Epistemological reflections on the change of the genetic model for the calcareous onyx.

Abstract

For almost 100 years the origin of calcareous onyx was explained by a syngenetic model. However, this model was ineffective when applied to mining and showed the need of another, epigenetic model. Argumentations for the first model and the reasons why ideas changed are analyzed here. The syngenetic model is attributed to an excess of confidence and a lack of epistemological vigilance in the use of the classical geological principles about the strata superposition, original horizontal sedimentation and lateral extension of strata. Such excess could persist due to two epistemological obstacles, such as basic experience and natural interpretation. The discovery of epigenetic characteristics of onyx mineralization made a change of model necessary. This change can be seen in the light of epistemological reflections which are basically inspired by kuhnian perspective. From this point of view, these characteristics are anomalies and promote a crisis, which in itself gives rise to an enigma. Later, when the epigenétic model was elaborated, the investigations were carried out again within the called normal science. The influence of the change of model on the economical exploration and exploitation of calcareous deposits is discussed. This also demonstrates the need of changing observation scales on a same object of study. Also stand out the importance of carrying out an epistemologic vigilance so that the explanations reached in a scale of observation are consistent with them carried out in other scales. This habit is as important as the observations themselves in order to reduce the researcher's subjectivity. The importance of epistemological reflection in owns scientific and professional practice and its significance for grade and post-grade studies are emphasized here. This is a condition for training future generations of critical and reflective professionals.