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BOLETÍN DE LA SOCIEDAD GEOLÓGICA MEXICANA http://dx.doi.org/10.18268/BSGM2011v63n2a15 |
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Estado actual del conocimiento, clasificación y propuesta de inclusión del término knickpoint en el léxico geológico–geomorfológico del español
State of the art, classification, and proposal for the inclusion of the term knickpoint in the Spanish geological–geomorphological lexicon
Miguel Castillo1,* y José Lugo–Hubp2
1 School of Geographical and Earth Sciences, University of Glasgow, University Avenue, G20 QQ, Glasgow, Reino Unido.
2 Instituto de Geografía, UNAM. Ciudad Universitaria, 04510, México, D.F.
*This email address is being protected from spambots. You need JavaScript enabled to view it..
Abstract
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.
Keywords: knickpoint, disequilibrium, stream long profile, fluvial system, bedrock rivers.
