Embed Size (px)
Citation preview
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: [email protected]
ALAN PALMER, Institute of Natural ResourcesCollege of SciencesMassey University,
Palmerston North, New Zealand.
email: [email protected]
COLIN MAZENGARB, Mineral Resources TasmaniaPO Box 56, Rosny Park
Tasmania, Australia.
email: [email protected]
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
