New Zealand Journal of Archaeology Index  >  Vol 30 Horrocks, Nichol, Cockrem and Shane

Localised Human Impacts on the Harataonga Coastal Landscape, Great Barrier Island, Northern New Zealand

 

Mark  Horrocks^1,4, Scott Nichol², John Cockrem³ and Phil Shane⁴

ABSTRACT

 

Here we present results of analyses of sediment profiles and cores, and coprolites,

from  Harataonga   Bay,    Great    Barrier   Island.    Using    a   range    of   analyses

(sedimentological, plant micro fossils, parasitological, microbial, and steroids and

myoglobin) we   concentrate   on   human   impact   and   reconstruction   of   the

geomorphology and vegetation of the near-shore environments. Two different sub-

environments are represented: dunes and alluvial plain. Dune instability coincides with

a major increase in disturbance-related plants (especially ground ferns) as a result of

forest clearance. The present form of much of the Harataonga dunes and the swamp

at the eastern end of the bay is directly a result of human impact, no earlier than 737

+ 178 ¹⁴C yr: BP. In the record from the alluvial plain of the main Harataonga

watercourse  at the western end of the bay, it is difficult to clearly resolve

sedimentary inputs that directly relate to human presence in this former tidal inlet that

was open to storm surge and stream floods. The only exception is the slopewash

materials forming the terrace surface, sediments of which bear pollen consistent with

vegetation disturbance. The landforms are natural but the rate at which the tidal inlet

was infilled to form a terrace was accelerated by human activity. The nature and

timing of the localised human impacts at Harataonga are consistent with those

observed elsewhere on Great Barrier Island and mainland New Zealand. Some of our

techniques (e.g. bacteria, steroids) are newly applied to coprolites in New Zealand

but none provided any useful information because of poor preservation.

 

SEDIMENTOLOGY,    PLANT    MICROFOSSILS,    COPROLITES, HARATAONGA BAY.

1 Microfossil Research Ltd, 31 Mont Le Grand Rd, Ml Eden, Auckland 1024, New Zealand.

2 Geoscience Australia. GPO Box 378, Canberra ACT 2601, Australia

3 Institute of Veterinary. Animal and Biomedical Sciences, Massey University, Private Bag 122 Palmerston North, New Zealand

  4 School of Geography. Geological and Environmental Science, University of Auckland, Private Bag 92-019, Auckland, New Zealand

Ó Copyright New Zealand Archaeological Association.  

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