1. Meeting of Young Geoscientists
Characterization of phyllosilicates from overpressured zones of Endrőd Formation (Makó Trough, Pannonian Basin, Hungary)
Tóth Ferenc
Ph.D. student
University of Szeged
Department of Mineralogy, Geochemistry and Petrology
Meeting of Young Geoscientists
Békéscsaba, 2013

2. Reveal of disputed processes and open questions
The aim of the study
Diagenetic processes of the Makó Trough
Published/unpublished reports
National/international literatures
Why the clay mineral alteration?
Great influence on diagenesis and HC
Available international references
Studies from Pannonian Basin
Contradictory results from Makó Trough
Did the overpressure influence the clay mineral alteration?
Reveal of disputed processes and open questions

3. Geological overview of Makó Trough

4. Lithological cross section
of Makó Trough
Executive summary on core analysis data and procedures on the wells drilled in the Makó trough. Final report; EDITED BY Zoltán Unger (2008), Geological Institute of Hungary (MÁFI), Budapest, Hungary, 64 p (unpublished).

5. Illite/smectite alteration

6. Macroscopic petrography
Hód-I well m
Unlayered, fine- grained, micaceous sandstone
Endrőd Formation – Vásárhely Member m
Classic marl, claymarl
Endrőd Formation – Tótkomlós Member
~ 5400 m
Fine-grained conglomerate
Endrőd Formation – Dorozsma Member

7. Identification of clay minerals
X-ray diffractometry (XRD) on Hód-I samples
Other researches (Bérczi & Viczián, 1972; Grasselly, 1973; Lovas, 2004)

8. Origin of the ˮsmectite anomalyˮ

9. Results of clay mineralogy
Very likely that the ˮsmecite anomalyˮ in the overpressured zones does not exist (Lovas, 2004)!
VERMICULITE has been identified as smectite (formed via chemical weathering of biotite)
Circumstances of vermiculite formation (Fe2+--> Fe3+)
Meteoric water
Diagenetical fluids
Early diagenesis
Burial
diagenesis
Petrography

10. Microscopic petrography
Hód-I well

11. Summary X-ray diffraction Petrography Overpressure could not
Changing in sedimentation
Identification of vermiculite
Petrography
Early calcite cement
Low level of mechanical compaction
Undeformed bioclasts
Dolomitization
Burial diagenesis
Absence of SO42-
Alteration of biotite
Reductive environment
Framboidal pyrite
BSR (mostly m, max 60°C)
Oxidative environment
Vermiculite in secondary pores
Overpressure could not
have influenced the clay
mineral alterations
Vermiculite could be formed
by burial diagenesis

12. Summary X-ray diffraction Petrography Overpressure could not
Changing in sedimentation
Identification of vermiculite
Petrography
Early calcite cement
Low level of mechanical compaction
Undeformed bioclasts
Dolomitization
Burial diagenesis
Absence of SO42-
Alteration of biotite
Reductive environment
Framboidal pyrite
BSR (mostly m, max 60°C)
Oxidative environment
Vermiculite in secondary pores
Overpressure could not
have influenced the clay
mineral alterations
Vermiculite could be formed
by burial diagenesis
Main questions
What kind of changing in sedimentation?
When and how does oxidative environment exist?
Was it a local or regional process?
Petrography (provenance)
Scanning Electron Microscopy (SEM)
X-ray Fluorescence (XRF) Analysis
X-ray Diffractometry (XRD)

13. Thank you for your kind attention!
I would like to express my great thank for helping in this study to Andrea Varga and Béla Raucsik.
Thank you for your kind attention!
Bérczi, I. & Viczián, I. (1973): Üledékes kőzettani vizsgálatok a dél-alföldi neogénben. Földtani Közlöny 103, 3-4, (in Hungarian).
Executive summary on core analysis data and procedures on the wells drilled in the Makó trough. Final report; EDITED BY Zoltán Unger (2008), Geological Institute of Hungary (MÁFI), Budapest, Hungary, 64 p (unpublished).
Hámor-Vidó, M. & Viczián, I. (1993): Vitrinite reflectance and smectite content of mixed-layer illite/semctites in Neogene sequences of the Pannonian Base, Hungary. Acta Geologica Hungarica 36, 1,
Judik, K. (2001): Agyagásvány átalakulások a Hódmezővásárhely-1 fúrás rétegsorában. MSc. thesis, Eötvös Lóránd Tudományegyetem Természettudományi Kar, Ásványtani Tanszék (in Hungarian).
Lovas, A. (2004): Az agyagásványok individualizmusa, a diagenezis során kialakuló szerkezeti állapotok és átmenetek regionális vizsgálata. T sz. OTKA final report (in Hungarian).