The delegates of the 7th International Geoscience Education Conference organized by IGEO and University of Hyderabad (UoH) had a one-day excursion to Nagarjuna Sagar Dam. The transect chosen for this field trip provided excellent exposures of various important characteristic features of Dharwar Craton in general, areas of Eastern Dharwar Craton in particular.
The first stop for the participants was made at about 35 km from Hyderabad at an exposure of neoarchean granite. Dr. Chetty, Dr. Babu, and Dr. Vijay Kumar, scientists from National Geophysical Research Institute were the field guides and provided a brief information and content on various rock outcrops. As the conference deals with the geoscience education, the education potential of the site for various school and college students was also discussed. Prof. Nir Orion circulated special design work sheets to the participants to collect their opinion on the educational potential as student’s activity of the site.
The second stop was about 45 km from Hyderabad to show a E-W trending mafic dyke which is exposed in form of two small hillocks on the side of road. This dyke continues for ~ 10s of kms with varying width. Partcipants photographed the dyke and appreciated the fact such dykes are common in the Dharwar Craton.
The third stop was around 50 km from Hyderabad which is an outcrop of a migmatite with all its characteristic features such as exclaves, flow structures melanosomes and leucosomes and pegmatitic veins. Again, apart from discussing the various geological features, participants also discussed the educational activities that can be carried out with the students at this location. It was interesting to know that such outcrops can be used to bring out logical thinking skills and system understanding within the students.
The fourth stop was made about 120 km from Hyderabad, where a part of east-west trending Peddavura schirt belt (PSB) is exposed. In the outcrop it can be seen that it is highly deformed and metamorphosed to green schist to amphibolites facies. Many participants were of the view that this outcrop would require higher level of understanding of earth processes than interpreted from a high school student’s point of view.
Participants later arrived at the Najarjuna Sagar Dam in the afternoon. The imporic structure of the Dam and vast water reservoir provided an excellent ambience for the delegates to have lunch and relax.
The last stop was further south along the road where a beautiful section exposing unconformity between basement granite and overlying horizontally bedded sedimentary rocks of Kurnool group of Cuddapah basin that are exposed on the downstream of reservoir. All the participants appreciated the fact that this unconformity represents an enormous time gap of ~ 2000 ma between Archaean basement and Neoproterozoic sedimentary sequences of 600 million years old.
Here participants divided themselves into different groups and discussed whether a site like this can be a suitable site for ITFI (International Team field investigation) activity which is a part of the International Earth Sciences Olympiad. These groups shared their ideas on how students would perceive it and the tasks that can be given to them.
Everyone enjoyed the field work and returned at the end of the day a bit tired but with long lasting pleasant memories.