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Summary Full report
Marble Arch Karst; Marble Arch Cave
Rec. Number:347File Number: H13
ESCC:IC
Locality Type:Cave Status: PASSI
Grid Reference: H121344 Not Entered
County: Fermanagh District:Fermanagh District Council
Period:Quaternary
Stages:Holocene
Lithostrat:No data
Site Description

The Marble Arch.
Highlights:
 
Introduction:
 
Description:
Marble Arch Cave is defined as the cave passages which are directly accessible from the various entrances in the immediate area of the main resurgence.
Entrance Series
There are four natural entrances which give access to the Entrance Passages, Grand Gallery, Lower Cradle and the Skreen Hill Passages of Marble Arch.
Lower Cradle, The Grand Gallery and the Entrance Passages
The Sruh Croppa and Aghinrawn Rivers meet underground, somewhere downstream of John Thomas' Hole and Upper Cradle Cave. The combined water from the Aghinrawn and Sruh Croppa Rivers enters the main chamber of Lower Cradle Hole
Lower Cradle: Main Chamber.
from a large sump on the western side of the chamber. There is a complex maze of abandoned high level phreatic passages above the entrance to Lower Cradle from Cradle Hole.
Lower Cradle: fossil phreatic tube, Upper Gallery.

Lower Cradle: Upper Gallery.

Lower Cradle: fossil phreatic tube, Upper Gallery.
The stream flows for 50m through a large north oriented 10m by 10m passage, with extensive clastic sediment banks including some grey laminated muds.
Lower Cradle: sediments in Main Chamber.
At this point the roof and floor of the passage drop rapidly and the passage trends E-W for 50m (the Ducks).
Lower Cradle: entering the Ducks, Main Chamber.
At the end of this E-W section the passage again trends north, as the stream flows through the Grand Gallery of Marble Arch, similar to the main passage in Lower Cradle. After 140m the Owenbrean River flows from a low sumped passage to the east and meets the combined Aghinrawn - Sruh Croppa Rivers at The Junction from where they flow to Marble Arch rising.
Northeast from the junction are a number of fossil passages, including The Flyover,
Marble Arch: the Fly Over.
from where it is possible to gain access to the downstream part of the Skreen Hill passages. Between The Junction and the rising the river flows across two large karst windows, The Wet Entrance,
Marble Arch: the Wet Entrance, collapsed doline and Show Cave entrance.
currently the natural entrance used as part of the tourist route within the cave, and another collapse doline just downstream. The other entrances to the system are located in the collapse dolines in the area of the resurgence and a rift adjacent to the path from the tourist building to the cave entrance.
In the area of the resurgence there are a large number of collapse dolines and the river rises at the base of a large limestone cliff with extensive breakdown. The Marble Arch is a natural bridge which has resulted from breakdown of cave passage between the arch and the resurgence.
The Marble Arch.
Skreen Hill Passages
The Skreen Hill passages of Marble Arch carry the underground course of the Owenbrean River. The Owenbrean enters Marble Arch Caves at Vicker's Choke, an extensive boulder choke associated with the Pollnagollum collapse doline. From here the stream flows through Skreen Hill 3 passage, a large fault controlled passage with extensive clastic and calcite speleothem deposits.
Marble Arch: flowstone and stalactites, Skreen Hill Three.

Marble Arch: flowstone and stalactites, Skreen Hill Three.

Marble Arch: column, Skreen Hill Three.

Marble Arch: stalagmites, Skreen Hill Three.

Marble Arch: pondulites on stalactites, Skreen Hill Three.

Marble Arch: etched calcite curtain, Skreen Hill Three.

Marble Arch: speleothems in Vickers Choke inlet, Skreen Hill Three.
After 640m the stream enters a 25m long sump before flowing through Skreen Hill 2, approximately 200m of large stream passage similar to Skreen Hill 3. There are a number of well developed calcite formations including a large canopy and extensive coarse, manganese oxide cemented clastic deposits in this passage.
Marble Arch: stalactites and flowstone, Skreen Hill Two.

Marble Arch: flowstone canopy, Skreen Hill Two.
The stream again sumps at the end of Skreen Hill 2, before reaching Skreen Hill 1.
Marble Arch: curtain, Skreen Hill One.

Marble Arch: stalactites, Skreen Hill One.

Marble Arch: speleothems, Skreen Hill One.

Marble Arch: gour pools and stalagmites, Skreen Hill One.

Marble Arch: helictite, Skreen Hill One.
Skreen Hill 1 is a large stream passage, although at the Moses Walk there is a marked lowering of the passage roof due to the presence of a 0.3m shale band within the mudbank limestones. The roof of Skreen Hill 1 is capped by a shale band along much of the passage, possibly due to collapse as a result of the structural weakness of the shale. Where the roof is not capped by the shale, the primary phreatic features, including good exposures of phreatic full and half-tubes, are preserved.
Marble Arch: fossil phreatic passage near Pool Chamber.
Of particular note in Skreen Hill 1 are wide notches cut into the passage sides, approximately 1m above normal flow levels. At the end of Skreen Hill 1 the Owenbrean River flows into a short sumped section, emerging just upstream from The Junction. A large sediment bank at the exit of Lake 1 (at the Moses Walk) has been sampled and analysed for palynology, indicating that the upper 0.5m of this bank was deposited during flood conditions between 7,500 BP and 3,500 BP (Jones & McKeever, 1987). The base of a stalagmite at the tourist entrance, which was damaged during construction of this entrance, has been dated at 76,367 ± 1,015yrs (Dr. F. McDermott, UCD pers. comm.). Skreen Hill Bypass This is a series of abandoned passages which bypass the sump between Skreen Hill 1 and Skreen Hill 2. Proceeding downstream from the Skreen Hill 3 Sump, a 2m by 5m abandoned passage on the right leads eventually to Skreen Hill 1. This passage can be followed for 150m to a boulder collapse which blocks the immediate way on. Climbing up gives access to an ascending canyon passage with a well developed phreatic tube (Crab Passage). At the top of Crab Passage a small chamber is entered. Climbing down through boulders leads to a short section of passage which enters Skreen Hill 1. Legnabrocky Way A small tributary stream enters Skreen Hill 2 at the sump connecting with Skreen Hill 1. This stream can be followed to a chamber with breakdown where the stream flows from a low slot, The Wet Wiggle. This leads to a low (1m high) passage with a cobble floor (Knee Breaker Passage). The passage progressively enlarges in size and eventually reaches up to 30m in height and 10m in width. There are extensive breakdown deposits and large quantities of clastic and calcite deposits including large quantities of straw stalactites and many other excellent speleothems.
Marble Arch: straw stalactite, Legnabrocky Way.
At the end of the passage approximately 4m of well laminated sands, silts and carbonate muds are exposed.
Marble Arch: sediments, Legnabrocky Way.
Legnabrocky way, although only carrying a small stream, is the largest passage in the Marble Arch System.
Importance:
 
Interpretation:
 
Conclusions:
 
Notes:

The Marble Arch Cave System is the main feature of the Marble Arch Karst of the Marlbank-Cuilcagh Mountain Region. For general information on the features and systems of the Marble Arch Karst, including this one, and a reference list, see site description 'Marlbank-Cuilcagh Mountain Region; Marble Arch Karst'.

Keywords
Minerals:Calcite
Rocks:Limestone, Shale
FossilGroups:No data
Fossil List:
Products:
Structures:fault, rift
Relations:No Data
Geomorph:breakdown, cave, clastic sediments, doline, pollen analysis, speleothem, straw, sump
Paleoenv:
NonGeol: 
Measurements
Length:No dataWidth:No dataHeight:No data
Depth:No dataArea:No data  
Access
Approach:Not entered
Restrictions:Not entered
Planning: 
Management: 
Development: 
Threats: 
Uses
Uses:Not entered
Potential:Not entered
Educ. Level:Not entered
References

Williams, P. W. 1970: Limestone morphology in Ireland. In Irish Geographical Studies, pp.105-124 Queens University of Belfast,

Map(s):

None entered

Map No:None entered
Rec Type ESCR report Recorder:  
Enterer: Doughty, P.J.
Updates: 17 Jul 2004 / 24 Dec 2003 / 25 FEB 97 / 18 NOV 96 / 17 JAN 96 / 11 JAN 96
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