*Marco Maffione 1 , Douwe van Hinsbergen 1
* corresponding author: m.maffione@uu.nl
1
Department of Earth Sciences, Utrecht University, Utrecht, The Netherlands
Conclusions The Tethyan Ophiolites
Results From the Paleomagntism: Initial Dyke Orientations
One of the cornerstones of plate tectonics, the well-known Wilson Cycle, predicts that repeat- ed cycles of separation and re-amalgamation of major plates shapes our planet, forming ocean basins and orogenic belts. A fundamental step in the Wilson Cycle is the closure of ocean basins, which may eventually lead to orogenesis. This process is accommodated by lithosphere consumption at subduction zones. Although our understanding of subduction dynamics has substantially increased in the last decades, the process of subduction initiation is still poorly de- fined. A key step to further our understanding of subduction initiation is to characterize the pre-existing lithospheric structures within ocean basins where new subduction zones form. Ex- isting models show that weakness zones such as transform faults, fracture zones, or oceanic de- tachment faults are needed to nucleate a new subduction zone.
One of the most dramatic events of the Mesozoic was the closure of the vast Tethys Ocean and the subsequent collision of Eurasia and Africa plates. Here we reconstruct the geometry of the mid-ocean spreading ridge system (spreading axis and transform faults) within the Tethys during the Middle Jurassic (~170 Ma) and Late Cretaceous (~95 Ma) using paleomagnetic con- straints from the ophiolitic complexes of the Balkan Peninsula (Serbia, Albania, and Greece) and Turkey. Based on the known Europe-Africa convergence directions and rates we discuss the possible scenarios and mechanisms that favored subduction initiation within the Tethys Ocean.
- , .
Paleogeographic Reconstructions of the Neo-Tethys Spreading Ridge
The spreading ridge systems of the Tethys Ocean
during the Jurassic and Cretaceous: constraints on the mechanisms of subduction initiation
Figure 3. Paleogeographic reconstruction of the spreading ridge system of the Neo-Tethys and intra-oceanic subduction zones during (a) the Middle Jurassic and (b) Upper Cretaceous.
Figure 1. Regional geological map showing the present-day distribution of the peri-Mediterranean ophiolites and the sampled ophiolitic bodies.
Acknowledgments
This work has been funded by ERC Starting grant 306810 (SINK) and NWO VIDI grant 864.11.004 both awarded to D.J.J.v.H. Many people contributed to this work by helping during the field campaign, laboratory analyses, and discussions, including N. Kaymakci, K. Onuzi, V. Cvetković, T. Morris, K. Peters, G.I.N.O. de Gelder, F. van der Goes, L. Koornneef, N. van Reijsingen, and D. Gurer.
Figure 2. Stereographic projections showing the distribution of the initial dyke orientations of the studied localities visualized using rose diagrams.
MIDDLE JURASSIC (~170 Ma) UPPER CRETACEOUS (~95 Ma)
N
Av. Strike 358.7°±8.5°
N = 450
Mirdita
N = 304
Av. Strike 313.8°±22.9°
Guevgueli
N
MIDDLE JURASSIC OPHIOLITES UPPER CRETACEOUS OPHIOLITES
N = 125
Pindos
N
Av. Strike 339.6°±12.7°
N = 250
Vourinos
N
Av. Strike
339.6°±12.0° Av. strike
038.4°±19.5°
N = 2850
Troodos
N
N = 375 Av. strike
008.3º±15.3º
N
Sarıkaraman
N
N = 125 Av. strike 010.0º±7.9º
Göksun
N
N = 125
Av. strike 339.3º±4.6º
N
CW solution CCW
solution
N = 500 Av. strike 055.0°±44.7°
N
Divriği
N
Av. strike 305.0º±44.7º
N = 500 CW
solution solution CCW
Guevgueli Vourinos
Pindos
Troodos
Kizildağ Göksun Divriği
Sarikaraman
Baer Bassit Mirdita
ANATOLIA
p p p
p p
p p p
p p p p p p
p p p
p p
p p
p p p
p
p
p
p
p p
p
p p
p p
p p p
p p p
p p p
p p p
p p
p p p
North Anatolian Fault
Jurassic ophiolites Cretaceous ophiolites
Iberia
Greater Adria
Taurides Africa
(Gondwana)
North America
(Laurasia) (Laurasia) Europe
Tethys Ocean
M Vo Pi
Gu
p p
p
p p
p
p p
Tethys Ocean Alpine
Tethys Iberia
Taurides Greater
Adria
Europe (Laurasia)
Africa
(Gondwana)
Arabia
p p
p p
p p
p
p p p p p p p
p p
p
p p
p p
p p p p p p p
