ESCR - Doonan Quarry, Doraville - Mineralogy

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Summary Full report
Doonan Quarry, Doraville - Mineralogy	Fermanagh

Site number:	532
ESCC:	EA
Locality Type:	Quarry (working)	Status:	ESCR
Grid Reference:	H193566 Centroid
Google maps:	54.45799,-7.70239
County:	Fermanagh	Council area:	Fermanagh & Omagh District Council
Period:	Tertiary, Devonian

Site Description
Doonan Quarry, Doraville, Co.Fermanagh, August 1997: access road.
Highlights:
Zeolites and pyroxenes in pipe vesicles within a Tertiary multiple dyke.
Introduction:
This site has been described by Preston within the Igneous/Tertiary Block (see Key Site 80 - Dora Ville Ridge) (see also Preston, 1967). A long, narrow quarry exposes a 90m-wide, NW-SE trending dolerite dyke which (in this area) intrudes and hornfelses Devonian shaley strata. Of mineralogical interest are dolerite pegmatites containing pyroxenes with internal hourglass structure (Preston, 1966) and zeolite-rich pipe vesicles and zeolitic joint coatings within the dolerite.
Description:
The older parts of the quarry at Drogan are now of little interest as rock surfaces are overgrown or caked with dust. Doonan Quarry, Doraville, Co.Fermanagh, 1997: dyke workings. Recent extraction has been from the NW end of the quarry in Doonan Townland and the quarry owners are cutting a deeper level within the quarry so that extraction is retreating to the SE. Close to the active face, but on the upper (older) part of the quarry, on the NE face is a spectacularly large cylindrical pipe vesicle some 2m in height, filled with a rubbly mass of zeolite and pyroxene crystals. The zeolites are mainly radial sprays of thomsonite with also laumontite and analcime. These form ball-like aggregates enclosing black crystals of pyroxene. The presence of laumontite is unusual as it is a high-temperature zeolite which is scarce in the Tertiary Igneous Province, though it occurs in the Killala dyke in western Ireland and at deep levels in the lava sequences on Mull and in Iceland. During site visits in July 1997 and September 1999, minor amounts of joint-coating zeolites were found in loose blocks of dolerite in the active part of the Doonan quarry. Doonan Quarry, Doraville, Co.Fermanagh: chabazite on joint in dolerite. These included well-formed chabazite (specimen lodged with the Ulster Museum).
Notes:
See also Key Site 80 - Dora Ville Ridge.

Keywords
Minerals:	Analcime, Chabazite, Thomsonite, Zeolites, Laumontite, Pyroxene
Rocks:	Dolerite, Hornfels, Shale
Structures:	dyke, pipe vesicle

Access
Management:
As stated by Preston (in Key Site 80 - Dora Ville Ridge), the quarry should be monitored regularly and new features recorded and sampled if appropriate. Continued quarrying at the deeper level will result in precipitous and inaccessible faces, but it may be possible to maintain access in certain areas.
Uses
Uses:	This site is located in a working quarry.


Record type:	ESCR report	Recorded by:	R. Nawaz and N.R. Moles
Entered by:	E M Porter
Last updated:	07 MAY 68

Enlander, I., Dempster, M. & Doughty, P., 2026. Doonan Quarry, Doraville - Mineralogy, County Fermanagh, site details. [In] Earth Science Conservation Review.
https://www.habitas.org.uk/escr/site.php?item=532. Accessed on 2026-11-06.

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