In the second half of 1892 it suddenly becomes obvious from the journal entries that Thomas has begun a completely new field of geological study, still rooted in the landscape of mid Wales that surrounded his home. It had been some time since he had led any fieldwork expeditions concentrating on the fossils of the Silurian period, a task he had often undertaken in the company of the Cambridge Professor Thomas McKenny Hughes, and on which he had written a paper for the Journal of the Geological Society published in 1879. ‘On the Upper part of the Cambrian (Sedgwick) and Base of the Silurian in North Wales’. Many people still called at his home to view his fossil collection, but the arrival in succession of five children with his second wife Frances make the focus of his attention increasingly domestic during the 1890s.
However, in August 1892 a new interest and body of knowledge suddenly and surreptitiously makes and appearance while he is mentoring two young ladies who with their mother were staying in the area:
20th August: I showed the Misses Nevins the glacial markings at Penygarth in the strophomena expansa zone and also at Gelli Grin. Indeed we were very successful at the latter place. I got a well preserved eye of an Asaphus [trilobite – Ed.] and what very much resembles Cythere aldensis. We all enjoyed the ramble and then Misses Nevins were highly pleased with their fossils, and the scenery. We got home at the dusk.
In transferring his interest from Cambrian and Silurian fossils to the influence of the action of Ice Age on the landscape, Ruddy was turning his attention from a period about 450 million years ago, the Silurian, to only about 1 to 2 million years in the past, a period of intensive study and much debate in the mid and late 19th century, the period of ‘recent’, in geological terms, glaciation. The great geologists Charles Lyell and Roderick Murchison were involved, arguing in effect against theories of the way landscapes were changed and shaped by the action go progressing and retreating glaciers.
In brief, the study which Ruddy began in a small notebook, now very much degraded by time (shown above) was to examine boulders left in the landscape and which were of a different age or rock formation from the underlying rock. and had been picked up or broken off by advancing glaciers, and then deposited some distance away from their origin as the glaciers retreated and deposited mixtures of boulders, smaller rocks and other deposits, including some displaced fossils in the landscape, this deposit known as glacial till.
The study of glaciation had not originally been centred on Wales and the border counties – it had originally been investigated in Scotland, and the contrasting landscape of East Anglia, particularly Norfolk.
As in many other places in Ruddy’s Journal, we become aware of pre-existing friendships and correspondences which are only mentioned at a later date, as on 7th September 1892:
Wednesday the 7th My correspondent, Mr A C Nicholson of Bronderw, Oswestry came to see me. He arrived by the 4.20 fast train. He had tea with us here and then I took him to the fruit room to see the fossils. Although he knew about them by report, he was very much surprised when he saw them spread out. We had a good look at them, and spent the rest of the evening chatting about geology, until suppertime. I went with him to his lodgings at Shopisaf after.
Thursday the 8th Mr. Nicholson went by first train to Llandrillo, then up the Berwyns to get the ash and greenstone rocks. He went over Chlochnant, Carnedd-y-ci, and to the top of Cader Berwyn, then along the ridge to Milltir Gerrig, on the Llangynog road. There I met him at 4:30 o’clock. He was very tired, but was pleased to have got specimens of the rocks on the way. He had long wish to see the same rocks. I showed him the Little Ash on the roadside Milltir Gerrig, then the felstone, and found Orthis alternata and other fossils. I found a Bellerephon in the rubbly shale between the felstone and Little Ash. The species is new to me and of much interest.
Mr Nicholson gave me the altitude above sea level at the well near the felstone on the roadside as 1500 feet. There are freshwater limpets in the rill at that altitude. The altitude at the stone on the boundary, dividing this county from Montgomery, was 1650 feet. We got to my house at about 8:30 o’clock. We thoroughly enjoyed a good feed, and particularly enjoyed a piece of fresh Dee salmon which Sir Henry kindly sent us.
Friday the ninth Mr. Nicholson came over at half past nine and looked over my fossils until dinner time. He had dinner with us, and after dinner I went to show him the Hirnant beds at Bwlch Hannerob and then the Tarannon and Wenlock shales.
After tea we packed his specimens I gave him, also fragments of fossiliferous Silurian rocks which he found in the glacial deposit with marine shells at Gloppa, Oswestry, and which he sent to me some time ago to name for him.
Mr. Nicholson had published a paper ‘ High-Level glacial gravels, Gloppa, Cyrn-y-bwlch, near Oswestry’ in the quarterly journal of the Geological Society in February 1892. His was one of the early investigations into the glacial geology of the Mid Wales and Shropshire area; the paucity of such investigation was noted ten years earlier, in 1882, Walter Keeping, who began his geological career at the Woodwardian museum in Cambridge, predecessor to the Sedgwick, and then became Professor of Natural Science at Aberystwyth, until 1880 when he became Keeper of the Yorkshire Museum, in his article The Glacial Geology of Central Wales in the Geological Magazine.
Gloppa, near Oswestry. Contorted glacial drift, sands and gravels. Contemporary photograph. British Geological Survey website.
Wednesday the 14th I received a handsome book as a gift from Mr Nicholson, entitled “Island Life” by Alfred Russell Wallace. It will be of great service to me as it is up-to-date in scientific research.
Mr. Nicholson’s visit obviously inspired Ruddy to begin in earnest his examination of his local landscape in the light of the new understandings of glaciation and its effects on the landscape.
Saturday the 17th [September 1892] I left here at mid day for the head of the Llangynog Valley. I got to the stone marking the boundary of the counties at 1:50 o’clock. I went to see the little patch of ash rock and could see that it rested conformably on sandy shales. The ash is about 10 feet thick, and is about 40 feet under the limestone outcrop, the same as it is at Gelli Grin. I once found a specimen of the Orthis flabellulum in the shales under the ash in the shales where they are quarried for mending the roads, but I failed to see anything this time. I also searched loads of the shale along the side of the road, but could not find a fossil.
I next crossed over the moor to the old phosphate mine to try and find Arenig boulders on the way or in the bed of the brooks near the mine. I could not find one after I left Brynselwrn ffrith. I found some angular blocks of the local ash, and an abundance of blocks of Denbigh grits; these are evidently from the base of the Wenlock at Bwlch-y-dwr. I found the local ash at the little stream where the old Bala and Llangynog road crossed it. I traced it up the hill towards the county boundary. Neither of these patches of ash are marked on the map.
I also found the upper end of the greenstone near the ash, and followed it down the brook to the road leading to the mine. Most of it keeps crumbling away into course sand all rather fragments. It runs as a dike with a rounded bosses diverging a little from the line. I found a few fossils at the old mine; the only thing of interest being at badly preserved Trochonema triponcata. I found a few specimens of one minute snail; Helix rupestris. The place where I found the Helix is about 1550 feet above sea level.
I next went to see massive shales in the brook some distance lower than the mine. The shales dip towards the bed of the brook and large masses have become detached and lie in the bed of the book like square pieces of masonry. Lower down there is a pretty cascade falling into a deep pool, which is almost shut in by walls of rock. I next crossed over to the little stream where I followed the greenstone again up the bed of the brook. It runs like a dyke with diverging round bosses, and has a sort of false bedding in some places. The dyke is about 15 feet in thickness and crumbles away into course sand and crumbles away into course sand and rotten pieces.
? Site of the Waterfall above
Copyright Eirian Evans, Creative Commons. Waterfall in Coed Llystyn
I have never seen any of the ashes or greenstones in N Wales crumble away in the same as the Trwyn Swch greenstone It is plainly an intrusive mass, and the shales resting upon it are much disturbed at the junction. In one place the greenstone is very hard and compact, and falls away from the rocky wall in square blocks.
I carried off specimens of the greenstone, but failed to find any fossils in the shales all along the ravine. I searched for fossils on the roadside Milltir Gerrig. I found good specimens of Orthis alternata in the usual place, but nothing lower in the beds. I could not get time for beds higher in the series. I left at 6:35 o’clock, and got home at 8:20. I had a beautiful day and much enjoyed it.
Examples of investigations of this new interest continue through the following years of the journal, and A. C. Nicholson visited again in August 1895.
A map of the direction of glacial drift across the British Isles pasted into the front of Ruddy’s notebook.