Soil Resources of European Volcanic Systems


Faial island, Azores - april 1999

Date of description: 29-04-1999

Authors: A.G. Jongmans, and F. van   Oort 

Faial island, Azores

 510 m


Map number and Coordinates: 


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Soil Climate: Mesic temperature regime, Udic moisture regime.
Topography: Gently undulating
Landform: Volcano
Land element: Slope,
Position: Middle slope
Slope: Steep , 10-15%
Form: Concave
Landuse/Vegetation: Extensive grazing, pasture
Human influences: Profile is situated in a road cut, renewed for 1 m.
Parent material: Pyroclastic material.
Effective soil depth: Deep
Erosion: No erosion features visible.
Drainage class: Well drained
Moisture conditions: Slightly moist


A1: 0-25 cm: 7.5YR 3/2; silt loam; few fine to medium gravel consisting of white pumice- and dark basaltic fragments, partially weathered; weak, very fine (sub) angular blocky structure; friable; few very fine to fine pores; common fine roots; 0-5 cm Fe coatings round pores; abrupt and smooth to:
A/C:  25-30 cm: 10YR 4/3 10YR 5/3; disturbed layered loamy sand; common fine to medium slightly to strongly weathered gravel consisting of pumice; friable and firm; few fine pores; few fine roots; abrupt and smooth to: 
2Ab: 30-45 cm; 7.5YR 3/2; clay loam; very few, very fine gravel; moderate ,medium, compound rough prismatic structure, subdivided into weak, very fine, (sub)angular blocky structure; friable; common very fine and fine pores; few very fine roots; slightly thixotropic; gradual and smooth to;
2Bw: 45-65 cm; 7.5YR 4/3; clay loam; weak very fine and fine subangular and angular blocky structure; friable; many very fine and fine pores; few very fine and fine roots; in the lower part of the horizon occurrence of angular fragments of the 2 C1 horizon; gradual and smooth to:
2Bw/C: 65-90 cm; This horizon consists of two parts: 2Bw material already described and angular pieces of 2C1 material which are described below; in the 2Bw material presence of fine textured allophane coatings with Fe compounds, diameter 1 mm.; clear and smooth to:
2C1: 90-110 cm; 10YR 3/1; clay loam; structureless massive; firm to extremely hard; presence of skew planes, coated by fine textured material 10YR 4/6 to 10YR 5/8, and Fe coatings, 5YR3/4 , few very fine pores coated with fine textured material 2.5YR 8/4 and Mn coatings 10YR 2/1; abrupt and wavy to:
2C2: 110-130 cm; indurated lapilli, partially covered by iron, 10YR 3/2, partially altered and thixotropic, locally allophane coatings 2.5YR 8/4; clear and smooth to:
3BC: 130-145 cm; 7.5YR 4/4; clay loam; weak very fine to fine subangular blocky structure; friable; many fine pores; 40% totally altered pumice fragments, 5YR 6/8; abrupt and smooth to
4Bw. Not described

Last modified 13 May 2002 by EG