ICELANDIC SOIL PROFILES

PROFILE EUR09 - IS
Hella - August 1999

Date of description: 28-08-1999 Authors: A.G. Jongmans, F. van Oort, and O. Arnalds Location: South Iceland, Hella, 600m NE of the farm Ytri-Tunga, 30m from the north-end of a 2 gr. old ditch, depth about 2.5m. Altitude: 50 m GPS co-ordinates: x 529400, y 7082600 Map number and co-ordinates Classification:     WRB (2001): Umbri-Vitric Andosol (Pachic and Orthidystric) ST (1999): Ashy, amorphic Oxyaquic Vitricryand

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Date of description: 28-08-1999

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

Location: South Iceland, Hella, 600m NE of the farm Ytri-Tunga, 30m from the north-end of a 2 gr. old ditch, depth about 2.5m.

Altitude: 50 m

GPS co-ordinates: x 529400, y 7082600

Map number and co-ordinates

Classification:    WRB (2001): Umbri-Vitric Andosol (Pachic and Orthidystric)

                        ST (1999): Ashy, amorphic Oxyaquic Vitricryand

Soil Climate; Cryic/ Frigid temperature regime; Udic moisture regime; annual rainfall: 1150 mm, mean annual temperature 4.50 C, mild winters but cool summers, 4-5 month growing season; became wetland with two drier and warmer periods when Birch forest dominated

Landform: Flat, with low gently sloping hills in between

Land element: Glacial plain, South Lowlands

Position: Middle slope

Micro topography: Hummocky level area

Landuse/Vegetation: Moderately grazed by horses; grass cover > 90%; Festuca rubra, Poa pratensis, and Descamptsia sp.

Human influences: Very noticeable environmental change about the Settlement 1125 yrs ago, increased aeolian deposition resulted in higher mineral content in the sediments and lighter soil colours. Profile is situated in a 2 yrs old ditch, 2.5 m deep

Parent material: 2.5-3m thick aeolian, tephra and organic materials. Site is near Mt Hekla and much influenced by volcanic activity in Hekla and Katla.

Effective soil depth: Moderately deep

Erosion: None

Drainage class: Somewhat poorly drained.

Internal drainage: Saturated for long periods, moderately, slow hydraulic conductivity (?)

Moisture conditions: Moist

EUR09 - IS.SOIL DESCRIPTION:

Ah:    0-55 cm; dark reddish brown (5YR 3/3); loam; the horizon has a high organic matter content; locally pockets of angular, fine gravely and sandy material; disturbed stratification, the entire horizon shows features of cryoturbation:

2C:     55-60 cm; a basaltic ash layer of 5 cm, very dark grey to black (2.5YR 2.5/0) with a loamy sand texture; friable; common fine to medium roots; clear and wavy to:

3H:    60-95 cm; dark brown (7.5YR 3/3); stratified horizon consisting of plant remnants; friable; common fine and medium roots; occurrence of discontinuous fine bands of basaltic ash; clear and wavy to:

3C:     95-100 cm; very dark greyish brown (10YR 3/2), with light spots of sand grains, light yellowish brown (10YR 6/4); no macro structure; friable; few fine roots; abrupt and wavy to:

4H:    100-230 cm; very dark grey to black (5YR 2.5/1.5); stratified horizon consisting of organic material with aeolian mineral and basaltic pyroclastic (black (2.5YR 2/0)) layers with a loamy sand texture and ranging in thickness from 1-10 cm; at 160 cm some mineral layers up to 2 cm consisting of lighter coloured rhyolitic material; organic material and ash layers are friable; at 120 and 170 cm wood remnants of birch up to 20-30 cm in size

WRB (2001): umbric horizon (0-55 cm); vitric horizon (0-55 cm; no volcanic glass data, but assumed to be more than 10%); vitric horizon (55-100 cm; Santiago data) no cryic horizon assumed between 0 and 55 cm despite cryoturbation features ((soil) temperature >0^oC):

 Umbri-Vitric Andosol (Pachic and Orthidystric)

 ST (1999): umbric epipedon (0-55 cm); andic soil properties (0-100 cm); organic soil material (>18% org. C between 60 and 95 cm); water saturation for long periods; 8x Si_o + 2x Fe_o > 5, 8x Si_o > 2x Fe_o:

Ashy, amorphic Oxyaquic Vitricryand