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Tenosols [TE]


Concept

This order is designed to embrace soils with generally only weak pedologic organisation apart from the A horizons. It encompasses a rather diverse range of soils, which are nevertheless widespread in many parts of Australia.

map
Distribution of Tenosols in Australia.
Soil Profile (View type example photo of Yellow-Orthic Tenosol).

Definition

Soils that do not fit the requirements of any other soil orders and generally with one or more of the following:

  1. A peaty horizon.
  2. A humose, melacic or melanic horizon, or conspicuously bleached A2 horizon, which overlies a calcrete pan, hard unweathered rock or other hard materials; or partially weathered or decomposed rock or saprolite, or unconsolidated mineral materials.
  3. A horizons which meet all the conditions for a peaty, humose, melacic or melanic horizon except the depth requirement, and directly overlie a calcrete pan, hard unweathered rock or other hard materials; or partially weathered or decomposed rock or saprolite, or unconsolidated mineral materials.
  4. A1 horizons which have more than a weak development of structure and directly overlie a calcrete pan, hard unweathered rock or other hard materials; or partially weathered or decomposed rock or saprolite, or unconsolidated mineral materials.
  5. An A2 horizon which overlies a calcrete pan, hard unweathered rock or other hard materials; or partially weathered or decomposed rock or saprolite, or unconsolidated mineral materials.
  6. Either a tenic B horizon, or a B2 horizon with 15% clay (SL) or less1 , or a transitional horizon (C/B) occurring in fissures in the parent rock or saprolite which contains between 10 and 50% of B horizon material (including pedogenic carbonate).
  7. A ferric or bauxitic horizon >0.2 m thick.
  8. A calcareous horizon >0.2 m thick.

Comment

It may be desirable to specify a minimum thickness for those A1 horizons which do not meet the requirements for a peaty, humose, melacic or melanic horizon. The inclusion of certain soils with conspicuously bleached A2 horizons may be questioned by some, but it is difficult to find a more appropriate place for them.

The Tenosols will differ from Rudosols by virtue of having either a more than weakly developed A1 horizon, an A2, or a weakly developed B horizon. As B horizons are difficult to identify consistently in some Tenosols, specific mention of a B horizon is omitted from some Suborders. They will obviously grade to Kandosols, and some difficulty may be experienced in separating medium-textured Tenosols from Kandosols. Here again, B horizon development is the key; Kandosols must have a clearly distinguishable, well-developed B2 horizon with more than 15% clay. Tenosols will also grade to Podosols, but the latter must have a Podosol diagnostic B horizon. In cold, wet environments, some Tenosols with peaty A horizons will grade to Organosols.

This revised edition of the Australian Soil Classification includes three major changes to the Tenosol order. First, the Calcenic suborder has been added to cover soils with non-calcareous A horizons, more than 0.2m thick, with highly calcareous sub-surface horizons, which fail to classify as Kandosols due to insufficient clay content (>15% clay is needed for Kandosols). Second, the former Orthic suborder has been split to include soil colour. Finally, the Sesqui-Nodular suborder has been added to bring together soils dominated by bauxitic or ferric nodules or concretions.

Suborders

  • Soils with a peaty, humose, melacic or melanic horizon, and are underlain within 0.5 m of the surface by a calcrete pan; hard unweathered rock or other hard materials; or partially weathered or decomposed rock or saprolite. An unbleached A2 horizon may be present between the dark surface horizons and the substrate material.
  • Chernic-Leptic [BF]
  • Other soils with a peaty, humose, melacic or melanic horizon. A conspicuously bleached A2 horizon is not present.
  • Chernic [BE]
  • Soils with a ferric or bauxitic horizon (nodules or concretions) that is at least 0.2 m thick and occupies >50% of the solum depth. The solum depth excludes cemented layers.
  • Sesqui-Nodular [IL] 3
  • Soils with a calcareous horizon (consisting of more than 20% pedogenic carbonate) that is at least 0.2 m thick.
  • Calcenic [IM]
  • Soils with a conspicuously bleached A2 horizon, and are underlain within 0.5 m of the surface by a calcrete pan ; hard unweathered rock or other hard materials; or partially weathered or decomposed rock or saprolite.
  • Bleached-Leptic [AW]
  • Other soils which are underlain within 0.5 m of the surface by a calcrete pan; hard unweathered rock or other hard materials; or partially weathered or decomposed rock or saprolite.
  • Leptic [CY]
  • Other soils with a conspicuously bleached A2 horizon.
  • Bleached-Orthic [GZ]
  • Soils in which the dominant colour class in the upper 0.5 m of the solum is red.
  • Red-Orthic [IN]
  • Soils in which the dominant colour class in the upper 0.5 m of the solum is brown.
  • Brown-Orthic [IO]
  • Soils in which the dominant colour class in the upper 0.5 m of the solum is yellow.
  • Yellow-Orthic [IP]
  • Soils in which the dominant colour class in the upper 0.5 m of the solum is grey.
  • Grey-Orthic [IQ]
  • Soils in which the dominant colour class in the upper 0.5 m of the solum is black.
  • Black-Orthic [IR]

Great Groups

Chernic-Leptic and Leptic Tenosols

Chernic Tenosols

  • Soils which overlie a ferricrete, petroreticulite, or a petroferric horizon.
  • Petroferric [EA]
  • Soils which overlie a hard siliceous pan.
  • Silpanic [EM]
  • Soils which overlie a calcrete pan.
  • Petrocalcic [DZ]
  • Soils with a thin ironpan.
  • Placic [EC]
  • Soils which have andic properties and has formed in basaltic tephric materials that may be visibly stratified.
  • Andic [AK]
  • Other soils which have formed in tephric materials that may be visibly stratified.
  • Tephric [HF]
  • Soils with a bauxitic horizon.
  • Bauxitic [AS]
  • Soils with a ferric horizon.
  • Ferric [BU]
  • Soils with a tenic B horizon or a transitional horizon (C/B) occurring in fissures in the parent rock or saprolite which contains between 10 and 50% of B horizon material (including pedogenic carbonate).
  • Inceptic [IA]
  • Soils which overlie hard rock.
  • Lithic [CZ]
  • Soils which overlie partially weathered or decomposed rock or saprolite.
  • Paralithic [DU]
  • Soils in which the B and C horizons consist of unconsolidated calcareous material which dominantly consists of sand-sized fragments of shells and other aquatic skeletons (identifiable under a 10 x hand lens).
  • Shelly [EL]
  • Soils which overlie marl.
  • Marly [DD]
  • Soils which overlie other unconsolidated mineral materials.
  • Regolithic [GF]

Sesqui-Nodular Tenosols

Calcenic Tenosols

  • Soils which overlie a red-brown hardpan.
  • Duric [BJ]
  • Soils which overlie a hard siliceous pan.
  • Silpanic [EM]
  • Soils which overlie a calcrete pan.
  • Petrocalcic [DZ]
  • Soils with a ferric horizon within the solum.
  • Ferric [BU]
  • Soils which have andic properties and has formed in basaltic tephric materials that may be visibly stratified.
  • Andic [AK]
  • Other soils which have formed in tephric materials that may be visibly stratified.
  • Tephric [HF]
  • Soils with an argic horizon within the solum.
  • Argic [AP]
  • Soils which overlie hard rock.
  • Lithic [CZ]
  • Soils which overlie partially weathered or decomposed rock or saprolite.
  • Paralithic [DU]
  • Soils in which the profile is non or only slightly gravelly (<10% >2mm) throughout, the soil material is either loose or weakly coherent both moist and dry, may have aeolian cross-bedding , and its texture is sandy (ie. S-LS-CS, up to 10% clay) throughout.
  • Arenic [AO]
  • Soils which overlie other unconsolidated mineral materials.
  • Regolithic [GF]

Bleached-Leptic Tenosols

Bleached-Orthic, Red-Orthic, Brown-Orthic, Yellow-Orthic, Grey-Orthic and Black-Orthic Tenosols

  • Soils which have a ferric horizon and overlies a red-brown hardpan.
  • Ferric-Duric [FK]
  • Other soils which overlie a red-brown hardpan.
  • Duric [BJ]
  • Soils which contains a ferric horizon and which overlie a ferricrete, petroreticulite or a petroferric horizon.
  • Ferric-Petroferric [GE]
  • Soils which overlie a ferricrete, petroreticulite or a petroferric horizon.
  • Petroferric [EA]
  • Soils which overlie a hard siliceous pan.
  • Silpanic [EM]
  • Soils which overlie a calcrete pan.
  • Petrocalcic [DZ]
  • Soils which contain a ferric horizon and which overlie a reticulite horizon.
  • Ferric-Reticulate [IS]
  • Soils which overlie a reticulite horizon.
  • Reticulate [EF]
  • Soils with a ferric horizon.
  • Ferric [BU]
  • Soils with a bauxitic horizon.
  • Bauxitic [AS]
  • Soils which have andic properties and has formed in basaltic tephric materials that may be visibly stratified.
  • Andic [AK]
  • Soils which have formed in tephric materials that may be visibly stratified.
  • Tephric [HF]
  • Soils with an argic horizon.
  • Argic [AP]
  • Soils with a tenic B horizon or a transitional horizon (C/B) occurring in fissures in the parent rock or saprolite which contains between 10 and 50% of B horizon material (including pedogenic carbonate).
  • Inceptic [IA]
  • Soils which overliehard rock.
  • Lithic [CZ]
  • Soils which overlie partially weathered or decomposed rock or saprolite.
  • Paralithic [DU]
  • Soils in which the profile is not or only slightly gravelly (<10% >2mm) throughout, the soil material is either loose or only weakly coherent both moist and dry, may have aeolian cross bedding, and its texture is sandy (ie. S-LS-CS, up to 10% clay) throughout.
  • Arenic [AO]
  • Soils in which the B and C horizons consist of unconsolidated calcareous material which dominantly consists of sand-sized fragments of shells and other aquatic skeletons (identifiable under a 10 x hand lens).
  • Shelly [EL]
  • Soils which overlie marl.
  • Marly [DD]
  • Soils in which the B horizon directly overlies other unconsolidated mineral materials.
  • Regolithic [GF]

Subgroups

These have been grouped into the various suborders, but not all subgroups will be appropriate for each great group of a particular suborder.

Subgroups of Chernic-Leptic Tenosols

Subgroups of Chernic Tenosols

Subgroups of Sesqui-Nodular Tenosols

  • Soils with a conspicuously bleached A2 horizon and a manganic horizon within the solum.
  • Bleached-Manganic [AY]
  • Other soils with a manganic horizon with the solum.
  • Manganic [DC]
  • Soils with a conspicuously bleached A2 horizon.
  • Bleached [AT]
  • Soils in which the major part of the solum is strongly acid.
  • Acidic [AI]
  • Soils in which the major part of the solum is not strongly acid and no part of the solum is calcareous.
  • Basic [AR]
  • Other soils in which at least some part of the solum is calcareous.
  • Calcareous [BC]

Subgroups of Calcenic Tenosols

Subgroups of Bleached-Leptic Tenosols

Subgroups of Leptic Tenosols

  • Soils with all the requirements for a peaty horizon except the thickness.
  • Subpeaty [ID]
  • Soils with all the requirements of a humose horizon except the thickness.
  • Subhumose [DR]
  • Soils with all the requirements of a melacic horizon except the thickness.
  • Submelacic [FF]
  • Soils with all the requirements of a melanic horizon except the thickness.
  • Submelanic [FG]
  • Soils in which the major part of the solum is strongly acid.
  • Acidic [AI]
  • Soils in which the major part of the solum is not strongly acid and no part of the solum is calcareous.
  • Basic [AR]
  • Other soils in which at least some part of the solum is calcareous.
  • Calcareous [BC]

Subgroups of Bleached-Orthic Tenosols

Subgroups of Red-Orthic, Brown-Orthic, Yellow-Orthic, Grey-Orthic, Black-Orthic Tenosols

  • Soils with all the requirements for a peaty horizon except the thickness.
  • Subpeaty [ID]
  • Soils with all the requirements of a humose horizon except the thickness.
  • Subhumose [DR]
  • Soils with all the requirements of a melacic horizon except the thickness.
  • Submelacic [FF]
  • Soils with all the requirements of a melanic horizon except the thickness.
  • Submelanic [FG]
  • Other soils with a manganic horizon with the solum.
  • Manganic [DC]
  • Soils in which the major part of the solum is strongly acid.
  • Acidic [AI]
  • Soils in which the major part of the solum is not strongly acid and no part of the solum is calcareous.
  • Basic [AR]
  • Other soils in which at least some part of the solum is calcareous.
  • Calcareous [BC]

Family Criteria

Note that in some suborders the soil depth may be the same as A1 horizon thickness. In those suborders it will not be relevant to record maximum B horizon texture.

A1 horizon thickness

Thin [A] : < 0.1 m
Medium [B] : 0.1 - < 0.3 m
Thick [C] : 0.3 - 0.6 m
Very thick [D] : > 0.6 m

Gravel of surface and A1 horizon

Non-gravelly [E] : < 2%
Slightly gravelly [F] : 2 - < 10%
Gravelly [G] : 10 - < 20%
Moderately gravelly [H] : 20 - 50%
Very gravelly [I] : > 50%

A1 horizon texture

Peaty [J] : see Peaty horizon
Sandy [K] : S-LS-CS (up to 10% clay)
Loamy [L] : SL-L (10-20% clay)
Clay loamy [M] : SCL-CL (20-35% clay)
Silty [N] : ZL-ZCL (25-35% clay and silt 25% or more)
Clayey [O] : LC-MC-HC (> 35% clay)

B horizon maximum texture2

Sandy [K] : S-LS-CS (up to 10% clay)
Loamy [L] : SL-L (10-20% clay)
Clay loamy [M] : SCL-CL (20-35% clay)
Silty [N] : ZL-ZCL (25-35% clay and silt 25% or more)
Clayey [O] : LC - MC - HC (> 35% clay)

Soil depth

Very shallow [T] : < 0.25 m
Shallow [U] : 0.25 - < 0.5 m
Moderate [V] : 0.5 - < 1.0 m
Deep [W] : 1.0 - < 1.5 m
Very deep [X] : 1.5 - 5 m
Giant [Y] : > 5 m

1 This means that a strongly developed B2w horizon in terms of colour development, is allowed in Tenosols provided the clay content does not exceed 15%.

2 This refers to the most clayey field texture category.

3 Genetically these soils are related to Podosols.

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