Bendigo Geographic Sub-Region
Central Otago wines, particularly Pinot Noir, are noted for their regional typicity. Winegrowers within the region also note sub-regional differences, based on both soils and weather patterns.
Māori Point vines grow on soils formed during the interglacial period after retreat of the Lindis glacier, almost half a million years ago and we are part of a distinct region which extends down the Cromwell basin as far as Northburn, close to Cromwell. Together with our neighbouring winegrowers, we have agreed to call this the Bendigo sub-region within Central Otago, and to register this as a Protected Geographical Indication (PGI).
The Cromwell basin was formed and sculpted into its present morphology by a series of glaciations, accompanied by elevation and subduction of underlying tectonic plates. The oldest Pliestocene glacier (Northburn, ≈ 1 mybp (1 million years before present)) extended down the Kawarau gorge as far as Clyde, with subsequent glaciations (Lowburn, ≈ 0.65 mybp; Lindis, ≈ 0.43 mybp) filling the Cromwell basin to successively lower altitudes. During the interglacials the valley floor was leveled by glacial melt-water, forming a series of ponds, lakes and braided riverbeds. The valley sides were formed by glacial lateral moraines, with the oldest at the highest altitudes.
The Eastern side of the Cromwell basin, from Maori Point down to Northburn, was last covered by ice during the Lindis Advance, ≈ 0.43 mybp. Since then, the valley floor has been formed by a succession of braided rivers present since the last glaciations. The Eastern side of the basin is formed by the lateral moraines of the Northburn, Lowburn and Lindis glaciers, with glacially polished schist rock formations above them, as shown in the schematic diagram.
The natural consequence of this geological history is a coherent block of land, extending from the foot of the Lindis ranges at Maori Point, past Northburn to the entrance to the Kawarau gorge. The valley floor is formed of glacial outwash gravels, lake sediments, and river boulders. The valley sides are layered lateral moraine, with the oldest soils at the highest altitudes. From the Bendigo basin through to Northburn there is a steep succession of layers, whereas further north, at the foot of the Lindis valley where two branches of the Lindis advance merged, there is a high deposit of Lindis moraine, with Lowburn and Northburn moraines higher up on the eastern side of the Ardgour valley. The natural boundary of the proposed Bendigo PGI is the summit of the Northburn advance, beginning at Maori Point (where subduction has lowered it almost to current river level), across to the Cluden moraine at the foot of the Lindis valley, and down the Eastern side of the Ardgour valley along to Bendigo and Northburn.