Foreword
Preface
Acknowledgements
Contents
Contributors
Introduction
1 Organisation
2 Brief Review of the Geology of Western Ireland
3 Practical Matters
3.1 Access to Private Lands
3.2 Road Network
3.3 Location
3.4 Climate
3.5 Safety Considerations
3.6 Country Code
3.7 Tourism
4 Geological Survey Ireland Products
4.1 GSI Maps and Reports
4.2 GSI Tellus Data
4.3 Geoheritage and Site Protection
4.4 GSI Field Guides
5 Useful Organisations
References
The Basement and Dalradian Rocks of the North Mayo Inlier
1 Introduction
2 Annagh Gneiss Complex
2.1 Mullet Gneiss
2.2 Cross Point Gneiss
2.3 Doolough Gneiss and Doolough Granite
2.4 Grenvillian Deformation and Metamorphism
3 Dalradian Supergroup
3.1 Age of the Dalradian Supergroup
3.2 Structure and Metamorphism in the N Mayo Inlier
4 The Clew Bay Complex
5 Excursions
5.1 Description of Localities in the Belmullet Area
5.2 Locality 2.1: Annagh Head (54.24168°, –10.107999°)
5.3 Locality 2.2: Termoncarragh (54.246331°, –10.074065°) to Scotchport (54.255119°, –10.074170°).
5.4 Locality 2.3: Doonamoo: (54.26921°, –10.0761°) and Aughernagalliagh (54.27496°, –10.06978°)
5.5 Locality 2.4: Grampian Group Metasediments (54.287520°, –10.026507°) and Contact with Cross Point Gneiss (54.20858°, –10.08410°)
5.6 Locality 2.5: Cross Point (54.20858°, –10.08410°)
5.7 Locality 2.6: Doolough Gneiss and Peralkaline Granite (54.141467°, -9.9524546°)
5.8 Description of Localities on Achill Island
5.9 Locality 2.7: Keem Bay (53.96957°, –10.19019°)
5.10 Locality 2.8: Rusheen Point (53.96573°, –10.15524°)
5.11 Locality 2.9: Doogort, Boulder Bed Formation (54.01434°, –10.01769°)
5.12 Locality 2.10: Minaun Heights View Point (53.95743°, –10.02723°)
5.13 Locality 2.11: Dooega (53.91795°, –10.01905°)
5.14 Locality 2.12: Ashleam Bay (53.90408°, -9.99333°)
5.15 Locality 2.13: Bunnafahy Conglomerate and Nearby F2 Folding (53.89541°, -9.99889°)
5.16 Locality 2.14: Claggan Bay (53.89290o, -9.99453o) - the Achill Blueschist
5.17 Locality 2.15: Headland South of Claggan Bay to the Winch West of Killeenabausty
5.18 Locality 2.16: Ooghnadarve (53.88495°, -9.98306°)
5.19 Locality 2.17: Carrowgarve (53.88005°, -9.96616°)
5.20 Achillbeg
5.21 Locality 2.18: Trawboderg (53.86450°, -9.94698°)
5.22 Locality 2.19: Trawboderg Pier (53.86144°, -9.94387°)
5.23 Locality 2.20: Southeast Achillbeg (53.85782°, -9.94390°)
5.24 Locality 2.21: Southwest Achillbeg (53.86120°, -9.95670°)
5.25 Locality 2.22: 175 m SSW of Achillbeg School (53.86335°, -9.95179°)
5.26 Locality 2.23: 185 m WSW of Achillbeg School (53.86431°, -9.95350°)
5.27 Locality 2.24: East Side of Dun Kilmore (53.86656°, -9.95848°)
References
The Slishwood Division and Its Relationship with the Dalradian Rocks of the Ox Mountains
1 Introduction
2 Excursions
2.1 Introduction
2.2 Excursion Localities in the Northeast Ox Mountains Inlier
2.3 Excursion Localities in the Lough Derg Inlier
References
The Central Ox Mountains
1 Introduction
2 The Dalradian
3 The Ox Mountains Igneous Complex
4 Structure and Metamorphism
4.1 Structure
4.2 Regional Metamorphism
4.3 Contact Metamorphism
5 The Excursion
5.1 Aim
5.2 Locality 4.1: Cloonkesh (53.893614°, -9.242484°)
5.3 Locality 4.2: Pontoon Bridge (53.986683° -9.198322°)
5.4 Locality 4.3: Callow—Lismoran (53.968781°, -9.031283°)
5.5 Locality 4.4: Cloonygowan (53.961533°, -9.021189°)
5.6 Locality 4.5: Zion Hill (54.100308°, -8.877857°)
5.7 Locality 4.6: Windy Gap (53.954158°, -9.315519°)
References
The Ordovician Arc Roots of Connemara
1 Introduction
2 Geological Outline
2.1 Stratigraphy
2.2 Structure
2.3 The Synorogenic Intrusive Suite
2.4 Metamorphism
2.5 Relative Timing of Magmatism, Metamorphism and Deformation
3 Dating the Magmatism and Metamorphism
3.1 Review of Existing Geochronological Work
3.2 Overall Conclusion and Prospect for Future Improvement
4 Overview: The Evolution of the Connemara Massif
5 The Excursions
5.1 Excursion 1: Dalradian Metamorphism and Structure Across the Mountains. Discovery Series Maps 38, 37 and 44
5.2 Excursion 2: Migmatites and Gneisses Near Maam Cross. Discovery Series Map 45
5.3 Excursion 3: Early Folds and the Older Dalradian Succession at Glencoaghan. Discovery Series Map 44
5.4 Excursion 4: A Tectonically-Emplaced Gabbro at Currywongaun, Letterfrack. Discovery Series Map 37
5.5 Excursion 5: The Mannin Thrust at Mannin Bay. Discovery Sheet 44
References
The Ordovician Fore-Arc and Arc Complex
1 Introduction
2 The Clew Bay and Deer Park Complexes
3 Excursion to the Clew Bay and Deer Park Complexes
3.1 Aim
3.2 Locality 6.1: Lecanvey Foreshore (53.774403°, -9.742747°)
3.3 Locality 6.2: Croagh Patrick, Reek Road (53.774384°, -9.640091°)
3.4 Locality 6.3: Croagh Patrick, Lenacraigaboy (53.769148°, -9.645088°)
4 The South Mayo Trough
4.1 Stratigraphy
4.2 Provenance
4.3 Tectonic History and Structure
5 Excursion to the North Limb of the Mweelrea–Partry Syncline
5.1 Aim
5.2 Locality 6.4: Tully (53.607459°, -9.750636°)
5.3 Locality 6.5: Bundorragha (53.607880°, -9.751577°)
5.4 Locality 6.6: Lettereeragh (53.615318°, -9.751642°)
5.5 Teevnabinnia: Locality 6.7 (53.642504°, -9.746739°)
5.6 Locality 6.8: Clashcame (53.660786°, -9.770517°)
5.7 Locality 6.9: Cushinyen (53.674422°, -9.785051°)
5.8 Additional Locality on This Route from Elsewhere in the Guide
5.9 Locality 6.10: Letterbrock (53.722627°, -9.583785°)
5.10 Locality 6.11: Sheeffry Cliff (53.660219°, -9.640250°)
6 Excursion to the South Limb of the Mweelrea–Partry Syncline and the Volcanic Complexes
6.1 Aim
6.2 Locality 6.12: Currarevagh (53.572419°, -9.600713°)
6.3 Locality 6.13: Cummer (53.576627°, -9.511426°)
6.4 Locality 6.14: Lough Nafooey, East End (53.576627°, -9.511426°)
6.5 Locality 6.15: Lough Nafooey Viewing Platform (53.578585°, -9.503884°)
6.6 Locality 6.16: Glensaul School (53.634384°, -9.428533°)
6.7 Locality 6.17: Drumcoggy
6.8 Locality 6.18: Croaghcrom (53.700554°, -9.435422°)
6.9 Locality 6.19: Bohaun (53.710772°, -9.423749°)
References
The South Connemara Group
1 Introduction
2 Stratigraphy
2.1 Gorumna Formation
2.2 Golam Formation
2.3 Lettermullen Formation
3 Age and Regional Correlations
4 Structure and Tectonic Significance
5 Excursion
5.1 Aim
5.2 Locality 7.1 Lettermullen (53.231890°, –9.746154°)
5.3 Locality 7.2 Lettermullen Western Fore-Shore (53.230572°, –9.757983°)
References
The Silurian of North Galway and South Mayo
1 Silurian
1.1 Killary Harbour–Joyce Country Succession (KHJC)
1.2 Croagh Patrick Succession
1.3 Louisburgh–Clare Island Succession
2 Killary Harbour–Joyce Country Succession
2.1 Aim of Excursion
2.2 Locality 8.1: Derry Bay North (53.597583°, -9.434674°)
2.3 Locality 8.2: Finny Church (53.567923°, -9.487486°)
2.4 Locality 8.3: Kilbride (53.570084°, -9.451363°)
2.5 Locality 8.4: Drin and Bencorragh (53.564764°, -9.493817°)
2.6 Locality 8.5: Owenduff Bridge (53.573714°, -9.794439°)
2.7 Locality 8.6: Lough Fee: (53.592468°, -9.831395°)
2.8 Locality 8.7: Gortnaling (53.598628°, -9.912364°)
2.9 Locality 8.8: Lettergesh Beach: (53.602154°, -9.908356°)
2.10 Locality 8.9: Salrock and Salrock School (53.602185°, -9.857188°)
2.11 Locality 8.10: Glassilaun (53.614860°, -9.874965°)
3 Croagh Patrick Succession
3.1 Aim of Excursion
3.2 Locality 8.11: Derryheagh and Cregganbaun (53.695560°, -9.799678°)
3.3 Locality 8.12: Kilgeever (53.765071°, -9.765410°)
3.4 Locality 8.13: Kilsallagh Upper (53.763179°, -9.705105°)
3.5 Locality 8.14: Emlagh Point (53.744148°, -9.897374°)
4 Louisburgh–Clare Island Succession
4.1 Aim of Excursion
4.2 Locality 8.15: Shivlagh Rocks (53.777794°, -9.796047°)
4.3 Locality 8.16: Cooneen Harbour (53.770229°, -9.830518°)
4.4 Locality 8.17: Clare Island Southeast (53.795999°, -9.957834°)
4.5 Locality 8.18: Clare Island Southwest (53.792903°, -10.018950°)
References
The Late Silurian to Upper Devonian Galway Granite Complex (GGC)
1 Introduction
2 Tectonic Controls on the Generation and Emplacement of the Galway Granite Complex (GGC)
2.1 Magma Generation
2.2 Magma Ascent During the Construction of the GGC
2.3 Magma Emplacement During the Construction of the GGC
3 Contact Metamorphism of the Country Rocks
4 Petrologic and Geochemical Aspects of the GGC
5 The Carna Pluton (Excursions 1 and 2)
5.1 Introduction to the Carna Pluton: The Spatial Distribution of Its Major Granite Types
5.2 Excursion 1: The Central Sector of the Carna Pluton, West of Carna
5.3 Excursion 2: The Northwestern Margin of the Carna Pluton, West of Roundstone
6 The Kilkieran Pluton (Excursions 3 and 4)
6.1 An Introduction to the Kilkieran Pluton: The Spatial Distribution of Its Major Granite Types
6.2 The Granites of Western and Eastern Blocks
6.3 The Granites of the Central Block
6.4 The Emplacement of the Kilkieran Pluton
6.5 Excursion 3: The Northern Contact of the Kilkieran Pluton at Glentrasna
6.6 Excursion 4: The Costelloe to Rossaveel Sector of the Kilkieran Pluton: Costelloe Murvey Granite and the Mingling Mixing Zone Granodiorite
7 The Omey Pluton and Its Thermal Aureole at Fountain Hill Beach, South of Claddaghduff.
7.1 Introduction
7.2 Geological Setting
7.3 Excursion 5: The Omey Pluton and Its Aureole
References
Devonian and Carboniferous
1 Introduction
2 Devonian
2.1 Locality 10.1: Letter (53.853261°, -9.423138°)
2.2 Locality 10.2: Graffa More (53.867401°, -9.360925°)
2.3 Locality 10.3: Croaghmoyle (53.925941°, -9.373238°)
2.4 Locality 10.4: Burren Mountain (53.924538°, -9.339399°)
2.5 Locality 10.5: Kings Hill (53.954232°, -9.315546°)
2.6 Locality 10.6: Tonacrock (54.022820°, -9.292056°)
3 Carboniferous of the Clew Bay Area
3.1 Locality 10.7: Bolinglanna (53.864850°, -9.899847°)
3.2 Locality 10.8: Lough Ard (53.877675°, -9.878718°)
3.3 Locality 10.9: Castlebar (53.882225°, -9.273217°)
3.4 Locality 10.10: Capnagower, Clare Island (53.812515°, -9.949958°)
4 Carboniferous of North Mayo
4.1 Locality 10.11: Ceide (54.308565°, -9.455869°)
4.2 Locality 10.12: Ballycastle Beach (54.294872°, -9.386396°)
4.3 Locality 10.13 Stella Maris (54.301173°, -9.389916°)
4.4 Locality 10.14: Downpatrick Head (54.318659°, -9.345733°)
4.5 Locality 10.15: Kilcummin Head (54.287490°, -9.214534°)
References
The Geology of Western Ireland: A Record of the ‘Birth’ and ‘Death’ of the Iapetus Ocean
1 Introduction
2 Palaeoproterozoic and Mesoproterozoic
3 Neoproterozoic Rock Units
3.1 The Slishwood Division
3.2 The Dalradian
4 The Cambro–Ordovician Rock Units
4.1 Clew Bay Complex
4.2 The Deer Park Complex
4.3 Cambro–Ordovician of South Mayo
5 The Grampian Orogeny
6 The Silurian
7 The Acadian
8 The Fair Head–Clew Bay Line (FCL)
9 Siluro-Devonian Granites
9.1 Devonian and Carboniferous
9.2 Outstanding Problems and Future Research
9.3 Conclusions
References
Data Sources for use in Pre- and Post-trip Exercises
1 Geological Maps
2 Geophysical Data
2.1 GSI Tellus Datasets
2.2 DIAS Gravity Data
2.3 BIRPS Deep Seismic Reflection Profiles
3 Geochemical Data
References
