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Our Next Lecture. Tuesday 9th November 2021 at 7pm on Zoom.
Metamorphic rocks in the northeastern Ox Mountains inlier .
Given by Professor Ian Sanders of TCD
Unusual metamorphic rocks, unique in these islands and rare in the world, are preserved in the northeastern limb of the Ox Mountains inlier, which is a narrow strip of old rock trending diagonally across the country to the SE of Sligo town and bordered on both sides by younger Carboniferous limestone. The rocks are derived mainly from basaltic and sedimentary parents, and they reached temperatures approaching 900°C and depths of between 30 and 40 km, probably about 470 million years ago during the early Ordovician period.
In the talk I will describe a suite of these rocks which I collected from an area south of Lough Gill. I will discuss the kinds of rock they were originally, before becoming metamorphosed. I will ask how the enormous depths and temperatures they are believed to have experienced were estimated and will show evidence for how the pressure and temperature conditions changed through time. I will ask how the age of the metamorphism has been inferred, and I will conclude by speculating briefly on how the story of these rocks relates to our general understanding of how plate-tectonic processes affected rocks in the west and northwest of Ireland during the early Ordovician.
The link to the lecture may be requested by emailing galwaygeology@gmail.com
This will be preceded at 6.15 by our AGM. All members are encouraged to attend this to have your say in the running of the association.
Metamorphic rocks in the northeastern Ox Mountains inlier .
Given by Professor Ian Sanders of TCD
Unusual metamorphic rocks, unique in these islands and rare in the world, are preserved in the northeastern limb of the Ox Mountains inlier, which is a narrow strip of old rock trending diagonally across the country to the SE of Sligo town and bordered on both sides by younger Carboniferous limestone. The rocks are derived mainly from basaltic and sedimentary parents, and they reached temperatures approaching 900°C and depths of between 30 and 40 km, probably about 470 million years ago during the early Ordovician period.
In the talk I will describe a suite of these rocks which I collected from an area south of Lough Gill. I will discuss the kinds of rock they were originally, before becoming metamorphosed. I will ask how the enormous depths and temperatures they are believed to have experienced were estimated and will show evidence for how the pressure and temperature conditions changed through time. I will ask how the age of the metamorphism has been inferred, and I will conclude by speculating briefly on how the story of these rocks relates to our general understanding of how plate-tectonic processes affected rocks in the west and northwest of Ireland during the early Ordovician.
The link to the lecture may be requested by emailing galwaygeology@gmail.com
This will be preceded at 6.15 by our AGM. All members are encouraged to attend this to have your say in the running of the association.
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GGA Talk: Remote Sensing of Soft-Rock Coastal Erosion Dynamics, Silverstrand Beach
This talk by Rachel Smith (2019 MSc in Coastal and Marine in Environments, NUI Galway) will focus on the use of remote sensing methods to characterize the spatial-temporal morphology of soft-rock cliff erosion at the glacial depositional feature, Derryloney Drumlin, at Silverstrand Beach near Galway. Rachel will outline the geological setting and characteristics of the drumlin that make it an ideal target for ongoing erosion monitoring and discuss the success of applied remote sensing at the site. The project was able to capture geomorphological data suitable for estimating eroded sediment volumes, cliff-top retreat rates, and the formation and destruction of geomorphic features on the beach. Photo credit: Rachel Smith (2021) |
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Dr Sadhbh Baxter of NUI Galway is giving a talk to the Belfast Geologists Society on Monday, 17th May at 7:30pm. The title is 'Western Wonders: a virtual geology trip in the west of Ireland' The login is:-Meeting ID: 864 1223 2517 Passcode: 0RSTR4 |
Our next Zoom lecture will take place at 7pm on Tuesday, 18th May. Dr. Tiernan Henry, Lecturer in Hydrology and Head of Earth and Ocean Sciences, NUI, Galway will give a talk entitled 'The Gowlaun: The Burren's Secret River.'
Look on maps of County Clare, and you'll see the Aille River marked, rising east of Lisdoonvarna, running through the Spa Well and on to the sea at Doolin. The only problem is when you go to the Spa Wells there are two rivers meeting - the Aille, which is by far the smaller of the two in terms of water volume, and the Gowlaun. But follow the Gowlaun on a map and it's only marked as a short stream. It rises at St Brendan's Well, where water can be seen gushing up from a fissure in the limestone. Follow this, and it takes you north and east to the valley between Slieve Elva and Cullaun, where the water rises at Killeany, draining from the caves that run along the flanks of the hills.
Data collected over recent months suggests that rainfall on the hills has an instant impact on the water levels in the caves, but there's a lag of four to five hours before the water starts rising at Killeany. Enough rain, and a turlough forms (in a matter of a couple of hours) below the rising. This water drains to the south, rising briefly then back underground before rising three to four hours later at St Brendan's Well.
And when the rain stops, the springs still run, because the upland peat continues to drain water. The system is built on two broad lithologies: the pure bedded limestone and the younger shales and sandstones. The system is enhanced by the peat on the uplands, retaining the water for weeks and slowly releasing it, making the springs perennial. We're not suggesting a name change, but the Aille is really the Gowlaun...
Click on the link below to join the meeting.
Time: May 18, 2021 at 7pm
Join Zoom Meeting, Meeting ID: 829 3910 5105
https://us02web.zoom.us/j/82939105105
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Look on maps of County Clare, and you'll see the Aille River marked, rising east of Lisdoonvarna, running through the Spa Well and on to the sea at Doolin. The only problem is when you go to the Spa Wells there are two rivers meeting - the Aille, which is by far the smaller of the two in terms of water volume, and the Gowlaun. But follow the Gowlaun on a map and it's only marked as a short stream. It rises at St Brendan's Well, where water can be seen gushing up from a fissure in the limestone. Follow this, and it takes you north and east to the valley between Slieve Elva and Cullaun, where the water rises at Killeany, draining from the caves that run along the flanks of the hills.
Data collected over recent months suggests that rainfall on the hills has an instant impact on the water levels in the caves, but there's a lag of four to five hours before the water starts rising at Killeany. Enough rain, and a turlough forms (in a matter of a couple of hours) below the rising. This water drains to the south, rising briefly then back underground before rising three to four hours later at St Brendan's Well.
And when the rain stops, the springs still run, because the upland peat continues to drain water. The system is built on two broad lithologies: the pure bedded limestone and the younger shales and sandstones. The system is enhanced by the peat on the uplands, retaining the water for weeks and slowly releasing it, making the springs perennial. We're not suggesting a name change, but the Aille is really the Gowlaun...
Click on the link below to join the meeting.
Time: May 18, 2021 at 7pm
Join Zoom Meeting, Meeting ID: 829 3910 5105
https://us02web.zoom.us/j/82939105105
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And once again we have been invited to join the CGA for their next lecture.
It will be by Dr. Richard Unitt, University College Cork on Wed. May 19th at 8pm.
It is entitled “Larkin's Quarry, Connemara - The Discovery of a World-Class Mineral Locality in Ireland”
A very recent discovery has put Larkin’s Quarry on the map!
All are welcome. To register for the Zoom meeting please email b.higgs@ucc.ie
It will be by Dr. Richard Unitt, University College Cork on Wed. May 19th at 8pm.
It is entitled “Larkin's Quarry, Connemara - The Discovery of a World-Class Mineral Locality in Ireland”
A very recent discovery has put Larkin’s Quarry on the map!
All are welcome. To register for the Zoom meeting please email b.higgs@ucc.ie
The Cork Geology Association will host a lecture on Wednesday 28th April at 8pm.
Dr. Peadar McArdle, former Director of the Geological Survey, Ireland, will give a talk on
“Thomas Weaver (1773-1855): Ireland's first economic geologist?”
Abstract: Before he was thirty, Thomas Weaver was a successful engineer and geologist who was managing Avoca's main copper mine as well as the nearby Woodenbridge gold workings. Born in Gloucester, he trained in Freiberg's mining academy, where the celebrated Abraham Werner was professor of geology. He would have been easily accepted as a member of Wicklow's Protestant Ascendancy. In the unsettled political climate of the 1790s he was a senior officer in the Cronebane Yeomanry and helped to suppress the 1798 rebellion. He carried out extensive geological mapping. His 1819 map and publication covered large areas of east and southeast Ireland, an enormous endeavour. It was much praised for its insights, including on the origin of Avoca's copper ore. In the 1820s he worked on many prospects around Ireland, including the Ross Island mine at Killarney. Around this time he mapped a large part of the south of Ireland, but his subsequent publication met with considerable criticism. He lived through an extraordinary revolution in geological ideas, during which he often took a dissenting role. His many contributions will be discussed.
All are welcome. Please register by emailing b.higgs@ucc.ie
Dr. Peadar McArdle, former Director of the Geological Survey, Ireland, will give a talk on
“Thomas Weaver (1773-1855): Ireland's first economic geologist?”
Abstract: Before he was thirty, Thomas Weaver was a successful engineer and geologist who was managing Avoca's main copper mine as well as the nearby Woodenbridge gold workings. Born in Gloucester, he trained in Freiberg's mining academy, where the celebrated Abraham Werner was professor of geology. He would have been easily accepted as a member of Wicklow's Protestant Ascendancy. In the unsettled political climate of the 1790s he was a senior officer in the Cronebane Yeomanry and helped to suppress the 1798 rebellion. He carried out extensive geological mapping. His 1819 map and publication covered large areas of east and southeast Ireland, an enormous endeavour. It was much praised for its insights, including on the origin of Avoca's copper ore. In the 1820s he worked on many prospects around Ireland, including the Ross Island mine at Killarney. Around this time he mapped a large part of the south of Ireland, but his subsequent publication met with considerable criticism. He lived through an extraordinary revolution in geological ideas, during which he often took a dissenting role. His many contributions will be discussed.
All are welcome. Please register by emailing b.higgs@ucc.ie
The next Tuesday lecture is on the 20th April at 8pm. and is entitled:-
"The Geology of the Clare Basin – constraining sediment sources, basin fill and palaeogeography."
Dr Martin Nauton-Fourteu - Earth and Ocean Sciences, NUI Galway
"The Geology of the Clare Basin – constraining sediment sources, basin fill and palaeogeography."
Dr Martin Nauton-Fourteu - Earth and Ocean Sciences, NUI Galway
"The Clare Basin of western Ireland consists of remarkable mid-Carboniferous sedimentation from deep-water to shallow marine settings. Outcrops along the coast of counties Clare and Kerry attract scientists from around the world to study these sedimentary deposits. Additionally, basin fill history has been hotly debated over the past decades with contrasting models. This talk will be composed of a review of the sedimentology of the Clare Basin, combined with recently acquired cutting-edge sedimentary provenance data, to shed light on the Clare Basin fill and Carboniferous paleogeography in Ireland."
It will be hosted on Zoom in association with the Irish and the Cork Geological Associations and the link is:-
https://us02web.zoom.us/j/84680290833 Meeting ID: 846 8029 0833
It will be hosted on Zoom in association with the Irish and the Cork Geological Associations and the link is:-
https://us02web.zoom.us/j/84680290833 Meeting ID: 846 8029 0833
Link: https://us02web.zoom.us/j/81015147840
It would be appreciated if you’d email: galwaygeology@gmail.com and let Hon. Sec. know that you are participating. |
Galway Geological Association (GGA) is please to announce a Zoom talk this evening at 7 p.m. (Tuesday, 23rd March.
Speaker: Dr. Bettie Higgs, Cork Geological Association Title of talk: Understanding the Earth: the work of Marie Tharp In 1912 Alfred Wegener first published his ideas on continental drift. He refined those ideas over the next 20 years, but continued to face resistance and ridicule from much of the scientific community. Why was this? When we look back on his ideas now they look remarkably far-sighted. This talk will tell the story of scientific egos and misplaced loyalties, and of how Wegener’s hypothesis eventually came to be accepted. It will explain the detailed and painstaking work carried out by another geoscientist, Marie Tharp, which when revealed to the scientific world was a turning point in the story and key to the development of the theory we now know as Plate Tectonics. |
Also today (Tuesday, 23rd March; at 2 pm): Eoin Moran, Director of Met Éireann gives a Z talk titled
Predicting the weather and future climate scenarios
Zoom link is https://nuigalway-ie.zoom.us/j/97109013365
Further details at: https://twitter.com/SIAM_NUIGalway/status/1372922866438656002
Predicting the weather and future climate scenarios
Zoom link is https://nuigalway-ie.zoom.us/j/97109013365
Further details at: https://twitter.com/SIAM_NUIGalway/status/1372922866438656002
This will be followed on Tuesday 20th of April 19:00 by a talk presented by Martin Nauton-Fouteu. Martin has recently submitted his PhD thesis on the Geology of the
Clare Basin and led a GGA field trip to The Bridges of Ross, Co. Clare in 2019. Again this will be on Zoom.
Clare Basin and led a GGA field trip to The Bridges of Ross, Co. Clare in 2019. Again this will be on Zoom.
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Our first event of the new year will be held on 20th January at 19:00 via Zoom.
Three Irish geological associations (CGA, IGA and GGA) have joined together to host a Zoom lecture by Dr. Chris Standish, from the University of Southampton, titled “An Irish El Dorado? Searching for the Source of Chalcolithic and Early Bronze Age Gold” To register email- irishgeologicalassociation@gmail.com before 20th January. |
The first use of gold in Britain and Ireland occurred during the Chalcolithic and Bronze ages; it was used to produce neck ornaments, bracelets, cups and cape fasteners. The source location(s) of this gold must be understood if we are to understand why this material was first considered valuable and so understand the patterns of its procurement, trade and exchange. There has been a long-held belief, but no proof, that this source was located in Ireland. Geochemical provenance studies offer a means by which the source(s) of metals can be traced. Dr. Standish will discuss both past and current attempts to source Britain and Ireland’s earliest gold. Probable source areas will be proposed, and the implications of these on the perceived value of gold in early metalworking communities will be explored.
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Galway Geological Association Lecture
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Michael O’Connell
Palaeoenvironmental Research Unit, NUI Galway Upland landscapes with particular reference to western Ireland: charting the course of change since the glaciers retreated. Date: Tuesday, 8th December 2020 Time: 20:00 Via Zoom. For link email: galwaygeology@gmail.com (free to GGA members; €10 annual subscription) |
Irish uplands are invariably treeless, usually covered by bog and heath, and support extensive grazing, often but not exclusively, by sheep. In this lecture, the history of how these important Irish landscapes evolved and the factors involved in bringing about the many changes that have shaped them — including geology, natural processes, climate and climate change, and human impact — will be discussed. The focus will be on the Galway/Mayo region but uplands elsewhere, including the Iveragh peninsula, Co. Kerry, will be considered.
Hand-coloured, engraved print depicting a pattern (pilgrimage) in the early nineteenth century at Mám Éan (view from the southern approach; Griffiths and Bartlett, 1835)
Hand-coloured, engraved print depicting a pattern (pilgrimage) in the early nineteenth century at Mám Éan (view from the southern approach; Griffiths and Bartlett, 1835)
Dr Matthew Parkes
Ní bheidh a leithéid arís ann. www.gsi.ie/en-ie/events-and-news/news/Pages. /Death-of-a-colleague---Matthew-Parkes.aspx |
The extended Geological Survey Ireland family was shocked and saddened to learn of the sudden death of one of our own, Matthew Parkes, over the weekend. Dr Matthew Parkes worked for many years in Geological Survey Ireland before moving to the National Museum of Ireland. He retained Scientific Visitor status at Geological Survey Ireland and maintained his connection with us through his work on the County Geological Audits, the Irish Fossil collection and database, and through his annual involvement in the BT Young Scientist exhibition. He encouraged education and outreach collaboration between Geological Survey Ireland and the National Museum of Ireland and their current project, an exhibition on Irish Geoscience, co-curated by Matthew, to mark the 175th anniversary of the establishment of Geological Survey Ireland will open at the National Museum of Ireland - Collins Barracks, Dublin, after current COVID-19 restrictions are lifted. Our sincere sympathy is with his family in Ireland and Britain, his geoscience and museum colleagues around the world and everyone saddened by his sudden death. |
Field trip to Mám Éan, Maumturk Mountain Range, Connemara; Saturday, 26th September 2020
Leader: Professor Michael O’Connell
GGA was fortunate, from the point of view of weather (couldn’t be better) and Covid-19 restrictions (level 3; re-introduction of level 5 had not yet appeared even on the horizon), that this one-day field trip happened at all! Bright and early on the Saturday morning at the end of September, eleven GGA members made their way to Maam Valley and the assembly point, namely the car park sought of Corr. Here the Western Way leads to Mám Éan pass. Nobody felt under any pressure as the way up (only 150 m ascent) was at a slow pace with many stops for observations and discussions, and enjoying magnificent views across the lowlands and the uplands of north Connemara and Joyce Country beyond. The group tackled topics as diverse as the Dalradian, Ordovician and Quaternary periods, including the Lateglacial climatic oscillation, the Holocene and the Anthropocene, and indeed more besides.
At the pass, schist outcrops overlooking the corrie lake provided the perfect spot for lunch and further open-air discussions in scenic surrounds. Having paid respects to St Patrick and thanking him for making it this far into Connemara, the group proceeded to the Recess side of the pass. From here, most of Connemara was on view, with the Twelve Bens to the west, and to the south Lissoughter, Cashel Hill and Errisbeg and the Atlantic coastline beyond. The opportunity was also taken to discuss the evidence for local glaciation and all that entailed for local landscape development.
For photographs, etc. see Twitter thread at https://twitter.com/MOConnell07/status/1310626231289872385
Also see the maiden tweet in the brand new GGA Twitter account @GalwayGga https://twitter.com/GalwayGga/status/1316486093177597954
Drawing of specimen of Phanerotinus cristatus discovered in 2017 in the town of Tuam, Co. Galway by GGA member Brendan Arrigan. The drawing is by Jonathan Skellorn, former Chairperson of the GGA. This fossil of exceptional quality is one of about fifteen such that have been discovered to date worldwide. They all relate to the Carboniferous Period, ca. 340 million years ago. www.gsi.ie/en-ie/events-and-news/events/Pages/Unveiling_of_fossil_Phanerotinus_Cristatus.aspx
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GGA member Brendan Arrigan made the discovery of his life when he chanced upon a splendid specimen of our emblem, Phanerotinus cristatus, embedded in a wall near Tuam. He found both the fossil and the counterplate, a rare occurence. After consultations with NUI Galway geologists and the National Museum it has been recovered for safe keeping and study.
Worldwide, only 15 of these unusually large fossils have ever been discovered to date, and they are only to be found in a band of limestone stretching between Ireland and Britain. Phanerotinus cristatus was a gigantic snail with spiny flanges around the outside. It lived on the sea floor at a time when Ireland was situated close to the equator and covered by a warm tropical sea.
An unveiling will take place at Tuam Library on Monday 30th September at 2pm by Cllr. Jimmy McClearn, Cathaoirleach of the county of Galway and Seán Canny TD, Minister of State Community Development, Natural Resources & Digital Development. The ceremony will be open to the public and will include a welcome from Koen Verbruggen, Director of Geological Survey Ireland, short talks by Brendan Arrigan about finding and rescuing the fossil, and by Matthew Parkes, geological curator in the Natural History Museum, putting the find into the context of a Geological Heritage Audit of County Galway. The fossil will be placed at Galway County Council Office, High Street, Tuam on public display in Tuam for a period of time and also at a branch of the National Museum of Ireland in Dublin.
Worldwide, only 15 of these unusually large fossils have ever been discovered to date, and they are only to be found in a band of limestone stretching between Ireland and Britain. Phanerotinus cristatus was a gigantic snail with spiny flanges around the outside. It lived on the sea floor at a time when Ireland was situated close to the equator and covered by a warm tropical sea.
An unveiling will take place at Tuam Library on Monday 30th September at 2pm by Cllr. Jimmy McClearn, Cathaoirleach of the county of Galway and Seán Canny TD, Minister of State Community Development, Natural Resources & Digital Development. The ceremony will be open to the public and will include a welcome from Koen Verbruggen, Director of Geological Survey Ireland, short talks by Brendan Arrigan about finding and rescuing the fossil, and by Matthew Parkes, geological curator in the Natural History Museum, putting the find into the context of a Geological Heritage Audit of County Galway. The fossil will be placed at Galway County Council Office, High Street, Tuam on public display in Tuam for a period of time and also at a branch of the National Museum of Ireland in Dublin.
The GGA field trip to South County Clare, 27th April, 2019
Photos courtesy of Prof. Michael O'Connell.
There is a paper from the journal Sedimentology describing the features to be seen at the Ross site that we visited. Thanks to Martin for this. If you would like to get a PDF of it, send an email request to galwaygeology@gmail.com. (use the 'contact us' form)
There is also a page on the web site of the Society for Sedimentary Geology (SEPM) devoted to the Gull Island Formation with many captioned photos including some of the things we were unable to see due to the tide and weather conditions.
http://www.sepmstrata.org/page.aspx?&pageid=472&6
Unfortunately, this event is fully booked.
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