Matienzo 2002

Cave exploration around Matienzo during Easter, Summer , October and December 2002

An early Easter, but the weather was kind and fifty people turned up, including a group of 5 Danes. The highlights of exploration at this time included Martin Holroyd surveying 600m in downstream Cueva Vallina through 5 sumps, significant inlets being discovered in Cueva Hoyuca, Cueva Helechales being bottomed and Hidden Hole being pushed close to Cueva Cefrales. Over 2.1km of new passages were surveyed.
In common with most of Europe, the summer weather was quite dismal,. Near the end of August, it rained enough in 12 hours to bring the main river up from a low level to flooding the fields and producing a torrent from the mouth of Cueva Arenal. Despite the weather, over 2.7km of new passage was surveyed: the main extensions were in Cueva Vallina (1.33km) and Hidden Hole (320m).

Four Valleys System
Cueva Hoyuca saw a fair bit of activity at Easter, with pushing trips in two inlets, one at the start of the Gorilla Walk and the other, Windy Inlet, near the end. The first is found on the right of the passage before dropping into the water. A draughting dig through boulders leads to a 4m climb up. The passage trends upwards passing over the Gorilla Walk and ending up about 30m above water level and 70m west of the starting point. Windy Inlet is a strongly draughting inlet about 3/4 the way along the Gorilla Walk. The passage is generally small to a 6m climb. Beyond is a rift excavated of boulders that leads to an aven that has been climbed to where the passage appears to finish close to site 253. (The survey was apparently taken using the wrong side of the clino - this needs correcting). The series is described as requiring SRT kit for 5m and 30m climbs. Site 253, a tight draughting rift, was subsequently excavated and work continued during the summer. Eventually, the cave "went" to a dismal small passage with inlets that became too small after 100m or so. The cave did not drop by much but has still to be surveyed. If an entry is achieved here, two or three hours might be cut off the lengthy trips to the end. The total length of the Four Valleys System increased by 378m to 43329m and then to 43437m when the new Roof Passage was surveyed in the entrance series during the summer.

A lot of interesting, if small, under and above ground exploration was carried out above Cueva Hoyuca and Cueva Riaño during the wet summer. One investigated area centred around site 253 and a set of sinks and resurgences above the Gorilla Work in Cueva Hoyuca. During a flood, a large quantity of water was seen to sink at site 1789, uphill of site 253. A small, draughting sink (site 1674), also below the main flood sink, was partially dug. Near to Chestnut Hole (site 102) and also above the Gorilla Walk, site 1793 was excavated to reveal a 5m deep pot, 3m diameter, with a bedding at the top connecting to a second entrance. A nearby draughting slot (1792) was dug for some 4m where continuations appear small. At Easter, some work took place at site 1672, on the side of a shakehole near to a shrine. This site was excavated of sandstone blocks to reveal a 7m pitch to an eyehole. This is also likely to be an inlet to the Cueva Hoyuca.
A second area of investigation, higher up the hill, centred on the two resurgences above sink 1618.  Thirty metres inside site 1617 a low passage was dug to open up a tight crawl into a chamber where progress could be made through calcited boulders. The second resurgence (1666), 50m to the NE was pushed and surveyed (in inappropriate clothes) to where progress required flat-out in either water or on a mud false-floor. The possible sinks for these resurgences were discovered some 300m to the north and about 20m higher up the hill (sites 1787 and 1788). At an altitude 60m higher an open shaft (site 1790) was found to choke 5m down and, above the road, shaft 1791 was removed of the boulder cap and found to be 5m deep. The next valley north of 1788 held site 1807, a low rock shelter. About 200m north, at site 1810, a 2.5m drop entered a small streamway and 4m of walking passage to a pool with no way out.
A number of holes were discovered around the downstream end of Cueva Riaño (site 105). The water in downstream Cueva Riaño drains into a sump and is next seen in the resurgence (site 575) some 300m to the west. After 150m on the surface the water then sinks into the top entrance of Cueva Espada (site 103). A couple of sites were excavated just east of the reinvestigated upstream passages in Cueva Espada: site 1801 (a choked crawl) and site 1800, where a few boulders were removed to reveal a 10m pitch with a slope down to water. Five further sites were investigated over the area where the sumped Cueva Riaño passages are thought to be. Site 1803 is a 1m high cave entrance to a 3m deep slot in the floor and a choke 6m in. A nearby, deep, vegetated depression has yet to be entered. In the valley running down to the resurgence, a depression under a chicken shed held an open, walk-in rift (site 1804). This dropped down and turned left to a narrow, calcited, 5m high rift. The constriction was excavated to a couple of squeezes into the continuation that again became too small with calcite. The site could be relatively easily opened up with generator and chisel. Thirty metres further down the valley at site 1805, a small drop is hidden by a wall and vegetation. At the draughting base, a few boulders were removed to enter a 10m long chamber, where various routes down a tight rift may be engineered in the future. Just north of the road in the same valley is site 1809 where a small chamber has ways on that require enlarging.
Digging continued in Mad Axe Woman Cave (1630) in Riaño. Moving southeast along the base of the hill side, site 644 was deemed draughting and diggable, and 50m further into the corner, site 1799 may have a possible way on under a right hand wall at the base of a 2m drop.
The bouldery mess in the southeast part of Cueva de los Tres Niños (site 565) was reinvestigated without revealing any more passage.
In site 1289 near Caravueso sink, the talus cone near the entrance was investigated and pottery removed.

North Vega, El Naso, Las Calzadillas and Cobadal
A small amount of activity took place on El Naso. In Cueva ABI (site 58), a complete resurvey was carried out. Some 250m southwest from the top quarry car park, site 1811 appears choked about 4m down but requires boulders removing to properly investigate. Sites 1812 and 1813 are possible digs and site 1814 is a walk-down rift that has yet to be explored.
Digging continued in the 415 corner: Pile of Pants (site 1655) had some shoring installed and the survey for site 715 (some 60m to west) was completed.
A number of the pitches in Torcón de la Calleja Rebollo (Toad in the Hole) were bolted for SRT and 16m surveyed brought the length to 6486m. At Las Calzadillas, above the end of Toad in the Hole, site 1429 was excavated into 2 small chambers and Cueva Selvijo, site 1209, drops 15m with a length of 25m and may be worth digging. Further down the road towards La Cavada, site 1815 was exposed by road workings. No way on was found after the significant boulder-floored entrance passage split into  number of passages and choked in all directions. Immediately above this site, a depth of about 30m was reached in a free-climbed rift at site 1816.
In Cobadal, the GPS was used to place some sites which are off our 1:5000 maps, including the main sink (553) and another nearby cave (site 1725) which was also dug and explored in draughting passage for 80m.

South Vega, Seldesuto and Alisas
Early on in the Easter trip, Cueva de los Helechales (site 408) was tackled up with the prospect of linking down to Coterón (site 264) or going west into the unknown. After pushing Snail Inlet above the 88m Hoedown Pitch for 83m, the explorers found the base of the pot became too tight after pitches of 13 and 17m. The cave ended in a disappointing fashion, still 80m above Coteron.
Hidden Hole (site 458) continued to provide passage. A 32m pitch in the Sherwood Forest area dropped down to a short length of passage each side of the pitch and a further 8m drop to end at the deepest point, some 130m down at an altitude of 215m. Rather more substantial passage was found at the main level (about 255m altitude) where the Slip Sliding Away series rose up to the northwest over mud banks and a long false floor, to a chamber with tubes, further explored in the summer. This is close to the upper entrance pitches of Cueva Cefrales (site 42) and that cave was subsequently dug on a number of occasions, but no connection was made. Hidden Hole was extended by 657m through the year bringing the length to 1368m.
The summer saw 3 trips into Cueva Cantones (TV Mast Cave). The aim here was to have a new team try to push down at the ends. However, more time is required for familiarisation before any new passage can be found and surveyed.
In Cueva-Cubio de la Reñada (site 48), various new explorations occurred. Mark Smith & Gavin McPherson dived in the upstream sump just after the Rub-a-Dub-Dubs gaining about 100m of underwater passage by the end of the summer. This is described as heading due west for about 100m and continuing in an impressive oval 3m high x 5m wide with a sandy floor. Exploration in known passage "behind" this sump noticed that there was a lot more water flowing out of this main sump than in any streams further in. Some checking out was done in the Castle Hall area: entry to a high level passage would involve a 10m climb but it can be seen to slope up with a rift going off; some "new" passage was entered at stream level and on the Ramp. The stream passage was surveyed in the summer: Castle Hall now has the Moat of Doom with a length of 117m. Avens opposite Bootlace Passage entrance have attacted some attention as they are quite near to a possible connection to Coterón and possibly more passage heading west. Climbing continues around Itchy Crutch. The total length of the SVS is now 26287m.
On the hillside above, various drops were checked out, continuing work started at Christmas 2001 when Tiano showed a number of holes. Site 1715 was surveyed to a 40m long, sloping chamber with some reasonable formations. Shaft 1722 was revealed as a 35m deep pot. Site 1719 was excavated to reveal an 18m deep hole that required further work. A 21m shaft (site 1713) choked at the base and site 1712 at 10m deep, also choked. Site 1708 is supposed to melt snow in winter but further work is required to enter small passage seen from the third small chamber. Site 1714 choked 9m down. The Twin Streams dig 1390 and Volcano dig 1391 continue to hold promise but require further work. Other small sites were explored: 1704, 1709, 1716, 1717 and 1719 where a 2m high bottom entrance climbed up to a top entrance through 25m of passage.
At Alisas, well above Seldesuto at around 525m altitude, a number of sites were examined. The large shaft of Torca del Rayo, site 1305, was finally bottomed after a couple of visits. A 15m entrance pitch leads to a slope down to -25m. A further pitch at the base of the entrance rope is a tighter 18m pitch that chokes at -33m. The newly discovered draughting shaft, site 1817, sounds promising as stones dropping through a tight section below a 5m climb down produce a satisfying boom some 20m below. Shaft 1818 was explored down a 10m pitch in a 5 x 3m rift to a depth of 13m with a shallow side chamber with stal. The well decorated chamber (site 1819) was documented.

Arredondo
On the other side of the hill, towards Arredondo, some exciting explorations occurred in Cueva Vallina (site 733). Above water, Breakthrough Chamber gave 96m of passage and, close to the bottom entrance - on the right hand side, The Secret Series revealed over 200m of cave at Easter and about the same in the summer. Also in the summer, 335m of "new" passage was surveyed to the left of the lower entrance passages, linking to the pitch from the upper series.
At Easter a team of 22 sherpas helped Martin Holroyd to dive the downstream sump and continue Phil Papard's explorations beyond sump 2 to end up with 500m of passage above water (with some nice stream passage up to 15m high) and 3 further sumps. At the current end, the underwater passage is getting larger and descending, but a large, muddy inlet was explored above water until it split and became small.
A group of Swedish cavers in Valline seem to have entered unexplored passage high above a bouldery chamber at the start of the summer explorations. This couldn't be found on a later trip but the team did start to push a 40m bolted climb around and up out of FN Passage. Albert's Grand Passage heads south east for 200m where a pitch drops back into the middle level. Skyhook Passage continues beyond the drop with various ups and downs until comfortable walking-size passage is reached that continues for 100m to a large shaft about 15m in diameter. This is likely to drop back into the middle Valline level - it also continues up - but the phreatic level can be seen continuing on the other side of the shaft. The length of Cueva Valline rose by 2.3km from 26676m before Easter to 28988m by the end of the summer. 
A strongly draughting dig (1730) some 40m west of Valline top entrance was excavated at Easter and summer but the way on appears too tight without furter work. The Water Tank Dig (1820) further to the west was also enlarged over three days.
In Cueva Molino (site 727) a 15m bolted route was climbed up a calcited wall in a large chamber halfway along the cave. It ended at 3m of passage with a choked drop down.

Ozana and Muela / Mullir
In SIma-Cueva del Risco, engravings near the end of the Pinto Gallery were photographed. These are in the area where the remains of a giant deer Cervus megaceros, a mono-bevelled assegai point and possible prehistoric faunal remains have been found. (The passage chokes at a probable collapsed entrance).
On the lower, western slope of Mullir, in Ozana a number of small holes were investigated: cave 1729, One Sock Pot (1726), JCB Pot (1727) and Probable Pot (1728). While using the GPS it was found that Cueva de Cuatribú (site 13) was way out  from where it "should" have been. It looks like it has wandered 400m from its first position in the jungle 30 years ago!
More substantial discoveries were found 200m above. On one particular trip, a team set out to explore known, but unexplored holes. However, the destination was not reached because of 10 unknown sites found on the way. These were site 1731 to 1740. Site 1734 was a 25m shaft, a 41m shaft at site 1738, and sites 1739 and 1740 being about 26m deep.
Before the summer expedition, the new SEAD website was seen and the various caves and shafts mentioned "integrated" into the Matienzo database and descriptions. Some of the sites on Muela / Mullir are undoubtably original explorations by SEAD but a number are repeats of explorations carried out by Matienzo cavers years ago. The sites have been numbered 1762 to 1785. The locations will be checked out as a number of these appear inconsistent with the altitude. One walk in the summer around the Hoya de Yusa on Muela failed to find a number of them and indeed found one 200m away from its stated location. However, 2 sites were positively identified as "old" sites - the Torca de Yusa (site 116, explored in 1975) is SEAD's M-11 which they have surveyed and extended, and site 135 (probably explored in 1980) is SEAD's M-14. On the same walk sites 1794 to 1798, 5 shafts up to 10m deep, were located but remain unexplored.
At the Ozana / Vega junction, in the small hum, Torca de Casa Blanca (site 1808) was excavated of its boulders and explored down an 11m pitch to a low streamway with inlets. The end becomes ver low at a possible choke / dig giving a length of 106m and a depth of 22m. The cave is similar to the nearby Cueva del Mazo (site 312) which also runs down over dipping sandstone beds. Both caves should resurge at site 368 on the northern side of the hum. 
On the Llueva side of Muela, above the track that goes to San Miguel from the farm house, site 1743 dropped down a 17m pitch into a well-decorated chamber. Twenty metres above, another wide open shaft (site 1821) was only 10m deep and immediately choked. Further down the track, sites 1591 and 1592 were documented. Just uphill of the farmhouse a small cave (site 1786) was entered down man-made steps. There were domestic utensil remains in a small pit beyond what appears to be wooden decking. To one side, nearer the entrance, is a straight 10m pitch to a 2x1m floor littered with more utensils and the remains of 3 rifles. There is also ammunition on the floor among the remains and boulders.

Other areas
In Rada, near the northern end of the San Miguel valley, Mark Smith and Gavin McPherson explored through the sump at Easter into reasonable passage that gave a total length of 402m.
At the Nacimiento de Campiezo (site 1106), Gavin McPherson pushed beyond the end of Rupert Skorupka's line through an awkward squeeze into a chamber above. This soon tightened up and the site now looks less promising.

Once more, there were more questions raised for the next year than were answered during 2002.

Acknowledgements
We were welcomed by Pablo at Bar German and the expedition is grateful for the camping facilities and the use of the restaurant for computing and drawing up. Unifix supplied the expeditions with SS 12mm bolts and the Ghar Parau Committee recommended a substantial grant. 

The list below shows links to those 188 sites which were extended or newly discovered over Easter and summer, or which have had surveys updated, entrance photos added or entrances repositioned with a GPS. The list also documents sites 1745 - 1760 that are links to "new" sites investigated in the area south of the Alisas-La Piluca ridge and documented by the French in Sous le Plancher no 4, 1989. There is also mention of some of them by AEC Lobetum in anon., 2000e: Actividades espeleológicas En Ruesga in Calar No 5, 2000. Federación Castellano-Manchega de Espeleologia. Torca de Blas (1760) has a full survey in that publication. Although out of "our area", these sites will have some interest to Matienzo cavers, particularly sites 1745 and 1760!
Also listed are sites 1762 - 1785, described on the web site of the Sociedad Espeleológica Alto Duero. The grid references appear unreliable in some cases.

2 Coverón, Cueva del; 3 Collusa, Cueva; 13 Cuatribu, Cueva de; 17 Jivero 2, Cueva de; 25 Risco, Sima-Cueva del; 27 Oñite, Cueva;
34
Adillos, Cuevas de los; 35 Arenal, Cueva del; 42 Cefrales, Cueva de los; 48 Reñada, Cueva-Cubío de la; 51 Beralta, Torca de;
58 ABI, Cueva del; 65 Cofresnedo, Cueva de; 71 Mostajo, Torca del; 75 Picón, Simas del; 85 La Cuevona, Abrigo de; 86 Cuvia, La;
102
Castañas, Cueva de la; 103 Entrambasaguas, Cueva de; 107 Hoyuca, Cueva; 116 Yusa, Torca de; 135 shaft;
138
Coberruyo, Cueva de; 177 Cuevuca, La; 250 shaft; 251 Canado, Sima del; 253 shafts - 2; 258 Calleja Rebollo, Torcón de la;
305
shaft; 330 cave; 333 Azpilicueta, Torca de; 334 shaft; 388 shaft; 408 Cueva de los Helechales; 423 Barandas, Cueva de;
458
Hidden Hole; 527 shaft; 528 shaft; 539 shaft; 553 Cobadal, Sumidero de; 565 Tres Niños, Cueva de los; 575 Resurgence Riaño;
628
cave; 644 cave; 715 shaft; 727 Molino, Cueva del; 733 Vallina, Cueva; 767 Wild Mare, Cave of the; 865 Cantones, Cueva de los;
880
dig; 900 Porquería, Torca de; 975 Marcos, Cueva de; 999 shaft; 1000 shaft; 1001 shaft; 1106 Campiazo, Nacimiento del;
1209
Selvijo, Cueva de; 1278 shaft; 1289 cave; 1305 Rayo, Torca del; 1312 cave?; 1319 Cuervo, Cueva del; 1390 dig; 1391 cave;
1429
cave; 1591 cave; 1592 shaft; 1617 cave; 1630 cave; 1655 dig; 1666 cave; 1667 dig; 1670 dig; 1672 dig; 1673 cave; 1674 sink;
1704
shaft; 1708 cave; 1709 cave; 1712 shaft; 1713 shaft; 1714 shaft; 1715 cave; 1716 shaft; 1717 shaft; 1718 cave; 1719 shaft;
1720
dig; 1721 shaft; 1722 shaft; 1723 shaft; 1724 dig; 1725 cave; 1726 One Sock Pot; 1727 JCB Pot; 1728 Probable Pot;
1729
cave; 1730 dig; 1731 cave; 1732 shaft; 1733 shaft; 1734 shaft; 1735 shaft; 1736 shaft; 1737 shaft; 1738 shaft; 1739 shaft;
1740
shaft; 1741 hole; 1742 dig; 1743 shaft; 1744 cave; 1745 Portillero de Tocornal, Torca de; 1746 Fuego, Torca del;
1747
Arroyo, Fuente del; 1748 shaft; 1749 Dieux, Grotte de; 1750 shaft; 1751 Azuela, Torca de la; 1752 Llaneces, Hoyo de;
1753
shaft; 1754 Portillo del Hoyo del Ramon; 1755 shaft; 1756 resurgence; 1757 cave; 1758 Orbitolines, Cueva de;
1759
Lledes, Hoyo de; 1760 Blas, Torca de; 1761 shaft; 1762 Sima CM-2; 1763 Sima CM-3; 1764 Sima CM-4; 1765 Sima CM-5;
1766
Sima CM-6; 1767 Sima CM-7; 1768 Sima CR-2; 1769 Sima CR-4; 1770 Sima CR-5; 1771 Sima CR-6; 1772 Sima CR-8;
1773
Sima CR-9; 1774 Sima M-8; 1775 -; 1776 -; 1777 Sima M-32; 1778 Sima M-39; 1779 Sima M-40; 1780 Sima M-41;
1781
Sima M-42; 1782 Sima M-47A; 1783 Sima M-47B; 1784 Sima M-48; 1785 Sima M-49; 1786 Tora Bora; 1787 sink;
1788
sink; 1789 sink; 1790 shaft; 1791 shaft; 1792 cave; 1793 shaft; 1794 shaft; 1795 shaft; 1796 shaft; 1797 shaft;
1798
shaft; 1799 shaft; 1800 shaft; 1801 cave; 1802 depression; 1803 cave; 1804 cave; 1805 cave; 1806 dig; 1807 cave;
1808
Casa Blanca, Cueva de; 1809 cave; 1810 shaft; 1811 shaft; 1812 dig; 1813 cave; 1814 cave; 1815 cave; 1816 shaft;
1817
shaft; 1818 shaft; 1819 cave; 1820 dig;

The list below shows links to those 45 sites which were extended or newly discovered in the latter part of the year, or which have had surveys updated, entrance photos added or entrances repositioned with a GPS.

59 Molino, Cueva del; 65 Cofresnedo, Cueva de; 81 Carcavuezo, Cueva de; 86 Cuvia, La; 139 shaft; 331 shaft;
333
Azpilicueta, Torca de; 339 shaft; 374 shaft; 565 Tres Niños, Cueva de los; 733 Vallina, Cueva; 852 dig;
875 Horse Trough Pot; 969 shaft; 1269 shaft; 1390 dig; 1457 shaft; 1544 shaft; 1749 Dieux, Grotte de; 1814 cave;
1821 shaft; 1822 Canado, Sima del; 1823 cave; 1824 cave; 1825 dig; 1826 shaft; 1827 cave; 1828 shaft;
1829 shaft; 1830 cave; 1831 shaft; 1832 dig; 1833 shaft; 1834 shaft; 1835 shaft; 1836 shaft; 1837 dig;
1838 cave; 1839 shaft; 1840 shaft; 1841 shaft; 1842 dig; 1843 dig; 1844 dig; 1845 cave

Juan Corrin, May, October 2002, January 2003

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