to another of alluvial fans, or as mass movement The Canterbury high country is subject to highly more or less permanently blocked drainage lines. variable weather and to seismic events, and although Cutting of the is shown by the a measure of landform stability developed as climatic continuity of late Otiran outwash surfaces to have conditions improved during the Aranuian, there is begun only after the recession of the glacier from the abundant evidence that local and internfittent events Bayfield 3 position--that is, after c. 17 000 years occurred which disrupted that stability. Intense ago. It may have been at least partially infilled and storms, some localised and others affecting wide then re-excavated during the Acheron Advances areas, are characteristic, and cause damage which is (Soons & Gullentops 1973). Some of the incision not easily or rapidly healed. Such damage includes may be attributable to water released as ice-marginal slips and gullying, as well as more or less dramatic lakes drained, possibly dramatically. Other smaller changes of stream course on alluvial fans. Even wind rivers have gorges which can only have been cut after may cause lasting damage to the land surface. Visible the ice retreated, such as that of the Cass immediately evidence of soil loss is widespread throughout the upstream of its junction with the Waimakariri. montane area and beyond, both in the dust clouds This period of landform disequilibrium and rapid which are common in the "Nor'wester" and in the readjustment to the changing conditions would have wind scalds and the complementary accumulations been time transgressive, the zone of adjustment of fine sediments around tussocks and shrubs. More following the receding ice margins. Its duration severe wind storms can result in overthrow of forest probably varied depending on the severity of the trees and consequent soil and slope modification readjustment that was necessary. In some locations (Burns & Tonkin 1987). it is still continuing--there are many streams whose Larger scale damage may result from seismic valleys can hardly be said to have achieved equi- events, and in particular from earthquake-induced librium with today's conditions. Nevertheless, the slope collapse. The identity of a number of late- most vigorous period of adjustment probably ended glacial moraines has been confused by their coinci- in three or four thousand years. It ended, not because dence with the debris of massive rock avalanches. of any abrupt climate change, but because a state of Examples are found throughout the high country-- near-equilibrium with the ice-free environment had in the Macaulay Valley (McSaveney & Whitehouse been achieved. Downcutting diminished, load 1989a), the Cass Basin, and in the Rakaia Valley reduced, and the building of alluvial fans slowed between the Power Station and the mouth of the down. Surface stability increased and soil develop- Acheron River. These and other massive rock ment was able to proceed. avalanches probably testify to a major seismic event of the kind suggested by Whitehouse (1983) and Accidents and extreme events Whitehouse & Griffiths (1983). Smaller landslides A geomorphic change requires a change in energy of indeterminate origin in the Cameron Valley have conditions. For example, lowered local base levels been inferred by Burrows et al. (1993) as probably and removal of support for slopes consequent on the occurring at a rather later date than those that des- disappearance of ice provide an increase in energy cended onto moraines in the larger valleys. Canter- for stream incision and mass movement. In contrast, bury in the Aranuian experienced seismic events that variations in frost frequency, precipitation, or sun- have had significant if localised effects on landforms, shine that are large enough to result in a change in and it is probable that more evidence remains to be vegetation type do not necessarily result in geo- interpreted from the record. The geomorphic impact morphic changes. The extent to which soils are of such events can be responsible for substantial exposed to agents such as wind, frost, and gully changes of style of erosion and deposition, and hence erosion is critical. A shift from one vegetation type any such changes should be used to reconstruct to another with little or no exposure of bare soil or climatic events only with considerable care. loss of roots is unlikely to have much geomorphic The rigorous mountain climate and ongoing impact. Thus, it is likely that only relatively large tectonic instability contribute to the creation of a changes in climatic conditions will be reflected in harsh environment, in which local erosion and its changes in the geomorphic character of a region. associated deposition can be frequently triggered. Such changes may be associated with variations in Superimposed on the climatic and tectonic elements Soons--Aranuian geomorphic environments in Canterbury 369 is the evidence of a fire history, demonstrated by a information, it is difficult to determine how wide- number of workers (see McSaveney & Whitehouse spread were the phases of aggradation and erosion 1989b for a useful summary), most recently by identified in individual valleys. While it seems Burrows et al. (1993). McGlone (1988) has pointed logical to assume that a significant change in climate to the significance of this in reconstructing past would affect a wide area, there is considerable climate conditions. McSaveney & Whitehouse variation in mountain meso- and micro-climates, and (1989b) note that fire has been an element in the high not all locations may be affected to the same extent. country for at least 40 000 years, and that at least in A change restricted to a single valley may indicate the last millenium deforestation associated with little, but a change that can be demonstrated to be burning has been responsible for erosion of steepland widespread may record an environmental change of soils as root strength has diminished. Burning is some importance. probably one of the most effective ways of triggering In reviewing the geomorphic evidence for climate rapid, substantial, and persistent geomorphic change, it is difficult to resist the impression that the changes in the montane environment. montane areas of Canterbury, from which much of the evidence comes, were, and are, especially sus- Paleosols, vegetation change, and ceptible to minor variations in climatic parameters. geomorphology The criteria for the selection of sites for tree-ring Paleosols such as those described by Burrows et al. study are based on the assumption that such localities (1993) offer evidence of more than one phase of are likely to be those of stress for vegetation, and landscape disequilibrium. Soil formation and burial implies that climatic variations reflected at such permit identification of an associated vegetation sensitive locations were probably not effective and cover, and successive paleosols tend to show identifiable at lower elevations. different vegetation assemblages. Unfortunately, paleosols are not so widespread that they can be readily used in reconstructing the history of an area, CHANGES BEYOND THE MONTANE as Tonkin & Basher (1990) have pointed out. Their AREAS absence, however, may in itself provide useful infor- mation as to the stability or relative youth of a surface Beyond the mountain catchments, readjustment of (Tonkin & Basher 1990). Palynological evidence, the larger rivers of Canterbury involved deposition including that relating to pollen dispersal, even from of sediments removed from the uplands at the sea- spot locations, can provide valuable evidence of ward margins of the plains. This was the continuation changes in the regional character of vegetation. of a transfer process that took place through succes- McGlone (1988) has used such information to infer sive glaciations and interglacials, and the correlation wider atmospheric circulation changes to account in of glacial advance and fan building is reasonably part for regional variations in vegetation through the well established. It affected even those rivers that had Aranuian. Nevertheless, as he points out, the little or no ice in their catchments, such as the recorded vegetation changes reflect a complex of Ashley, where the cold phases of the Pleistocene environmental changes, not all of which are climatic would have resulted in a change not only in the or climate controlled. However, climate parameters temperature regime but also in the water balance, are important, and an ability to trigger geomorphic leading to reduction of vegetation cover and changes may provide an indication of their magni- extensive frost weathering. This was reflected in tude. An increase in avalanche activity and/or heavily loaded streams and alluvial fan building aggradation of valley floors might indicate persistent within upland catchments, such as Lees Valley, and colder or wetter conditions--or some combination on the plains. The geomorphic impact of climate of both--at high altitudes. Alternatively, they might change on the downlands of North and South be evidence of increased storminess, as Grant (1982) Canterbury is less clear. Changes between tussock/ has demonstrated in Hawke's Bay. Part of the scrub associations and forest may have resulted in problem in using such information is to establish the some increased susceptibility to mass movement, areal extent of evidence of change. Another part is which in turn may locally have affected stream to translate evidence of a widespread change in soil behaviour. On the whole, however, it seems likely type, vegetation cover, and landforms into a quanti- that much of the impressive stream incision in some tative measure of the magnitude of climate change. parts of North Canterbury in particular is a reflection Because of the lack of detailed chronological of tectonic and seismic activity (Yousif 1987). 370 New Zealand Journal of Botany, 1994, Vol. 32

Coastal changes in the Aranuian known, let alone the details relating to climate The coast provides no indicators of local environ- change. mental change that can be correlated with the fluc- The Aranuian rise of sea level drowned first the tuations identified in the montane soil and vegetation broad Canterbury coastal plain and then the deep record. The youngest fan sediments of the Canter- valleys of the peninsula. At the southern end of the bury Plains extend beyond the present coast, forming plains and to the north of the peninsula, a barrier and the long gentle offshore profile of the Canterbury lagoon coast developed. Near and to the north of the Bight and Pegasus Bay. Fluvial deposition was Rakaia mouth, the angle presented by the coast to countered by wave action in much the same manner the southerly swells eventually resulted in destruct- as it is today. A sequence of barriers was built, ion of the barriers and lagoons, erosion of the toes reflecting the interplay of storm waves and river of the alluvial fans, and the movement of gravel flow. Each of these barriers in turn was moved northwards. Several authors (Speight, R. 1930; landward and eventually overwhelmed as sea level Armon 1973; Lawrie 1992) have described the rose (Herzer 1983). Alluvial deposition was replaced consequences in the change of direction of the coast by lagoonal and marine sedimentation along the toe and the gradual construction of a spit across the of the fans, but complicated interactions took place mouth of what was the combined estuary of the as storm waves and river floods alternated in impor- Selwyn and Waimakariri Rivers. Once the growing tance in reworking and providing the products of spit encountered the mass of the peninsula, further inland erosion to the coast. Until approximate alongshore movement of gravel was prevented, the stability was achieved at c. 6000 years ago, the rise spit pivoted at its narrow western end and widened of sea level was a dominant influence on coastal at its eastern end into the broad barrier of today. processes. This was a function of global, not local, Lakes Ellesmere (Waihora) and Forsyth (Wairewa) change. resulted from the closure of the barrier, certainly within the last 5000 years, and possibly quite Banks Peninsula recently. Similar, if smaller, lagoons along the coast Projecting roughly halfway along the Canterbury north of the peninsula also reflect the reworking of Plains, Banks Peninsula is responsible for the material brought down by the rivers, and together contrast between the coast of the Canterbury Bight with a complex of beach ridges and dunes offer the and of Pegasus Bay. It blocks movement of sediment possibility of further elucidating Aranuian events. from the bight to the bay, and results in the formation of one of New Zealand's more notable coastal features, Kaitorete Spit--not, as various writers have CONCLUSION pointed out, a spit, but more correctly a barrier beach, albeit on a grand scale. The alternation of climatic conditions indicated by During the Otira Glacial, the peninsula was not the vegetation sequences of inland Canterbury is not high enough to have carried glaciers, but it may have replicated in any of the known coastal sequences, nor experienced severe cold climate conditions on its hill in the history of the plains and downlands. This leads summits (Harris 1983). Many of its slopes carry a to consideration of the implications of the concept mantle of colluvium derived from the rocky crags of landscape sensitivity. The Canterbury high forming those same summits. It offered refuges for country probably was, and is, much more sensitive a range of plants in its deep valleys, from which the to relatively small changes in climatic parameters sea was absent for most of the Otiran. Thick loess than are the lower hill and plains. It thus provides a deposits accumulated on its slopes, and while there better record of Aranuian climate change than lower is some evidence that this was reworked from a country, and this record appears to be more clearly general cover to accumulate on the lower slopes, seen in the history of vegetation change than it does most of the gullying and superficial mass movement, in the landforms. Overall, the landforms show only which is a feature of the peninsula, seems to be the effect of the gross change from glacierised to related to recent deforestation. The peninsula may non-glacierised conditions, and the downstream have recovered rapidly from the effects of Pleisto- effects (literally) that this produced in energy and cene cold climates, and offered a favourable supply of detritus. Where evidence of alternating environment for vegetation recovery during the stability and instability is found, it must be remem- Aranuian. Unfortunately, the broad outline of the bered that landforms, and particularly fluvial and Quaternary history of the peninsula is not well mass movement forms, respond to a number of Soons--Aranuian geomorphic environments in Canterbury 371 controls other than climate. Earthquakes, floods, and Carter, R. M.; Carter, L.; Johnson, D. P. 1986: Submergent storms have all contributed to the alternation of shorelines in the SW Pacific: evidence for an erosion and deposition, and the effects of occasional episodic post-glacial transgression. Sedimentology fire episodes could be significant. In building up a 33: 629-649. history of environmental changes in the Aranuian, Clayton, L. 1968: Late Pleistocene glaciations of the it is likely that the emphasis must continue to rest Waiau Valleys, North Canterbury. New Zealand heavily on information provided by vegetation journal of geology and geophysics 11: 757-767. sequences. Fitzharris, B. B.; Mansergh, G. D.; Soons, J. M. 1992: Basins and lowlands of the . In: Soons, J. M.; Selby, M. J. ed. Landforms of New Zealand. Auckland, Longman Paul. 531 p. ACKNOWLEDGMENTS Gage, M. 1958: Late Pleistocene glaciations of the Waimakariri Valley, Canterbury, New Zealand. Ian Owens, Blair Fitzharris, Neville Moar, and an anonymous referee are thanked for their comments on a New Zealand journal of geology and geophysics draft of this paper, as is Anita Pluck for drafting Fig. 1. 1: 123-155. Gellatly A. F.; Chinn, T. J. H.; Rothlisberger, F. 1988: Holocene glacier variations in New Zealand: a review. Quaternary science reviews 7: 227-242. REFERENCES Gellatly, A. F.; Rothlisberger, F.; Geyh, M. A. 1985: Holocene glacier variations in New Zealand Armon, J. W. 1973: Late Quaternary shorelines near (South Island). Zeitschrifi fiir gletscherkunde und Lake Ellesmere, Canterbury, New Zealand. New glazialgeologie 21: 265-273. Zealand journal of geology and geophysics 17: Grant, P. J. 1982: Coarse sediment yields from the upper 63-73. Waipawa River basin, Ruahine Ranges. Journal Burns, S. F.; Tonkin, P. J. 1987: Erosion and sediment of hydrology (N.Z.) 21: 81-97. transport by windthrow in a mountainous beech Harris, S. A. 1983: Infilled fissures in loess, Banks forest, New Zealand. In: Beschta, R. L.; Blinn, Peninsula, New Zealand. Polarforschung 53 (2): T.; Grant, G. E.; Swanson, F. J.; Ice, G. G. ed. 49-58. Erosion and sedimentation in the Pacific Rim. InternationaI Association of Hydrological Science Herzer, R. H. 1983: Late Quaternary stratigraphy and publication 165: 269-270. sedimentation of the Canterbury continental shelf, New Zealand. New Zealand Oceanographic Burrows, C. J. 1988: Late Otiran and early Aranuian Institute memoir 89. Wellington, Department of radiocarbon dates from South Island localities. Scientific and Industrial Research. 71 p. New Zealand natural sciences 15: 25-36. Lawrie, A. 1993: Shore platforms at +6-8 m above mean Burrows, C. J. 1989: Aranuian radiocarbon dates from sea level on Banks Peninsula and implications for moraines in the Mount Cook region, New Zealand. tectonic stability. New Zealand journal of geology New Zealand journal of geology and geophysics and geophysics 36:409-415. 32: 205-216. Mabin, M. C. G. 1984: Late Pleistocene glacial sequence Burrows, C. J.; Russell, J. B. 1990: Aranuian vegetation in the basin, mid Canterbury. New history of the , Canterbury. I. Zealand journal of geology and geophysics 27: Pollen diagrams, plant macrofossils, and buried 191-202. soils from Prospect Hill. New Zealand journal of botany 28: 323-345. McGlone, M. S. 1988: New Zealand. Pp. 557-603 in: Huntley, B.; Webb, T. III ed. Vegetation history. Burrows, C. J.; Duncan, K. W.; Spence, J. R. 1990: Dordrecht, Kluwer Academic Publishers. 803 p. Aranuian vegetation history of the Arrowsmith Range, Canterbury. II. Revised chronology for McSaveney, M. J.; Whitehouse, I. E. 1989a: An early moraines of the Cameron Glacier. New Zealand Holocene moraine in the Macaulay River valley, journal of botany 28: 455-466. central Southern Alps, New Zealand. New Zealand journal of geology and geophysics 32: 217-223. Burrows, C. J.; Randall, P.; Moar, N. T.; Butterfield, B. G. 1993: Aranuian vegetation history of the McSaveney, M. J.; Whitehouse, I. E. 1989b: Anthropic Arrowsmith Range, Canterbury, New Zealand. erosion of mountain land in Canterbury. New III. Vegetation changes in the Cameron, upper Zealand journal of ecology 12: 145-163. South Ashburton, and Paddle Hill Creek Powers, W. E. 1962: Terraces of the Hurunui River. New catchments. New Zealand journal of botany 31: Zealand journal of geology and geophysics 5: 147-174. 114-129. 372 New Zealand Journal of Botany, 1994, Vol. 32

Salinger, M. J. 1984: New Zealand climate: the last 5 Suggate, R. P. 1965: Late Pleistocene geology of the million years. In: Vogel, J. C. ed. Late Cainozoic northern part of the South Island, New Zealand. palaeoclimates of the Southern Hemisphere. New Zealand Geological Survey bulletin n.s 77. Rotterdam, A. A. Balkema. 520 p. Wellington, Government Printer. Soons, J. M.; Burrows, C. J. 1978: Dates for Otiran Tonkin, P. J.; Basher, L. R. 1990: Soil-stratigraphic deposits, including plant microfossils and techniques in the study of soil and landform macrofossils, from Rakaia Valley. New Zealand evolution across the Southern Alps, New Zealand. journal of geology and geophysics 21: 607-615. Geomorphology 3: 547-575. Soons, J. M.; Gullentops, F. W. 1973: Glacial advances Whitehouse, I. E. 1983: Distribution of large rock in the Rakaia Valley, New Zealand. New Zealand avalanche deposits in the central Southern Alps, journal of geology and geophysics 16: 425-438. New Zealand. New Zealand journal of geology and geophysics 26:271-279. Speight, J. G. 1963: Late Pleistocene historical geomor- Whitehouse, I. E.; Griffiths, G. A. 1983: Frequency and phology of the Lake Pukaki area, New Zealand. New Zealand journal of geology and geophysics hazard of large rock avalanches in the central 6: 160-188. Southern Alps, New Zealand. Geology 11:331- 334. Speight, R. 1930: The Lake Ellesmere spit. Transactions Yousif, H. S. 1987: The application of remote sensing to of the New Zealand Institute 61: 147-169. geomorphological neotectonic mapping in North Stevens, G. R. 1980: New Zealand adrift. Wellington, A. Canterbury, New Zealand. Unpublished Ph.D. H. & A. W. Reed. 442 p. thesis, University of Canterbury.