1. Fault-related folds in the Gerecse mountain
Várkonyi Attila
Eötvös University Dept. of Regional Geology
MTA-ELTE Geological Geophysical and Space Science Research Group
2012, Tatabánya

2. Overview Types of extensional fault-related folds
Extensional fault-related folds in the Dogger quarry
Backstripping of the deformation phases
Evolutionary model for the Dogger quarry
Stereographic evidences
Microtectonic investigation
Similarities with the Tölgyhát quarry
General model
Conclusion

3. Fault-related folds, segmented faults
theoretical figures
Two types: normal and
reverse rotation
A to F normal rotation
G to H reverse rotation
Rykkelid & Fossen (2002)

4. Vertically segmented faults
Fodor et al. (2005)
Vertically segmented faults
Footwall anticline
Hangingwall syncline
Smeared clay’s importance
In the hidrocarbon trapping
Koyedole et al. 2003

5. Location
Gerecse mountain

6. Structures of the Dogger quarryW E

7. Structures of the Dogger quarryW E

8. Deformation along the main fault
Vertically segmented fault consist of three segments:
Two normal and
One reverse fault
Antitethic faults connected to the layer paralel shear
The marl drag into the fault plane

9. Deformation backtsepping by Move1. 2. 3. 4. 6. 5.

10. Evolution model of the Dogger quarry ? 2. Vertically segmented faults
2. Overstepping fault segments
2. Plastic marl
3. Increasing bending of marl
4. Listric fault in hangingwall
5. Connecting fault segment
6. Antitethic faults
6. Rotation to reverse fault ?

11. Stereographic explanation
Extensional regime
Normal faults
Oblique-normal faults with
strike-slip component
Evidence of extensional
fold

12. Microtectonics Oriented samples Kinematics of the fault
Two generations of calcite
Calcite fibers – syn-kinemaic

13. Fault-related fold in the Tölgyhát quarry
Sasvári et al. (2009)

16. Rykkelied & Fossen (2002)

17. General model Overlap zone Connecting fault segments Listric fault
Antitethic fault
Fodor et al.

18. Conclusion
Each investigated fault-related folds and vertically segmented faults are connect to the Kisgerecse Marl
It is not a unique phenomenon
The folds were originated by extension
This deformation strucutures can be general in the Gerecse mountain

19. Thank you for your attention!
Acknowledgement: Grateful thanks for my supervisor Dr. László Fodor, and Attila Petrik, Barbara Beke, Orsolya Győri, Ábel Szabó