{"id":355,"date":"2018-10-24T10:17:00","date_gmt":"2018-10-24T08:17:00","guid":{"rendered":"http:\/\/sources-diatomees.univ-bpclermont.fr\/?p=355"},"modified":"2018-10-26T08:59:40","modified_gmt":"2018-10-26T06:59:40","slug":"source-salee-du-ruisseau-des-trois-sauts-de-leyvaux","status":"publish","type":"post","link":"https:\/\/sources-diatomees.geolab.uca.fr\/?p=355","title":{"rendered":"Source p\u00e9trifiante et sal\u00e9e du ruisseau des trois sauts de Leyvaux"},"content":{"rendered":"

Spring associated to limestones of \u00ab\u00a0ruisseau des trois sauts\u00a0\u00bb at Leyvaux<\/em><\/strong><\/p>\n

Situ\u00e9e dans le Cantal, cette source se localise assez facilement au regard du travertin de grande dimension qui couvre le versant o\u00f9 l’\u00e9mergence apparait.<\/p>\n

Cette source est sous la gestion du Conservatoire des Espaces Naturels d’Auvergne depuis 2010.<\/p>\n

Un \u00e9chantillon de diatom\u00e9es a \u00e9t\u00e9 pr\u00e9lev\u00e9 le 24 octobre dans une des \u00e9mergences et sur le travertin, l\u00e0 o\u00f9 l’eau s’\u00e9coule. Un biofilm tr\u00e8s d\u00e9velopp\u00e9 a \u00e9t\u00e9 observ\u00e9 au niveau de l’\u00e9mergence.\u00a0Des mesures de\u00a0la biomasse algale par la teneur en chlorophylle \u2018a\u2019 ont \u00e9t\u00e9 faites sur le biofilm\u00a0\u00ab\u00a0libre\u00a0\u00bb et sur celui\u00a0se d\u00e9veloppant sur le travertin gr\u00e2ce \u00e0 la sonde \u00ab\u00a0bbe BenthoTorch\u00a0\u00bb. Diatom\u00e9es mais \u00e9galement cyanobact\u00e9ries sont pr\u00e9sentes.<\/p>\n

La conductivit\u00e9 est de 3820 \u00b5S\/cm, la temp\u00e9rature de 14.4\u00b0C et le pH: 6.84. Les eaux sont faiblement oxyg\u00e9n\u00e9es (0.7%).<\/p>\n

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Located in the Cantal, this source is located relatively easily with the large\u00a0limestones that covers the slope where emergence appears.<\/span><\/em><\/p>\n

This source is under the management of the Conservatoire d’Espaces Naturels d’Auvergne since 2010.<\/em><\/p>\n

A sample of diatoms was collected on October 24, 2018 in emergence and on\u00a0limestones where the water flows. A highly developed biofilm has been observed at the level of emergence. Measurements of the algal biomass by the chlorophyll content ‘a’ were made on the \u00ab\u00a0free\u00a0\u00bb biofilm and on that developing on the\u00a0limestone using the \u00ab\u00a0bbe BenthoTorch\u00a0\u00bb probe. Diatoms but also cyanobacteria are present.<\/span><\/span><\/em><\/p>\n

The conductivity is 3820 \u03bcS \/ cm, the temperature is 14.4 \u00b0 C and the pH is 6.84. The waters are poorly oxygenated (0.7%).<\/span><\/span><\/em><\/p>\n

\"\"\u00a0\u00a0 \"\"<\/p>\n

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L’\u00e9mergence o\u00f9 les diatom\u00e9es ont \u00e9t\u00e9 collect\u00e9es, est situ\u00e9e \u00e0 environ 20 m au dessus du ruisseau (rectangle rouge), au-dessus d’un important d\u00e9p\u00f4ts de travertin. Ce travertin a \u00e9t\u00e9 \u00e9tudi\u00e9 par Fr\u00e8re H\u00e9ribaud en 1920.<\/p>\n

The emergence where the diatoms were collected, is located about 20 m above the stream (red rectangle), above a large travertine deposits. This\u00a0limestone was studied by Fr\u00e8re H\u00e9ribaud in 1920.<\/span><\/em><\/p>\n

\"\"\u00a0\u00a0 \"\"<\/p>\n

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Les Navicula<\/em> sont tr\u00e8s pr\u00e9sentes comme les cyanobact\u00e9ries.<\/p>\n

The Navicula are present as cyanobacteria.<\/span><\/em><\/span><\/p>\n