Expedition: 2009

In July 2009, we spent a further month in Russia, this time exploring the northern basins around Kotel’nich and the Sukhona River. The UK team consisted of Mike Benton (Bristol), Andy Newell (BGS), and Greg Price (Plymouth), and the Russian side was led by Alexey Kurkin (PIN). The objectives were to carry out intensive fieldwork in both zones in order to understand the nature of sedimentation, stratigraphy, and stable isotopes in these classic basins, and to use this information to compare with events in the southern and central European Russian plate.

Kotel’nich┬áis especially famous as a major source of fossil tetrapods, most notably the pareiasaur Deltavjatia, known from dozens of near-perfect skeletons preserved in strange scour structures. As the type zone for the Kotel’nich tetrapod faunal complex, we were keen to understand aspects both of taphonomy and stratigraphic significance. In doing this work, we joined a team from Kazan’ University, and were able to visit all the sites and record the sedimentologuy and fossiliferous horizons in detail.

The area around Kotlas, along the banks of the North Dvina river, has been a classic area for fossil tetrapods also, and we worked first a the Sokolki sites, south of Kotlas, where Amalitzky had excavated numerous pareiasaur skeletons early in the twentieth century: his vast excavation pit is still visible. We then spent a couple of weeks working up and down the River Sukhona, a tributary of the North Dvina that joins at the town of Velikiy Ustyug, supposed home of Father Christmas (Dyed Moroz in Russian). Russian bio- and magnetostratigraphers had long made a special study of the sedimentary succesion along the Sukhona, and we were able to log the entire succession, noting horizons with tetrapod footprints, tetrapod skeletal fossils, plants, deeply rooted paleosols, and insects, and to tie the succession with existing dating schemes using ostracods, fishes, and magnetostratigraphy.

Throughout the fieldwork, Greg Price sampled carbonate paleosols, and studies of stable isotopes in these samples will supplement existing information on palaeoclimates from sedimentology, palaeobotany, and paleosols.