Soil Resources of European Volcanic Systems



Route1- August 1999

Date of description: 26-08-1999

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

Location: NW Iceland, (farm on Route N 1, 200m west of Hvammstangi road intersection)

Altitude: 40m

GPS co-ordinates: x 504800, y 724850. '

Map and co-ordinates:

WRB (2001): Orthidystri-Vitric Andosol
ST (1999): ashy, amorphic Typic Vitricryand

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Soil Climate: Cryic/Frigid temperature regime, Udic moisture regime. Annual rainfall 550 m m; mean annual temperature 2.5C, mild winter, cool summer.

Topography: Gently rolling

Landform: Glaciated upland

Land element: Slope, west facing

Position: Middle slope

Slope: Gently sloping

Form: complex

Micro topography : Hummocky area, hummocks are somewhat steep, 20-50 cm high and 0,5-1.5 m2 in size, but shapes and sizes are variable.

Landuse/Vegetation: Typical "half drained", strongly disturbed vegetation; > 80% grass cover with Carex species, (Taraxacum, Polygonum) and other flowers.

Human influences: Shallow ditch (1.5m deep, 20 yrs old) about 12m from the pit.

Parent material: Bedrock is about 10 000 yrs old glacial tilt, mostly basaltic. On the top of it are about 1 m thick aeolian and tephra deposits, mostly basaltic but with distinctive rhyolitic tephra layers. Soil has formed in aeolian and tephra sediments.

Effective soil depth: Moderately deep

Rock outcrops: none

Erosion: Currently little to no erosion.

Drainage class: Somewhat poorly drained.

Internal drainage: Saturated tor extended periods due to frost blockage, moderately hydraulic conductivity

External drainage: Slow run-off

Groundwater: No flooding but covered with snow 2-6 months per year. Very deep groundwater 100-150 cm

Moisture conditions: Mois



O: 0-5 cm; dark reddish brown (5YR 3/2); dominantly partly decomposed organic material; some mineral particles are present; very weak fine granular structure; clear and smooth to:

Ah: 5-17 cm; dark reddish brown (5YR 3/3); loam; weak, fine sub angular blocky/granular structure; friable; pores are not detectable; common very fine and fine roots; abrupt and wavy to:

AC: 17-35/50 cm; dark reddish brown (2.5YR 3/4); organic clay loam; few, fine, angular basaltic gravel, fresh and slightly weathered; weak very fine sub angular blocky structure; friable; no pores detectable; common very fine and fine roots; altered basaltic tephra spots, 5YR 2.5/1, in the top of the horizon; abrupt and wavy to:

2BC: 35/50-65 cm; dark reddish brown (5YR 3/2), and dark reddish brown (5YR 2.5/2); stratified horizon; organic clay loam; moderate fine platy structure; friable; few fine to medium iron mottles, brown to dark brown (7.5YR 4/4); common, fine to coarse roots; smooth to:

3BC: 65-73 cm; brownish yellow (10YR 6/6) and yellowish brown (10YR 5/4); organic loam; no macro structure; friable; common fine and medium roots; few, distinct iron mottles, red (2.5YR 5/8); smooth to:

3CB: 73-82 cm; stratified horizon, consisting of H4 tephras from Hekla (4000 yrs BP) having two colours: lower part yellowish brown (10YR 5/4), upper part (3 cm) very dark grey to black (5YR 2.5/1); thickness of the individual layers range from 0.5-4 cm; light coloured tephra: loam; dark coloured tephra: organic clay loam; moderate fine platy structure; friable; common fine and medium and few coarse roots; very few, fine and medium iron mottles, red (2.5YR 5/8); abrupt and smooth to:

4Bw: 82-90/100 cm; dark reddish brown (5YR 3/3); organic clay loam; few coarse partly altered basaltic gravel and stones; weak, fine sub angular blocky; friable; common fine roots; few, medium, distinct iron mottles, red (2.5YR 5/8), dominantly concentrated along pores and stones; abrupt and wavy to:

4B/Cg: > 90/100 cm; dark grey (5Y4/1); clay; many coarse gravel to boulders, sub angular, altered; no macro structure; friable; common, medium and coarse, prominent iron mottles, red (2.5YR 4/8), dominantly concentrated around pores and stones; few fine roots;



WRB (2001): no histic or folic horizon (org. C content less than 20%); vitric horizon (more than 10% volcanic glass between 5 and 90/100 cm; P-retention > 25%; Alo + Feo > 0.4 throughout); BS < 50% between 17 and 90/100 cm throughout:

Orthidystri-Vitric Andosol

 ST (1999):  no histic or folistic horizon (org. C content less than 20%); andic soil properties between 0 and >90/100 cm; 8x Sio + 2x Feo > 5, 8x Sio > 2x Feo, except for AC (17-35/50 cm):

Ashy, amorphic Typic Vitricryand

Last modified 30 April 2004 by EG