of Maud Meijers
of the Armenian Block and its foreland: constraints on Tethyan plate reconstructions
bending during the Phanerozoic
The South Armenian Block
(SAB) rifted away from the African margin in early to middle Jurassic times,
~200-160 million years ago (see figure below). It collided with the Eurasian
margin in the late Cretaceous (~83-70 Ma), where it is still positioned.
The ages of rifting
and collision are mainly based on geological evidence and a single paleomagnetic
study, which is unsatisfactory for plate reconstructions. The position
of the SAB is not yet determined with respect to the African and Eurasian
margins that were separated by a 3300 km wide ocean in the ~80-40 Myr following
rifting, according to recent APWP paths. The suggested - but widely ranging
- ages of rifting and collision of the SAB as well as its unknown position
in the intervening time span are not suitable to develop a robust paleogeographic
reconstruction modified after Dercourt et al. (2000) during Early Kimmeridgian
Using paleomagnetic data,
which provide not only paleolatitudes but also information on tectonic
rotations, we aim to exactly pinpoint the timing of formation of this arc-shaped
geometry, and from this information we aim to derive the responsible mechanism.
research, based on
in rocks that align
with the Earth’s dipolar
at the time of deposition,
is the only
way to quantitatively
provide paleo- latitudes, and should therefore be
conducted in the region
of the SAB
to enable the paleogeographic
reconstructions of the Tethys ocean.
The collision of the
SAB with Eurasia in
late Cretaceous times
occurs much earlier than the accommodation of shortening in the Kura fold-and-thrust
belt that results from collision of Arabia, which is very recent: only
during the last 5 Myr, according to Forte et al. (2010).
Both collision mechanisms
however, could explain the arc-shaped geometry north of the SAB.
drilling (again ...)
and Big Mount Ararat
In the autumn of 2009,
we started with a first paleomagnetic fieldwork, aided by financial support
from the Darius
consortium. Preliminary measurements provide already some promising results.
Fieldwork will be continued in 2010.
in the Sout Armenian Block
Publications of Maud Meijers
M.J.M , Van Hinsbergen, D.J.J., Langereis, C.G., Altiner, D., Dekkers,
M.J., Kaymakci, N. and Stephenson, R.A. (2010). Pervasive Paleogene remagnetization
of the central Taurides fold-and-thrust belt (southern Turkey) and implications
for rotations in the Isparta Angle, Geophys. J. Int.,
G., Lippert, P., van Hinsbergen, D.J.J., Meijers, M.J.M. and Kapp, P. (2010).
Paleolatitude and age of the Indo-Asia collision,
Geophys. J,. Int.,
M.J.M. (2010). Tethyan evolution of the Black Sea region since the Paleozoic:
a paleomagnetic approach (PhD thesis Utrecht University), Geologica
M.J.M., Hamers, M.F., Van Hinsbergen, D.J.J., Van der Meer, D.G., Kitchka,
A., Langereis, C.G. and Stephenson, R.A. (2010). New late Paleozoic paleopoles
from the Donbas Foldbelt (Ukraine): implications for the Pangea A vs. B
controversy, Earth and Planetary Science Letters, 297,
M.J.M., Kaymakci, N., Van Hinsbergen, D.J.J., Langereis, C.G., Stephenson,
R.A. and Hippolyte, J.-C. (2010). Late Cretaceous to Paleocene oroclinal
bending in the Central Pontides (Turkey), Tectonics, 29, TC4016, doi:10.1029/2009TC002620.
M.J.M., Langereis, C.G., Van Hinsbergen, D.J.J., Kaymakci, N., Stephenson,
R.A. and Altiner, D. (2010). Jurassic-Cretaceous low paleolatitudes
from the circum-Black Sea region (Crimea and Pontides) due to True Polar
Wander, Earth and Planetary Science Letters, 296, 210-226.
M.J.M , Vrouwe, B., Van Hinsbergen, D.J.J., Kuiper, K.F., Wijbrans, J.
, Davies, G.R., Stephenson, R.A., Kaymakci, N., Matenco, L. and Saintot,
A. (2010). Jurassic arc volcanism on Crimea (Ukraine): implications for
the paleo-subduction zone configuration of the Black Sea region, Lithos,
M. J. M. 2005. Palaeomagnetic data from Crimea (Ukraine): New constraints
for Mesozoic plate tectonic reconstructions of the southern margin of
the East European Platform (revised 2008). Cambridge, CASP Reports, Black
Sea Project (Phase II): 48