REPORT ON THE 3RD INTERNATIONAL WORKING MEETING ON PALEOPEDOLOGY (Rauischholzhausen, Germany, September 22-28, 1997)

J.Catt

This working meeting was organised jointly by ISSS Commission V and Paleopedology Working Group (= INQUA Commission on Paleopedology), and was held in the beautiful setting of Rauischholzhausen Castle, the conference centre of Giessen University, approximately 100 km north of Frankfurt. It was supported financially by ISSS and the German Research Foundation, and was attended by 70 participants from 11 countries. There were 10 poster papers and 36 oral presentations over the three days September 24-26, also two 1-day pre-conference field tours and a 2-day post-conference excursion. The local organisers, Drs Peter Felix-Henningsen and Thomas Scholten, laid the gastronomic and scientific foundations for an enjoyable meeting, which successfully brought together pedologists interested in the effects of past climate change on surface soils and paleopedologists concerned with interpreting past climate change from buried soils.

The excellence of German paleopedological research over the last half century became clear on the field tours, which were led by Arno Semmel, Michael Weidenfeller, Ludwig Zöller and Peter Felix-Henningsen. On September 22 we spent the morning in the large quarry of Heidelberger Zement AG at Mainz-Weisenau, which exposes a thick sequence of Plio-Pleistocene sediments and paleosols overlying Tertiary limestones. After lunch kindly provided by Heidelberger Zement AG, we examined the southern wall of the Dyckerhoff Zement GmbH quarry west of Wiesbaden-Erbenheim, which shows a detailed sequence of Würm loesses and paleosols overlying an Eemian soil developed in grey Cromerian sands. At both these sites, careful field and laboratory work by Semmel and others has demonstrated that very detailed paleoclimatic histories can be obtained from loess deposits and paleosols in accumulative sites (dells).

In the late afternoon soil profiles associated with a burial mound of the Hallstatt period were examined in the forest near Hofheim am Taunus. A strongly developed Parabraunerde (luvisol) had developed on top of the mound in 2500 years, and on nearby medieval colluvium a luvisol had developed to almost the same extent in <1000 years. This evidence for such rapid clay illuviation provided much speculative conversation that evening over supper with local wine in the garden of Arno Semmel's house in Hofheim.

The next morning we travelled south to Nussloch, about 10 km south of Heidelberg, to see two sections showing an even more detailed sequence of loesses and paleosols of the last glacial-interglacial cycle resting on red and yellow soil-sediments of Upper Miocene and Pliocene age (the Bohnerz-Lehme). Ludwig Zöller and members of the BIMACEL project demonstrated some of the ongoing work at this impressive site, which is providing a very detailed and well-dated sequence of Würm climatic changes.

After lunch we visited a spectacular roadside section near Forst on the western margin of the Upper Rhine Graben. A sequence of loesses with interglacial paleosols dislocated by small step faults was faulted against Lower Triassic Buntsandstein, which had been weathered to saprolite by hydrothermal activity along the main fault. Thermoluminescence dating suggests that the youngest red Bt horizon on the downthrow side probably dates from oceanic oxygen isotope stage 7, and this gives a maximum age for the latest episodeof faulting. However, precise levelling a few kilometres to the north has shown that tectonic movements still occur in the area, though most of the current activity is associated with parallel faults to the east of Forst. The attractions of this site supplemented by wines from the local vineyard delayed our departure, and we were late arriving that evening at Rauischholzhausen.

The oral presentations were divided into five sessions on (a) polygenetic concepts of surface (relict) paleosols, (b) recognition, classification and modelling of soils with relict properties, (c) implications of paleosol features for agriculture, forestry and the environment, (d) buried paleosols as a tool for reconstructing and modelling past environmental change, and (e) archeology and dating of paleosols. Papers from sessions (a) and (c) will be published in a special issue of Catena, and the remainder in a single volume of Quaternary International, the official journal of INQUA.

After the conference, Peter Felix-Henningsen led an excursion to see Mesozoic and Tertiary deep weathering mantles on Miocene basalt. A lower part of a deep ferralitic weathering profile near Lich, SE of Giessen was demonstrated. Parent material is basalt and basalt tuff middle of Miocene. Earlier the laterite with bauxite nodules had been mined, at present only the underlying saprolite. The main topic of the remaining 1 1/2 days was an upper Mesozoic to Tertiary weathering

mantle up to 150 m thick due to deep weathering as a result of warm and humid climates during a long period of landscape stability. In several exposures in the transition area from the northeastern Eifel to the lower Rhine Embayment south of Bonn, and the eastern Hundsrück parts of the saprolite developed from Devonian clay and silt slates were demonstrated. Results of soil physical, -chemical and especially extended mineralogical and clay mineralogical studies were presented by P. Felix-Henningsen to explain in detail the weathering process which gave a deep understanding of the regular genetic units of the saprolite: an oxidation horizon below the (mostly erdoded) soil, divided into a bleached zone followed by an accumulation zone of sesquioxides. Underneath follow brown, red and purple-reddish "Hunsrück iron stones", then an oxidation zone s.str. over the reduction zone of the more or less fresh slates.and on Devonian slates between the north-eastern Eiffel and the Lower Rhine embayment south of Bonn. In the latter, which are up to 150m thick, physical, chemical and mineralogical data were used to explain the weathering processes and the nature of the various saprolite units, which included an eroded bleached zone below the surface soil, an accumulation zone of sesquioxides, brown, red and purplish "Hundsrück ironstones", an oxidation zone sensu stricto and a reduction zone over the fresh bedrock.

The main conclusions arising from the Working Meeting were that (a) paleopedology can account for many of the features influencing the behaviour of surface soils, which are not explained by the current soil environment, and (b) better studies of current pedogenesis are needed to interpret past climatic change from the long sequences of buried soils preserved in Quaternary loess and other deposits. Future meetings such as that planned for 1998 in Lanzhou, China, will develop further this profitable symbiotic relationship between ISSS and INQUA.

The property was first mentioned in a charter book of the monastery of Fulda between 750 and 779, initially a fief of the Lords of Eppstein until the Archbishop of Mainz acquired it completely in 1369. From then on the vassals called themselves Lords Rau of Holzhausen, members of the knights on the eastern bank of the Rhine. The last member of the Rau family served as an officer in the Hessian army. When Hessia became part of Prussia he refused to change to the Prussian army and sold all his property to the ambassador's delegate Stumm.

The new owner was prudent enough not to call the place Stummholzhausen. Ferdinand Stumm was a resident of a place called Neunkirchen in the Saarland and member of a famous family of industrialists. He became imperial ambassador in Madrid and was ennobled by emperor Friedrich in 1888. Many famous lords, earls, and dukes were his guests, among others emperor Friedrich and the duke of Hessia. He resigned as an envoy in 1890 and died in 1925 leaving him 35 years to care about the castle and the park. His eldest son, Ferdinand von Stumm jr., inherited the castle and sold the complete Holzhausen property in 1937. The castle was bought by the Kerkhoff-Foundation in Bad Nauheim and then leased to the University of Giessen in order to conduct experiments in agriculture. The forest was sold to Mr. von Waldhausen, while the castle and the adjacent park were made available to the public. A school was founded in the castle for the instruction of kindergarden teachers. After having been confiscated as nazi property by the allied forces in 1945, the castle and the park became property of the state of Hessia and were put at the disposal of the Justus-Liebig-University of Giessen as a conference centre.

The castle of Rauischholzhausen was designed by the architect Carl Schaefer, a student of Gottlieb Ungewitter, in the style of "Klein-Potsdam". The construction lasted from 1871 to 1878 and the castle was lavshly decorated for the hosting of noble guests. In 1873 the building collapsed because the foundation had been misconstructed. Carl Jonas Mylius and Alfred Friedrich Bluntschli, both students of the architect Semper, were commissioned to redesign the castle maintaining Schaefer's original concept. In 1875 the construction of the roof and the South East wing were completed. The main building, reminding of an English manor house, was finished a year later. In 1878 the half-timber wing of the building was completed.

When Rau von Holzhausen first lived on the location of today's castle he stood at the castle mill, which is located at the lower entrance to the park and was built in the 16th century. In today's pond there was a water castle which could be approached through a mighty portal which still adorns the atrium of the castle. The door frame is decorated by a lion's head with a ring in his mouth and the ionic colums may be identified as belonging to the renaissance style.

The park is designed in the English style and contains almost 300 different species of trees. Two little creeks run through the park and form several ponds connected by artificial cascading waterfalls. Pretty sculptures, like Lithuanian princess, a female slave in bondage, a virgin, and a tired rambler may be found between groups of trees.