ESCR - Lindsay's Leap, Mourne Mountains

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Summary Full report
Lindsay's Leap, Mourne Mountains	Down

Site number:	541
ESCC:	ED
Locality Type:	Quarry (disused)	Status:	ASSI
Grid Reference:	J371291 Approximate
Google maps:	54.19299,-5.89947
County:	Down	Council area:	Newry, Mourne & Down District Council
Period:	Tertiary
Stages:	Eocene, Palaeocene
Lithostrat:	Granite, Mourne Mountains Granites

Site Description
Lindsay’s Leap, Mourne Mountains, Co.Down, May 1997.
Highlights:
Granite with greisen veins and occasional drusy cavities containing crystals of smoky quartz, feldspars, biotite, stilbite and fluorite.
Introduction:
Lindsay’s Leap, Mourne Mountains, Co.Down, May 1997: quarry. The granite quarries at Lindsay’s Leap are on the NE side of Thomas’s Mountain above Newcastle. The occurrence of replacement (greisen) veins at this site is described by Dr. J. Preston in Key Site 1103 - Mournes - Lindsay’s Leap [Igneous/Tertiary Block]. This is the best and most accessible occurrence of such veins in the Mourne Mountains.
Description:
The veins are dark green to black in colour, range from a few millimetres to several centimetres in width, and mainly comprise mica and chlorite which has replaced minerals in the pre-existing granite. Occasionally the veins have a narrow central seam of topaz and chlorite, or of quartz, and have cavities containing stilbite. Of additional interest is the occasional occurrence of drusy cavities in the granite within the most recently worked quarry (the easternmost of the group at Lindsay’s Leap). Lindsay’s Leap, Mourne Mountains, Co.Down, May 1997: quartz, feldspar and stilbite in druse in granite. Although drusy cavities are much less abundant here than at The Diamond Rocks, they can reach larger dimensions (up to 15cm across) and may contain spectacular, 1-2cm size crystals of dark brown smoky quartz, white orthoclase and pale brown stilbite. Stilbite has usually crystallized later than the other minerals and often coats them. Green fluorite and colourless topaz occur less commonly. Cavities can be lined with only one mineral (e.g. quartz, orthoclase, stilbite) or may display a zonal arrangement whereby different minerals predominate in different parts of the same cavity. Pipe-like cavities have been observed, similar to pipe amygdales in lavas, indicating upward migration of pockets of fluid in the congealing magma.
Notes:
See also Key Site 1103 - Mournes - Lindsay's Leap.

Keywords
Minerals:	Biotite, Chlorite, Fluorite, Quartz, Stilbite, Topaz
Rocks:	Granite, Greisen
Structures:	drusy, mineral vein, vugh

Access
Management:
Quarrying activity has recently (1999) ceased at this site but abundant spoil material remains. This should be retained and not obscured to maintain the availability of specimen material.


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. Lindsay's Leap, Mourne Mountains, County Down, site details. [In] Earth Science Conservation Review.
https://www.habitas.org.uk/escr/site.php?item=541. Accessed on 2026-11-06.

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