Using time by students and teachers: obstacles and explanatory register in coupling biology-geology

In this paper , we shall discuss, theoretically, obstacles and explanatory register to understand how to build a problem in science, especially when using time in coupling geology and biology. We shall also explain time in its geologic and didactic approaches. We try to understand the incommensurability of time and its infinitesimal division when using it to demonstrate a relationship between biology and geology. In literature, time is divided into three types: deep, sagittal or cyclic. Which types of time is used by students and teachers? Educationally, we seek to answer these questions: which obstacles students and teachers are faced with when they use to a type of time? Do students and teachers work in the same explanatory register when they relate time to other concepts