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







Explanatory Notes

to the Geological Map-series of the North-eastern Part

of the Mórágy Block (1:10 000)

Edited by

Zoltán BALLA, László GYALOG

Written by

Zoltán BALLA, Géza CSÁSZÁR, Zoltán GULÁCSI, László GYALOG, Miklós KAISER,

Edit KIRÁLY, László KOLOSZÁR, Balázs KOROKNAI, Árpád MAGYARI, Gyula MAROS,

István MARSI, Péter MOLNÁR, Ágnes ROTÁRNÉSZALKAI, György TÓTH

With contribution of

Jolán ANGYAL, Gergő HAVAS, Vera MAIGUT, Szabolcs NAGY, Olga PIROS,

Ferenc SÍKHEGYI, Dezső SIMONYI, Margit TRESZNÉSZABÓ, Gábor TURCZI,

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Budapest, 2009

Copyright Magyar Állami Földtani Intézet (Geological Institute of Hungary), 2009 All rights reserved!

Serial editor:

László GYALOG Reviewer:

Tamás BUDAI English text:

Zoltán BALLA, Edit KIRÁLY, Balázs KOROKNAI, Klára PALOTÁS, Ildikó SELMECZI, Tibor TULLNER Linguistic reviewer:

Philip RAWLINSON Technical editor:

Olga PIROS, Dezső SIMONYI Cover design:

Dezső SIMONYI

Supported by the Public Agency for Radioactive Waste Management

Pulished by the Geological Institute of Hungary Responsible editor:

László KORDOS director

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Printing house:

Innova-Print Kft.

Introduction (Zoltán Balla) . . . . General Overview . . . . The Exploration Program of the Üveghuta Site . . . . The Map Series and its Expanatory Notes (Zoltán Balla, László Gyalog) . . . . History of the Exploration . . . . History of the Geological Investigations (Zoltán Balla) . . . . Study of Geological Sequences . . . . Ófalu Group (Lower Palaeozoic) . . . . Bátaapáti Metasandstone Formation (Lower Palaeozoic) . . . . Mórágy Granite Formation (Lower Carboniferous) . . . . Triassic–Jurassic . . . . Rozsdásserpenyő Alkali Basalt Formation (Cretaceous) . . . . Miocene (László Gyalog) . . . . Quaternary (István Marsi) . . . . History of the Investigation of the Geological Structure . . . . Tectonic Studies . . . . Structural Geological Field Measurements and their Interpretation (Gyula Maros) . . . . Study of the Mecsekalja Zone . . . . Remote Sensing . . . . Geodynamic Monitoring . . . . Rock-stress Measurements . . . . History of Geological Mapping . . . . The Map and Description of Béla Jantsky (Zoltán Balla) . . . . Early Materials of the Exploration in Üveghuta (László Gyalog, Zoltán Balla) . . . . Materials of the Ground-based Geological Exploration in Üveghuta (László Gyalog, Zoltán Balla) . . . . Mapping Activities in Üveghuta (László Gyalog) . . . . Geological Mapping . . . . Tectonic Investigations . . . . Deepening and Logging of Hand-drilled Boreholes . . . . Laboratory Analyses . . . . Ground-based Boreholes and their Investigation (László Gyalog) . . . . Boreholes Deepened prior to the Exploration of the Üveghuta Site . . . . Boreholes Deepened in the Frame of the Exploration of the Üveghuta Site . . . . Dug Wells, Trenches and their Mapping (László Gyalog) . . . . History of the Geomorphological Investigations (Miklós Kaiser) . . . . Tunnels, Underground Boreholes and their Investigation (László Gyalog) . . . . Tunnel Driving . . . . Tunnel Mapping . . . . Underground Boreholes . . . . History of Geophysical Investigations (Zoltán Balla) . . . .



9 9 10 11 13 13 13 14 15 15 18 18 18 19 21 21 21 22 23 23 23 24 24 25 26 26 26 28 28 28 28 29 29 31 31 32 32 32 32 33 33 34

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Airborne Geophysical Survey . . . . Ground-based Geophysical Surveys . . . . Nationwide Surveys . . . . Regional Surveys . . . . Ground-based Surveys in the Frame of the Üveghuta Exploration . . . . Site Selection . . . . Site Suitability Assessment, Phase 1 . . . . Site Suitability Assessment, Phase 2 . . . . Ground-based Raw Material Exploration . . . . Complementary Ground-based Exploration . . . . Cone Penetration Tests . . . . Measurements in Ground-based Deep Boreholes . . . . Preparatory Works . . . . Site Suitability Assessment, Phase 1 . . . . Site Suitability Assesment, Phase 2 . . . . Complementary Ground-based Exploration (2004–2006) . . . . Well-logging . . . . Measurements in Tunnels or in Underground Boreholes . . . . Seismology . . . . History of Raw Material Exploration (Zoltán Balla) . . . . Geological Sequences (Zoltán Balla) . . . . Geological Setting of the Mórágy Block . . . . Palaeozoic Formations . . . . Lower Palaeozoic, Ófalu Group (Zoltán Gulácsi, Balázs Koroknai) . . . . Studervölgy Gneiss Formation . . . . Goldgrundpuszta Phyllonite member . . . . Kövespatak Quartz Phyllite Formation . . . . Juhhodályvölgy Limestone Formation . . . . Aranyosvölgy Serpentinite Formation . . . . Erdősmecske Amphibolite Formation . . . . Palaeozoic Sequences in Separate Formations . . . . Lower Palaeozoic, Bátaapáti Metasandstone Formation (Balázs Koroknai, Zoltán Gulácsi) . . . . Lower Carboniferous, Mórágy Granite Formation (Zoltán Gulácsi, Edit Király) . . . . Monzogranitic Rocks . . . . Hybrid Rocks . . . . Monzonitic Rocks . . . . Leucocratic Dyke Rocks . . . . Xenoliths (Edit Király) . . . . Triassic–Jurassic Sequences (Géza Császár) . . . . Middle Triassic, Csukma Formation; Upper Triassic, Karolinavölgy Sandstone Formation . . . . Upper Triassic – Lower Jurassic, Mecsek Coal Formation . . . . Lower Jurassic, Vasas Marl Formation . . . . Lower Jurassic, Hosszúhetény Calcareous Marl Formation . . . . Cretaceous Sequences . . . . Rozsdásserpenyő Alkali Basalt Formation . . . . Subvolcanic Dyke Rocks (Zoltán Gulácsi, Zoltán Balla) . . . . Intrusive Breccias (Erzsébet Rálisch) . . . . Hydrothermal Phenomena in Connection with Alkali Volcanites (Balázs Koroknai) . . . . Hydrothermal Phenomena and their Products . . . . Hydrothermal Veins (Edit Király, Zoltán Gulácsi) . . . . Fissure Fillings Comprising a Mineral Paragenesis Characteristic of Greenschist faccies . . . . Quartz Veins and Dykes, Silicified Zones . . . . Fe-dolomite Dykes and Veins . . . . Multigenerational Carbonate-Limonite veins . . . . Calcite Veins . . . . Argillaceous veins . . . . Products of Hydrothermal Alteration (Edit Király) . . . .

34 34 34 34 35 35 36 36 36 37 37 37 37 38 38 39 39 39 43 46 48 48 49 53 54 55 56 57 57 57 60 61 62 64 65 68 68 68 69 69 73 73 73 73 78 79 81 81 81 82 82 83 83 83 84 84 84

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Neogene Sequences . . . . Lower Miocene, Karpatian, Budafa Formation, Budafa Sandstone Member (László Koloszár, László Gyalog) . Upper Miocene, Pannonian Sediments: Kálla Gravel Formation, Kálla Gravel and Tihany Formation undi-vided, Tihany Formation (László Gyalog, László Koloszár) . . . . Quaternary Sequences . . . . Lower–Middle Pleistocene, Fenyvestető Red Clay Formation (Zoltán Balla, László Gyalog, László Koloszár) . . . . Pleistocene, Udvari Loess Group . . . . Correlation of Typical Loess Sediments (László Gyalog, Zoltán Balla) . . . . Evolution Model of Hilltop Loess Sequences (Zoltán Balla) . . . . Generic Characteristics of the Udvari Loess Group (István Marsi, László Gyalog) . . . . Pleistocene, Udvari Loess Group Undivided (István Marsi, László Gyalog) . . . . Udvari Loess Group Undivided, Typical Loess . . . . Udvari Loess Group Undivided, Slope Deposit . . . . Lower–Middle Pleistocene, Paks Loess Formation (István Marsi, László Gyalog) . . . . Paks Loess Formation, Typical Loess Sequence; Udvari Member, Üveghuta Member . . . . Slope Deposits of the Paks Formation: Slope Deposit Undivided, Solifluctional Deposit . . . . Middle–Upper Pleistocene, Mende Formation (István Marsi, László Gyalog) . . . . Mende Formation, Typical Loess Sequence; Basaharc Member, Dunaújváros Member . . . . Mende Formation, Bag Tuffite Bed . . . . Slope Deposits of the Mende Formation: Slope Deposit Undivided, Solifluctional Deposit . . . . Quaternary Slope Deposits (István Marsi, László Gyalog) . . . . Slope Deposits Undivided . . . . Pleistocene Slope Deposits . . . . Upper Pleistocene – Holocene Slope Deposits: Fine-Grained Slope Deposit, Debris-Bearing Slope Deposit . . . . Upper Pleistocene – Holocene Deluvial Sediments . . . . Holocene Deluvial Sediments . . . . Slide Deposits . . . . Middle Pleistocene – Holocene Slide Deposits . . . . Holocene Slide Deposits . . . . Quaternary Valley-Fill Sediments (László Gyalog, Árpád Magyari, István Marsi) . . . . Fluvial Sediments . . . . Lower–Middle Pleistocene Fluvial Sediment . . . . Middle Pleistocene Fluvial Sediment . . . . Lower Holocene Fluvial Sediment . . . . Holocene Fluvial Sediment; Upper Pleistocene – Holocene and Upper Pleistocene Fluvial Sediment Fluvial-Deluvial Sediment . . . . Proluvial-Deluvial Sediment . . . . Paludal, Fluvial-Paludal and Lacustrine Sediments . . . . Middle Pleistocene Fluvial-Paludal Sediment . . . . Upper Pleistocene Paludal Sediment . . . . Holocene Paludal Sediment . . . . Holocene Fluvial-Paludal Sediment; Upper Pleistocene – Holocene Fluvial-Paludal Sediment . . . . Holocene Lacustrine Sediment . . . . Weathering Sequences (Zoltán Balla) . . . . On Palaeozoic and Mesozoic Formations . . . . On the Mórágy Granite Formation . . . . On the Rozsdásserpenyő Alkali Basalt Formation . . . . On Cainozoic Sediments . . . . Structure . . . . Structures Connected to the Variscan Orogenesis (Balázs Koroknai) . . . . Magmatic Structures . . . . The Pluton of the Mórágy Granite . . . . Leucocratic Dykes in the Mórágy Granite . . . . Ductile Structures . . . . Foliation . . . . 86 92 92 95 95 98 99 103 103 103 104 104 107 108 108 111 113 114 115 115 115 116 116 117 117 118 119 119 119 120 121 121 123 123 124 124 124 125 125 126 126 126 126 129 129 131 131 132 132 133 134 134 135 136

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Mylonites . . . . Fold . . . . Intersection Lineation . . . . Stretching Lineation . . . . Transitional Ductile-Brittle Structures . . . . Brittle Structures (Gyula Maros, Balázs Koroknai) . . . . Structures Connected to the Alpine Orogenesis . . . . Folded Structures (Balázs Koroknai) . . . . Brittle Structures (Gyula Maros, Balázs Koroknai) . . . . Individual Fractures . . . . Individual Fractures in the Mórágy Formation . . . . Joints of Cretaceous Alkaline Volcanic Dykes . . . . Individual Fractures in Cainozoic Sediments . . . . Fault Zones in the Mórágy Formation . . . . Types of Fault Zones . . . . Microtectonic and Laboratory Characterization of the Core Zones of Fault Zones . . . . Determination of the Orientation of the Fault Zones . . . . Pole Distribution of the Fault Zones . . . . Brittle Structural Model of the Area . . . . Structural Pattern of the Mecsekalja Zone (Balázs Koroknai) . . . . The SE Boundary of the Mecsekalja Zone . . . . The NW Boundary of the Mecsekalja Zone (Zoltán Balla, Géza Császár, Balázs Koroknai) . . . . The Inner Structure of the Mecsekalja Zone . . . . Geomorphology (Miklós Kaiser) . . . . Hill-Profile Forms . . . . Fluvial and Proluvial Forms . . . . Mass Movement Forms . . . . Anthropogeneous Forms . . . . Geological History (Zoltán Balla) . . . . Palaeozoic (Balázs Koroknai) . . . . Early Palaeozoic . . . . Early Carboniferous Granite Intrusion (Edit Király) . . . . Metamorphism and Tectonics . . . . Late Palaeozoic . . . . Mesozoic (Géza Császár, Zoltán Balla) . . . . Triassic–Jurassic . . . . Cretaceous . . . . The Mesozoic History of the Mecsekalja Zone . . . . Cainozoic (Zoltán Balla) . . . . Palaeogene . . . . Neogene . . . . Early–Middle Miocene . . . . Late Miocene . . . . Pliocene . . . . Quaternary . . . . Process of the Formation of Quaternary Hilltop Sequences . . . . History of Valley Floors . . . . Evolution of Valley Sides and Slopes . . . . Summary of the Quaternary Evolution . . . . Hydrogeology . . . . Recharge and Discharge Conditions (Ágnes Rotárné Szalkai) . . . . Precipitation . . . . Infiltration . . . . Natural Discharges . . . . Springs, Watershooting . . . . Ascendencies of Subsurface Water along Surface Streams . . . . Evapotranspiration . . . . 137 137 138 139 139 139 139 140 140 141 141 141 142 143 144 144 145 146 147 147 148 151 151 152 155 156 157 158 158 160 164 166 167 167 168 169 169 169 169 170 170 171 172 172 174 175 176 177 177 177 178 179 179 179 180 181 183

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The Evolution of Water Balance . . . . The Hydrogeological Setting (György Tóth, Péter Molnár) . . . . The Path of Water from Precipitation to Groundwater Table (in the Three-Phase Zone) . . . . The Path of Water in the Two-Phase Zone below the Groundwater Table . . . . The Path of the Water in Unconfined Ground Water until the Zones of Ascendancy to the Ground Surface . . . . The Path of the Water from Ground Water in the Fresh Granite to the Unconfined Ground Water of Valley Floors . . . . The Path of the Water from the Unconfined Ground Water of Valley Floors to the Ascendancies . . . . . Utilisable Mineral Raw Materials (Zoltán Balla) . . . .

***

Annex I. Contents and Compilation of Maps and Cross sections . . . . Geological Map with Observations (Balla Zoltán, Gyalog László) . . . . Relief and Geological Map of the pre-Cainozoic Basement . . . . Geological Map of the Basement . . . . Fracture Map (Gyula Maros) . . . . Map of the Basement Relief . . . . Relief and Geological Map of the Pre-Quaternary Complexes . . . . Map of the Contour Lines at the Base of the Mende Loess Formation and at the Base of the Slide Bodies . . . Geological Map without Slope Sediments . . . . Geological Cross Sections and Principal Stratigraphical Column (László Gyalog) . . . . Geomorphological Map (Miklós Kaiser) . . . . Map of Groundwater Relief (György Tóth) . . . . Annex II. Petrography and Electron Microprobe Analyses of the Mórágy Granite (Edit Király) . . . . Monzogranitic Rock Group . . . . Hybrid Rock Group . . . . Contaminated Monzogranites . . . . Monzonite Contaminated with Leucocratic Segregations . . . . Monzonite with K-Feldspar Segregations . . . . Monzonitic rock group . . . . Very Fine-Grained Monzonites . . . . Fine-Grained Monzonite . . . . Medium-Grained Monzonite . . . . Leucocratic dykes . . . . Aplite . . . . Microgranite and Granite Porphyry . . . . Leucocratic Monzogranite . . . . Xenoliths . . . . Annex III. The Coordinates of the Exposures (Mentioned in the Text and Displayed on the Geological Map with Observations) . . . .

List of the Enclosures

1. Geological Map with Observations (László Gyalog, Miklós Kaiser, Zoltán Balla, István Marsi)

2. Relief and Geological Map of the Pre-Cainozoic Basement (Zoltán Balla, Zoltán Gulácsi, Gyula Maros, Ferenc Síkhegyi)

3. Relief and Geological Map of the Pre-Quaternary Complexes (Zoltán Balla, Zoltán Gulácsi, Gyula Maros, Ferenc Síkhegyi)

4. Map of the Contour Lines at the Base of the Mende Loess Formation and at the Base of the Slide Bodies (Zoltán Balla, Ferenc Síkhegyi)

5. Geological Map without Slope Sediments (Zoltán Balla, Zoltán Gulácsi)

6. Geological Cross Sections and Principal Stratigraphical Column (László Gyalog, Balázs Koroknai, Gyula Maros

7. Geomorphological Map (Miklós Kaiser) 8. Map of Groundwater Relief (György Tóth)

183 183 183 184 186 187 189 189 190 190 191 192 194 195 195 195 196 197 199 199 203 204 205 206 207 207 207 210 212 212 213 213 213 215

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The so-called Üveghuta Site, named after the earlier-existing settlement of Üveghuta, is situated in the area of the present-day village of Bátaapáti in Tolna County. It was this site that proved to be suitable for the disposal of low- and intermediate-level radioactive waste from the Paks Nuclear Power Plant. At the beginning of the project the geological exploration was financed by the Paks Nuclear Power Plant Co. (in the following: PNPP Co.) and later by the Public Agency for Radioactive Waste Management (from 2008 onward a public utility, non-profit-making company; in the fol-lowing: Puram) but it has always been governed jointly with the Geological Institute of Hungary (in the folfol-lowing: MÁFI). With regard to its methods and detail this exploration was fully compatible with those that had been conducted in raw material occurrences in Hungary during previous years; in certain respects it was even more concentrated, com-plex and up-to-date.

GENERALOVERVIEW

The National Repository of Radioactive Waste (in the following: NRRW) is situated at the Üveghuta Site and this accounts for the practical significance of the site itself.

The Üveghuta Site is located in the NE part of Geresd Hills, which are situated in the SE foreland of Mecsek Mountains. The hills are largely made up of loess, whereas Lower Carboniferous granite and — in a narrow band in the NE margin — Lower Palaeozoic metamorphic and Jurassic sedimentary rocks, which occur on the floors of the valleys in between. Along the hill margins upper Miocene (Pannonian), and in the SE, lower Miocene sediments can be encoun-tered; these extend between the loess and pre-Cainozoic sequences. In terms of deep geology granites and metamorphic rocks have been uplifted in relation to their surroundings: hence this area is referred to as Mórágy Block in the geolog-ical literature.

Due to the fact that the thickness of the Cainozoic sediments does not exceed some dozen metres and continuous bod-ies of granites and metamorphic rocks are widely extended on deeper valley floors, the sedimentary cover was removed from the 1:500,000 and 1:200,000-scale geological maps of Hungary in this area, thus illustrating exclusively granitic and metamorphic rocks. In reality, however, barely 9% of the base area1is covered by the rocks of the “Block” (which anyway only occupy narrow valley floors or the narrow bands extending along the side of wider valleys making up dis-continuous exposures).

Before the exploration carried out for the present study, geological knowledge about this area was restricted to a scarce network of exposures, only making it possible for some elementary conclusions to be made on the geological set-ting of the basement. The knowledge on the Neogene and Quaternary cover was even more obscure, hence the picture drawn up about the overlying beds was essentially based on analogies acquired from remote areas.

The drilling and geophysical exploration of the Üveghuta Site provided a unique opportunity to attain geological knowledge about both the basement and overlying beds. In relation to this process, the thorough geological mapping of the area made a serious contribution.

The most crucial element of the basement tectonics of the area is the Mecsekalja Zone which is filled by Lower Palaeozoic metamorphic rocks. To the NW and SE of this zone Jurassic sedimentary and Lower Carboniferous granitic rocks are extended, respectively.

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THEEXPLORATIONPROGRAM OF THEÜVEGHUTASITE

A National Project was initiated in 1992 for the final disposal of low- and intermediate-level radioactive waste pro-duced by nuclear power plant. In its framework, a surface geological exploration was directed by MÁFI between 1993 and 2003 and MÁFI provided the professional manager of the subsurface geological survey. The leading role was played by the Mecsekérc Environmental Protection Public Company (later Public Limited Company, in the following: Mecsekérc) between 2004 and 2006.

Following a nationwide then regional study of the available literature — and taking into consideration public opin-ion — a field exploratopin-ion was conducted in three zones. This resulted in the selectopin-ion of the surroundings of Üveghuta as being most suitable for the future site. A process of subsurface disposal was decided upon as being appropriate for this site, while surface disposal was selected for two others. This area was chosen by the Final Document of the National Project (Burson-Marsteller… 1996) as being suitable for further exploration.

Initially the geological exploration proceeded on the basis of contracts between PNPP Co. and MÁFI. In the middle of 1998 as a result of the passing of the Act CXVI of 1996 on atomic energy, the role of PNPP Co. in the disposal of radioactive waste (as well as in the conclusion of contracts and putting them into effect) was taken over by the newly established Puram.

The exploration was designed to be carried out in three stages. The first of these would focus on site selection, the second would involve a suitability study of the site, and the third would be an evaluation of the site and its environment. Considering the overall content of the exploration, these three stages corresponded to the internationally-adopted three phases (i.e. site selection, site specification and site justification); in this sequence the outcome of phase 2 is absolutely crucial for the declaration of geological suitability.

The IKIM (former Ministry of Industry, Trade and Tourism) Decree 62/1997.(XI. 26.) on the Geological and Mining Requirements for the Siting and Planning of Nuclear Facilities and Radioactive Waste Disposal Facilities does not spec-ify this threefold subdivision in stages, neither does it define the number of phases or their contents. Rather it lays down a unique requirement which differs from the three-stage model: i.e. the first step should be initiated on (i) the drawing up of an individual exploration plan, (ii) it should be terminated by an individual report and (iii) both these should have administrative authority/approval. At the same time it formulates the requirements for geological suitability with exten-sive scrutiny as compared to the international practice (IAEA 1999), and leaves the declaration of suitability until right to the end of the exploration.

This decree was passed when the second of the original three stages was already in the process of execution. Furthermore, it did not contain any instructions with respect to how the activities already taking place should be man-aged. Consequently, the exploration necessary for the conclusion of the studies performed upon the bases of several con-tracts (BALLAet al. 1999) was simply notified to the South Transdanubian Regional Office of the Geological Survey of

Hungary (in the following: MGSZ DDTH) and the notification was accepted by the office.

Although this exploration was intended to be comprehensive, there were several vague issues and unexplained prob-lems that were left behind; these demanded that the exploration should go on. The next stage of the geological explo-ration was the ground-based exploexplo-ration designed to be carried out over one and a half years (BALLAet al. 2002). This

was authorised by the MGSZ DDTH. It was completed with an integrated interpretation of the huge amount of data, results and other pieces of information. Its final report (BALLAet al. 2003) was approved by the MGSZ DDTH, which

declared in favour of the geological suitability of the site for the final diposal of low- and intermediate-level radioactive waste coming from nuclear power plants. At the same time it agreed that subsurface geological exploration would be required for site implementation.

The IKIM Decree 62/1997.(XI. 26.) does not take into account the geological exploration following the suitability declaration nor it mention the subsurface geological exploration. Nevertheless, the MGSZ DDTH took on the authorisa-tion of the exploraauthorisa-tion design (SZŰCSet al. 2004). For the most part this had been prepared by MÁFI but already carried

out within the framework of a Puram–Mecsekérc contract. The final report, also prepared by MÁFI, was approved by the Pécs District Inspectorate of Mines (the legal successor of the MGSZ DDTH). Simultaneously, Puram was authorised by the South Transdanubian Regional Institute of the National Service for Public Health and Health Officers to implement the construction of the NRRW. Subsequently, projects started in 2008 are not qualified as geological explorations although they obviously include some geological exploration components. These Explanatory Notes outline the state of geological knowledge immediately prior to the site implementation.

This knowledge was further developed by MÁFI’s contract with Mecsekérc, commissioned by Puram. Within its framework geological mapping was conducted and boreholes made in one segment of the area in order to study Cainozoic sediments with the aim of possible raw material exploration. The information thus acquired was built into the final report (BALLAet al. 2008) in terms of both maps and the present explanatory material.

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THEMAPSERIES AND ITSEXPANATORYNOTES

Geological mapping together with a number of other activities aimed at acquiring thorough knowledge on the geo-logical setting were invariably vital components of the exploration of the Üveghuta Site. The scale of the exploration on the full 72 km2study area was 1:10,000 but that of the actual site was obviously much more detailed.

The present work is the explanatory material of the Üveghuta 1:10,000 map series (Enclosures 1–8). Concerning the Enclosures 1-5, Enclosure 1 presents the observed exposures (including the number of those specified in the text) as well as the drift geological map. Enclosure 2 displays the relief and the geological map of the basement; Enclosure 3 illus-trates the relief and geological map of the pre-Quaternary deposits (apart from the basement ones including also the Lower- and Upper Miocene sediments); Enclosure 4 features the boundary of the two formations of the loess assemblage (Udvari Loess Group) as well as the base contour lines of the Mende Loess and the slide bodies; and Enclosure 5 pres-ents the geological map of the area without the slope deposits. Enclosure 6 specifies the basement sequences and the overlying beds in cross- and conceptual columnar sections. Enclosure 7 features the geomorphology of the area, where-as Enclosure 8 illustrates the relief of the groundwater. The content and compilation of the map series is described in Annex 1. From the enclosures the Chapters Geological sequences and Structure are the explanations of the geological maps and cross sections referring to tectonic content (Enclosures 1–6). Chapter Geomorphology elucidates the geomor-phological map (Enclosure 7). Chapter Hydrogeology is devoted to the description of the groundwater relief map (Enclosure 8). The maps were compiled based on the materials prepared during the exploration of the Üveghuta Site between 1995 and 2008, essentially making use of the enclosures of the final report (BALLAet al. 2008). The

explanato-ry material was prepared on the basis of the texts of the mapping report (GYALOGet al. 2006c) and of the final report

(BALLAet al. 2008). In this work it is also intended to present some other vital results of the geological exploration.

The tablesandfiguresclosely associated to the explanatory material have been enclosed in the basic text. Large maps

and sections were folded in enclosures. The materials specifying some issues of the basic text in detail were presented

in annexes. Photos were emplaced in plates following the annexes. All figures and annexes were compiled in digital

for-mat.

The explanatory text is bilingual. The first one is the Hungarian text including the figures, the bilingual title and cap-tions. It is followed by the English text only with references to the figures. The tables are included in both texts. The title and the captions below the photos in plates are bilingual as well.

The page numbers of the basic text and the enumeration of the figures and tables included therein are continuous. The page as well as table, figure and photo numbering of the annexes follow that of the basic text. The page numbering of the English text follows the Hungarian one, whereas the table, figure and photo numbers are identical with those in the Hungarian text.

In the refernce list, the publications written in languages other than English, German or French, the name of the abstract or — if it was missing — the whole work was given in one of those three languages; in its absence the title was simply translated into English.

The name of the editors and authors of the Explanatory Notes, as well as the contributors to the compilation of fig-ures and annexes are specified in the title page in alphabetical order. The authors of certain chapters, annexes and enclo-sures can be found in the table of contents. If the author of a certain chapter was not specified it is presented by the first name appearing upward in the hierarchical order of titles. The authors and contributors of the enclosures are listed on the enclosures themselves. The list of mapping geologists is presented in Enclosure 1.

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The exploration conducted in the Üveghuta Site and its environment played a fundamental role in acquiring knowl-edge on the geological setting of the area. From 1995 onward the exploration was carried out using ground-based meth-ods and this process took place for almost a decade; from 2005 the ground-based exploration was accompanied by under-ground methods. From 2006 the final underunder-ground exploration was performed and this was completed in 2008.

The ground-based exploration in Üveghuta is now subdivided into the following phases: preparatory works (1995–1996),

— site selection (1997),

— site suitability study, phase 1 (1997–1998), — complementary suitability study (1998–1999), — site suitability study, phase 2 (2001–2003), — ground-based row material exploration (2003),

— complementary ground-based exploration (2004–2006).

During the preparatory period the Site and its environs were explored as one of the objects selected by the nation-wide, then regional screening program. In 1996 the decision was made to select and concentrate on a single object. In accordance with the international practice the Site was first selected and then its suitability studied. Paying attention to particular considerations the suitability study was subdivided into three phases. The ground-based raw material explo-ration was performed entirely independently of the Site (albeit within the area considered as its environs). The comple-mentary ground-based exploration went on simultaneously with the underground survey in order to elucidate some still unresolved questions.

The main tool of the underground exploration was the driving of tunnels accompanied by boreholes penetrated from the resulting tunnel. Both the tunnel and the underground boreholes contributed essentially to acquisition of geological knowledge about the granitoid body.

In the next passage the groundbased exploration will be outlined. First the history of geological exploration and geo-logical mapping will be presented. This will be followed by details about the ground-based boreholes and their study, accompanied by the history of geomorphological research. Finally, tunnels, underground boreholes and their examina-tion will be described. The history of the geophysical surveys and raw material exploraexamina-tion will be outlined separately.

HISTORY OF THE GEOLOGICAL INVESTIGATIONS

The recognition of sequence groups and their structural characteristics constitutes an independent unit and they are thus presented separately.

STUDY OFGEOLOGICALSEQUENCES

The first effort to discover more about the broader surroundings of the Mórágy Block (“Geresd Hills” in geographi-cal terms) was the scientific exploration and geologigeographi-cal investigation of the Mecsek Mountains in the first decades of the 19thcentury. Given that coal mining was the decisive aspect inspiring geological exploration during this period there were hardly any studies made of the surrounding hilly terrain until the last quarter of the century.

The detailed geological revelation of the region started with mapping; this resulted in the 1:144,000-scale map series

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of Transdanubia including the Pécs–Szegszárd sheet (Magyar Királyi… 1880); the latter incorporates the area of the present study. However, accompanying explanatory material for this earlier work has not been found.

Due to its scale the 1:300,000 geological map of Hungary (BALOGH, K. et al. 1956) and its explanatory notes

(BALOGH, K. et al. 1958) provide only a schematic picture about the geological setting of the region concerned.

Similarly, the geological (FÜLÖP 1984) and basement-geological maps (FÜLÖP, DANK 1987) published in the

1:500,000 series of the Geological Atlas of Hungary furnish only some broad outlines of the geological characteristics of the area. In the related explanatory notes (HAAS1996) only two pages (pp. 9–11) are devoted to the fundamental

aspects of the compilation, while the description of the sequences represented on the map is completely missing. The Pécs sheet of the 1:200,000 geological map series of Hungary (WEIN et al. 1965) and its explanatory notes

(FORGÓet al. 1966) offer reasonable outlines on the geological knowledge of the area.

The Baja sheet (FRANYÓet al. 2005) of the 100,000-scale geological map series of Hungary presents an area

partial-ly relevant for the exploration dealt with in this study, albeit with obvious generalisation due to its scale. The explanato-ry notes of the map series (GYALOG2005) include a brief description of the sequences of the area.

With regard to the basement units the exploration area is essentially made up of the rocks of the Mórágy Granite Formation. The latter is confined from the NW by the Ófalu Group, which forms the material of the Mecsekalja (Sub-Mecsek) Zone, whereas Jurassic sedimentary sequences can be encountered further NW (of which only the Vasas Marl Formation is exposed on the surface). These are covered overlying beds of the Cainozoic. Cretaceous dykes (the Rozsdásserpenyő Alkali Basalt Formation) occur all over the three sub-areas.

As for the overlying beds of the Cainozoic, the lower Miocene Budafa Formation can be found in the SW and NW parts of the area. With regard to the upper Miocene (Pannonian) beds the Kálla and Tihany Formations are present in the peripheries of the region.

With respect to the Quaternary sequences, the hilltops and partly the hillsides are constituted by the sequences of the Lower–Middle Pleistocene Fenyvestető Red Clay Formation, together with the Lower–Upper Pleistocene Udvari Loess Group. Simultaneously, Pleistocene–Holocene fluvial (fluvial-proluvial and fluvial-paludal) sediments as well as Holocene lacustrine sediments occur in the valleys, whereas in the valley sides Pleistocene–Holocene (deluvial, slide and solifluctional) slope deposits (and Upper Pleistocene paludal sediments) can be encountered.

Ófalu Group (Lower Palaeozoic)

The metamorphites of the East Mecsek Mountains were considered by VADÁSZ(1953) as the schistose cover of the

granitoid body, whereas SZÁDECZKY-KARDOSS(1959) thought of this body as the source of palingenic granitoid magma.

In agreement with the latter concept a comprehensive presentation of the metamorphites was provided by JANTSKY

(1979). According to JANTSKY(1979) and SZEDERKÉNYI(1996b) metamorphites occur both in the Mecsekalja Zone and

in association with the Mórágy Granites. FÜLÖP(1994) followed the concept of Szederkényi, T. and JANTSKY, B. in

pre-senting the Ófalu Schists and the Mórágy Granite, respectively; hence he looked at some aspects of the metamorphites (the stratified migmatites) in both sequences.

In the work of the afore-mentioned authors the metamorphites constituting the Mecsekalja Zone can be correlated — with some readjustments — as presented in Table 1.

Of the listed ten different rocks the serpentinite (10.) obviously did not fit into the picture, therefore it was distin-guished by SZEDERKÉNYI(1996b) as the independent Ófalu Serpentinite Formation. The assignment of the crystalline

limestone (1.), phyllite (2.) and amphibolite (9.) to the same rock sequence of common origin by no means evident. According to JANTSKY(1979) the rocks of

vol-canic and volcanomict origin, as distinguished by SZEDERKÉNYI (1996b), could correspond

altogether to the stratified migmatites of espe-cially high diversity.

In summary, it can be noted that both authors emphasise the similarity in the grade of metamorphism as a common feature of the ten different rocks; however, evidence is missing on whether they had a common origin before they were subjected to metamorphism.

On the subject of the joint metamorphosis and the especially heterogeneous rock material, a conclusion was arrived at that all these rocks make up the infilling of the Mecsekalja Zone as megabreccia. They are derived from diverse

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stratigraphic and tectonic units but they were subjected jointly to the Variscan metamorphosis in their present location. Accordingly, all metamorphites were integrated in a new lithostratigraphic unit — first in Ófalu Formation (GYALOG,

BUDAI2004, KIRÁLY, KOROKNAI2004), then in the Ófalu Group; the latter has been subdivided in the present work on a

lithological basis.

Bátaapáti Metasandstone Formation (Lower Palaeozoic)

Concerning the metamorphites associated with the Mórágy Granite, the situation is further complicated by the fact that the granites were regarded by JANTSKY(1979) as a segment of the ultrametamorphic series. He described

metasand-stone, metaconglomerate as well as “cordierite, sillimanite and staurolite-biotite paragneiss” in the “regional metamor-phic series of amphibolite facies”. This is given no mention at all by SZEDERKÉNYI(1996b). According to the

classifica-tion of the latter they could be part of the Mórágy Complex consisting of metamorphites beside granites. With regard to these metamorphites Szederkényi notes simply that they comprise gneiss, mica schist and amphibolite but with respect to the entire spatial extent (in Southern Transdanubia and the Great Hungarian Plain) of the complex. Hence it is not clear where he classified the metamorphites, which are incorporated in the granite, according to JANTSKY(1979).

During the work of this project the metamorphites embedded in the granite were first assigned to the Bátaapáti Metasandstone Member (GYALOG, BUDAI2004, KIRÁLY, KOROKNAI2004), thus making it part of the Ófalu Formation.

However, it was later specified as a new lithostratigraphic unit referred to as the Bátaapáti Metasandstone Formation. Mórágy Granite Formation (Lower Carboniferous)

The three main sequence groups of the Mórágy Granite as it is known today — the porphyritic base rock (= monzo-granite), the mafic inclusions (= monzonite) and the leucocratic dykes — were clearly distinguished in former studies as well (Table 2).

ROTH(1875, 1876a, b) provided field names, whereas the first microscopic and petrochemical examination was

per-formed by PAPP, REICHERT(1929). PAPP(1952) stated that the rocks concerned are transitional to alkali sequences. BUDA

(1985) recognised that the Mórágy rocks bear monzonitic signatures. In the classification of JANTSKY(1979) hybrid rocks

forming the transition between the porphyritic base rock and the mafic inclusions can already be recognised (“skialith-ic, nebulithic porphyroblastic granite” and “diatexite”).

Just over fifty years ago JANTSKY(1953) disclosed that the granite had been subjected to dynamometamorphism as

well as to cataclastic and mylonitic deformation and it was foliated at about 60°.

After some time the authors started tacitly or openly to move away from the hypothesis that the Mórágy Granite was formed of intrusive magma. With regard to the development of the granitoid rocks, a turning point came when SZÁDECZKY-KARDOSS(1959) suggested that “instead of being magmatic the granitoid rock body is a metasomatic

assem-blage of migmatic origin”. This presumption fundamentally changed the conception of Hungarian geologists and this will be demonstrated thematically below.

Since VADÁSZ(1914) the ageof the granitoid body has been considered pre-Permian. It was later refined by VADÁSZ

(1935) as Variscan (TELEKI1941, VADÁSZ1953). With regard to the age of the anatectic (i.e. “migmatic”,

“metasomat-ic”) granite formation, the respective suggestions of pre-Variscan, Caledonian (CSALOGOVITS 1964), and even

Precambrian (SZEPESHÁZY1968, 1969, 1973; JANTSKY1975, 1979) ages were also raised, although the majority of the

authors (VADÁSZ1960; WEIN1967; SZÁDECZKY-KARDOSS 1967, 1969; GHANEM, RAVASZ-BARANYAI 1969; BUDA1985,

1990, 1994; BUDA, NAGY1995; BUDAet al. 1999, 2000) remained with the Variscan hypothesis even after the conception

change. The Variscan origin seemed to be supported by the K–Ar dating (BALOGH, Kad. et al. 1983) as well.

Table 2. A The main groups of the Mórágy granitoid rocks as specified in the works of different authors

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During the decade following the conception change initiated by the article of SZÁDECZKY-KARDOSS(1959), the

ana-tectic-metasomatic concept of origin prevailed in the views of Hungarian authors with respect to the granite formation (WEIN 1967; SZÁDECZKY-KARDOSS 1967; FÖLDVÁRI-VOGL, BÖJTÖS-VARRÓK 1968). Later, however, migmatisation was

explained by SZÁDECZKY-KARDOSS(1969) through the intrusive, injection metamorphic effect of the granite. It represents

a significant change in contrast to the original concept (which featured the granite as the productinstead of the causeof

migmatisation).

Nevertheless, the mineralogical-petrological characteristics of the granite were explained and described by a num-ber of authors including GHANEM, RAVASZ-BARANYAI(1969), SZEDERKÉNYI(1974, 1975, 1985), JANTSKY(1975, 1979) and

BUDA(1968, 1969, 1972, 1974, 1975, 1981a, b, 1990, 1994, 1995; BUDA, NAGY1995; BUDAet al. 1985). They assumed

an anatectic-metasomatic origin. A fundamental aspect of this view was that the granite was roughly coeval with the metamorphosis of its neighbouring sequences. Consequently, little attention was devoted to the metamorphic phenome-na of the granite — which had already been noted by ROTH(1875, 1876a, b) and described by JANTSKY(1953) — and

they were only mentioned briefly. JANTSKY(1979) thought of it as retrograde metamorphism preceding cataclasis and

milonitisation which had occurred later than the Early Jurassic.

According to BUDA(1972, 1975) granitisation took place at a temperature around 450 °C. Owing to subsequent

warm-ing the K-feldspars of the base material were partly mobilised and this resulted in the granodioritic composition of the Mecsek rocks. Metasomatic K-feldspar crystallised and granite aplites formed in the granite due to the released K, Si and Al.

Initially, the metasomatic origin of the K-feldspar — qualified formerly as “porphyritic” —was thought of as an important element of the anatectic-metasomatic origin. Two generations of K-feldspars were distinguished by BUDA

(1994) concerning their structure: the intermediately ordered and ordered ones. The first one occurs in the base materi-al, whereas the second one appears as porphyroblasts. He suggested that only the K-feldspar of the base material had been crystallised by the anatectic melting, while porphyroblasts formed as a result of subsequent K-metasomatosis. According to his examinations of ordering, HÁDEN(1997) also deduced that the temperature of the crystallisation of large

K-feldspars was presumably around 500-550 °C —i.e. they are derived from metasomatic processes. Hence the most crucial element of the anatectic-metasomatic origin introduced by SZÁDECZKY-KARDOSS(1959) — the in situmelting —

became uncertain. (This was because larger granitoid bodies do not commonly originate from magmas having different origins, although crystallisation might take place at various distances away from the melting place.) It is not by chance that that the in situ melting has not been emphasised in recent works (BUDA1996, 1998, 1999, BUDA, DITRÓI-PUSKÁS

1997; BUDAet al. 1999, 2000).

BUDA(1981a) thought that differentiation and the comparatively large water pressure had played an important role in

the crystallisation process of the granite. Later, he dismissed differentiation as being opposed to the anatectic-metaso-matic origin (BUDA1985); nevertheless, he preserved the concept that the melt was rich in volatiles. He assumed that

biotite and ilmenite had crystallised first at a low temperature followed by the leucocratic components. The granitoid body cooled down slowly allowing K-feldspars to form an ordered structure.

Certainly, the anatectic-metasomatic origin refers to the base granite. In this respect mafic inclusions can be inter-preted most simply as the particles of the original, pre-melting mass of rock, thus preserving its solid state during the partial melting —i.e. the palaeosome of the migmatites (BUDA1974; JANTSKY1975, 1979). These inclusions were

qual-ified as featuring a basic composition (BUDA1974), suggesting that the base granite and the rock of the inclusions have

different origins (BUDAet al. 1985). It seemed to be supported by the high rare-earth-element content of the base

gran-ite as opposed to the low one of the mafic inclusions (BUDA1990).

Instead of being basic the composition of the inclusions is essentially intermediate (i.e. syenitic, monzonitic, diorit-ic, see BUDA1996, 1998, 1999). However, Buda noted that titanite, chromite, ferrodiopside, the zoned plagioclase of

labradorite (An60) composition, the Mg-rich actinolitic hornblende and the Mg-biotite together with the D and O18ratio all refer to basic magmatic origin. The inclusions are also foliated (JANTSKY1979) and their amphiboles of actinolite and

actinolite-hornblende constitution indicate a postmagmatic or metamorphic alteration (BUDA1995).

Some years ago it was suggested that although the inclusions were of basic composition, the two rocks — i.e. those of the base granite and the inclusions — were the products of two simultaneously existing and crystallising melts (BUDA

1999; BUDAet al. 1999, 2000). This eliminated the most crucial argument of the in situ anatectic-metasomatic origin of

the base granite, as represented by the presence of highly metamorphic inclusions which preserved their solid state dur-ing the partial meltdur-ing.

Leucocratic dykes make up the third component of the Mórágy granitoid body and they have always been consid-ered as the crystallisation product of an intrusive magmatic melt. This was reconciled with the anatectic-metasomatic origin by BUDA(1968, 1972, 1974, 1975). He consideredthe dykes to be the low-temperature (<450 °C) products of

K-metasomatosis following the mobilisation of the potassium of granodioritic rocks. Afterwards BUDA(1990) regarded the

same dykes as derivatives of residual melt; later he emphasised the individual origin of the dykes (BUDA1996, 1998,

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During the exploration performed it was recognised that, on the one hand, large K-feldspar crystals were crosscut by acidic dykes; on the other hand, both the base rock and the dykes are affected by foliation and metamorphosis of a diverse grade. The first observation made the metasomatic origin of large K-feldspar crystals highly uncertain; and the second one proved unambiguously the fundamental role of metamorphic phenomena in understanding the true features of the Mórágy Granite (which is younger than the crystallisation of K-feldspars).

During the Üveghuta exploration all these aspects required careful consideration of the hypotheses made about the formation of the Mórágy Granite. In order to achieve this some 100 thin sections prepared of fresh granites from the bore-holes were examined by UTENKOV(2003). As a result he drew the following conclusions:

— Large K-feldspars are of magmatic origin; their metasomatic development is excluded by both the composition and the fabric of the minerals.

— The petrological diversity of the base granite is the result of magmatic differentiation. Different rock types are essentially constituted by the same mineral paragenesis. Their relationship was controlled by the process of the melt’s cooling as well as by its volatile content.

— Instead of having a granitic origin the Mórágy rocks are of a monzonitic type. It occupies a quite extraordinary position among magmatic rock series: instead of a composition change tending to eutectic its crystallisation can be described by the temporal succession of mineral parageneses.

— The material of both the mafic inclusions and the dykes are intimately associated with the base granite: the inclu-sions are the early and the dykes the late products of crystallisation of the same magma.

Concerning the aforementioned conclusions, it was the derivation of the base granite and the mafic rocks from the same magma that seemed to be ambiguous. Hence — after BUDA(BUDA1996, 1998, 1999; BUDAet al. 1999, 2000) —

these two rock types are regarded as the results of two different magmas, respectively.

During the exploration it was concluded that the Mórágy granitoid rocks should be separated from the Mórágy Complex —as defined by SZEDERKÉNYI(1996b) —and, including both metamorphites of amphibolite facies and

gran-itoid rocks, they should be considered as a new lithostratigraphic unit referred to as the Mórágy Granite Formation (GYALOG, BUDAI2004, BALLA2004, KIRÁLY, KOROKNAI2004).

Following the review of the complete drilling core material, BALLA(2002) subdivided the base granite and the mafic

rocks into two and three groups, respectively. In the base granite he distinguished a knotty (more acidic) type and a grained (more basic) type. He emphasised that they appear commonly as being separated in space and outlined their dis-tribution in the area explored by the boreholes. He assigned mafic rocks to dotted (medium-grained), aphyric (small-grained) and small-porphyritic (fine-(small-grained) types. He emphasised that their appearance depended on the proportion in which they were present in larger rock volumes: the highest and the lowest results appear in dotted and small-porphyrit-ic patterns, respectively. He outlined the assimilation phenomena evident in the contact zone of the base granite and mafic rocks. He revealed that the base granite plays the active role, whereas the mafic rocks play a passive one; the two rocks get in contact, although the latter also remains in a ductile state. He described that the fabric of the decisive major-ity of Üveghuta rocks features some sort of orientation and he distinguished the following three types concerning the grade of foliation: striped, vermicular and fractured.

This subdivision of rocks was used in the geological mapping of trenches (GYALOGet al. 2003h) with the following

modification of the nomenclature: knotty porphyritic, grained rarely-porphyritic granitoid; and dotted  medium-grained, aphyric  small-grained aphyric and small-porphyritic  fine-grained small-porphyritic dioritoid rocks1. Sequences representing the transition between the granitoid and dioritoid rocks were considered to be of a hybrid nature, and of these contaminated diorite and contaminated monzogranite were distinguished. Among the latter, diorite perme-ated with granite and feldspar veins and K-feldspar (mega-crystalline) diorite were differentiperme-ated.

During the geological logging of the 2002–2003 Üveghuta boreholes (BARABÁS, András et al. 2003a–c, GYALOGet

al. 2003a, c–g, k–m, o) this system was further refined. Given the thin-section definitions of KIRÁLY(2003a–i),

monzo-granite and quartz diorite were differentiated within the granitoid rocks on the one hand, whereas dioritoid rocks were referred to as monzonite and, instead of the notion “permeated with granitic and feldsparry veins”, the expression “con-taminated with leucocratic schlieren” was introduced (BALLA2003a).

The rocks were presented in detail by PEREGI(2003). Comparing the visual and microscopic definitions he stressed

that they correlated statistically but there were quite a number of deviations on a broad scale. Consequently, separa-tion of monzogranite and quartz diorite was omitted during the explorasepara-tion in 2004–2005 (PEREGI, GULÁCSI 2007,

KIRÁLY, GULÁCSI2008) with respect to the geological logging of ground-based boreholes (GYALOGet al. 2006a, d–g),

the documentation of tunnels (MOLNOSet al. 2007a, b, 2008) and the geological logging of underground boreholes

(GYALOG, ALBERT2007, GYALOGet al. 2006h, 2008e–d). This last action finalised the nomenclature used in the

pres-ent work.

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Triassic–Jurassic

In the exploration area only some fragments of the Eastern Mecsek Triassic (TÖRÖK, Á. 1998) and Jurassic series

(NÉMEDIVARGA1998) occur. These are mainly in boreholes and only the Lower Jurassic Vasas Marl can be observed in

outcrops.

Sequences (i.e. sandstone and marl) making up the transition between the Gresten and Allgäu Facies were assigned to the Vasas Marl Formation. They can be observed in the NW periphery of the exploration area, NW of the Mecsekalja Zone which confines the granitoid body. The formation was described by NAGY, E. (1969) and HETÉNYI(1964, 1966).

However, the first detailed specification of the related sequences occurring in the exploration area was provided by CSÁSZÁR(2005a); this was the result of field observations in the frame of the geological mapping (GYALOGet al. 2006c).

The boreholes established in the NW corner of the area, years or possibly decades prior to the Üveghuta exploration, penetrated a number of related sequences. These include the Middle Triassic Csukma, the Upper Triassic Karolinavölgy Sandstone, the Upper Triassic – Lower Jurassic Mecsek Coal and the Lower Jurassic Hosszúhetény Calcareous Marl Formations (albeit in strongly reduced intervals). Their classification and description are the results of the work of CSÁSZÁR(2005a) and CSÁSZÁRet al. (2007).

Rozsdásserpenyő Alkali Basalt Formation (Cretaceous)

In his work in 1950, JANTSKY(1953) qualified mafic dykes occurring in the area of the Mórágy Block as lamprophyre

and he associated them essentially with granitoid magmatism. They might have been referred to as “minette” and “kersan-tite” by PAPP(1952, Table 2) or they might also have even been the “basic dykes” reported by ROTH(1875, 1876a, b, Table

2). MAURITZ, CSAJÁGHY(1952) defined the material of these dykes (on the basis of thin sections) as bostonite,although they

expressed some doubts. (For example, orthoclase or microcline may be expected in bostonite but, instead, sanidine occurs in the Mórágy dykes.) They also suggested a possible relationship with the Mecsek phonolites but did not exclude the pos-sibility that their generation was associated with granitoid magmatism. SZÁDECZKY-KARDOSS(1955, p. 391) also noted that

the bostonite, together with the (Mecsek?) trachydolerite, is younger than the (Velence) granite.

Bostonite debris was described in Permian and Upper Triassic sediments by BARABÁS, A. (1956) and IMREH(1956).

In agreement with this, VADÁSZ (1960) noted that “the pre-Permian age of the bostonite is evident” although “the

bostonite dyke is undoubtedly younger than the granite and its magmatism cannot be associated to it either”.

OVCHINNIKOVet al. (1965) recorded an age of 110 million years by the K–Ar method on a trachydolerite taken from

a quarry in Kismórágy, suggesting an Early Cretaceous date.

GHANEM, RAVASZ-BARANYAI(1969) thought that the bostonite was of a post-orogenic origin. JANTSKY(1979), on the

other hand, assigned it to Lower Cretaceous on the basis of material from the core of Borehole Alsónána–1 in which bostonite and limburgithoid trachydolerite occur simultaneously.

SVINGOR, KOVÁCH(1978) recorded 142±20 and 143±9 million years as a singular age and 142±8 million year as an

average age for two samples using the Rb–Sr method. These results are much closer to Early Jurassic than to Palaeozoic. At the start of the work in Üveghuta mafic dykes occurring in the area of the Mórágy Block were assigned to the Mecsekjános Formation (KÓKAI 1995, 1997, 1998b, KÓKAI, TURTEGIN 1995). This formation is typical of the Lower

Cretaceous volcanic zone of the Eastern Mecsek, and the zone is underlain by a thick Mesozoic sequence. Two distinct series were distinguished within the Lower Cretaceous volcanic assemblage by HARANGI, ÁRVÁNÉ(1993) as specified below:

— Slightly differentiated series: ankaramite – alkali basalt, predominantly lava rocks. The rocks are highly porphyrit-ic; phenocrystals are composed of olivine and clinopyroxene. The same minerals can be encountered in the matrix togeth-er with plagioclase and frequent Fe–Ti-oxide mintogeth-erals.

— Highly differentiated series: Na-basanite–phonotephrite–tephriphonolite–phonolite; these are all being dykes. They are unsaturated in silicon, apart from the plagioclases; biotite and amphibole (kersutite) are also frequent and apatite is comparatively abundant as well.

The two series cannot be derived from the same magma and their rocks differ in terms of their palaeomagnetic direc-tions as well. The dykes are presumably younger but K–Ar dating does not provide more reliable results due to the high standard deviation.

According to all these aspects the above-described alkali-volcanic dykes were first assigned to the Rozsdásserpenyő Trachyte Formation (GYALOG, BUDAI2004, BALLA2004). In the present work they have been as a new

lithostratigraph-ic unit referred to as the Rozsdásserpenyő Alkali Basalt Formation. Miocene

The lower–middle Miocene sequences of the area were described by HÁMOR(1970) in a monograph. His study did

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was performed during the detailed, 1:10,000-scale geological mapping of the Mecsek Mountains. A published map and explanatory notes were produced with reference to the W part of the area (Ófalu sheet, HETÉNYIet al. 1976a, b).

Lower Miocene sequences occurring in the area were assigned by KÓKAI(1998a) to the Budafa Formation. They were

mentioned by KOLOSZÁRet al. (2000) from the S part of the Hidas Basin (Boreholes Cikó C–4 and –5) and from

out-crops NW of Feked. He described them as loose, fossil-free gravelly sand, sandy gravel and boulder. KOLOSZÁR(2006)

assigned the sequences of the Budafa Formation, to its Budafa Sandstone Member (GYALOG1996, HÁMOR1998). This

classification is accepted in the present work as well.

The Pécsszabolcs Limestone Formation of the Badenian was mentioned (HÁMOR1970) beyond the study area, close to

its NW and SE boundaries, with a detrital succession (boulders at the bottom, finer sediments upwards). In the course of the geological mapping, one of the exposures was arranged into this stratigraphic interval as the Lajta Limestone Formation (CSÁSZÁR2005). Later on, due to the absence of faunistic evidence it was also regarded as a part of the Budafa Formation.

Upper Miocene (Pannonian) sediments were already shown (on the E side of the Rák Brook, in the valley of the Köves Brook and on the S side of the Lajvér Brook E of Kismórágy) on the 1:144,000-scale map (Magyar Királyi… 1880). In the 1:10,000-scale Ófalu map sheet and its explanatory notes for the W part of the study area (HETÉNYIet al.

1976a, b) upper Pannonian yellow, limonitic, gravelly sand is displayed in the frame of the study area.

Since the publication of the lithostratigraphic subdivision of Pannonian sequences of Hungary (JÁMBOR1980), no

mention of Pannonian units of the study area appeared until the beginning of the present exploration. The 1995 geolog-ical mapping (CHIKÁNet al. 1995) and the industrial exploration of the Bátaszék brickyard provided some of the

infor-mation for the investigation of the upper Miocene (Pannonian) beds of the area. Several studies of the Pannonian sedi-ments of the brickyard were carried out by the Faculty of Geology and Palaeontology of the József Attila University of Szeged (SZÓNOKY1992, 1996; LENNERT1985). The last detailed elaboration of the fossil assemblage was presented in

LENNERTet al. (1999).

The upper Miocene (Pannonian) sediments of the area were first described by KOLOSZÁR (1998). KOLOSZÁRet al.

(2000) assigned them to the lower Pannonian Csákvár Claymarl Formation (clay and sand in vicinity of the brickyard caly pit) as well as to the upper Pannonian Kálla Gravel (gravelly sand, sand) and Somló Formations (sand, marl, clay-marl, limy marl etc.).

On the basis of their qualification by KOLOSZÁR, GYALOG(2006) — with reference to their facies — they are assigned

to the Kálla Gravel and Tihany Formations (GYALOG1996). Quaternary

With respect to the Quaternary sediments of the area, the first serious scientific report which provided data that is still relevant today was the work of Szabó, J. (1863). Among the young overlying beds he notes the 20-30 m thickness of the loess as well as the outcrops of the red clay and Pannonian sediments.

The work of ROTH(1875, 1876a, b) can essentially be assigned to the same period; he distinguished Miocene

sedi-ments and the level of granitic gravel underlying the Pleistocene sedisedi-ments as a result of the examination of the grani-toid rocks of the “Fazekasboda-Mórágy ridge”.

With regard to the Quaternary beds, apart from the loess covering the main part of the area, the Pécs-Szegszárd sheet (Magyar Királyi… 1880) of the 1:144,000-scale map series of Transdanubia illustrated the alluvium of the main water courses and the bean-ore-bearing red clay. The latter underlies the loess in one of the tributaries of the Köves Brook which is situated near the boundary of Bátaszék.

Among the synthesising works produced at the turn of the century the geological textbook of BÖCKH(1909) and the

works of HORUSITZKY(1910) and LÓCZY, sen., (1910) should be noted as specifying important Quaternary aspects of the

exploration area as well. Horusitzky was the first to make an attempt to set up a classification system for Hungarian Pleistocene sediments. He distinguished “lower“ and “upper Pleistocene”, suggesting one glacial in the lower part and two glacials, two interglacials and a postglacial period in the upper one. Lóczy emphasised the difference between the palaeoclimatic conditions of Northern Europe and Hungary and thought that the formation of Hungarian Quaternary sed-iments could be compared with those in the East Asia.

Based on field data, in the first half of the 20thcentury specialists suggested four glacial periods, whereas palaeonto-logical data implied only three parts of one glacial period including pre-glacial, glacial and post-glacial climatic periods (KORMOS1910, 1911). Eventually the four periods were accepted as being valid.

After the mapping carried out at the end of the 19thcentury no detailed Quaternary investigations took place in the narrower exploration area for decades. What can be regarded as a “new” mapping campaign began with KADIĆ(1925)

who mapped the region between Szekszárd, Tevel and Bonyhád on a scale of 1:25,000. Concerning his observations in Sárköz, he was the first professional geologist to study the area and to distinguish between the lower and upper flood-plain levels. During his study he confirmed that red clay horizons occurring within the loess assemblage formed several levels in the hilly regions; he considered these to be lens-like features that “do not reach far”.

(20)

With regard to investigations which dealt with the area in the related period, the structural work of PÁVAI VAJNA

(1925) and the morphological study of BULLA(1937) have to be emphasised. Mapping activities which took place in the

same period (and which partly included South-Eastern Transdanubia as well) were summarised by STRAUSZ(1952); its

morphological evolution was discussed by SZABÓ, P. Z. (1957).

During the second half of the 20thcentury, due to the partial retreat of geology, geography took on a serious commit-ment with regard to the investigation of Quaternary sedicommit-ments together with their stratigraphic and genetic examination. The studies of LEÉL-ŐSSY(1953) and LÁNG(1955) are the most important of the geographic-geomorphological

investi-gations which took place at the beginning of the 1950s. In his 1955 work Láng was the first to describe the slide-affect-ed nature of loess sequences in the Szekszárd Hills.

In this period the most detailed synthesis of the Quaternary of the area was provided by MIHÁLTZ(1953), who

sum-marised the related data of 22, 1:25,000-scale map sheets in the frame of the lowland (so-called “bicycle”) mapping. He reported that red clay overlay limestone bench(es) with calcareous nodules in the Pannonian–Pleistocene boundary; this is especially characteristic to the S of the Mecsek. It is followed by 30-40 m-thick loess further up the profile and divid-ed by loam horizons (4 in Báta and 8, eventually 9 in Paks). VITÁLIS(1959) furnished new data about the SW part of the

area, especially with respect to the degradation of the granitoid body of the Geresd Ridge towards Karasica, the differ-ent fluvial cycles, and the stratigraphic features of the loess.

The morphology of the stretch of the Danube Valley in the immediate vicinity of the area and the geological setting of the region were reported by PÉCSI(1959a). Regarding both geomorphological and Quaternary-evolutionary aspects, it

provided more detailed information than any other previous work up to that time. He published the structural geological results of his studies in separate papers (PÉCSI1959b). The investigations of PÉCSI(1965, 1967, 1975, 1977, 1985a) and

his colleagues played a determining role in the study of the Quaternary of the area with respect to both the nomenclature and correlation of Quaternary sediments, especially loess and the genetic features of the young sediments.

ÁDÁM(1964, 1966, 1967) initiated an especially detailed geographic, geomorphological and geological investigation

of the Szekszárd Hills with the objective of producing a geoscientific synthesis. His works can be regarded as the out-standing summary of all the results acquired up until that time. However, due mainly to the lack of drilling exploration, his works do not provide fundamentally new information.

The works of KRIVÁN(1955, 1960a, b) are of fundamental significance regarding a number of aspects, including the

stratigraphic classification of the loesses of Hungary and South-Eastern Transdanubia. This is especially true with respect to the Paks loess, the climatic subdivision of the Quaternary period and the chronology of the terraces in the Danube’s floodplain. A similarly important basis for regional stratigraphic correlation is provided by pyroclastic rocks whose regional investigations are also partly associated with his work (KRIVÁN1957, KRIVÁN, RÓZSAVÖLGYI1964).

The investigation of the petrological, structural and stratigraphic features of the Bár basalt volcanism, together with the determination of its stratigraphic position, also played an important role in the geological exploration of the area (KASZAP1963, SZEDERKÉNYI1964, VICZIÁN1965, GHONEIM, SZEDERKÉNYI1977, BALOGH, Kad. et al. 1982).

The research of the red clay — partly subdividing and partly underlying the loess — became a significant aspect of Quaternary research. According to VADÁSZ(1968) the age of the red clay embedded between the Pannonian sediments and

the loess is partly Pleistocene but pre-Pleistocene red clays also occur. On the basis of the analogy with the Neogene-consid-ered occurrences that can be traced from China to England, PÉCSI(1985b, 1986) regards the “true red clays” underlying the

loess Pliocene. The partial assignment of the red clays to the Pleistocene was enabled by the processing of the geological Key Borehole Tengelic T–2 and by the correlation of some of its log sections with the Bár Basalt Formation (HALMAIet al. 1982).

Pécsi and his research fellows summarised the results achieved during their several-decade-long Quaternary research in a number of works. Among them the work of PÉCSI(1995) can be regarded as fundamental in the stratigraphic

subdi-vision of loess sequences. Stratigraphic, sedimentological and palaeoecological features of the region’s loess sediments were examined by HUM(1997, 1998, 1999a, b, 2000a, b, 2001a, b), HUM, FÉNYES(1995), HUM, SÜMEGI(2000), as well

as by SÜMEGI, KROLOPP(1995). At the same time, the investigations of HORVÁTH, E. et al. (1992), POUCLETet al. (1999)

and HUM(2005) furnish knowledge (among other items) on the area concerning the volcanic tephra levels.

A new era in the geological and Quaternary research of the Mórágy Block began in the 1980s and 90s when diverse applied geological evaluations of the region constituted the main part of investigations within the geological exploration. Applied research in the area was initiated by the suitability study (JUHÁSZ1989a, b) of the radioactive waste

reposi-tory planned in the environs of Ófalu. The stratigraphic revision of the results of the drilling exploration in the related material available (in manuscript) was made by CHIKÁN(1989). The Key Borehole Ófalu Ó–4, established by MÁFI

dur-ing the Ófalu exploration, was the first one with a thoroughly documented log and all-embracdur-ing examination that pen-etrated both the loesses and the red clay as well (CHIKÁNet al. 1989).

The knowledge on the overlying beds of the region was considerably broadened during the mapping program of Somogy, Baranya and Tolna Counties. The latter was performed by MÁFI between 1988 and 1994 and also included a number of mapping boreholes (CHIKÁN1994, 1995). The related results acquired by field examination, drill-core logging

Figure

Table 2. A The main groups of the Mórágy granitoid rocks as specified in the works of different authors
Table 3. Activities of uranium exploration in the environs of the Mórágy Block
Table 5. Lithostratigraphic units of the mapping area
Table 6. Petrographic and litostratigraphic classification of the Palaeozoic crystalline basement rocks of the Mórágy block according to the different authors
+7

References

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