Tectonic and paleoclimatic significance of Quaternary to Holocene-aged river terraces of

the Waipaoa Catchment, east coast, North Island, New Zealand.

MICHAEL MARDEN, Landcare Research Private Bag 445

Gisborne, New Zealandemail: mardenm @landcareresearch.co.nz

KELVIN BERRYMAN, Institute of Geological & Nuclear SciencesP. O. Box 30 368

Lower Hutt, New Zealand.email: k.berryman@gns.cri.nz 

ALAN PALMER, Institute of Natural ResourcesCollege of SciencesMassey University,

Palmerston North, New Zealand.

email: A.S.Palmer@massey.ac.nz 

COLIN MAZENGARB, Mineral Resources TasmaniaPO Box 56, Rosny Park

Tasmania, Australia.

email: cmazen@mrt.tas.gov.au

Symbol Base Tephra Age

Quat. undifferentiated Qun Rotoehu 110 000+Waipaoa 4 W4 Rotoehu 90 000-110 000

Waipaoa 3 WRe Rotoehu c.50-60000

Waipaoa 2a WMn Mangaone c. 33 000

Waipaoa 2 WOm Omateroa 28 220 ±630Waipaoa 1b WKk Kawakawa 22590 ±230Waipaoa 1a WOk Okareka c. 18 000

Waipaoa 1 Wrk Rerewhakaaitu 14700 ±110

Holocene 8 HWh Waiohau 118500 ±60Holocene 7 HKp Karapiti 9820 ±80Holocene 6 HRm Rotoma 8530 ±10

Holocene 5 HMa Mamuka 7250 ±20Holocene 4 HWk Whakatane 4830 ±20Holocene3 HWm Waimihia 3280 ±20

Holocene 2 HTp Taupo 1850 ±10Holocene 1 HKa Kaharoa 770 ±20

Holocene undifferentiated Hun

Big Picture Scenario

• Construct sediment budget for the Waipaoa basin for specific time periods as constrained by dated terraces spanning the last 100ka

• Establish differences in mechanism drivers, scale and timing of periods of slope adjustment due to river incision across subcatchments within Waipaoa basin

Reliant on Good Databases

• Improve knowledge of terrace ages through tephra analyses and GPS especially in tributary catchments

• Intensify work on Holocene terraces

• Establish timing of major periods of sedimentation and storage volumes in tributary valley floors

• Improve knowledge of subsurface geometry of tributary streams and the main stem of the Waipaoa