Origin and age of erosion surfaces in the upper drainage basin of Waiapu River, northeastern North Island, New Zealand

Abstract

In the upper drainage basin of Mata Ri ver, a tributary of the Waiapu River, hilltop height accordances at two levels, 500-580 m and 560-640 m above sea level, are observed. Both hilltop height accordances are inferred to represent erosion surfaces developed over folded Neogene rocks. The lower erosion surface is estimated from geomorphological position relative to the Mangamaunu Upland and tephrochronology to have been formed during a period of25 000--30 000Received 24 March 1987, accepted 21 October 1987 years from prior to c. 35000 years ago to c. 12400 years ago (late Otiran). This lower erosion surface is not an elevated peneplain but was originally formed at a high level similar to its present altitude. The lower erosion surface was probably formed by cryoplanation under cooler and slightly drier climatic conditions than present with a sparse vegetation cover. The age of the higher erosion surface is not known but it must be much older than c. 35 000 years.

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

“…Roadcut sections and peat bog cores record sequences of Late Glacial and Holocene tephras preserved on the axial ranges, but none older than the~17.7 ka Rerewhakaaitu Tephra (Vucetich and Pullar, 1969;Yoshikawa et al, 1988;Froggatt and Rogers, 1990;Lowe et al, 1999). In particular, the widespread~26.5 ka Kawakawa Tephra is absent above 800 m a.m.s.l.…”

“…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).…”

Stratigraphy and chronology of a 15 ka sequence of multi‐sourced silicic tephras in a montane peat bog, eastern North Island, New Zealand

“…Subsequent statistical analyses of all available ages on Waiohau Tephra generated mean ages that do not difl r significantly from this age (T. It is possible that these new ages contain a component if older carbon derived from catchment inwashing durii | a period of instability at around the time of deposition >f Waiohau Tephra (cf. Yoshikawa et al 1988;McGlone 199 ), and hence may overestimate the age of the tephra by sevs »1 hundred years. Evidence for such inwashing, hence probai e "old" carbon contamination, includes the overthickeni g (reworking) of the upper part of the Waiohau Tephra, I e lithological change from peat to mud following s deposition, and the relatively high proportion of degrac d pollen grains in samples taken from immediately above it (Newnham & Lowe in prep.).…”

Available water capacities of key soil layers in the Gisborne‐East Coast region, New Zealand

“…The Raukumara Range is composed mainly of well indurated early Cretaceous sandstone and mudstone with a younger sequence of alternating sandstone and mudstone in the south-eastern margin. Rivers are deeply incised as a result of rapid uplift in the order of 3-4 mm yr' during the Late Quaternary (Yoshikawa et al 1988). …”