1992-Present: Paleogeographic origin and terrane fragment ages of the Caribbean Plate
In association with Emile Pessagno (UTD), John Lewis (George Washington University), and Hans Schellekens (University of Puerto Rico) and Andrew Kerr (Cardiff University) our work has established a much older age for the Caribbean plate than was expected as well as proven a Pacific realm origin for much of it. The age is approximately 195 Ma for deep marine cherts, an age of approximately 30 Ma earlier than any ocean existed between North and South America. Our data ended residual speculation that the Caribbean plate formed in situ and solidified the case for Pacific origin.
Our work has provided the ages and origins for numerous terrane fragments on several islands that have proven difficult to decipher. The terrane fragments are on the islands of La Desirade, Dominican Republic, Jamaica, and Bonaire. More refined paleogeographic reconstructions were suggested based on our newly discovered stratigraphic and paleontologic discoveries.
1995-present: Dinosaur paleoecology in the Big Bend (video)
In Texas we have been occupied with excavations of dinosaurs in Big Bend National Park and to the west in Terlingua. This work has been supported by the National Science Foundation and by Bell Helicopter. Many of the bones are on display at the Dallas Museum of Natural History where an entire skeleton will eventually be mounted. Our discoveries include a sauropod adult that may very well be the largest dinosaur yet discovered in Texas. We are also the first to discover a juvenile sauropod assemblage, this one trapped in lake sediments. We are now settling in for in-depth paleoecological studies of the various sites.
1988-2003: Origin of the Permian reefs, Chihuahua
Permian reefs in Sierra Plomosa, Chihuahua are well exposed and contain shallow-water faunas similar to the better-studied rocks of the Permian Reef Complex in Texas and New Mexico. The reefs are found in complicated juxtaposition to basinal clastic rocks. Sliding of reef blocks into adjacent deep water may have occurred in the case of the smaller reef bodies. Such a means of emplacement is not unknown in other areas, but has not previously been discovered in this region.
1989-1991: Plate tectonic history of north coast of Puerto Rico
I was able to work out and publish the origins, rotations, and final assembly of terrane fragments along the north coast of Puerto Rico while principal paleontologist for the Toa Baja scientific drilling project. Additional funds from the drilling project supported the fieldwork necessary to complete the project.
2001-2006: Constructing a different approach to effective training of science teachers
Earth science is one of the favored subjects for study by teachers at all levels seeking graduate degrees at the University of Texas at Dallas. Field investigations in earth science, by definition, are hands-on activities. Pursuant to this realization, geological field work is not simply adjunct to class instruction. Field work is a vital component of all earth science programs for teachers. Experimentation into field trip design indicates that the most effective type of trips are longer-term, localized studies that expect a great deal from the teachers. Didactic approaches, especially those conducted by professional geologists, are much less effective than constructivist methods that emphasize active learning, proper communication, and practical feedback. Our department has committed itself to this new approach.
2001-2007: Effective teaching in the undergraduate science classroom
Successful service courses are saving many a geology department from extinction. Courses can only be successful if well managed. More often than not, well-managed is not synonymous with the old lecture format. Our pre- and post-testing indicates that instructors must be creative, engage in active learning, communicate effectively for no more than 20 minutes without a pause, utilize hands-on activities, and test frequently, efficiently, and effectively. Adopting web-based, course management software is highly recommended, at least as a adjunct. Such an effort is time-intensive when begun but becomes quite manageable with a year or so. Enrollment will soar if a course is properly implemented. Students of all majors will have a positive encounter with science. The initial experiment proved successful and is undergoing expansion into other classes.
2001-2007: Getting back to Socrates, research into best practices in undergraduate classrooms
Classroom practices can be divided into two major categories based on learning theory. The first, behaviorism, is based on the work of B.F. Skinner. The second, constructivism, is based on cognitive theory. In the behaviorist classroom the instructor and the textbook are the source of almost all knowledge. Conversely, constructivism, the understanding of which has developed rapidly during the past two decades, proposes that students best learn by actively constructing their own understanding. In a constructivist classroom, students are given the opportunity to build upon prior knowledge and understanding. Students investigate possibilities and propose solutions of their own or their group's creation. Assessment is affected by asking students to perform real-world tasks or to develop real-world solutions. Student performance is evaluated utilizing a rubric designed to evaluate the success of the learner who, in this instance, is much more autonomous and has performed within an initiative-rewarding process. Although constructivism has been practiced at least since Hippocrates by the best of teachers, modern constructivism is based on brain research and the understanding of how learning occurs.
Progressive educational practices stress teaching for meaning wherein lessons are structured with embedded, repetitive experiences that require students to be actively involved in a dynamic, interactive teaching environment. Students are moved to the center of the discovery process. Students and instructors are considered resources. Students construct a body of knowledge via their own cognitive processes. Exercises in discovery are the structural foundation of the course. Prior knowledge connects with newly developed insights and becomes the foundation for future insights.
The instructor guides the process as facilitator who constructs lessons that are sufficiently mutable to permit student exploration and yet remain relevant to the curriculum at hand. The process is often one of focusing on topics rather than on minutiae. Constructivist exploration of topics almost invariably leads to discovery and correct utilization of minutiae. Learning usually progresses from the concrete to the abstract as familiarity expands.
Investigations are ongoing at universities in Kenya, Ghana, and Rwanda. Additional research is ongoing into establishing an educational system in the midst of the civil war in Somalia.
Honorary Membership, Science Teachers Association of Texas, in recognition of outstanding service