Pascal Bertran

Micromorphology of atlantic rankers on the coast of northern Portugal

Summary The micromorphological examination of atlantic rankers on the coast of northern Portugal shows the importance of alternating phases of landscape stability and instability during the genesis of the profiles. Archaeological artifacts and marine deposits allow the dating of these events. Recent pedogenesis is characterized by the formation of a microgranular structure and the illuviation of amorphous organic matter. Remnants of an older leached phase in the Gelfa section reflect an initial weakly base desaturation stage. During historical times the soil was buried under eolian sands.

ESTUDIO GEOLÓGICO PRELIMINAR DEL ALERO ROCOSO CERRO CASTILLO (PATAGONIA AUSTRAL, CHILE)

* ABSTRACT The study of the Cerro Castillo rockshelter (Patagonia, southernmost Chile) identify four main sedimentary phases: 1) deposition of calcareous detritus derived from the fragmentation of the rock wall during the early Holocene, 2) development of a decalcified forest brown soil dated to ca. 4800 14 C BP, probably in connection with a wet period, 3) formation of a colluvial calcareous humus horizon, associated with a steppic vegetation and 4) deposition of cattle excrements. The microartefact content (lithic industry, charcoal, bone fragments) of the layers shows significant fluctuations along the stratigraphy. These are attributed either to anthropogenic (multiple human occupation) or natural factors (artefact redistribution due to overland flow, bone dissolution in the palaeosoil).