A note on the vertical distribution of boulder fields in the archipelago of Åland (Ahvenanmaa)
Boulder field ; Coastal environment ; Fluvioglacial features ; Periglacial features ; Sea level ; Sedimentary ; Spatial distribution ; Sweden
The distribution of boulder fields situated in three different parishes in Åland is discussed. It has been found that the majority of the boulder fields are situated at altitudes that correspond to Ancylus-transgressions and an early Litorina
Boulder depressions in central Sweden. Remnants of a pre-Late Weichselian landscape?
Drumlin ; Erratic boulder ; Glaciation ; Moraine ; Palaeogeography ; Periglacial features ; Quaternary ; Sweden
During geomorphological mapping of an area in central Sweden, it was found that areas of boulder depressions tended to be mutually exclusive with drumlinized and Rogen moraine areas of Late Weichselian origin. This irregular erosion pattern probably
reflects the fact that the Late Weichselian ice sheet was partially frozen to its bed. If the situation is the same in other parts of Fennoscandia, boulder depressions may prove to be a helpful feature when searching for warm- and cold-based areas
New perspectives on colluvial boulder deposits in the southwestern Great Basin, USA
Colluvial boulder fields are ubiquitous on desert hillslopes in the Basin and Range Province. Five chronometric methods indicate that colluvial boulder fields in this region have been active in the late Pleistocene and Holocene. A new method
is presented to constrain the ages of colluvial boulder fields, using the presence of stable rock varnish and 36Cl. Rather than interpreting colluvial deposits from the traditional desert geomorphology framework of relict or active, the AA. suggest
Extensive boulder erosion resulting from a range fire on the type-pinedale moraines, Fremont Lake, Wyoming
In July 1988, the Flatfish Range Fire burned over the type-Pinedale moraines at Fremont Lake, Wyoming, and caused extensive exfoliation of exposed boulder surfaces. Fire-induced exfoliation may account for differences in boulder size and abundance
on Pinedale and Bull Lake moraines. Surface dating methods using varnish or cosmogenic nuclides may yield exposure ages that are too young if the consequences of ranges fires are not considered when sampling boulder surfaces that are within about 2 m above
Vegetation types in this zone in the Department of La Paz east of Lake Titicaca includes scrub forest, grassland, rock and boulder fields, wetlands and agricultural and ruderal fields. Strong human impact is said to explain most of these vegetation
landscapes may be greatly altered not only by direct tsunami run-up orthogonal to the shoreline, but also by episodes of vigourous backwash and by water flow sub-parallel to the coastline. Deposition of large boulders is also associated with severe tsunamis