People at Fort Hoofddijk

Chris van Baak
back to People of the Fort
Mr. C.G.C. van Baak
Paleomagnetic Laboratory
Fort Hoofddijk
Department of Earth Sciences, 
Utrecht University 
Budapestlaan 17
3584 CD Utrecht 
The Netherlands 

Phone +31 30 253 1361

Research of Chris van Baak

Glacio-Marine Transgressions of the Early and Middle Pleistocene Caspian Basin, Azerbaijan
Establishing an unambiguous timescale for the Late Neogene deposits of the Eastern Paratethys region has been a problem for years caused by contradicting paleomagnetic results and local biostratigraphic schemes. This work aimed to create a reliable magnetostratigraphy for key sections in Azerbaijan.
In the past 7 Myr, the Caspian Basin has been characterized by large lake-level variations with differing amplitudes. After the restriction during the deposition of the Mio-Pliocene Productive Series, a number of important transgressions took place in the Plio-Pleistocene. 

The earliest of these large transgressions of the Caspian Sea is the Pliocene Akchagylian transgression, which marks the end of the Productive Series and the beginning of the Pliocene Akchagylian deposition in the Caspian Sea. This transgression has at present an age of 3.4 Ma. A similar transgression is found at the boundary between the Apsheronian and Bakunian regional stages.


Some suggested time scale solution
The origin of the these transgression has been linked to eustatic highstands, that caused overflow of marine waters into the Caspian Sea. Younger (Late Pleistocene) transgressions have been interpreted in terms of overflow of pro-glacial lakes during extensive glaciations when land-ice blocked the north-flowing rivers from Scandinavia to Siberia. A detailed age for these transgressions allows for discriminating between a glacial and marine origin, which is the scope of my Msc-project.

Lokbatan section (Azerbaijan, near Baku) 

Creating a reliable magnetostratigraphy for key sections in Azerbaijan, is a first step. The boundary between uppermost Productive Series and the Akchagylian regional stages, as observed in the Lokbatan section, has in the most likely scenario an age of 2.5 Ma, which is radically different from the existing age. The younger regional stages, the Apsheronian and the Bakunian, yield ages for their lowerboundary of older than 1.8 Ma, and 0.88 Ma. 
Transgressions at the base of both the Akchagylian and the Bakunian fall within cold intervals of the Pleistocene (marine isotope stages 100 and 22 respectively), and are thus likely to have an origin related to northern hemisphere glaciation. Existing models for Late Pleistocene ice-dammed lakes and reverse driver drainage (and possibly increased precipitation) stretching from Scandinavia to West Siberia are hypothesized for these transgressions, and may prove that there was at times a connection between the Arctic Ocean and the Caspian Sea. Existing biostratigraphic data does not contradict this hypothesis, or does, in the case of the Caspian seal, even strongly support it.

Model of the glacial-interglacial drainage hypothesis as used for the Akchagylian transgression.

publications Publications of Chris van Baak