Suggestion for a typical study site,
BLANCA & MIJAS Mts KARST, South Spain

Dear Mr. Daoxian,

Firstly, I want to congratulate you for your designation as President award of IAH.

I am the spanish research professor at the University of Malaga (Andalucia, Spain), that wrote to you in 1991 to solicitate some publications. I am a member of a Research Group in Hydrogeology, created in 1990 by Prof. Francisco Carrasco Cantos, that works on the southern Spanish aquifers, fundamentally, in carbonated aquifers. At the moment, we have the following lines of research principally:

- Hydrogeology of karstic systems using hydrodynamics, hydrochemical and isotopic methods. Actually there is a doctoral thesis in course to study Sierra Nieves, a karstic system with 200 km² of surface that is a Biosfere Reserve of the UNESCO.

Before the study of Sierra Nieves, in my doctoral thesis, I studied another carbonated massif (Sierras Blanca and Mijas) with the same surface, but it is the most important aquifer in the Costa del Sol area.. We continue investigating in Blanca-Mijas carbonated aquifers, in the framework of an Integrated Action (International Programme Picasso 97) with French and Spanish colleagues (M. Bakalowicz, J. Mudry and I. Antiguedad), to study carbonated aquifers in different European areas-- with distinct climatic and tectonic contexts-- to compare the results.

- Hydrogeology of unsaturated zone of the karstic aquifers, we have been working in the Nerja Cave system. Nerja Cave is an exceptional cavity with 5 km of sweep, originating after Upper Pliocene. Since 1990, we have been studying the infiltration processes (with hydrodynamics, hydrochemical and isotopic methods). In 1993, where published a book (I am sending you this one, by mail apart), where all the results obtained up to May 1992 are presented, although actually these results are partially exceeded.

- Groundwater contamination for landfill leachate, this is the subject of another doctoral thesis that is being carried out, principally in the landfill that is on the carbonated aquifers.

We have solicitated, with other colleagues, a Project to study the climatic changes in Spain during the last 800,000 years B.P. from the research data in karst aquifers.

I am informing you about these aspects so that you know our principal lines of research and because my Research Group is very interested in participating and collaborating in the activities of the IGCP 299 "Geology, Climate, Hydrology and Karst Formation", giving our results and experiences about the southern Spanish karst. Prof. Claude Drogue (University of Montpellier 2, France) has been in Malaga to visit us to know the aquifers studied and he was interested in them. I am sending you the completed form of typical karst area now that I have all the data.

Blanca and Mijas mountains belong to Alpujarride complex, an important tectonic complex of Betic Cordillera (southern Spain). Tejeda and Almijara mountains also belong to this complex, including the Nerja Cave system, and other massifs situated more to the east, which are indicated on the map I am sending you. All the massifs are similar geological and hydrogeological features: the stratigraphic serie is made for paleozoic metapellites (migmatites and gneises in Blanca-Mijas, schistes and quarzites in Sierra Almijara and more eastern) and triassic carbonated materials (marbles in Blanca-Mijas and Almijara, calcaires and dolomies more eastern). These materials were folded in the alpine orogeny, they are in the actual position since Lower Miocene -when Betic Cordillera is structured-. However, the massifs are potentially karstificable (not covered by other unkarstificable materials) after Upper Miocene, when they were affected by faulting associated to Pliocene and Quaternary uplift and approximation of African and European plates.

The Alpujarride massifs present normal shape limestone mountains, with scarce karsts forms. On the surface, for example, dolines and poljes practically do not exist, only karren can be see sometimes. In the interior some isolated caves, generally of small size. However in the borehole we can see that there is dissolution continuing the fractures.

In Alpujarride outcrops the mean temperature is 17 or below. The annual mean precipitation decrease from 700 mm in Blanca-Mijas to 430 mm in eastern area. It can snow on the highest peaks of the mountains. The precipitation is very irregular, in a few days all the year rain can fall.

The vegetation (normally bush-wood) is scarce due to over-timbering and also forest fires. The karst surface is nearly bare, the soil has little thickness.

Normally, the groundwaters are calcic and magnesic bicarbonated, with electrical conductivity lower than I mS/cm (approximately 0.5 mS/cm of mean value). The limestone denudation rate is lower than 50 mm/ka.

Alpujarride carbonated aquifers have traditionally been considered to have little karstificated behaviour. However, in Blanca and Mijas mountains, the study of the hydrochemical and hydrodynamic analysis as the lithologic column and the pumping tests data observed in drilling wells has permitted differentiating two types of aquifers: karstic systems and fissured systems. Karstic systems are represented in the western sector of Sierra Blanca, where calcitic marbles outcrops. They are characterized by abrupt variations in spring flow as in the chemistry of the water in response to the rainfall. It can be adapted to the hierarchized aquifer model. Fissured systems are represented in the eastern sector of Sierra Blanca and in Sierra Mijas and are made up of dolomitic marbles. They are characterized by very gentle fluctuations in the spring flow as in the chemical composition of the water. They can be related as the capacity and transmissive elements model.

Moreover Blanca mountain is not exploited, while the aquifers of Mijas mountain are very exploited for water supply to the Costa del Sol touristic area. In some aquifers, for example Torremolinos system, this exploitation originates down to 70-80 m of table water, but recovering relatively well with the rainfull.

For all these reasons, we want to propose Blanca and Mijas mountain as a typical karst area of Alpujarride complex (southern Spain).

By mail apart, I am sending you some articles to complete the information of typical karst area. In a few weeks I will send you a copy of my doctoral thesis "Hidrogeolooia de acuiferos carbonatados en las Sierras Blanca y Mijas (Cordillera Betica, Sur de Espana)" actually in press, also nearly an article which submitted in Journal of Hydrology and others works which are in preparation.

Finally, I’d like to have some copies of the last publications of your Research Group.

Philippe Gombert.

Dear Professor,

In answer to your message of April the 2th 1996 on Internet (GROUNDWATER@ias. Champlain. edu), I've sent a fax to you on May the 11^th 1996 (ref : L 1432/GF96/PUBLI).

As promised in this fax, you will find now a "tire-a-part" of the French Academy of Sciences publication I've just received. It regards a new method of karstic denudation calculation based on input of climatic data. The method is rather complex and takes into account the calculation of all the calcocarbonic equilibrium constants, the real evapotranspiration and the soil pCO₂, but I have simplified the formulation: now you just need to enter the annual rainfall R (mm) and the average annual temperature of the atmosphere T(° C) to calculate first a climatic index called i₂₀

and then enter it the following formula to obtain the average value of karstic denudation called "Maximal Potential Dissolution" DNW (mm/ky or M³/km²/year):

DMP = - 4,14× 10^-5 i₂₀ ³ + 1, 93× 10^-2 i₂₀² + 8,02× 10^-1i₂₀ - 10,5

The DMP is equivalent to classical Puhna's karstic denudation or Corbel's specific dissolution as you can see in my publication. The advantage of the DMP is that you take directly into account two of the three main climatic agents that contributes to karstification (water inflow and temperature) and that the third one (water concentration in pCO₂) is then calculated from the first ones. So you can modelize the effect of different climates on karstogenesis.

I've already written to you I was interested by a modest participation to the IGCP 379 program. It concerns the first goal of you paper which is "to assess the contribution of carbonate rocks to the content of CO₂ in atmosphere through karst processes, especially dissolution and precipitation" and the second focus of research emphasis with "the role which karst processes may play in global greenhouse gas budget".

With the DMP approach, it's possible to calculate the contribution of karst processes to

the world carbone budget on the basis of the following hypothesis:

The actual absorption rate of carbon by karstic dissolution can be estimated to 160MtC/year or ~ 0.2 GtC/year. In a recent report on greenhouse gas effect (Lavoisier Tec & Doc ed., Paris, report n° 31, November 1994, 76 p.), the French Academy of Sciences indicates that there must be a unknown carbone sink in the continental biosphere: this sink is supposed to absorb 1.4 ± 1.6 GtC/year. In first approximation, we can consider the contribution of karstic dissolution is around 11 % of this "unknown carbon sink".

I'm working now to obtain more accuracy in this calculation: I must calculate the effective karst dissolution values (estimated by DMP) for each karstic country and add them all over the world to obtain a more precise total carbone absorption value.

With the DMP approach, I can also modelize the changing of karstic denudation rate in response to climatic changes: I must enter estimated future evolution of rainfall and temperature values for different part of the world and especially the karstic countries. I'm now looking for tables of these estimated values depending on different scenarios.

As I've written to you in my last fax, I'm now working as Senior Hydrogeologist in an european cooperation water resources program in Burkina Faso (Africa): thus I'm very far away from bibliographic sources on karst! If you find some interest to my modest researches, please help me to find the estimated future values of rainfall and temperature. I will consider as a great honour to be authorized to publish my little contribution at your IGPC next workshop.

Sincerely,

Ph. GOMBERT

Ante Sarin (Zagreb, Croatia)

This contribution might enter the first and second objectives of the IGCP 379, i.e. to the objectives:

1 - To assess the contribution of carbonate rocks to the content of CO₂ in atmosphere through karst processes, especially dissolution and precipitation, this aspect of the global carbon cycle has been little studied to date.

2 - To compare the annual balance of CO₂, between the atmosphere and karst systems under different geological, climatic and ecological environments.

However,it might become even another, its own objective - well, up to you.

The research cooperation proposal is basic on air extremely interesting idea launched (as early as in , 1963) by the distinguished Slovene geographer, Prof.Dr. Ivan Gams, that the amount of carbonates dissolved in karst river water reveals the intensity of karstification upstream the sampled and chemically analised water site. This, naturally, takes into account the availability of long-time monitoring of flow rates at those sites. If the monitored sites of not too large pertaining catchment areas are chosen for the study and if the geological and physiographic conditions in those areas are sufficiently known, a geochemical parameter, let's call it the carbonate solution module, CSM, (expressed in kilograms of carbonates per year per square kilometre of the pertaining catchment area), could be determined. If the values of this parameter show an understandable and logical relationship with the geological and physiographical features of the pertaining catchment areas, we shall be satisfied.

Meanwhile, we know that too many factors may affect the values of that parameter (lithology, geological structure, tectonic deformations, general relief, underground and surface karst forms of relief, hydrology, meteorology, CO₂ content in the air) . Therefore, shall we be able to understand and explain all those controlling factors? Well, we shall try to do it by doing our best.

After your decision (on our participation or not) and (if "yes") , the participating Croatian and Slovene researchers shall discuss and approve the programme of research activity. A preliminary plan of activity might be as follows:

(1)Since the research is a continuation of ideas, research and cognitions achieved by the eminent Slovene geographer, Prof.D. I.Gams, it is necessary to make a review and synthesis of his research (19 published articles on that topic!) in the very beginning of this research work.

(2)It is necessary to discuss and decide which monitoring sites in Slovenia (if any, concerning extensive Prof. Gams' work dedicated exclusively to Slovenia) an Croatia should be comprised into this research work. They will be, very probably, (a) the mouths of several large karst rivers,(b) the mouths (or any other spots) of small karst rivers (having small catchment areas), and (c) many karst springs. Namely, the karst springs, particularly those the water of which has no high residence time, will be the main basis of this research. The water points - where the rate of flow and water quality were monitored regularly (enough -frequently) during ten or even more years will be privileged.

(3) Up to the proposals authors opinion, there are no many stations in Croatia and Slovenia where air quality (i.e. CO₂ content) is monitored, particularly with a sufficient time density. Anyway, all the available data will be used and meteorological (or meteoro-chemical) experts will be consulted in order to understand the distribution of that gas in the studied areas during this research.

(4) A thorough hydrogeological effort will be made to estimate the extensions (i.e. the boundaries) of the catchment areas pertaining to the monitored sites in order to get accurate data for the calculation of the carbonate solution module, CSM, and to understand the hydrogeological conditions controlling the relevant processes within the selected catchment areas.

(5)If the researchers find a logical and consistent relationship between the CSM values and the pertaining hydrogeological and other physiographical conditions within the studied catchment areas - what they hope to achieve - they will reach their goals.

(6) If the research idea (or, at least its results) incites an interest for this research work of the scientists from the other parts of the world - from different physiographical, particularly hydrogeological, and ecological environments - the researchers will be satisfied and they will be ready to offer to the other researchers all their data, knowledge and experience.

The names and addresses of the proposed participating researchers from Slovenia and Croatia are listed within the attached annex.

Ante Sarin

Research proposer

(Croatian and Slovene proposal for participation under the topic "To what extent the carbonate solution module (Gams’ approach) reflects karst processes")

ANNEX - LIST OF PROPOSED PARTICIPATING RESEARCHERS

- Dr Andrej KRANJC and

- Dr Janja KOGOVSEK

Karst Research Institute

Slovene Academy of Science and Arts
Titov trg 2, SL-66230 Postojna, Slovenia
Tel: +386 67 24 781, Fax: +386 67 23 965

-Prof.Dr Stjepan BAHUN and

-Prof.Dr Esad PROHIC

Faculty of Science, University of Zagreb
Zvonimirova 8, HR-10000 Zagreb, Croatia

- Prof.Dr Edo PRELOGOVIC and

- Ms Tanja VAZDAR (M.Sc.)

Faculty of Mining, Geology and Petroleum Engineering
University of Zagreb
Pierottijeva 6, HR-10000 Zagreb, Croatia
Tel: +385 1 440 278, Fax: +385 1 440 008

Dr Nives STAMBUK-GILJANOVIC

Institute of Public Health

Vukovarska 46, HR-21000 Split, Croatia
Tel: +385 21 515 977, Fax: +385 21 525 195

-Mr Josip RUBINIC

"Hrvatske vode", Water Management Office - Labin/Rijeka
Zelenice 18, HR-52220 Labin, Croatia
Tel: +385 52 855 227, Fax: +385 5 856 820

-Ms Sanja KAPELJ (M.Sc.) and

- Mr Ante SARIN (M.Sc.), (proposed) research group leader
Institute of Geology
Sachsova 2, HR-10000 Zagreb, Croatia
Tel:+385 1 6152 300, Fax: +385 1 6150 571

Suggested by Dr. Linda K. Ayliffe of Australian National University, a cooperative project to reconstruct palaeoclimate variation along the line of south China, Indonesia and Australia using speleothem proxies is under consideration.

This project aims to solve some of the long standing problems of establishing accurate chronologies for terrestrial climate/environmental change in Australia and east Asia during the late Quaternary. To achieve this aim it is intended to date speleothems in Australia, Indonesia and China using the high precision TIMS (Thermal Ionisation Mass Spectrometry) U/Th dating method. Speleothems are formed by chemical interactions between rain water, biogenic soil CO₂ and the limestone bedrock and are sensitive indicators of the status of local hydrological balances, the extent of their formation being governed by the degree to which precipitation exceeds evaporation at particular sites. The frequency of speleothem formation over time therefore, can be used as a sensitive proxy for changes in effective precipitation.

One of the main outcomes of this project will be to provide information on the longterm interactions between the Asian monsoon and Walker circulations by the precise dating of speleothcms from China, Indonesia and Australia. In the process of conducting this research, international links will be forged between Dr. Linda K. Ayliffe and other Australian scientists with Professor Yuan of the Institute of Karst Geology in China and with Dr Hontoro from the Indonesian Institute of Sciences in Indonesia. These two international collaborations will be essential to the success of this part of the project. The results of the proposed research will add greatly to our knowledge of the main factors controlling climate in the Australasian region and, via validation of GCM predictions, will contribute significantly to our abilities to accurately predict future climate change.

Obviously, the project fits the aim of IGCP 379, and PEP II of IGBP/PAGES. Preliminary works have already been done in Naracoorte, Australia and south China, especially Guilin. Few samples taken from a 2.7 m tall stalagmite in Guilin have been sent to ANU for TIMS dating.

(Yuan Daoxian reported)

Do Tuyet

Hanoi, Jan. 14th 1997

Dear Sir,

Thank you very much for your letter and newsletter from the 379 project belong IGCP. On the occasion of the new year, I would like to wish you and your family a good health, happiness and successfulness in karst study for the people of China and the world.

Athough Vietnam has about near 20% area of karst in its total area, but the investigation and exploration for karst is still backward. Up to now, we have only a project, which is considered as the first project for study of karst geology. The object of the project is karst of the North - West region , where is near by Yunnan karst. In my opinion, there is not so much difference between the Yunnan karst and the North - West Vietnam one.

We think that you have good experience and are very successful in karst study not only in Yunnan but in the whole China also, It will be very happy for us if you accept our invitation in co-operation with us for our project. Possibly, you will take part in short fieldtrip and process the data with us (in next Oct. or Nov.,). If our desire would be accepted, the official invitation will be issued in next time.

I apologize for my sudden proposal and hope to receive your sympathy and pardon.

With guidance indicating in your letter, I have had a contact with Dr. Ngo Ngo Cat, Dr. Pham Thi Thanh Van and we have a short discussion on our contribution to 379 project. We think that we should try as possible we have for successfulness of the international project led by you.

Looking forward to your informations

Yours very sincerely,

Dr. Do Tuyet