Resumo

CASTILLO, Miguel  e  LUGO-HUBP, José. State of the art, classification, and proposal for the inclusion of the term knickpoint in the Spanish geological-geomorphological lexicon. Bol. Soc. Geol. Mex [online]. 2011, vol.63, n.2, pp.353-364. ISSN 1405-3322.

The term knickpoint is commonly used in geomorphology to distinguish any abrupt change in the channel slope observed along a longitudinal stream profile. Knickpoints are an expression of disequilibrium in a fluvial system and occur in both alluvial and bedrock rivers. Advances in fluvial geomorphology and landscape evolution indicate that knickpoint formation is related to tectonic, climatic and geomorphic processes. Nonetheless, at present there is no formal definition for the term. Present usage of the term knickpoint does not provide information about its triggering factors. Thus, the word knickpoint describes only a morphological property of channels. The term needs to be formally defined in Spanish, since it has been used on a casual basis. In this paper the term knickpoint is reviewed and a genetic classification is developed. Five different types of knickpoints are distinguished: glacial, lithologic, tectonic, eustatic and glacio-isostatic. It is proposed here that the term knickpoint be adopted into the geomorphic and geologic Spanish lexicon by including the genesis as an adjective attached to the noun.

Palavras-chave : knickpoint; disequilibrium; stream long profile; fluvial system; bedrock rivers.