IGCP 299-Report from Austrian Subgroup "RBBSTALER ALFEN"
Rudolf Pavuza (Museum of Natural History Vienna)

1. General

1.1 Topography

The area described lies at the Northern Boundary of the Eastern Alps in Central Europe at about 47^o55’ N, 14^o45’ E. It mainly consists of moderate relief mountains and has an altitude range from 360 to 1170 m a.s.l. Only a few small palteaus can be observed.

1.2 Vegetation and soil

Mostly mixed woodlands (80%) with minor grasslands at low altitudes and a few alpine meadows at about 1000 m. Brown loamy soil dominates the soil profile with thicknesses up to 1 m.

1.3 Climate

A mean annual precipitation of 1400 mm and temperature of 6.7 yields an actual runoff of nearly 1000mm per year being typical for the northern margin of the Eastern Alps.

1.4 Geology

The area lies in the (Cretaceous) overthrust belt of the "Northern Calcareous Alps" with at least two tectonic nappes and some internal overthrusts. One can find a stratigraphy from the lower Triassic up to the older Cretaceous with upper Triassic dolomites, limestones and evaporites as main karst rocks. Intense folding and several generations of faults finally yield a rather complex karst system.

1.5 Hydrology

Estimated water balances for the different catchment areas lead to the conclusion that the greater part of the infiltrating water (50-90%) does not reappear in springs and creeks but flows directly into the ground water systems of the adjacent valleys. Runoff for springs and creeks is in the range from 400 to 900 l/s---depending from the actual meteorological circumstances---for the 70 km² area.

Based on the geological situation there are three types of karst waters: dolomite, limestone and sulfate water with higher mineralisations in the areas with evaporites. TDS varies from 350 mg/l in open system to 1100 mg/l in closed systems of ascending waters (due to high sulfates contents). Basing on this data only, an overall denudation rate of 15 mm/ka can be calculated but most of this dissolution may occur in the near surface zone.

Due to the fact that dolomite are dominating in most areas not so many of the well know karst features can be observed. For the dolomite areas dry valley--only active for short periods during flood events---are quite typical. In the limestone/evaporite areas there are caves up to 500m long (mostly canyons near the actual bass of the local karst complex), some dolines but no karren. Cave deposits are from local origin mostly. Rather typical are numberous tufa-deposits, maybe related to somewhat higher sulfate contents. Tufa ages may range up to several hundred of years. Some of the dolines and the small plateaus are related to an ancient (upper Cretaceous) landscape with nearly no relief.

Over all there seems to be a discrepancy between the potential subsurface dissolution and the extent of the caves mapped so far even in the limestone areas.

There are only a few hints to this matter so far. Variations in the chemistry of the tufas may indicate climatic changes in the last centuries or even some changes within the catchment areas. As the dry valleys in the dolomite areas are clearly older that the Pleistocene valley fillings it is obvious that the karst water table has reached deeper parts of the aquifer alreadly before the Pleistocene even in the dolomite areas where a higher "porosity" occurs due to more intensive jointing.

Problems occur mainly due to intensive forestry with numberous roads, doubtful forestry measures combined with an increased input of atmospheric chemicals (SO₂, NOx). Local hygienic problems arise because of illegal dumping.

There is still plenty of high quality karst water available in this area. As dolomited dominate, there are good filtration capacities combined with good aquifer--characteristics. There are good possibilities for groundwater exploitation in the adjacent valleys.

At several points there are ascending springs with water temperatures up to 5° C above the annual air temperature at the spring location. These springs show nearly no annual variation of chemistry and discharge.

Photo 1.   The cave developed at Dummdalen, south Norway, showing that hydrodynamic
action may be the important agent of the karst development

University of Bergen, 1st-3rd August, 1996

Attendance

66 delegates from 20 countries (United Kingdom, Israel, Austria, Australia, Germany, Canada, Italy, France, Norway, Sweden, Romania, Czech Rep., China, Slovenia, Japan, Belgium, New Zealand, Hungary) presented 45 papers and 20 posters.

Keynote talks
Dating cave deposits (Prof. Derek ford)
Paleoclimate inferences from stable isotopic studies of speleothem (Prof. Henry Schwarz)
Chemical kinetics, speleothem growth and climate (Prof. Wolfgang Dreybodt )
Thematic sessions
Speleothem stratigraphy and chronogy
"Shopov-bands" and other high-resolution stratigraphic information in speleothems
Stable isotopes in speleothems
Cave stratigraphy and paleomagnetism
Cave biology and paleontology
Regional karst and cave analyses

Talks were very well presented and prompted much discussion. Attendance was exceptional for all sessions. Informal discussions were conducted at the end of the Days 1 and 3, a summary of matters discussed and suggested objectives can be found below.

Papers are published in-
S.-E. Lauritzen (ed.)(1996)Climate Change. The Karst Record. Karst Waters Institute Special Publication2, 196pp. Karst Waters Institute, West Virginia. ISBN 0 9640258-1-7.

Copies available in the U.S. from Karst Waters Institute, Inc.
P.O. Box 490
Charles Town, West Virginia 25414, USA. http:// www. uakron. geology. edu/ kwi. html
and elsewhere from Stein-Erik Laurizen
Department of Geology, University of Bergen, Allegaten 41, N-5007 Bergen, Norway

Informal business meetings of IGCP 379, PAGEP-III and various UIS commissions were held during the evening of Day 1.

Two field excursions were organised,a pre-excurision day trip (15 members) incorporsting karst and glacial features near Bergen , and caving in the fjord lands. Field guides are available from Stein-Erik Lauritzen (address as above).

The majority of papers focused on paleoclimate records from speleothems. It is clear that if such records are to be more widely accepted by the scientific community, many points need to be addressed by those in the field, such as site specificity, non-linear response and thresholds, need for multiple proxy climate indicators on individual samples, field calibration, awareness of precisions and accuracy, attention to scale/ resolution of sampling, investigation of growth rates, investigation of crystal morphologies and characterisation of hiatuses.

All records will be locally and regionally specific. This important with regard to the IGCP379 (Karst Processes and Carbon Cycle) and IGBP-SPEP(Speleothem-Pole-Equator-Pole) projects. Detailed investigation of the trends and values of present day stable isotopic signatures with respect to water balance, temperatures, precipitation and host limestone is crucial if international correlation projects are to succeed.

Inventory of speleothems held in the numerous laboratory collections of the world or, if this is too large a project, a record of sampled locations and scientific institution. This will help with correlation projects, prevent duplicate sampling and hence CONSERVATION of karst deposits.

Communication between various projects, commissions and speleothem users would be improved by the set-up of a WWW page (to be administered by Dr. Andrew Baker, University of Exeter, UK). An IGCP379 WWWpage could be produced along the same lines(see for example http://superior.carleton.ca/%7Etpatters/IGCP 367htrnl).

Further meetings were suggested to (1) maintain links forged at this meeting and provide updates of ongoing research and (2) foster further links with other researchers not attending the meeting. Note that there was a significant under-representation of US researcher at the the meeting. Hence the call for session meetings at the International Speleogical Congress in Switzerland (1997), International Geomorphological Conference in Bologna(1997)and an international geological(?) conference in USA or Canada in 1998 (to be arranged). Details to appear on WWW page or circular to attendees and members of the various commissions.

Dr. David A. Richards
Department of Earth Sciences,
University of Leeds,
Leeds, LS2 9JT,UK.

SUMMARY AND ACHIEVEMENTS
-----THE SYMPOSIUM OF CLIMATE CHANGE:
THE KARST RECORD

Li Bin (Institute of Karst Geology, Guilin, China 541004)

Supported by IGCP 379 and Bergen University, I attended the symposium Climate Change: The Karst Record, and the followed excursion to the karst areas of north Norway.

The symposium was jointly sponsored by the Department of Geology, Bergen University, Norway, and the Karst waters Institute of U. S.A., and held at the Department of Geology, Bergen University from 1st to 4th of August, 1996. There were 72 participants from 22 countries attending the symposium. There were 47 papers presented in the symposium, and 27 papers on poster presentations. in addition, 3 scientists were invited to give the keynote, namely, Derek Ford: Dating Cave Deposits, Henry P. Schwarcz: Paleoclimate Inferences from Stable Isotopic Studies of Speleothem, Wolfgan Dreybrodt: Chemical Kinetics, Speleothem Growth and Climate.

During the symposium, an informal meeting for IGCP 379 was held in the evening of 1st of August.

After the symposium, there was a two-week karst excurision in northern Norway. the field trip includes the major karst areas of Nordland, and gives some very interesting karst landforms and caves under special conditions. There were 26 persons joining the excursion (including 11 graduate students from Bergen University).

There were 72 participants from 22 countries attending the syposium, and they exchanged 74 papers in the symposium. The contents include:

A. Speleothems as high-resolution records of various palaeoclimatic proxy data;

B. Cave sediments and stratigraphic information, including paleomagnetism;

C. Climatically influenced changes in karst processes and landforms;

D. Biostratigraphy and archaeology in caves;

E. The relation of recent speleofauna to environmental changes.

Based on the papers above and the discussions in the symposium, the achievements could be summarized as follows:

There are 36 papers that directly discuss the high resolution paleoenvironment reconstruction with speleothems, and the involved areas include Afica, America, Australia, China, Czech, England, Japen, Meditterranean area, New Zealand, Norway, Poland, Saudi Arabia, Slovenia etc. Therefore, the results show that karst caves are unique repossitories for various forms of paleoclimatic information, being well protected from destructive processes acting on surface , and the powerful dating methods available for speleothems combined with their highly resolvable stratigraphy make them unique among terrestrial deposits and a valuable complement to deep-sea sediments.

In order to get a high resolution paleoenvironmental records, the information extraction is very important, incluing accurate dating data, climate proxy data ( air temperature, precipitation) and ecology proxy data and so on.

A. Dating methods: Some papers give the data on the basis of normal methods, e.g. a countimg U-series dating method, LCS ¹⁴C dating. But most of papers applied new and accurated methods, e.g. TIMS U-series dating, AMS dating. At the same time, a paper discusses a new dating method U-Pb dating of Quaternary age speleothems that would extend the dating range, and a paper compares and evaluates the dating results of different method--- TL, ESR, ¹⁴C, ²³⁰Th/²³⁴U. Based on the discussion, most of people hold that TIMS U-series dating may provide more accurated dating data and improve the reolution if the samples are in keeping with the demands.

B. Climate proxy data: How to get the climate proxy data is also important for the paleoenvironement reconstruction. Many papers discuss the stable isotope (d ¹⁸O) records , and some papers discuss the geochemistry records (e.g. trace element record). Although , many results show that the isotopic records in speleothem can be correlated with the records of deep-sea sediments or ice core, it should be careful to explain speleothem isotope record because the equililbrium conditions are more complicated in caves.

Another method for climate proxy data is from the information of ‘Shopov Bands’. Some papers give very high resolution records (e.g. annual to daily ), and some papers discuss the observation results on the present carbonate deposit, e.g. the relationship between luminescence and discharge variations in stalagmite drip waters; Growth rate, grey level and luminescence of stalagmite lamine. Combining ‘Shopov Bands’ with oxygen isotop record, a chinese paper discuss the monsoon record from a stalagmite. Therefore , the datailed studies on ‘Shopov Bands’ and other climate proxy data may contribute significantly to enhance the resolution and the presision of the prediction of the future climate changes.

C. Ecology proxy data: Some papers discuss the paleo-ecology record (especially vegetation change) on the basis of d ¹³C analysis. Even though there is no much more discusses on the basic knowledge about the carbon isotope formation in speleothem, in the cave environment and in the soil CO₂ and so on, but it is very possible to extract the information about the vegetation change in an area from the carbon isotope record in speleothem.

Besides speleothems as high-resolution records, speleothems can also be used to study the sea level changes, the glaciation history and so on. And also, cave sediments and stratigraphic information can provide some important palaeoenvironment information.

One of the foci of IGCP 379 is to get high resolution karst records for paleoclimate reeconstruction. Therefore, the many ideas and the progresses of this symposium are very important or benefical to the project.

(1) The papers show that it is possible to get high resolution paleoclimate reconstruction from karst records, and also the results can be correlated in the world.

(2) The participants held that the results of single sample were not enough to explain or reconstruct the paleoclimate in an area, and multisamples might be necessary. This idea is in keeping with that of IGCP 379.

(3) The participants held that the results of speleothems should be compared with other proxy data, e.g. ice core, deep sea sediments, which is easily done by IGCP 379 because the purpose of the project is to make a corrlection in the world.

(4) The participants held that if conditions permit, to define local trends related to temperature should be correlated with the historical data. Accordingly, IGCP 379 may be better to accept this idea.

(5) participants held that the studies are not only on the speleothems, but also on the environment conditions, including hydrogeology, geology , geochemistry and ecology and so on. If IGCP 379 can get these data, it would be very useful for the future studies, and the summary can give researchers some principle to choose samples and caves.

(6) participants held that it was important to set up a www home page or a discussion group for the subject, which must be very useful for IGP 379, and if no body is to do this, the project should do it first because it is very easy to collect the related data and exchange ideas.

Li Bin (Institute of Karst Geology, Guilin, Guangxi, China 541004)

This field trip took 12 days, and investigated the major karst areas and about 14 caves (including the longest cave with 11 km, the largest cave and the typical cave) in north Noway. Based on the trip, I have got a basic knowledge about the karst development background and the characteristics.

The size of some caves is very similar to those in south China, e.g. big passage, big chamber, but passaes of most caves is canyon-shaped or tube like (developed along the fractures). At the same time, their altitude difference is large (most of them larger than 100 m in a short distance). The carbonate rocks are marbals with different colors or textures. According to those basic characteristics, the favour conditions for the cave formation include a. high precipitation (3000 - 4000 mm/a in high mountain areas). b. high altitude difference in a short distance ( the caves often developed by fjord (sea level) or glacial lake (close to the sea level), c. marbal band between non-carbonate rocks (which means more allogenic water), d . last glacial activity. Accordingly, the erosion may be the main mechanism. The speleotliem is rare (there are some flowstone or very small stalagmite or stalactite), and there are riched collapsed blocks.

The normal-shaped mountain is the major landforms. There are some macro surface karst features, e.g. collapsed dolines with more than 100 m across and 50 m depth, dry valley (developed after glacier action), as well as some micro features, e.g. grikes, rillenkarren and rinnenkarren (always developed on slopes or related to the accumulated snow).

Report from Japanese Working Group of IGCP 379