Glacial advances in the Rakaia Valley, New Zealand

Abstract

Re-alignment of the road near the Rakaia Gorge bridge (S82) has clearly exposed deposits of the Woodlands and younger glacial advances, and their erosional or faulted relationships. Renewed geomorphological mapping in the area indicates that the Tui Creek Advance was in three phases, not one as previously recognised, so that it may have the status of a full glaciation. New details of the deposits and geomorphology related to the three phases of the last ( Acheron) advance of the Otira Glaciation indicate greater aggradation than previously supposed, and the formation of a complex of lakes during fluctuations of the glacier.

Differentiation of late Pleistocene terrace outwash deposits using geomorphic criteria: Tekapo valley, South Island, New Zealand

“…The paleochannel systems observed on the terrace surfaces represent the last channels on that surface prior to incision (Maizels 1986), so that they are likely to include a range of aggradational and degradational forms. Progressive glacier entrenchment appears to have acted as a major control on terrace incision (McGregor 1963;Soons 1972;Tuck 1975;Wellman 1979;Liedtke 1980), while high volumes of meltwater discharge associated with rapid ice melt would have provided the mechanism for rapid and substantial downcutting (e.g., Tonkin et al 1974;Fitzharris et al 1982). Periods of ice wastage were probably accompanied by the extensive accumulation of loess, derived from freshly deglaciated and still non vegetated terrain.…”

Correlation of fluvial terraces within the Hikurangi Margin, New Zealand: implications for climate and baselevel controls

“…an upland or geomorphological) perspective (e.g., Pillans, 1991 and references therein), but recently the role of other controls such as sea level (baselevel) and tectonics has started to be addressed (e.g., Leckie, 1994;Browne and Naish, 2003;Berryman et al, 2000, submitted for publication). Most of the fluvial terrace studies to date have also been on an individual river or catchment basis (e.g., Powers, 1962;Vella, 1963;Soons and Gullentops, 1973;Vella et al, 1988;Yoshikawa et al, 1988;Palmer et al, 1988;Eden, 1989;McIntosh et al, 1990;Bull, 1991, chapter 5;Almond, 1996;Berryman et al, 2000), albeit with limited correlations to well preserved terrace flights such as the Rangitikei valley terraces in the lower North Island (Milne, 1973b) and glacial outwash terraces in north Westland, South Island (e.g. Suggate, 1985;Suggate and Waight, 1999).…”

Structure and neotectonics on the Main Divide, upper Wilberforce valley, mid Canterbury, New Zealand

“…The ages of these glaciated surfaces are unknown, but some estimates are possible. The Main Divide region and its valleys were extensively glaciated until c. 14 000 yr ago, and retreat of ice from the main valleys did not occur until c. 10 000 yr ago (Soons & Gullentops 1973;Burrows & Russell 1975). Additional glacial advances occurred in the Rakaia catchment c. 4500 yr ago, and continued until <1000 yr ago (Burrows & Russell 1975).…”