Quaternary environmental change in New Zealand: a review

Abstract

The discovery that orbital variations are the driving force behind Quaternary climate change provides an impetus to set local and regional records of environmental change into the global context, a principle that has been strongly embraced by Quaternary scientists working in New Zealand. Their major achievements and significant current initiatives are reviewed here. The importance of the New Zealand Quaternary stems from its geographical context: a climatically sensitive, remote oceanic, southern location spanning 17 degrees of the mid-latitudes; an obliquely convergent plate boundary setting resulting in a high mountain range athwart the prevailing westerlies, active volcanism, a youthful and dynamic landscape, and mountains high enough to maintain glaciers today; and a remarkably short prehistory. The resultant records show marked environmental changes due not only to climatic oscillations but also to vigorous, active tectonism and volcanism. The Taupo Volcanic Zone, containing the world's strongest concentration of youthful rhyolitic volcanoes, has produced at least 10 000 km3 of magma in the last 2 Ma. Climatic interpretations of records from marine sediments in the New Zealand region, together with several long sequences of alternating marine and terrestrial sediments, indicate broad synchrony with Northern Hemisphere events (within limitations of dating), although there are differences in detail for shorter-term climatic events. It is not yet certain that glacial advances coincided precisely with those in the Northern Hemisphere or were of similar duration. Late Cainozoic glaciation commenced c. 2.6-2.4 Ma but the record of glacial deposits is fragmentary and poorly dated except for the most recent events. The Last (Otira) Glaciation, from c. 100-10 ka, was characterized by at least five glacial advances including during the Last Glacial Maximum from 25 to 15 ka, when snowlines fell by 600-800 m. New Zealand evidence for cooling during the Younger Dryas stade is equivocal whilst isotopic records from speleothems, and other data, indicate warmer and wetter conditions from 10-7 ka, broadly conforming with records from mid-latitude Northern Hemisphere locations. Future advances will require sampling at shorter timescales, improvements in the accuracy and precision of existing dating methods and the development of new ones, extension of palaeoecological techniques to cover the full potential of new Zealand's diverse biota, and a stronger emphasis on quantification of palaeoclimatic parameters.

Stratigraphy, age, and correlation of voluminous debris‐avalanche events from an ancestral Egmont Volcano: Implications for coastal plain construction and regional hazard assessment

“…An age of 47 14 C ka (ANU-5642), estimated to be the equivalent of up to c. 55 cal ka, was reported by Newnham et al (2004). The occurrence of Rotoehu Ash in marine cores off north-eastern New Zealand indicates likely deposition during early OIS 3 (Wright et al 1995;Newnham et al 1999Newnham et al ,2004, consistent with an age of c. 50-55 ka.…”

Avifaunal changes revealed in Quaternary deposits near Waitomo Caves, North Island, New Zealand

“…The LGM at about 18 000 14 C yr BP saw temperatures depressed by as much as 5°C below present and lowering of snowlines by 600-800 m. Whether treelines were lowered by an equal amount is doubtful, but vegetation communities certainly changed drastically over the period. Most sites of LGM age south of 37°S had a pollen flora indicating a vegetation similar to that at or above the present treeline (Newnham et al 1999).…”

“…The period from the Otira Glacial (Oxygen Isotope Stages 2, 3) to the late Holocene period was marked by substantial climatic and associated vegetation changes throughout New Zealand (McGlone 1988;Newnham et al 1999). The LGM at about 18 000 14 C yr BP saw temperatures depressed by as much as 5°C below present and lowering of snowlines by 600-800 m. Whether treelines were lowered by an equal amount is doubtful, but vegetation communities certainly changed drastically over the period.…”

“…As it was usually an inhabitant of closed-canopy forest (Worthy 1990), A. didiformis would mainly be expected from sites deposited when interglacial conditions prevailed, if such sites are in regions where closed-canopy forests were not present during the Glacial period. Most sites south of 38°S are in this category (Newnham et al 1999).…”

Geomorphology of the Rees Valley, Otago, New Zealand

“…Barrell, 2011;Barrell et al, 2011;Newnham et al, 1999). Seven glacials have been correlated with Marine Isotope Stages (MIS) 2, 3, 4, 6, 8, 10 and 12, as well as five interglacials correlated with MIS 1, 5, 7, 9 and 11.…”