Drunken Horse Hole

Concerning the possible relationship between Poul Eich Oíta and Poul Aillte.

The townlands of Ballynahown, Ballyryan, and Crumlin have been subjected to increased scrutiny following the discovery, and exploration, of the latest "Green Hole"; Cliff Cave or Poul Aillte. Dived for one thousand metres to surface in a wide streamway pushed for  two kilometres to an obstruction within the low bedding, JW, supported by MM, (2015). The present end of the bedding plane passage, (January 2016), is estimated as 700/800 metres south of Poul Eich Oíta. It is possible, if the survey data is accurate, and the intervening geology kind, that the surrounding catchment area may have contributed significant drainage potential toward the development of Cliff Cave, (Poul Aillte). Poul Eich Oíta or another adjacent site may well provide an alternate, more accessible route into the system below, at an estimated depth of eighty metres, rather than negotiating entry through the unpredictable marine entrance located at the base of a cliff facing west into the Ocean.

Archaeological implications regarding the discovery of stalagmite within Cliff Cave.

Cliff Cave was formed by the action of fresh water draining from the area of Knockaunsmountain, not by marine erosion. Today, 2016, the entrance is approximately ten metres below sea level; dependent on the state of tide. The passage floor inside the entrance drops slightly then levels off. Extrapolation of the present cave floor level out to sea provides an approximate location where the ancient coastline once meandered, suggesting a distance from the present coastline when the cave was formed of up to one kilometre. Of note is a submerged stalagmite located some six hundred metres from the entrance of Cliff Cave at a depth of around eight metres. This stalagmite could not have formed under fresh or salt water therefore it must pre-date the period when the cave became permanently inundated. This substantial piece of stalagmite boss would, if successfully examined, provide a date when it formed, and so offer an indication of the period prior to which Cliff Cave developed. In turn this date would be invaluable to offer shape to the earlier coastal landscape, possibly during the Mesolithic period, (5500 - 4000BC). An entirely different piece of stal was found broken nearer the entrance, (2014), and is awaiting examination in Bristol, (2016); it  appears  somewhat decayed. There are presently, (2012 - 2016), ongoing archaeological excavations uncovering evidence of Mesolithic activity along the coast from Fanore south to Doolin, These sites would benefit enormously with a clearer understanding of where these sites were in relation to the contemporary coastline; though a precise sea level in relation to the coastline remains wholly dependant on the dynamics of Isostatic movement.

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Isostasy / Eustacy; associated effects.

Broadly defined; Isostasy is the gravitational equilibrium relationship between a land mass and presence of an Ice Cap. Upon formation the increasing weight of the ice cap presses down upon the land mass, as the ice melts the land mass "floats" back buoyed up by molten magma underneath: Eustasy relates to the uniform depth of the ocean/s.

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Glaciation. 

Evidence of past glaciation is present throughout the Burren. Most obvious are the isolated boulders, (Glacial Erratics), extant on the limestone karst. Further evidence,  in the form of smaller erratics, are found underground. Several examples have been found in Drunken Horse Hole; of interest are the many hundreds found, and continuing to be found, along the stream passage of Fraggle Rock.

Erratics in Drunken Horse Hole, (Poul Eich Oíta)

Digging thus far, (March 2016), has exposed a beautiful, vertical pot measuring three metres in length by one and a quarter wide. Several small rounded examples of erratic were found among the initial upcast debris, as the site was being cleared; no accurate provenance of context or depth is therefore attributable.  However, at a depth of two metres more erratics were encountered. The first within a dry, stiff clay by AB, (11th Feb 2016); the largest  six inches, (150mm), in diameter being predominantly white/cream with black grains throughout. A second group was unearthed by PC, (15th Feb 2016), among an area of angular stone debris in the southern area of the pot, also at a depth of two metres suggesting contemporaneous deposition, their appearance being similar to each other. A wide variety of erratics, some indeed similar in appearance to those at Drunken Horse Hole are to be found within Fraggle Rock located five kilometres to the south-west. 

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Explanation.

As close as can be determined from available data the two glacial episodes referred to above are,
Midlandian Glacial maximum, estimated as 80,000 - 13,000 years ago (Mitchell & Ryan 2001, 61)
Munsterian Glacial maximum, estimated as 300,000 - 130,000 years ago (Mitchell & Ryan 2001, 68)

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