XXV Jornadas Cientificas de la Sedeck Los sistemas

XXV Jornadas Cientificas de la Sedeck Los sistemas kársticos entre Arredondo y Matienzo Juan Corrin, Peter Smith and Philip Papard (Expedición Espeleológica a Matienzo) 11/02/2022 1

Matienzo Valley looking north from Fuente las Varas 11/02/2022 2

The Matienzo Area n n n 26 km 2 imperviously-floored closed valley north of the Asón and its ridge east of Riva Water from surrounding caves sinks at the north end flowing through a 55 km system to Secadura in Voto. This paper covers two 35 km systems under the north Asón ridge and their possibilities for yet forming another 100+km system 11/02/2022 3

Caves in the Matienzo Area ? ? ? 11/02/2022 4

The Caving Expeditions Spanish expeditions – 1960’s n British-led since the 1970’s n Members from: UK, Spain; Denmark; Norway; Netherlands; Italy; Australia and Singapore. n Expedition based at Bar German in Matienzo n Data on 350 km of caves and 4000+ sites are open on: http: //matienzocaves. org. uk 5 11/02/2022 n

South Vega System n n n Behind Comellantes resurgence is the 33 km long and 317 m deep- South Vega System Complicated system - deep pitches, between large passages on different levels Water enters the sy system in the west A dye test from Torca del Hoyón showed a weak positive - needs repeating, and iitt would only be a fraction of the flow seen The rest ma mayy come from the Alisas area or from the south (Vallina)? 11/02/2022 6

South Vega System 11/02/2022 7

South Vega System 11/02/2022 8

Cueva del Arenal n n n This half a Km cave lies above a cliff west of the end of the South Vega System Normally it draughts out strongly with no water flow, but in flood a large stream cascades out. This cave may be a flood overflow for water beyond the end of the South Vega system, and if the final choke could be passed it could be to an old higher level route to the Alisas area! 11/02/2022 9

Cueva del Arenal 11/02/2022 10

View up Vega valley to Alisas - South Vega System/Cueva Vallina under ridge on left. 11/02/2022 11

Cueva Vallina n n On the Arredondo side of the ridge, lies the 33 km Cueva Vallina Levels appear to correspond with passages in the South Vega System about 500 m away. Torca del Hoyón Sistema de La Vega Sur, Cueva Vallina Cueva del Molino N-S vertical section of caves between Rio Asón and Matienzo 11/02/2022 12

Cueva Vallina n n n Large passages on a several levels, split into two equal parts (I & II) by a boulder squeeze Vallina II: ongoing work to link to the South Vega System and also push to the west Vallina I: main passage chokes, but the draught suggests it should extend to the east Water from Vallina I & II flow to the west via short sumps to a 110 m still open sump This sump heads towards Cueva Molino, but as Molino runs to the NW a dye test is needed 13 11/02/2022

Cueva Vallina I 11/02/2022 14

Cueva Vallina II 11/02/2022 15

Cueva Molino n n Complex cave with strong draught indicating a dry connection to higher ground Ends at a large sump dived to 340 m and -82 m by Rupert Skorupka In 2011 good weather allowed Chris Jewell and Artur Kozlowski to push past – 93 m to 885 m at a depth of -12 m Sump is still open and heading N-W towards Alisas 11/02/2022 16

Cueva Molino 11/02/2022 17

Sistema del Alto del Tejuelo 11/02/2022 18

Testing of drainage routes n n n Torca del Hoyón dye test needs repeating, but other tests sites need to be involved We suggest joint work with groups working to the west and south of Alisas, and the water authorities so the hydrology can be mapped and possible extent of cave systems indicated To facilitate this process the British Expedition believes in open access to all our information, which can be found on our website at http: //matienzocaves. org. uk 11/02/2022 19

Questions? 11/02/2022 20