Longford-Roscommon Sheet 12

            1:100,000 series index

Area covered by the Map and Booklet

Area covered by Map


Booklet Contents

  • INTRODUCTION
    • Time
    • Plate tectonic theory
    • Reading the geological map
    • Viewing the rocks
    • Rocks: The foundation of the Longford-Roscommon landscape
    • A BRIEF GEOLOGICAL HISTORY OF LONGFORD-ROSCOMMON
      • An ancient ocean
      • Mountain building and granites
      • A desert
      • A tropical sea
      • Deep freeze
          • MINERAL RESOURCES
            • Metallic Mineral Deposits
            • Coal Deposits
            • Industrial Minerals
                • HYDROGEOLOGY
                  • Regionally important aquifers
                  • Locally important aquifers
                  • Poor aquifers
                      • THE LOWER PALAEOZOIC ROCKS
                        • Introduction
                        • Northern Belt
                            • TRACT 2
                            • TRACT 3
                            • PALAEOENVIRONMENTAL INTERPRETATION: STROKESTOWN AND GOWNA GROUPS
                              • Central Belt
                            • TRACT 4A
                            • TRACT 4B
                            • TRACT 5
                            • TRACT 7
                              • Lower Palaeozoic Structural Geology
                            • THE NORTHERN BELT
                            • THE ORLOCK BRIDGE FAULT
                            • CENTRAL BELT: TRACT 4
                              • Lower Palaeozoic plate tectonic environment
                              • Metamorphism
                                  • THE DEVONIAN ROCKS
                                  • THE CARBONIFEROUS ROCKS
                                    • Early Carboniferous Clastic successions
                                    • Undifferentiated "Basal Clastics"
                                    • Courceyan (Tournaisian) Succession
                                    • Late Tournaisian - Visean Shelf Succession - Northwest
                                    • Visean shelf succession - Northwest
                                    • Visean shelf succession - East
                                    • Visean basinal succession
                                    • Sedimentology and palaeogeography of Courceyan rocks
                                    • Sedimentology and palaeogeography of Visean rocks
                                    • Carboniferous volcanic rocks
                                    • Structural Geology of Carboniferous sequences
                                        • IGNEOUS ROCKS
                                          • Caledonian igneous intrusions
                                          • Carboniferous igneous intrusions
                                          • Tertiary igneous intrusions
                                              • REFERENCES AND ADDITIONAL READING LIST
                                              • KEY LOCALITIES
                                              • APPENDIX 1 & 2

                                                  •  Two Plates from the Booklet


                                                    Oakport Limestone

                                                    Thick, massive beds of The Oakport Limestone Formation,  overlain by well-bedded strata of the Ballymore Limestone Formation. The contact
                                                    is marked by the irregular surface near the bottom of the face, Keeloges (Boyle) Quarry, Co. Roscommon.

                                                    Photo by Ian Somerville.










                                                    Lucan FormationThinly bedded limestones and shales of The
                                                    Derravaragh Cherts (Lucan Formation), Mullingar by-pass.

                                                    Photo by C. McDermot