PALAEOENVIRONMENT CHANGES ANALYSIS USING PROGRAMMING TECHNIQUES: OSTRACODS ASSEMBLAGE AS CLIMATIC PROXY
This work aim is to design some computer activities based on common geological problems. During the last years, geology grade students feel dissatisfaction on “Introduction to Computation” subject. The students don’t understand the requirement of any programming language on their education profile and do not perceive the programming language as an important skill for geology. To solve this situation, teachers from two different subjects, “Introduction to Computation” and “Complements of Geology”, analyzed the problem and decided to propose new laboratory activities in the context of real geological situations.
The proposed activity was developed in three stages. First, the real geological problem is explained by the “Complements of Geology” teacher. Second, the students are introduced by the “Introduction to Computation” teacher the programming exercise that they will have to solve to create a useful computer tool. Third, and helped by both teachers, the students solve the geological problem using the computer program.
The selected activity was the analysis of climate change based on a paleoclimatic proxy. The paleoclimate proxies are physical, chemical and biological materials preserved within geological records that can be analyzed and correlated with climate or environmental parameters in actual times. These data help us to understand how the Earth's climate system varied before and after human alteration of the landscape. In this practice we propose to the students the usage of ostracod crustaceans as a tool to study palaeoenvironmental changes.
The proposed activity includes a palaeoenvironmental study developed at different water pools from Bardenas Reales zone (Navarre, Iberian Peninsula) based on ostracods assemblage analysis. The distribution of ostracods is related with physico-chemical parameters of waters (T, salinity, pH or dissolved oxygen) and the sediment characteristics (grain-size, sedimentation rate...). The statement of the problem provides the catalogue of the ostracods species assemblage recognized at the different pools located on different lithological substrates in a geologic map. The students analyze the diversity of ostracod assemblages in each pool and then the variability of species using the Fisher Index, which can be used to group the pools. At the same time they recognize the relative abundance of a specific ostracod specie in each set and correlate the specific specie with a specific Fisher group. They must observe the map where the pools are located and notice the orientation, the scale and the leyend. They can realize that the pools are located on different lithologies, and as the lithology influences on water physical parameters (salinity, pH…), the students are induced to discern a possible relationship between the occurrence of specific ostracod species and the lithology and, between the water and the lithology.
To obtain the Fisher index of a pool, the students must implement a computer algorithm based on iterative control flow structures. This exercise is a clear example of convergence problems where the student must discern between available iterative control flow structures and different convergence criteria.
Once the activity was finished, some students were interviewed in order to obtain their opinion. Most of them showed to be satisfied with the new experience, although pointed that they had certain problems to understand some of the geological concepts.