Soil Descriptions

Descriptions of soil map units arranged physiographically (i.e. according to where it occurs in the landscape)

Ash and coral colluvium-mantled terrace scarps of raised coral islands.

Ash covering tuffs and limestone on the highest surface of ‘Eua.

Ash-covered tuffs or limestone of the highest surface of ‘Eua.

Ash-covered tuffs or limestone on the highest surface of ‘Eua.

Ash-mantled coral terrace scarps.

Ash-mantled coral terrace.

Ash-mantled coral terraces.

Ash-mantled raised coral limestone terraces and scarps.

Ash-mantled raised coral limestone terraces.

Ash-mantled raised coral terrace.

Ash-mantled rims of raised coral limestone.

Ash-mantled rolling slopes on coral terrace.

Basaltic andesite lava on central ridge and upper terrace.

Basaltic ash merging with lava flows on the east and southeast side of the island.

Beach ridge.

Calcareous marl and limestone on raised terraces and hilly land at both ends of Mango Island.

Calcareous tuffs on mid slopes of the hill area on Mango Island.

Coastal and lagoonal swamps.

Coastal beach ridges

Colluvium (from ridge and upper terrace) occupying a belt concentric to Vaipoa and Tu’avao soils.

Easy rolling plateau on western side of Vava’u.

Easy rolling surfaces of ash-covered coral limestone terraces.

Foot slopes, valley floors and depression on reworked ash mantling raised coral terraces.

Form on alluvial materials in south and southwest of island.

Form on coral sand overlying limestone concentric to Hihifo soils extending to the coast.

From vitric ash on slopes of caldera rim occupying north and west half of the island.

Low lying coastal and lagoonal swamps.

Low-lying coastal areas.

Low-lying ground, often old raised lagoon areas.

Occur behind the coastal beach deposits.

Occur on exposed coral limestone platforms along east coast of larger atolls.

Old coral limestone and admixed ash around coral pinnacles of central Nomuka Island.

Older ash on raised coral limestone terrace.

Organic rich sediments in swamps and depressions.

Rewashed ash in closed sinkhole depressions and hollows on Nomuka Island.

Rolling surfaces of ash-covered coral limestone terraces.

Sand plains behind coastal beach ridges.

Slopes of terraces, scarps of hilly land.

Sloping surfaces of ash and colluvium covered coral terraces.

Steeply sloping terrace scarps and valleys within dissected terraces.

Surfaces of the central depression and minor terraces therein. Thin ash on volcanic alluvium on coral limestone.

Uplifted and ash- mantled coral surface.

Uplifted and ash-mantled coral surface.

Uplifted ash-mantled coral surface.

Varying mix of volcanics and coral sand form on lower terrace on colluvium from top ridge and upper terrace.

Weakly weathered basaltic lavas developed on northwestern, northeastern and southern ledges on inside of caldera.

Weathered ash overlying organic sediments around edges of the swamp on Foa islands.

Young ash and andesitic tuffs on slopes around the base of the hill area on Mango Island.

Young ash and wind-blown sand inland of coastal margins.

Young ash around coastal fringe in centre of Foa and Ha'ano islands.

Young ash in broad depressions in interiors of Uiha and Lifuka islands.

Young ash on hill slopes in the centre of Tungua Island.

Young ash on raised terrace in centre of Ha'afeva Island.

Young ash on slopes in the centre of Nomuka Island.

Young ash on the interior of Lifuka Island.

Young ash over older ash or limestone on Uiha Island.

Young ash overlying coral sand on the coastal fringe.


Source of soil descriptions

Cowie, J.D.; Searle, P.L.; Widdowson, J.P.; Orbell, G.E. 1991. Soils of Tongatapu, Kingdom of Tonga. DSIR Land Resources Scientific Report 21.

Halavatau, S. 1998. The effects of soil fertility on root crop production in Tonga. Ph.D thesis, University of Queensland.

Orbell, G.E.; Rijkse, W.C.; Laffan, M.D.; Blakemore, L.C. 1985. Soils of part Vava’u Group, Kingdom of Tonga. New Zealand Soil Survey Report 66.

Wilde, R.H.; Hewitt, A.E. 1983. Soils of ‘Eua Island, Kingdom of Tonga. New Zealand Soil Survey Report 68.

Wilson, A.D.; Beecroft, F.G. 1983. Soils of the Ha’apai Group, Kingdom of Tonga. New Zealand Soil Survey Report 67.


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