Print this pageAAPG ANNUAL CONFERENCE AND EXHIBITION
Making the Next Giant Leap in Geosciences
April 10-13, 2011, Houston, Texas, USA
Student Conceptions and Misunderstandings About the Core Concepts of Sequence Stratigraphy
(1) Earth and Atmospheric Sciences, Purdue University, West Lafayette, IN.
We conducted an in-depth assessment of 27 students’ content knowledge of the principles of sequence stratigraphy. All students (10 juniors, 15 seniors and 2 graduates) were enrolled in advanced undergraduate stratigraphy courses at three research universities in Midwest U.S. Participants took between 2 and 9 geology courses prior to our study. 60% of students were majoring on geology and 40% on environmental geosciences. 40% of students had 2 or more field-based courses. Data were collected over 3 semesters, and included semi-structured research interviews, spatial visualization tests, classroom observations and embedded lab assignments. Using constant comparative analysis, we documented students’ conceptions of principles such as eustasy, base level, accommodation, and depositional sequence, sequence boundaries. From these data we developed assertions about the nature of student comprehension of this material and mapped conceptual connections and conceptual change as a result of instruction.
Results indicated that 60% of students poorly integrated tectonics, climate and time in their sequence stratigraphic models. 70% were unable to correctly predict the response of carbonate margins to sea level fluctuations, and had a misconceived or absent notion of base level. 80% of participants had a poor grasp of time scales associated with different depositional sequences and flooding surfaces. Problems were also observed with recognizing unconformities in the field and distinguishing the origin of accommodation space. Our data also suggested that terminology prevented proper scaffolding of concepts during learning, and that time in profession may not be a good predictor of mastery of these concepts or terms. In addition students’ spatial skills seemed to correlate loosely with students’ ability to understand sediment deposition and distribution in response to sea level fluctuations. We completed a preliminary differentiation among a true alternate conceptions, misunderstandings and instructional bias. For example, the balance between understanding based on physical sedimentology vs integrated sequence concepts as being related to instructional emphasis and past field experience. Post course analysis of a subsample suggested that a successful conceptual change was possible; students were able to correlate depositional environments and cyclicity. However, some alternative conceptions persisted (e.g. the concept of eustasy and base level remained elusive).