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The Pakoka River is a river of the Waikato Region of New Zealand's North Island. It flows southwest from its source southeast of Raglan to reach the northeastern end of the Aotea Harbour. The catchment is made up of just over of waterways.〔(page 58 of West Coast Liaison Zone Subcommittee agenda August 2014 - Aotea Harbour Catchment Condition Survey )〕 == Geology == The most notable features of the Pakoka valley were formed by Upper Pliocene–Lower Pleistocene Okete Volcanics about 2 million years ago. These rocks form the top of the Wharauroa Plateau, where the Pakoka rises. They also flowed down from a vent about a kilometre northwest of Bridal Veil Falls to block the valley and form the falls. From its source the river soon drops about , cutting into Coleman Conglomerate a Puaroan (in the Tithonian epoch, about 150 million years ago) poorly sorted conglomerate of sandstone and siltstone, containing andesitic pebbles up to in diameter. A rock arch and several notable bluffs are formed of late Whaingaroan Ahirau Sandstone formed about 28 million years ago. Although classified as sandstone, it looks more like limestone, with 40-60% calcium carbonate content and lapiez features in massive (lacking internal structures), blue-grey, calcareous, fine sandstone. Apart from recent alluvial deposits, the other main rock in the valley is Hauturu Sandstone, which is mid to late Whaingaroan, about 30 million years old. It is commonly knobbly due to resistant bands and lenses of hard calcareous sandstone in soft friable quartzofeldspathic sand〔Geology of the Raglan-Kawhia Area: Institute of Geological & Nuclear Sciences (N.Z.), Barry Clayton Waterhouse, P. J. White 1994 ISBN 0-478-08837-X〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pakoka River」の詳細全文を読む スポンサード リンク
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