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International Atomic Energy Agency IUREP N.F.S. No. 93 October 1977 Distr. LIMITED Original: ENGLISH

INTERNATIONAL URANIUM RESOURCES EVALUATION PROJECT

IUREP

NATIONAL PAVOURABILITT STUDIES

FEDERAL REPUBLIC OP GERMAN?

77-8846

INTERNATIONAL URANIUM RESOURCES EVALUATION PROJECT

IURSP

PAVOURABILITT STUDIES

IUREP N.P.S. Ho. 93

FEDERAL REPUBLIC OF GERMAHT

CONTENTS

PAGE

1. INTRODUCTION AND GENERAL GEOGRAPHY 1.

2. GEOLOGY OP THE COUNTRY IN RELATION TO POTENTIALLY FAVOURABLE URANIUM AREAS

3. PAST EXPLORATION 4-

4. PRESENT STATE OP EXPLORATION 6.

5. POTENTIAL FOR NEW DISCOVERIES 7.

BIBLIOGRAPHY 8.

FIGURE: Ergebnisse der Uranprospektion in der Bundersrepublik Deutschland

INTERNATIONAL URANIUM RESOURCES EVALUATION PROJECT

Working Document

Federal Republic of Germany

1. Introduction.and General Geography

The Federal Republic of Germany is situated in Central Europe. It covers an area of 250 000 square kilometres and has a population of 60 millions. The Federal Republic consists of 10 individual states. The capital of the country is Bonn.

The northern and northwestern parts of the country are formed of flat lowlands, the Norddeutsche Tiefebene. Towards the south follow hilly and mountaineous regions with elevations not exceeding 1000 m. In the southwestern and southeastern regions the elevations may reach 1500m in the Black Forest and Bayerischer Wald. The foreland of the Alps and the northern part of the Alps itself with elevations close to 3OOO. m make up the southern part of the Federal Republic.

The main rivers - Rhine, Weser and Elbe - are directed towards northwest and drain the country to the North Sea. Only the southern part is drained by the southeast running river Danube.

The climate is moderate, generally with frequent snow during the winter season and warm periods during the summer. The precipitation is distributed uniformly throughout the year.

Due to the high industrialization a dense network of railroads, highways and motorroads exists.

- 2 - - 2 -

Centres of industrialization and population are the Rhine-Ruhr district, the Rhine-Main area around Frankfurt-Karlsruhe and the area of Stuttgart. Major centres in the north are Hamburg, Bremen and Hannover.

2. Geology of the Country in Relation to Potentially Favourable Uranium Areas.

For the purpose of the report the areas potentially favourable for uranium deposits are subdivided into areas/covered with sediments and such with igneous rocks and crystalline basement

With respect to the 'composition and presence of favourable conditions only some units of Paleozoic sediments can be regarded as potentially favourable^Graptolithic shales of Silurian age in Franconia were investigated due to their similarities with the black shales in Sweden. The concentrations of Uranium are generally low and the units containing uranium are found to be too small to consider these sediments as economically interesting. Large parts of the country are covered with Devonian and Carboniferous sediments,With the exception of some small basins in the Upper Carboniferous; all other sediments are unfavourable'.

During the Late Carboniferous and Early Permian (kotllegendesy in some intramontanous basins continental conditions during the sedimentation favoured the formation of uranium accumulations. Those basins with Late Carboniferous-Early Permian sediments are found in the Saar-Nahe trough and in some areas of the Black Forest as well as in northern Franconia. The uranium concentrations are found in sandstones and shales, predominantely in fine - to medium - grained arkosic sandstones with reducing environment close to overlaying claystones rich in organic material or containing coal. Some smaller occurences and - 3 -

one deposit were found. The sediments of the Permian Kupferschiefer show syngenetic concentrations of uranium, but of low grade ((%/ 50 ppm).

During Early Triassic continental conditions continued during the sedimentation of the Buntsandstein. Some low-grade mineralizations associated with base metals were found in grey claystones. In Pranconia and Wlirttemberg the Keuper formation offered favourable conditions during the Late Triassic. The arkosic sandstones of the Burgsandstein and Stubensandstein were deposited under favourable continental conditions. Some indications were found.

With the exception of some small concentrations in phosphatic "bone beds", no favourable conditions are known to exist in Jurassic sediments.

In parts of central and southern Germany continental sediments were deposited during the Cretaceaous. No uranium concentrations have been found so far.

In some parts of the country Tertiary sediments of continental origin are developed. Uranium was found in Tertiary basins associated with lignites. But the potential for uranium concentrations of economic value must be considered as limited.

Rocks of Precambrian age are not very frequent. Quartz pebble conglomerates of the Elliot Lake - Witwatersrand type do not exist.

In the German part of the Bohemian Massif some indications for the presence of uranium concentrations are found in major tectonic elements of the basement. _ 4 -

The majority of igneous rocks with potential uranium accumulations are of Hercynian age, e.g. granites and related veins, hydrothermal deposits and volcanic rocks of acid to intermediate composition.

According to the occurrences found in the past, the best j conditions seem to exist in the Moldanubian and | Saxothuringian zone of the Hercynian orogeny. The Rheno- | hercynian zone must be regarded as less favourable. The ] most promising areas are the Black Forest and the Bavarian •*' j part of the Bohemian Massif (Fichtelgebirge, Oberpfalz, 1 Bayerischer Wald).

Uranium associated with rhyolithic and other acidic, porphyries as well as certain volcanic rocks of intermediate composition were found in the Saar-Nahe trough. The concentrations related to these Permian volcanics are generally low.

3. Past Exploration

During the past 20 years at least initial reconnaissance prospecting has been carried out in all areas of geological interest. Investigations have heen carried out in the A Hercynian massifs of the Black Forest, odenwald, NE Bavaria, Harz, the Paleozoic sediments of the Kheinisches Schiefer- gebirge, the Permian volcanics of the Saar-Nahe region and all areas with favourable sedimentary formations, namely Early and Late Paleozoic, Triassic, Jurassic, Cretaceous and Tertiary age. •

Initial prospecting included hydrogeochemical surveys, carbbrne surveys and surveys on foot and, to a lesser extent, airborne prospecting. Geochemical surveys of stream sediments, radon surveys and detail ,ed radiometrie work, followed by drilling and trenching, have been carried out in promising areas. — 5 —

During initial prospecting and detailed exploration, both the federal and state geological surveys were involved whereas the actual work was carried out namely by industrial companies.

During previous exploration activities two occurrences were found which can be regarded as deposits of economic interest. One is the hydrothermal deposit near Menzenschwand in the southern part of the Black Forest. Pitchblerde and minor coffinite are associated with hematite, quartz, barytine, some fluorine and small amounts of base metals. Some parts of the vein contain high-grade ore. The deposit is still under.exploration. f

The second deposit was discovered in Late Carboniferous arkoses and claystones near Geroldsau in the northern Black Forest. This sedimentary deposit is situated in the Oos trough super- jacent to acidic granites. Further explorations are planned.

Some smaller occurrences are known in the Black Forest, including the old Wittichen mine, where uranium is associated with Co, Ni and Bi.

In the Permian volcanics of the Saar-Nahe trough one small deposit was mined, it was bound to a felsitic porphyry. Some other concentrations are known, but they are of no economic interest.

In Early Permian grey sediments of the Saar-Nahe trough some occurrences were discovered. So far none of them is of economic interest.

In northern Franconia, at Stockheim, uranium is associated with coal seams. The potential seems to be limited. - 6 ~

During detailed exploration of the Bavarian part of the Bohemian Massif, several small occurrences were discovered. They occur in the fluorine deposit of WSlsendorf, in quartz veins af ,>!ahring and Bayerischer Pfahl or as hydrothermal impregnations in granites near Tirschenreuth and WeiSenstadt,

In sedimentary rocks small occurrences were found in grey arkosic sandstones and claystones of Early Permian (Rot- liegendes) age near Oberraoschel, Rheinland-Pfalz. The size of the mineralization is small.

In the grey facies of the Triassic Buntsandstein limited occurrences are found in the Hardegsen clay in Lower Saxony and Hessen. In Bavaria (Franconia) and Wxirttemberg, sandstones of Late Triassic (Keuper) age showed uranium concentrations. In Franconia these concentrations occur in the carbonatic and phosphatic cement of the Burgsandstein. In Wiirtteraberg the Stubensandstein of the same age shows uranium associated with plant remains.

Other sedimentary rocks, including favourable units of Cretaceous and Tertiary sandstones, have not shown any interesting potential.

4 • Present state, jof exp^lorajbion

Studies on geologically favourable areas are currently carried out by industrial companies and government organizations. These studies are mainly based on previous results and include a re-evaluation of the uranium potential

At present five mining companies are engaged in field exploration. Almost all parts with favourable geological conditions are held under concessions. - 7 ~

Uranium resources. cost range 30 0 /lb tJLCL,

reasonably assured: 1 500 t U estimated, additional; 3 000 t U cost range 30 - 50 £ /lb U30Q reasonably assured: 500 t U estimated additional: 500 t U

5• Potential^ for_iinewimdiiscoveriesii According to what is geologically known about the country, the chances for the discovery of large quantities of low-coast uranium resources must be considered to be limited. The potential for new discoveries of those deposits can be estimated to be around 10 000 t U.

The potential for very low-grade uranium ore, such as granites, low-grade sedimentary rocks (sandstones, shales) can be estimated to range between 10 000 - 50 0O0 t U or possibly more taking into account very low-grade concentrations in shales. This material is not mineable under present conditions. Environmental considerations may prevent mining in the future.

Compiled fcy P Barthel 1977 • 8 -

Bibliography

ABELE, G., BER6ER, K., SALGER, M. (1962): Die Uranvorkommen im Burgsandstein Mittelfrankens. - Geologica Bavarica, k9 p. 3-90, Miinchen

BARTHEL, F. (1977): Die Uranprospektipn in der Bundesrepublik Deutschland. - in press.

BARTHEL, F. (197*0: Review of Uranium Occurrences in Permian Sandstones in Europe, with Sejpcial Reference to Uranium Mineralizations in Permian-Sandstones. - Formation of g^ Uranium Ore Deposits. Proceedings of a Symposium, Athens 6-10 May 197^. IAEA Vienna.

BRAUN, E. v. (1965): Die mit Bundesmitteln unterstiitzte Uran- prospektion der Jahre 1956-1962. - Schriftenreihe Bundesminister fur wissenschaftliche Forschung H. 5»1H. Miinchen.

BULTEMANN, H.W. (1965): Die Uranvorkommen Ellweiler in Rheinland- Pfalz und Menzenschwand im Schwarzwald. - Erzmetall, 18,2. S. 79-83.

DREYER, G., EMMERMANN, K.H., REE, CHR. (1971): Uran-Quecksilber- vererzungen in Eruptivgesteinen des pfalzischen Rotliegenden. - ^^ N.Jb. Miner. Abb. 115, S. 1-30, Stuttgart.

ERTLE, H.J., KNEUPER, G., MULLER, H. (1977): Sedimentary uranium occurrences in the Upper Carboniferous of the northern Black

Forest. - Recognition and Evaluation of Uraniferous Areas. Proc. s Techn. Com. Meeting Vienna, 17.-21.11.1875 IAEA, Vienna 1977.

GUDDEN, H., SCHMID, H., CARDOSO, J. (197*0: Uran in Bayern. Inoffizieller Bericht des Bayerischen Geologischen Landesamtes.

GUDDEN, H. (1976): Uran in Bayern. - Bergbau 9, S. 361-366. •» Q —

KlRCHHEIMER F. (1952): Die Uranerzvorkommen ±m mittleren Schwarz- wald. - Mitt. Bl. Bad.Geol. Landesanstalt (l95l). KIRCHHEIMER, F. (1953): Weitere Unterstichungen iiber das Vorkoramen von. Uran im Schwarawald. - Abh. Geol. L.A. Baden-Wiirtteroberg 1, S. 1-60. KIRCHHEIHER, F. (195?): Bericht iiber das Vorkommen von Uran in Baden-¥iirtternberg. - Abh. Geol. L.A. Baden-Wiirttemberg 2, S. 1-127. LUDWIG, G. (1961): Zur Genese der uranhaltigen Grauen Hardegsener Tone im mittleren Buntsandstein des Werra-Leine-Gebietes. - Geol. Jb. 78, l>5-138» Hannover

WENDT, I., LENZ, H., HOHNDORF, A. (197'*)! Das Alter des Barhalde- Granites (Schwarzwald) und der Uranlageratatte Menzenschwand.- Geol. Jb. E 2, S. 131-143, Hannover. Ergebnisse der Uranprospektion in der Bundesrepublik Deutschland

1 : 2000 000

Bundesanatalt fiir Geowtssenscfiaften und Rohstoffo - 2 -

2. Geology of the Country in Relation to Potentially Favourable Uranium Areas.

r • For the purpose of the report the areas potentially favourable for uranium deposits are subdivided into areascovered with sediments and such with igneous rocks and crystalline basement.

With respect to the 'composition and presence of favourable conditions only some units of Paleozoic sediments can be regarded as potentially favourable^] Graptolithic shales of Silurian age in Franconia were investigated due to their • -•"•• similarities with the black shales in Sweden. The concentrations of

thelate e carboniferous and Early Permian (kotliegendesy l^^in_jBome irntramont^npuntramontangus basinsjcontinental conditions during the sedimentationV^favoured the formation of uranium accumulations. Those basins with Late Carboniferous-Early Permian sediments are found in the Saar-Nahe trough and in some areas of the Black Forest as well as in northern Franconia. The uranium ••

one deposit were found. .-*>A 3^n"e sediments of the Permian Kupferschiefer show syngenetic concentrations of uranium, but of low grade (*•50 ppm).

During Early Triassic continental conditions continued during the sedimentation of the Buntsandstein. Some low-grade mineralizations associated with base metals were found in f grey claystones. In Franconia and Wurttemberg the Keuper formation offered favourable conditions during the Late Triassic. The arkosic sandstones of the Burgsandstein and Stijbensainjdstein were deposited under favourable continental conditions. Some!indications were found.

With the exception of some small,concentrations in phosphatic "bone beds", no favourable conditions are known to exist in Jurassic sediments.

In parts of central and southern Germany continental sediments were deposited during the Cretaceaous. No uranium concentration have been found so far.

In some parts of the country Tertiary sediments of continental origin are developed. Uranium was found in Tertiary basins associated with lignites, ^3ut the potential for uranium concentrations of economic value must be considered as limited,

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Rocks of Precambrian age are not very frequent. Quartz pebble conglomerates of the Elliot Lake - Witwatersrand type dc not exist.

In the German part of the Bohemian Massif some indications for the presence of uranium concentrations are founds in major tectonic elements of the basement.