A GEOLOGICAL MEMOIR

Te Awamutu Courier, Volume 53, Issue 3827, 30 October 1936, Page 12

A GEOLOGICAL MEMOIR

TE ANGA AND THE MARAKOPA RIVER. FIRST KING COUNTRY SURVEY. (By G. R. C.) When Laurence Cussen was engag ed upon the triangulation of the King Country he made a rapid exploration into the Marapoka district. Part ol his observations on that most inter esting area, an,d indeed, notes on th; district from Te Kuiti through to ths west, passing Te Anga, are to be found in a Parliamentary paper dat ed 1885. Extracts from the report read: “Leaving Mangawhitikau the ole native track to Marakopa crosses the Tapuae range, partly through bush aud partly through fern openings passing through old. native plantations where the land is very rich and the vegetation luxuriant. 'This old track has not been used for many years past, and it is a rough and difficult one to travel. The district is remarkable for the number of subterranean water courses and rivers. The track strikes the Marakopa river at Te Anga, and there clover and grass seem very plentiful. The river is navigable by canoes up to this, point. At the mouth of the Marakopa river arc a few native whares, and in all about a dozen reside here. At low tide there is about four feet of water near the mouth, and the channel is about 100 feet wide.” There follows a descripF.cn of the precipitous coast north and south from the bar. He mentions also the rich deposit of ironsand at Hari Hari. At laharoa (rather a famous place in Maori history) “there was at one time a considerable area of good agricultural land, and it was a very pros perous native settlement. Drift sand now covers most of it, and before long all the arable land will be covered.” One of the most desperate of Maori conflicts took place at Taharoa, which we notice to-day on account of the fresh water lake of the same name, hich is joined to the sea by a small shallow stream. OLD VOLCANIC CONES. All round the mouth of the Marakopa river we are confronted with a landscape which speaks redolently ol the past. The lonely mountain peaks (some of them ancient volcanic cones) each surrounded by a store of legend, bear silent witness to far off days when a civilisation passed away lived closely about. The little village of Te Anga, which is rapidly progressing now that roads Lave supplanted the slow laborious canoe voyage, was existent in Cursen’s day. “The country about is broken and very 'picturesque, high limestone cliffs fringing- the river banks and appearing above the trees in the forest.” Descending the steep hill road into Te Anga more than one new traveller to the district has been struck with the impressive situation of the settlement. Not far away is <he roaring cataract of water, the , Marakopa falls. Every stream and -river hereabouts repays investigation. Geologically thq record is one of tremendous upheavals,, eartli tilts and subsidence. The streams flow for the earlier part of their routes along ancient valleys, but before they meet levels of sea near Te Anga, they plunge down rocky declines beneath huge boulders, the spectacle one of rough confusion. A virgin field for speculation awaits the incipient scientist in the locality. Time could be profitablyspent in getting pictures of the very broken landscapes, but throughout the area is an illimitable field for interesting discovery, REMNANTS OF THE ANCIENT TRAIL. Parts of the old native trail which was so important a link a century and more back can be located still. It was a more or less direct route, one of the very few trails from the interior to this part of the west coast. It must naturally figure more than once in storied and legendary incidents. Whatever the associations of the Marakopa river in this respect, the three places must be closely linked; the easily navigated river from the Tasman sea, a track which ran from Kinohaku on the upper reaches of Kawhia harbour, and the overland track to Mangawhitikau, which all met at Te Anga, the flood plain of descending hill streams. LATER GEOLOGICAL INVESTIGATION. What we know of the geology of the region is only fragmentary, but is intensely interesting. It is based principally on a flying visit which 1 ark made in 1886-87, the able observations qf Cussen, and more recently in 1922, a reconnaissance made by Henderson and Grange for the Government. From the latter report the' following facts are gleaned: The Marakopa district is described as partly cleared, partly a broken and deeply dissected plateau. The highest elevation on the coast is the mountain of Maungamangero, 2,656 feet. Neighbouring summits are Moeatoa Mountain, 1,206 feet —a peak which figures in some of James Cowan’s collected legends of the locality—and Whareorino Mountain, 2,130 feet, a summit scarcely less noted in story. Most of the streams begin on the Tawairoa and Hauturu plateaux, which it is supposed at one time extended at the same altitude right to the coast. Support for the theory is lent by the “flat” prospect one views looking across this country from an elevation near the coast which has not been affected by the earth depression (say on Orangiwhao trig, 996 feet, on Albatross Point). Views from such summits are indeed not the least remarkable features of an unique district. From Te Anga through to Waitomo and Te Kuiti tertiary rocks are most prominently represented by the limestone series; continuously to be found in varying degrees of thickness, and weather worn to a degree depending on their purity. The source of the Marakopa river is in a basin extending eastward to the watershed of the Mokau and Waipa rivers. It flows in a “mature” valley five or six hundred feet above the sea for several miles before plunging down the falls near Te Anga. The Tawarau stream similarly begins life in well formed valleys, and reaches a narrow gorge (at the point where land subsidence has taken place) down, which it cataracts fcr five miles over and under enormous

boulders before it reaches the flood plain at Te Anga. “STORIES IN ROCKS.” From Tc Anga the Marakopa flows between the walls of a precipitous valley witli scarcely any fall; on one side mesozoic rocks are found and on tlie south side tertiary limestones, the contrast in age series of the opposite sides being due to a fault line. Seven miles from the sea the river is tidal, but at one time it is said all this rich' silt plain was an inlet from the sea which the river has gradually lilled up. The levels which at one time existed, and which have been so contorted by uplift of earth blocks in some parts and subsidence elsewhere, are widely illustrated, but it is very difficult for the layman to piece together any consistent geological sequence in the broken countryside which 'he sees. Kawhia harbour itself is a “drowned” valley ot the rivers which empty therein—it has definitely subsided, and this general depression would be revealed all along tlie coast, were it not for tlie rock spurs protruding which have aided sand consolidation, and formed that series of inland shallow lakes (Taharoa and Rototapu), and the estuary harbours of Kawhia and Aotea.