| 1. |
- Olvmo, Mats, 1956, et al.
(författare)
-
Saprolite remnants as indicators of pre-glacial landform genesis in southeast Sweden
- 2005
-
Ingår i: Geografiska Annaler Series a-Physical Geography. - : Informa UK Limited. - 0435-3676 .- 1468-0459. ; 87A:3, s. 447-460
-
Tidskriftsartikel (refereegranskat)abstract
- Twenty-six sites with remnants of gravelly saprolites (grus) have been located in southeast Sweden. Joint block hills (castle kopjes) and steep rock walls with weathered joints as well as rounded boulders are documented to have an origin in deep weathering and subsequent stripping of saprolites. The saprolite remnants and landforms result from the fragmentation of the re-exposed sub-Cambrian peneplain along fracture systems. Only shallow saprolites occur on the elevated intact parts of the sub-Cambrian peneplain, while saprolites up to 20 m thick are encountered in areas where the sub-Cambrian peneplain is fractured and dissected. Neogene uplift with reactivation of the weathering system is thought to be the main cause of saprolite formation. Deep weathering is thus judged to have been the major agent of landform formation in the study area, while glacial and glaciofluvial erosion has contributed mainly by stripping saprolites, detaching corestones, and plucking joint blocks along weathered joints.
|
|
| 2. |
- Franzén, Lars, 1950, et al.
(författare)
-
Small Scale Glacial Erosion Forms and Their Possible Relation to Post-Glacial Weathering
- 1991
-
Ingår i: Geografiska Annaler. - 0435-3676 .- 1468-0459. ; 73:1, s. 1-7
-
Tidskriftsartikel (refereegranskat)abstract
- The paper describes several types of small scale forms on the stoss side of a roche moutonnee surface, recently exposed in a gravel pit in the Fjaras bracka complex, SW Sweden. The forms were filled with weathered rock debris. When excavated, they showed a striking resemblance to 5 forms generally accepted to be shaped by glacial/glaciofluvial erosion. In addition to these forms there were irregular cavities for instance smoothly rounded throughs and irregular rough surfaces resembling those claimed to be preglacial weathering forms. In spite of the few observations made, many small scale glacial erosion forms are likely to be the result of a three-step process i.e. glacial pressure deformation of the bedrock, subsequent weathering of the deformed rock, and finally excavation of the deformed rock by exogenic processes. Further on it seems probable that many rough surfaces of the type described in the paper are the result of glacial pressure deformation and subsequent weathering
|
|
| 3. |
- Olvmo, Mats, 1956
(författare)
-
Meltwater canyons of the "kursu" and the "skura" type.
- 1985
-
Ingår i: Geografiska Annaler. - 0435-3676 .- 1468-0459. ; 67A:1-2, s. 133-137
-
Tidskriftsartikel (refereegranskat)abstract
- ABSTRACT."Kursu-valleys" and "skuror" are special types of meltwater canyons in solid rock found in Sweden. A northern and a southern concentration are observed in the Norrbotten area and in the south Swedish Highland, respectively. This paper deals with some observations from the southern area. In this area it is apparent that many canyons are incised into rock plateaux. For these localities a subglacial origin is proposed. Alternative explanations- cannot be excluded for other localities.
|
|
