The role of tributary mixing in chemical variations at a karst spring, Milandre, Switzerland, , Perrin J. , Jeannin P. Y. , Cornaton F. ,

SummarySolute concentration variations during flood events were investigated in a karst aquifer of the Swiss Jura. Observations were made at the spring, and at the three main subterraneous tributaries feeding the spring. A simple transient flow and transport numerical model was able to reproduce chemographs and hydrographs observed at the spring, as a result of a mixing of the concentration and discharge of the respective tributaries. Sensitivity analysis carried out with the model showed that it is possible to produce chemical variations at the spring even if all tributaries have constant (but different for each of them) solute concentrations. This process is called tributary mixing. The good match between observed and modelled curves indicate that, in the phreatic zone, tributary mixing is probably an important process that shapes spring chemographs. Chemical reactions and other mixing components (e.g. from low permeability volumes) have a limited influence.Dissolution-related (calcium, bicarbonate, specific conductance) and pollution-related parameters (nitrate, chloride, potassium) displayed slightly different behaviours: during moderate flood events, the former showed limited variations compared to the latter. During large flood events, both presented chemographs with significant changes. No significant event water participates in moderate flood events and tributary mixing will be the major process shaping chemographs. Variations are greater for parameters with higher spatial variability (e.g. pollution-related). Whereas for large flood events, the contribution of event water becomes significant and influences the chemographs of all the parameters. As a result, spring water vulnerability to an accidental pollution is low during moderate flood events and under base flow conditions. It strongly increases during large flood events, because event water contributes to the spring discharge

Der Karst der Juraklippen in der niederösterreichischen Waschbergzone. Versuch einer morphographischenn Darstellung., 1956, Riedl, H(elmut).

[Leiser Berge, Katzloch (6847/1), Klafterburnnerhöhle (6847/2), Staatzerloch (6847/3), Staatzerberghöhle (6847/4)]

Der Karst der Juraklippen in der niederösterreichischen Waschbergzone Versuch einer morphographischenn Darstellung, 1956, Riedl, H.

Triashöhlen und Knochenbrekzie mit Nothosaurus bei Olkusz (Krakau-Tschenstochauer Jura)., 1961, Wojcik, Z.

[Polen]

Triashöhlen und Knochenbrekzie mit Nothosaurus bei Olkusz (Krakau-Tschenstochauer Jura), 1961, Wojcik, Z.

Estimation de la dissolution superficielle dans le Jura, 1967, Aubert D.

Report of the Leeds University Expedition to Some Caves in the Djurdjura Mountains, Algeria, 1966, 1968, Milner A. J.

Phenomenes et formes du karst jurassien, 1969, Aubert D.

Observations on marked and unmarked Trichoptera in the Barehohle in Lonetal (Swabian Jura)., 1973, Dobat Klaus

1.The Bàrenhòhle, one of the ten caves situated in the episodically water-bearing valley of the Lone (Swabian Jura), serves as summer quarters for the total of ten species of Trichoptera, most of which are Micropterna nycterobia and Stenophylax permistus. 2.Counts carried out in this cave from 1967-1972 and observations of flood and dry-periods of the Lone during the same years make evident that the number of Trichoptera flying into the cave seems to depend in a large measure on the seasonal activity of the creek: a steady flow of water makes the undisturbed development of larvae possible and results in high numbers of individuals entering by air, while intermittent water-flow disturbs the development of the larvae and results in few individuals entering. 3.Such factors as darkness, humidity, and temperature which cause or favour the active entrance by air of Trichoptera into the cave as well as the "diapause" taking place in the subterranean region are considered. 4.Dynamically climatized caves or caves which are too small are rarely occupied by Trichoptera; they evidently prefer larger caves with climatically balanced regions (comparatively low temperatures and high atmospheric moisture) not too far from the entrance. 5.Trichoptera start flying into the Barenhohle generally in May; the highest number of individuals and copulating couples may be found as early as July. They start flying out by the end of July or in August/September, the last of them leaving the cave generally in September or October. 6.Two attempts at marking (on 28th June all Trichoptera to be found in the cave were marked with black ink, on 4th July all yet unmarked with red ink) gave better evidence of their disposition and time of copulation as well as of the number of arriving unmarked and departing marked specimens. 7.The Trichoptera marked with black ink stayed in the cave for a maximum of 85 days, the ones marked with red ink for a maximum of 79 days. Food intake was not observed during this period, and there was no indication of the insects' leaving the cave during their diapause. 8.Trichoptera are characterized by a remarkably long time of copulation: a specimen marked twice was in copula for 22 days, and before copulation it had been in the cave for 49 days.

The colonisation of some caver in the Jura by Niphadobota alpine Bezzi (Dipt. Tipulidae)., 1973, Turquin M. J.

Three new localities of Niphadobota (=Chionea) alpina in the French southern Jura allow the author to state that this insect's climatic requirements explain the biogeography of the species; the origin of the colonization of caves by this dipteran is considered.

Observations on marked and unmarked Trichoptera in the Barehohle in Lonetal (Swabian Jura)., 1973, Dobat Klaus

1.The Bàrenhòhle, one of the ten caves situated in the episodically water-bearing valley of the Lone (Swabian Jura), serves as summer quarters for the total of ten species of Trichoptera, most of which are Micropterna nycterobia and Stenophylax permistus. 2.Counts carried out in this cave from 1967-1972 and observations of flood and dry-periods of the Lone during the same years make evident that the number of Trichoptera flying into the cave seems to depend in a large measure on the seasonal activity of the creek: a steady flow of water makes the undisturbed development of larvae possible and results in high numbers of individuals entering by air, while intermittent water-flow disturbs the development of the larvae and results in few individuals entering. 3.Such factors as darkness, humidity, and temperature which cause or favour the active entrance by air of Trichoptera into the cave as well as the "diapause" taking place in the subterranean region are considered. 4.Dynamically climatized caves or caves which are too small are rarely occupied by Trichoptera; they evidently prefer larger caves with climatically balanced regions (comparatively low temperatures and high atmospheric moisture) not too far from the entrance. 5.Trichoptera start flying into the Barenhohle generally in May; the highest number of individuals and copulating couples may be found as early as July. They start flying out by the end of July or in August/September, the last of them leaving the cave generally in September or October. 6.Two attempts at marking (on 28th June all Trichoptera to be found in the cave were marked with black ink, on 4th July all yet unmarked with red ink) gave better evidence of their disposition and time of copulation as well as of the number of arriving unmarked and departing marked specimens. 7.The Trichoptera marked with black ink stayed in the cave for a maximum of 85 days, the ones marked with red ink for a maximum of 79 days. Food intake was not observed during this period, and there was no indication of the insects' leaving the cave during their diapause. 8.Trichoptera are characterized by a remarkably long time of copulation: a specimen marked twice was in copula for 22 days, and before copulation it had been in the cave for 49 days.

The colonisation of some caver in the Jura by Niphadobota alpine Bezzi (Dipt. Tipulidae)., 1973, Turquin M. J.

Three new localities of Niphadobota (=Chionea) alpina in the French southern Jura allow the author to state that this insect's climatic requirements explain the biogeography of the species; the origin of the colonization of caves by this dipteran is considered.

Schweizer Höhlenrettungsübung 1975 im Jura., 1975, Hollender, W(erner).

[Schweiz]

Karstic Fills in the Clusette Tunnel (Jura of Neuchatel Switzerland)., 1975, Meia Jean, Pochon Michel

The piercing of a road tunnel in the flank of a limestone (Malm) anticline in the Neuchatel Jura uncovered karstic forms transformed for the most part, by decarbonated soils. Mineralogical analysis of these latter, through the use of X-ray diffraction, reveals a great analogy with the surface soils. At more than 200 meters depth, the same allochtone mineralogical suite of aeolian origin which constitutes the largest part of the soils of the High Jura Mountains in Switzerland, is found: an abundance of ferriferous chlorite, and of quartz, plagioclase and potassic feldspar. The various factors favouring this deep infiltration are discussed.

Schweizer Höhlenrettungsübung 1975 im Jura, 1975, Hollender, W.