PROFILE N5 - PAZ

      Date of description: 29-04-1999

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

      Location: Faial island, Azores

      Altitude: 510m

      Latitude:

      Longitude:

      Map number and Coordinates:

      Classification:

 

 

 

 

 


      Soil Climate; Mesic temperature regime, Udic moisture regime.

      Topography: Gently undulating

      Landform: Volcano

      Land element: Slope,

      Position: Middle slope

      Slope: Sloping (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: Moist


N5 - PAZ SOIL HORIZON DESCRIPTION:

 

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

 

 


PROFILE N6 - PAZ

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 


      Soil Climate; Mesic temperature regime, Udic moisture regime.

      Topography: Hilly

      Landform: Volcano

      Land element: Slope,

      Position: Middle slope

      Slope: Located on a sloping (5-10%) slope; main slope is moderately steep

      Form: Straight slope

      Landuse/Vegetation: Forest, Cryptomeria japonica, Pittosporum undulatum, Erica agorica, Rubus, Fern

      Human influences: Profile is situated in a road cut, renewed for 1 m.

      Parent material: Basaltic pyroclastic material.

      Effective soil depth: Deep

      Erosion: No erosion features visible.

      Drainage class: Moderately well drained.

      Moisture conditions: Moist


N6 - PAZ SOIL HORIZON DESCRIPTION:

 

A1 0-35/40 cm; 5YR 3/2; clay loam; strong very fine granular in clustered distribution pattern, and strong fine and medium subangular blocky structure; very friable; common very fine and fine pores; few to common fine to medium roots; charcoal fragments; clear and smooth to:

 

AB 34/40-40/50 cm; 7.5YR3/4; clay loam; few fine subrounded totally altered gravel; pockets of strong very fine granular structure; strong fine and medium angular and subangular blocky structure; very friable; few to common very fine and fine pores; few fine and medium roots; dead roots, partially decomposed are present; clear and smooth to:

 

2AB 40/50-60/70 cm; 7.5YR 3/2; clay loam; few partially and totally weathered subrounded gravel, 2.5YR3/4 ,thixotropic; dominantly moderate fine (sub)angular blocky structure, in channels strong very fine granular structure; common very fine and fine pores; few fine roots, partially decomposed; gradual and smooth to:

 

2Bw1 60/70-95/100 cm; 10YR3/3; clay loam; few totally weathered gravel, 2.5YR3/4; very weak coarse prismatic structure, subdivided into strong very fine angular blocky structure; in channels locally strong fine granular structure; friable; common very fine and fine pores; few fine and medium roots; few dead roots; gradual and smooth to:

 

2Bw2 95/90-125 cm; 7.5YR3/4; clay loam; common fine medium and coarse totally and partially weathered gravel,in vesicles in the fragments yellowish/white allophane coatings; moderately fine angular blocky structure; friable; many fine and very fine pores; very few fine roots; dead roots present; clear and smooth to:

 

2Bw3 125-140 cm; 5YR4/4; clay loam; many fine to medium and coarse subrounded fresh ,partially and totally weathered gravel; common very fine and fine pores; few fine roots; dead roots present; abrupt and smooth to:

 

3C >140 cm; 2.5YR3/2; alteration of bands of fine gravel and gravely clay loam; bands are thixotropic; yellowish fine textured coatings.