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Ahnenschacht

by Roger Stenner

A REPORT OF SCIENTIFIC WORK CARRIED OUT DURING THE 1967 EXPEDITION

I was invited to join the expedition to organise a programme of scientific work that could be carried out during the exploration of the cave.  This work would not be such as to hinder the purpose of the trip, the descent of the shaft.  In Austria, I was to maintain a surface base camp with telephonic communication with the parties in the cave.

 

Scale is Depth in Metres

SURVEYED BY V.L.H.O. 1961

The provisional plan was to analyse water samples collected from the surface and from the cave for carbonate, calcium, magnesium and aggressiveness towards calcium carbonate (these analyses to be made at the base camp using transportable laboratory) to collect water samples for a comprehensive analysis in England; to check progress in the cave using an altimeter with a second altimeter at base camp to give the necessary corrections; to study water and air temperatures in the cave; to collect rock samples for analysis in England.  The provisional plan relied on members of the exploration and tackling teams being able to collect samples, measure temperature and altitudes and during the making of the plan, this did not sound unreasonable.

This was the plan, however, in practice there was no surface water to study, and because of the difficulties met within the cave only two sets of water samples were collected, and one water and air temperature measured in the cave.  Springtails were seen but none collected.  After returning to the valley a resurgence was examined but it is not known whether a water connection exists between this and the Ahnenschacht.

The altimeter work was more successful.  The measurements at the base camp were started in clear hot weather.  A thunderstorm swept the mountain that night. The following day was dry and windy, but the night brought another thunderstorm, and the ten hours of heavy rain put an end to the assault on the shaft.  The surface altimeter changed 178ft. in this time.  Three sets of readings were duplicated at different times, giving a check on the method of correcting the results.  (See footnote 1).

Readings were taken at the foot of the tenth pitch illustrate the method of correcting readings.  The values off the corrections were obtained from a graph by plotting readings made at the base camp with the second altimeter.

FOOTNOTE 1.   For further reference B.B. Nos 148, 161, and to the section on the use of a barometer in the book on Cave Surveying now being prepared by members of the Mendip Survey Colloquium.

FOOTNOTE 2.   The method of measuring the aggressiveness of water towards Calcium Carbonate devised by the author is explained in a paper in the course of preparation.

STATION

ENTRANCE

FOOT OF 10th PITCH

 DATE

23-8-67

23-8-67

24-8-67

25-8-67

TIME (HRS)

18.15

23.45

09.40

02.50

ALTITUDE (FT)

4942

4590

4640

4695

CORRECTION (FT)

0

-45

-115

-16

CORR. ALT. (FT)

4942

4545

4525

4530

DEPTH (FT)

0

450

470

465

The altitudes quoted are relative to an arbitrary value of 5,000ft. for the base camp.  The altimeters are graduated to 20ft., and the readings were estimated to 2ft.

RESULTS:-

1.                  Pool at Schachthalle:  Water 3.5oC., Air 4.6oC.

2.                  Drip feed above pool at ⅓rd. pints/min.

3.                  Resurgence: Water temperature 6.8oC.

 

SITE

 

1  (POOL)

2  (DRIP)

3  (RESURGENCE)

 

Calcium…………………

70

68

79

Magnesium……………...

22

19

29

Bicarbonate……………..

83

84

101

Permanent Hardness……

9

4

7

Chloride…………………

0

0

0

Aggressiveness………….

0

+6

+1.5

pH……………………….

8.0

7.6

7.1

Saturated pH…………….

8.0

7.8

7.4

All values expressed as 105 conen (M).  (105 x Molar Concentration).

The following cautious observations can be made: -

1.                  Water temperatures are lower than those met in British caves.

2.                  Calcium to magnesium ratios are unlike those met within the major caving area of Britain.

3.                  Absence of chloride, if this is a regular feature, may have unexpected biological consequences.

Analysis of rock and water samples brought back to England is not yet complete.

GENERAL OBSERVATIONS

If it at all possible a separate party should be available with the sole purpose of being responsible for the collection of samples and data.  It is not fair to exploration teams to ask them to undertake this extra work.

The author has information on the choice and package of chemicals and apparatus for expeditions, and has first hand knowledge of the special problems of carrying out chemical analysis in primitive working conditions.  I will be very happy to share this knowledge, either by direct correspondence, or if the Editor wishes this, by means of a B.B. article.