Avenc Lo Fornàs

A 55 m deep cavity in Horta de Sant Joan, known as lo Fornàs, with a large entrance above a chamber and a sector of pits.

Horta de Sant Joan • Terra Alta 90m 55m

EspeleoWorld

Avenc Lo Fornàs

A 55 m deep cavity in Horta de Sant Joan, known as lo Fornàs, with a large entrance above a chamber and a sector of pits.

Horta de Sant Joan · Terra Alta

Length: 90 m · Depth: 55 m

Updated record

https://espeleoworld.com/en/c/avenc-lo-fornas

Information can change. Always verify coordinates, access, weather, and cave conditions before setting out.

Topographic map of the main entrance — Main entrance · ICGC topographic map

A 55 m deep cavity in Horta de Sant Joan, known as lo Fornàs, with a large entrance above a chamber and a sector of pits.

Characteristics

Type: Pothole
Municipality: Horta de Sant Joan
Region: Terra Alta
Unit: Port, el
Length: 90 meters
Depth: 55 meters
Major Unit: Serralada Prelitoral
Lithology: Limestone
Updated on EspeleoÍndex: March 21, 2020

Location

About 70 metres below the summit of the Tosseta Rasa, on its NW slope, just above the edge of the forest.

The area can be reached from Horta de Sant Joan – Mas de la Franqueta (here you must leave the car) – Refugi de les Clotes – coll de Carabasses – Tosseta Rasa. It is more accessible via the track from el Caro – Mola de Catí – camí de la Gabarda – les Foies – Tosseta Rasa.

Entrances

Always verify coordinates and access conditions before setting out.

Fornàs, Avenc Lo
Elevation: 1142 m
40.846680, 0.325580
UTM 31T (ED 50) 274640 4525383
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Topographic

Avenc Lo Fornàs - Topography, Horta de Sant Joan, Terra Alta

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Espeleoindex · CC BY-NC 4.0, https://creativecommons.org/licenses/by-nc/4.0/ · Image © its author.

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Photos

Avenc Lo Fornàs - Photo, Horta de Sant Joan, Terra Alta

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Espeleoindex · CC BY-NC 4.0, https://creativecommons.org/licenses/by-nc/4.0/ · Image © its author.

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Description

Morphology

The entrance, more than 15 metres in diameter, extends above a chamber of 36 x 26 metres, completely covered with large blocks and thick vegetation, among which a magnificent specimen of yew stands out. At the highest point of the entrance there is a second opening that leads through a small passage into the main pit. On the South side of the base of the pit there are two continuations: one is a narrow passage 10 metres long that ends in a small chamber. The other opens about 6 metres above the floor and connects with a vertical sector formed by three pits of 13, 16 and 4 metres. A magnificent example of a collapse pit.

Speleothems

Also worth noting is the significant reconstruction process existing in the area of pits.

Hydrology

At its bottom there is a small pool of water. In past times quite a lot of water must have flowed through the cavity, as the clear signs of forced flow in the crawlway situated to the south of the chamber seem to show.

History

Known since time immemorial by the people of the area, who call it “lo Fornàs” as if it were a gigantic lime kiln.

The first speleological exploration of which we have record is the one carried out by members of the SES – CE Puigmal (Barcelona) around the year 1959 – 1960, who called it de la Tosseta Blanca. Members of the UEC – Tortosa had also explored it around 1970 and called it Cova Karst (at the entrance pit) and Avenc del Mussol (at the inner pits). In June 1979 members of the Espeleo Club de Gràcia visited it and published their record the following year, giving it 65 metres of depth.

During one of the ERE – CEC campaigns in the Terra Alta, they visited it in January 1981 and a new survey was made which had remained unpublished until now.

We update the record (March 2020) including the two surveys that were missing, the one published by the Espeleo Club de Gràcia (1979) and the one by the SES – Club Esquí Puigmal (1959), unpublished.