Maraton
Summary
The main achievements of the expedition were the discovery of a new entrance to the system, and the exploration of the very deepest parts of Primadona, facilitated by a deep camp. Persistent exploration despite heavy rain and the collapse of our main entrance yielded 1.15km of new passage, much of this found below 690m of depth. Additionally we continued our exploration of the Hallelujah branch and discovered an easier route between the Monatip connection passage and M16.
Exploration
Surface leads
Rowan Cave
Rowan cave started as a surface dig after its small entrance had been found on a hiking trip. The entrance is located on the south-easter grassy slopes of Tolminski Kuk, being only a couple of minutes walk due east of the main hiking path.
After several rocks forming an unstable bridge over the entrance pitch were removed, a P5 was descended, after which the cave closed down again. A return trip enabled the further digging of a pitch head, which led to a drop of seven metres, surrounded by loose rocks. There was no continuation at the bottom, making Rowan Cave 18 m long, and 14 m deep.
Janet’s Little Cave
This was originally explored in the early 2000’s, with mentions in the original Hollow Mountain book written by ICCC, but no survey existed until now. On the way to Rowan Cave, the entrance to this cave was spotted again, and due to the enticing draught, it was decided to resurvey it, in order to gauge where the remaining digging leads might be headed.
This cave was thus surveyed to a length of 89 m and depth of 16 m, but no further digging efforts took place this year.
Belladonna - A new entrance
Belladonna
On the abseil route down to Primadona is a conspicuous 1 meter diameter hole, leading to a tube, set into one of the vertical faces of the cliff. After 3 years of abseiling past this obvious hole this year a team finally investigated it this expedition by swinging in from the existing route.
Beyond the tube the cave opens out immediately. A small pitch to a ledge leads to a second 20 metre pitch into a large chamber. From the end a further 20 metre pitch drops into another large chamber which intersects the cliff face again.
This second Chamber is the Drugi Vhod entrance to the system which was briefly explored and abandoned during the first exploration into Primadona. This is directly above the main Primadona entrance chamber and a small pitch and traverse brings you to the top of the snow slope on our usual route down.
Even before the subsequently described events it was suggested that the Belladonna entrance was preferable to the cliff as you are sheltered from falling rocks and the weather and there was some discussion about derigging the cliff. Belladonna is now the 9th entrance into Sistem Migovec.
Goodbye Primadona - the collapse
The main entrance to Primadona was a large snow filled chamber with a very large opening to the cliff. Climbing down the snow slope brings you to a low crawl, which leads to the cave proper. This crawl was dug by the Slovenians during the early explorations, and so on one side is just the bottom of the scree slope that the snow rests on.
As one team exited from a long trip this slope collapsed, and filled the crawl with rubble. It collapsed just after the first of the three person team had gone through it, leaving two trapped just inside the cave. There were thankfully no injuries. The free caver confirmed the state of the other two (it was still possible to communicate) and exited to raise the alarm on the plateau.
A small rescue began. Though concerned by the collapse we knew the other two were uninjured and in a good way to wait for retrieval via another entrance. A few hours later they were reached by a second team via the Monatip entrance and escorted out.
Drugi Vhod
With our main entrance gone, eyes turned to the Drugi Vhod entrance. We had no information about it other than that it existed. We spent a couple of days re-exploring and rebolting resulting in a connection with Bear Pitch, which allowed us to resume deep exploration.
Drugi Vhod is best accessed via the new Belladonna entrance, as this avoids an up-pitch. From the large open chamber a small crawl and squeeze leads the top of a spacious 30 metre pitch. This lands on a boulder floor, and the way on continues in a narrower rift pitch. This improves quickly and the final hang descends another 20 metres down a steeply sloping phreatic to rejoin at the head of Bear Pitch.
The general consensus is that this way in is an improvement over the old entrance. It is far more stable and has fewer awkward pitch heads.
Deep pushing
Setting up camp at Moonraker
Within days of the expedition arriving on the Migovec Plateau, several teams were dispatched underground to ferry all the necessary equipment to build a new campsite at the muddy but dry passage of Moonraker. In practice, this involved checking and re-rigging the main ‘trade route’ to the camp where needed, carrying the pre-packed tackle-sags containing tent, rollmats, stoves, food and sleeping bags. Over these bounce trips, the expedition novices familiarised themselves with the route to camp.
At the same time, the two Cave-Link stations were set up as had been planned. The intermediate station was deployed along the Mary’s Café passage, at depth 250 m, while the second deeper station ran from a depth of 600 m, at the campsite. The camp set up team secured a connection to the surface, using the Café relay on their first night.
Ad Aspera Per Aqua
This rectilinear 100 m long passage was immediately pushed by the second camping team. It is essentially the upstream continuation of the Aqueduct rift, ending at a high drippy aven. Along the length of the passage, some sections of low streamway are encountered. This is the most southerly passage in Primadona. The aven was not climbed further.
Artemis, Tartarus, Lachrymosa
The second ug camping team also surveyed Artemis (93 m), which begins with a boulder choke in the floor of Klic Globin pitch. A short drop into roomier passage leads to a chamber where a loud shower enters and cascades down into a lower boulder blockage. The chamber is high and elongate, with the same NNE-SSW orientation as the Aqueduct above. Below the first Artemis chamber, more water enters as a permanent stream, joining the cascade down a 20 m pitch. At the bottom of the lower chamber, the water continues its course, but this was left as an open lead for the next team.
The third camping team investigated the leads around Artemis. North of the upper chamber, a high level continuation (Tartarus, 48 m) ends under the boulder chokes of Klic Globin. South and through the heavy drips, an inclined tube (Lachrymosa, 92 m) drops over the top of a small sump pool. The upstream continuation becomes a low stream passage, where the banks are covered with limestone and haematite pebbles.
The water is almost certainly coming from Ad Aspera Per Aqua and the Aqueduct. The small sump is likely perched, feeding the main stream appearing in the lower parts of Artemis.
Poseidon Rift, Street-Wise Hercules
Poseidon rift is the downstream continuation of Artemis. This open lead was a logical choice for the following campers.
Beyond a short 5 m pitch, a narrow constriction close to the water flow was hammered at length to make it passable. Beyond, the cave drops in a series of inclined pitches to a boulder choke. On the far side of the choke, it is possible to ascend to a large, unclimbed aven. In the boulder choke itself, a route was found that regained the stream passage and left as the next lead. In total, 81 m were surveyed in Poseidon Rift.
Another pushing trip saw the exploration of this continuation (Street-Wise Hercules, 41 m surveyed). The short pitch led to a narrow and arduous passage high above the water, which finally broke out into a deep rift of sizeable dimensions. Disto measurements made from the deepest survey point there suggest another 38 m of depth to be gained.
A final push was made in this area, but as it coincided with high water levels, no survey was made. Street-Wise Hercules is the deepest surveyed point in Primadona, at a depth of 810 m below the Plateau surface.
The Hallelujah Branch: deeper and more complex
Octarine, Death Star
Octarine and Octarine core are a series of small pitches and chambers connecting the end of Purgatory/Alabaster to a window on the long final pitch of Bath.
Initially overlooked as the way down Bath was more appealing, Octarine did turn out to be a smaller and more arduous route and therefore was mostly derigged. However just before it's reconnection with Bath, a small series of three pitches descends, and does not reconnect with known passage despite it's proximity. These pitches join a low sandy passage, Death Star.
To the North West Death Star connects with a window half way down the first Canticle For Migovec pitch. In the other direction, South East and towards blank mountain, it grows in size to become a spacious walking sized canyon passage. The limit of the exploration is a 10m pitch where the passage beyond appears to enlarge further.
Not only is passage extremely promising but it is one of the few dry and relatively shallow leads remaining in Primadona.
Angel Delight, Sump 404 Lead not Found
The far end of Testify!, found in 2018 was the deepest point in the Hallelujah Branch, reaching 620 m below the Plateau surface. Left as an open lead, this was a logical option for an experienced, fast moving team. In the middle of the expedition, one team travelled to the lead and continued the exploration of the branch. Finding a new underground camp location to make this branch more accessible was also on the cards.
Angel Delight (62 m surveyed) is a series of several short but roomy and dry pitches, landing on the same fine white sand dunes found elsewhere in the Hallelujah Branch. At the bottom of the last 10 m split-pitch, a short 2 m down climb to the south leads almost immediately to a perched sump. This is Sump 404 Lead Not Found (40 m). On the far northern side, a short flat-out crawl drops into a very low draughty passage, where the floor is made up of water-logged white sand and silts. Eventually, the ceiling drops too low to allow further progress. This pitch series was therefore derigged and marks the deepest point of the Hallelujah branch.
The Hallelujah stream passage
When the Hallelujah streamway was first discovered it was followed until the water disappeared into a small crack in the floor. Beyond a larger space and the sound of water falling several meters in the open were frustrating indications that the cave continued. However it was thought that capping or feathers and wedges would be needed to pass the constriction. Exploration continued in the high bypass to Sweet Baby Jesus, where to our surprise we never rejoined the water.
A return this year to assess the lead resulted in the discovery of a squeeze bypass to the crack that allowed a subsequent team to follow the stream. Beyond the squeeze a 4m pitch lands in a small spray lashed chamber. A stooping passage leads immediately to a 3m pitch in close proximity to the water, which shoots out in a small jet. The water then hits a ledge and completely drowns the next 10m pitch in spray. Luckily a parallel dry pitch can be accessed via a crawl which lands in a roomy chamber next to the stream.
This was the limit of exploration. From here two pitches descend at least another 10m. One close to the stream and another drier way but it seems likely these join up quite quickly. It is also possible that there is an easily accessed window in this chamber. Exploration and surveying was cut short by a flood pulse so the exploring party exited quickly. It is hoped that the passage will be named Beam Me (the fuck) Up.
Wishing Well - A new connection
Preparation in M2
Of great interest this year were a number of undescended shafts located in the connection passage between M16 and Monatip entrances. Due to our interest in pushing Primadona, little pushing had been done in this area before. Due to the location of the connection passage, entrance was normally made through the M2 entrance, which although more challenging, was shorter than the connection via M16. First, a team set off to complete the M2 to Monatip through trip. Upon exiting, they reported a large number of undescended shafts, more than we had anticipated, and along the full length of the connection passage. The rigging in M2 was also reported to be in need of some attention. This was rebolted and rerigged over two further trips, to provide a safe route to the pushing front.
Wishing Well
From several recces a twin undescended shaft was identified in the connection passage, relatively close to the connection with NCB passage. A team went and dropped the smaller pitch (P30), into a large chamber 15m across with one wall completely missing and rocks appearing to tumble into a void for around 4 seconds. Upon inspecting the opposite wall of this void, the team noticed a rope on the opposite side. Surveying and returning to the surface, the rope was identified as belonging to the Mig Country traverse, near the start of the M16. A second team then bolted a 45m traverse on a wide ledge from the new discovery (christened Wishing well), to the Mig Country traverse, exiting via M16. 156m was surveyed in total here.
This discovery is of great utility for future exploration in the Monatip connection passage, as the time from the surface to the pushing front has been cut down from 3hrs to 1hr.
:( (sad face)
With a team entering from M16 and using the new Wishing Well route, the second of the twin shafts (P36) was descended and discovered to be blind. The name sad face comes from the expression of the explorers upon discovering that their lead immediately died, and for an experiment in using emojis on survex.
Other finds, resurvey
Power Grab
Building on the discovery of Electric Dreams (2017) by traversing above Karstaway pitch, and the discovery of Odessy (2018) by traversing across Electric Dreams, a further pushing and traversing trip was completed this year. A team dropped the P5 at the end of Odessy and found themselves in a large window on the electric dreams pitch. Traversing over this pitch on steadily vanishing ledges, the team reached another window. Squeezing through a small abandoned stream passage led to a tight pitch, which was visually confirmed to reconnect to a lower part of Electric Dreams. 43m of passage was surveyed in Power Grab.
Below Pivnica - resurvey and an interesting push
During the expedition, we continued our resurvey efforts down towards the old deepest part of Primadona, though this was hampered by high water levels. At the end of the expedition two Slovene cavers returned to the lead at the bottom of Donji Milanovac, not visited for 18 years. An ongoing pitch series was discovered and surveyed. The pitch series runs parallel and is close to the Klic Globin rift, we expect the two routes to converge either in Poseidon Rift or Street-Wise Hercules, however further exploration is required to confirm this.
Future prospects
Sistem Migovec still has plenty of going leads, however with the pushing fronts becoming ever deeper we must plan our exploration carefully for next year. Several groups discovered this year that the deep leads in Primadona are particularly rain-sensitive, so future exploration must rely on settled weather. As an alternative and as training for new expedition members, the newly discovered Wishing Well will provide a fast route to the upper Monatip passage which contains many unexplored shafts and is relatively shallow. We hope to continue pushing Primadona until it reaches at least 900m of depth, although signs of reaching the water table are starting to show.
Surveys
At the end of the 2019 expedition we switched from Survex to Therion for our survey compilation and drawing and we decided to attempt to redraw the entire system in Therion. This means that we did not produce a definitive 2019 version of the drawn survey but instead we have been continously producing our work in progress versions as we have redrawn. These can be found here:
https://github.com/iccaving/migovec-survey-data/releases
The Primadona/Monatip/Ubend surveys are complete and represent most of the 2019 exploration. They are still a bit rough and we plan to work on their aesthetic appeal once the redrawing is done.