Ph. Renault


Distinction is made between the experiment which “demonstrates” having an argumentative value - and the experiment which “questions” nature by isolating one factor and by determining the mode of its action. The concept of experiment in geology and in geodynamics and the distinctions between geodynamics and geophysics are discussed. Karstic geodynamics considers the action of fluids - mainly liquids - on a soluble rock. It is a science bordering the different branches of geochemistry, hydrology, the mechanics of rocks, and geophysics. Researches in karstic geodynamics are based upon measurements obtained through field surveys, or upon the utilization of a subterranean laboratory. However, in the laboratory this hardly surpasses the stage of experimental demonstration. A series of simple experiments are enumerated to exemplify the above statement, like the one where the attack of a diluted acid on a soluble rock is utilized, in order to enable us to classify the major problems encountered in karstic corrosion. The last chapter discusses the bicarbonate equilibriums of Ca-CO2. Experiment furnishes the empiric criterion on which scientific theory is founded. Each discipline has its own methodology dependent on the object under study having experimental criteria of different nature. This is particularly true in case of such distant phenomena which no longer have a common ground with human dimensions like space for astronomy or time for geology. In such cases the possibilities of “instrumental” experimentations are very limited. After a brief recollection of the principles of experimental procedure and the history of the experiments attempted by geodynamicians (tectonics, geomorphology, etc.) we will analyze several methods of investigation and by relying exactly on the example of karstic corrosion we shall determine those which have a value for the science of karstology.