Saturday, 17 December 2022

Ken O'Hara-Dhand in the 21st Century: an appreciation

Ken O'Hara-Dhand.  K is our hero; not living in Prague, he inhabits Middle England; Nottingham and Leicester and environs. Not a youngish office worker, a mature geoscientist, nominally retired (in 2001 he was 65) but actually entering his most productive period. This is a very subjective appreciation; one persons point of view. An appreciation essentially of the last part of Ken's life- the loessic years considered; its a 21st Century view, the final tranche of the 1936-2020 span- adventures in loess world.


NTU.  In the late nineteen nineties Dr Mike Rosenbaum left Imperial College and moved to Nottingham Trent University as Professor of Geotechnical Engineering. His job was to develop research programmes in engineering geology and ground engineering. Ken had been working with Dr R at Imperial and eventually drifted over to NTU to continue the association; he joined the geotechnical team at NTU. On 29 September 2001 Ken gave a seminar in the Civil Engineering Department, very few records of this event remain but it was recorded that he mentioned loess and Greens functions (which relate to Fourier analysis and Fourier transformations - of which more later) Loess was mentioned, the fateful word was uttered.

Dr Raj Kumar.  Raj came from India to work at NTU as a visiting research fellow. He arrived in September 2002 and he and Ken set about investigating the formation of quartz silt using a model glacier system which they developed.  Actually the idea of using a Bromhead ring shear machine as a model glacier had originated with Janet Wright while she was doing her PhD at Queens Belfast. She was looking at ways of producing quartz silt for loess deposits and used a Bromhead ring shear machine to produce shear and crushing stresses to break sand grains. The Bromhead was a machine designed for use in soil mechanics laboratories which could produce a long time continuous shear stress. A circular sample could be deformed by circular platens and very long term tests were possible. Janet suffered from some problems with her Bromhead; it was not her machine (borrowed from another department) she was working within the close time constraints of a PhD project; she could not make significant modifications to the machine, and and she had to test other possible methods of producing silt- she could not concentrate solely on glacial grinding. Raj and K had more freedom of action. They designed and made rougher platens to more accurately represent the ground and glacier surfaces and they had their own dedicated Bromhead machines- new state of the art Bromheads in the NTU soil mechanics laboratory. Janet did not produce much silt from her machine but the K and Raj machines were very productive. Their best result (see illustration from a paper by Markovic & Smalley) was to show the stages in the deformation of sand grains by measuring the height of the sample vs. comminution time.  [It has been suggested that this was the most significant research result produced by a Bromhead- but that would doubtless be disputed]. The sand sample is deformed; initially there is some slight dilatant expansion, then particle breakage begins; the Moss defects are activated and the conversion of sand to silt is achieved relatively quickly. Long term grinding takes the system close to the comminution limit. Enormous amounts of glacial grinding can produce ground systems containing large amounts of very small quartz particles (e.g. the Canadian quickclays) but a just-right amount of grinding (say to the end of stage 3)gives the quartz silt for loess deposits.



Golden Age.  The proposed Golden Age of Loess Research in East & Central Europe is from 2006 to about 2020 (the onset of Covid which closed everything down). So K was there at the start of the golden age.  The seeds were sown at the LoessFest in 1999 but the golden age bloomed in 2006 with the Marsigli loess meeting at the University of Novi Sad in Voyvodina in Serbia. The beginning of a large scale appreciation of the wonders of the loess in all parts of the Danube basin but particularly in parts where the river is augmented by flows from the Drava, Tisza and Sava and other large tributaries from the Alps and the Carpathians. The Marsigli loess meeting was in Novi Sad. Marsigli is credited with the first recognition and representation of loess in the Danube bank deposits [see blog for. K visited Stari Slankamen one of the classic loess exposures- one day maybe to be the site of the Loess Museum and participated in the celebrations at the great fortress of Petrovaradin -that great bastion of the Austro-Hungarian Empire. K lived in the Voyager Hotel on Strazilovska Street and ate in the Palermo cafe just around the corner.

Giotto Loess Research Group. The eccentrically named Giotto Loess Research Group came into existence at NTU. Giotto (as far as we know) had nothing to do with loess- the association is a purely NTU phenomenon. During K's time at NTU there were many reconfigurations and renamings of the civil engineering section and many moves of people and plant. NTU was building and rebuilding; the old Art School was built into a new construction in such a way that the external walls became internal divisions and this resulted in K's office being dominated by a large bas-relief of Giotto that great pioneer of Italian Art- so he gave his name to the Loess Group. He looked down on the production of Loess Letter. LL was produced at NTU from LL35 to LL65- thats fifteen years of continuous production.

Venus in Vienna.  The 2008 Annual Meeting of DEUQUA was in Vienna and it included a special section on loess. DEUQUA is the German Quaternary Association- a venerable and respectable organisation. The meeting in Vienna served to celebrate the discovery of the Venus of Willendorf in loess ground on the banks of the Danube in 1908. The DEUQUA dinner(veg options for K) was held in the Naturhistorische Museum where the Venus is displayed. She is only 11cm tall but has a large salon all to herself. She is estimated to be around 25-30 000years old. She is carved from oolite which may have come from the Lake Garda region. She was discovered by Josef Szombathy on August 7 1908 so the DEUQUA meeting celebrated the centenary of her discovery in the Danube loess.     The INQUA Loess Group had met in Austria in the previous year at Krems which had become famous in loess folklore because it was at the Rifle Range in Krems that Julius Fink and George Kukla had shown the effectiveness of the Danube loess as a palaeoclimatic indicator '17 interglacials after the Olduvai event' i.e. 17 major climate changes in the last 1.7 million years; evidence for the multi-event Quaternary.

The Second LoessFest.  The first LoessFest was held in 1999 at Heidelberg and Bonn. This was to celebrate the naming and definition of Loess by Karl Caesar von Leonhard in 1824. It was a great success; a large international meeting to discuss all aspects of loess. The main driver of the event was Professor Edward Derbyshire and he worked hard to raise funding for as many people as possible to attend. Ten years later there was an echo- a second LoessFest held at the University of Novi Sad in Voyvodina. In 2009 travel to Novi Sad was awkward; bus to Heathrow, then flight to Zurich, flight to Belgrade, drive to Novi Sad.  K was accommodated in NS at one of the residences of UNS. This was located beside the River Danube and a modest distance from UNS proper. The journey between residence and university was accomplished by a stroll along the path beside the Danube- a brilliant way to start a day of discussions. The LoessFest in 2009 was quickly followed by the GeoTrends meeting in 2010 and K had a particularly happy meeting. His best moments were spent in discussion with Biljana Basarin talking about Fourier series and Fourier transforms (the K idea of heaven). Biljana was interested in Milankovitch cycles to control climate change in the Quaternary period so she was keen to apply Fourier principles to the cyclic nature of events.

Birds in Loess.  The 2011 Loess meeting was in Poland, at the University of Wroclaw. There was a field trip to the east, into Ukraine, in particular to a quarry at Korshiv (a place that used to be in Poland but is now in Ukraine- quite close to the border).  Good exposures of loess in the quarry and a remarkable population of sand martins. The exposed loess banks made ideal nesting territory for the birds and it was noticeable that they chose the best parts of the loess profile to excavate and nest in. To build a nest you need excavateability and shear strength, a compromise is required- which was later named the Heneberg compromise after the pioneer investigator.. The sand martins provided a fine demonstration of the remarkable nature of loess ground, and this suggested the use of birds as a loess 'indicator' ;birds will find loess for exploring geoscientists. Actually it turned out that, as suggested by Zdzislaw Jary, the best bird as a loess indicator was the bee eater, for some time the national bird of Hungary- the great loess inhabitant. Merops apiaster- the European bee eater favours loess as nesting ground and is widespread in Europe. Four papers were produced on the bee-eater/loess interaction and these provided satisfactory indicators of loess-like ground in Africa and Australia. There appears to be no (very little) loess in Australia but the Australian bee eater- the Rainbow Bird- does indicate regions of ground which are very loess-like. The Australian interaction is of particular interest.



Windy Day meetings at Leicester(2012) & Southampton(2013). The'Windy Day' meetings were held every year; an informal discussion of aeolian geomorphology- a chance to talk about sand and loess (see blog for 6 August 2022). The 18th WD meeting was held at Leicester University and K participated. The 19th meeting was held at Southampton University and was a bit unusual in that it was a long way from the usual Midlands milieu. Ken went on the bus, and so did Arya Assadi Langroudi. Arya was going to make his first presentation at a scientific meeting and he was understandably a bit apprehensive. Ken reassured him and offered encouragement and the presentation went well. The K-AAL relationship developed and K was able to offer more support when the PhD was due to be submitted.

ED@80: at UNS in 2012.  K back in the UNS residence; more walking along the Danube path, more conferences with Biljana, more exciting discussions of Fourier series and their consequences.  Ed Derbyshire to UNS to celebrate his contribution to Loess world. An exciting excursion to the south-east towards Belgrade, to the Roman settlement of Viminacium and a Roman dinner complete with wine in amphorae. This was a very impressive celebration for Professor Derbyshire and led to the publication of two notable volumes of loess papers (in Catena and Quaternary International). Viminacium was largely exposed because of associated mining for near surface coal- which also exposed some remarkable mammoth remains- visited and admired. It was at this ED@80 meeting that Randall Schaetzl of  Michigan St University  proposed that Loess Letter be totally published online- he undertook to publish the entire LL oeuvre, which amounted to 70 issues from his base at East Lansing.

GeoTrends 2 at Wroclaw (2017). The last of the Central European adventures. K stayed at the Figa Hostel in Cybulskiego Street;  Tom Hose was there and they had long conversations on most arcane topics but mostly on putting down plank floors in attic rooms. The meeting included a very impressive field trip to the south-western part of the country, into the Sudetic Geopark. Landscape models were admired.



The travellers stayed at the Hotel Sonata in Duszniki Zdroj in the Klodzko valley, very near to the Czech border- a very impressive hotel. The very final excursion was a voyage through a forest near Dobra (near Wroclaw) essentially to gather mushrooms (great care being taken to avoid collecting the rare and protected species) for dinner at the house of Zszislaw Jary- and a farewell to Poland.


Finale 2018. K drove down to Northampton for the 25th Windy Day meeting- his last scientific excursion. He took Ian Smalley and a Chinese visitor. They all admired the new Northampton campus and were very careful to return their identification devices. Ken was still writing occasional poetry and it seems fitting to end this appreciation with a few simple lines of K verse:

For the time I will reside/                                        In a universe in dimension five /                             In my immortal soul of light I am alive/        Awaiting in what new life I will survive/                                                                                                      So when I am gone be happy for me    [KOHD]

Tuesday, 13 September 2022

Ecosystem services provided by bee-eater birds in loess deposits

 Wenny D G,  DeVault T L,  Johnson M D, Kelly  D,  Sekercioglu,  Tamback D F,  Whelan C J. 2011  Perspectives in ornithology:  the need to quantify ecosystem services provided by birds.  Auk 128, 1-14

Whelan, C.J., Wenny, D.G., Marquis, R.J.  2008.  Ecosystem services provided by birds. Annals New York Academy of Sciences 1134, 25-60.

Nesting spaces provided  by bee-eaters to : 

Rock sparrow;  House sparrow;  Spanish sparrow;  Tree sparrow; Sand martin;  Little owl;  European roller;  Pied wagtail;  Ethiopian starling; Hoopoe;  African pied starling;  African hoopoe.  

Casas Criville A, Valera F. 2005.  The European bee-eater (Merops apiaster) as an ecosystem engineer in arid environments.  Journal of Arid Environments 60,  227-238.










Smitha  B, Thakar J,  Watve M.  1999.  Do bee-eaters have a theory of mind?   Current Science 76, 574-577

Purger, J.J.  2001.  Numbers and breeding distribution of the Bee-eater (Merops apiaster) in province Voivodina (northern Serbia) between 1997 and  1990.  Vogelwelt 122, 279-282.



Saturday, 10 September 2022

The Languages of Loess

 Look out for generalizations- mostly kept under control but occasionally escaping and behaving irresponsibly.  Loess is a Chinese phenomenon- found all over the world but at its biggest and thickest and most impressive in China.  Loess is a critical part of the Chinese landscape and the first writing about Loess must have been in Chinese. As Chinese is promoted as a World language perhaps more of these early writings will become accessible and available.  A digression already- this is the age of the Chinese language; all made possible by the coalscence of the language and advanced computer technology- read 'Kingdom of Characters' by Jing Tsu, published by Penguin in 2019.

"Computers are finally able to process Chinese! Long live square characters."  Chen Mingyuan 1980

The marriage of computer + Chinese language may lead to all sorts of remarkable and marvellous effects and will surely result in increased publication in Chinese, about Loess. But this is for the future. This discussion is essentially historical.  Scientific writing about Loess was initially a European affair.



Ding Hong, Li Yanrong, Yang Yang, Jia Xia  2019.  Origin and evolution of modern loess science 1824-1964.  Journal of Asian Earth Sciences 170, 45-55.

Zhang Y, Guan L, Liu Q.  2018.  Liu Tung sheng: a geologist from a traditional Chinese cultural Background who beame an international star of science. Journal of Asian Earth Sciences 155, 8-20.

Russian

Rogers CDF  Dijksra TA  Smalley IJ  1994  Hydroconsolidation and subsidence of loess: studies from China, Russia, North America and Europe- in memory of Jan Sajgalik.  Engineering Geology 37,  83-113

Why this EG reference; what is the relevance of hydroconsolidation?  It has been claimed that this is the first paper to give some consideration to the five loess languages: Chinese, English, German, French, Russian- the five languages in which most papers on loess are/were published. Loess soil structure collapse is a problem on all continents- a practical problem considered in all local languages- and all international languages. Andre Dodonov once remarked that 90% of loess research in the Soviet Union was devoted to the study of collapse and subsidence- which is not really a surprise when one considers the coincidence of population and collapsing loess ground in the east of the country. Much loess research was published in Russian- collapse studies reviewed in Rogers et al (1994). There were always transmission and translation problems- right to the end of Soviet times the term 'collapsibility' caused problems and much Russian work was not appreciated because of this single problem.

Kriger probably remains the key person in Russian loess bibliography. Nicolai Ivanovich Kriger- a much published but little appreciated star of the literature in Russian. Actually having stated that it must be noted that Marton Pecsi, during his years as President of the INQUA Loess Commission, did work closely with Kriger, and their joint efforts served to promote interest in Loess in Russian.


N.I.Kriger (photo taken at the time of the IGC in Moscow in 1982 (by IS). It appears to be the only photograph of Kriger extant, various searches have not revealed another; also it would be useful to know his dates and something of his history. From the bibliographical point of view the most useful Kriger work is Kriger 1965 the book he produced for INQUA  at Boulder USA in 1965.


Kriger, N.I.  1965.  Loess- its characteristics and relation to the geographical environment.  pub. Izd-vo Moscow 296p. (in Russian).  Only 1350 copies of this invaluable work were printed and they are extremely scarce. It is a particularly useful book because of its bibliographical content. There must be other relatively large scale studies of Russian loess (loess in Russian) but none appears to rival the Kriger volume. Sections of Kriger 1965 were reprinted in Loess Letter Supplements but these were not widely circulated and are probably as rare as the original. 


German

The Rhine Valley; for a long time for the OED the home of loess. The first European writings on loess were in German



Monday, 29 August 2022

Slobodan Markovic goes to LoessFest 1999

 In 1824 Karl Caesar von Leonhard defined Loess in volume 3 of his great work : Charakterstik der Felsarten. That was a beginning for loess studies.  1999 was just about the 175th anniversary of that remarkable loessic event and a conference was held to mark the occasion. It was held in Heidelberg and Bonn and was the largest and most ambitious Loess conference ever attempted. It was organised by Edward Derbyshire, Ian Smalley & Ludwig Zoeller.

ED made enormous efforts to raise funding so that distant scholars could attend, and as a result there were loessic contributions from far and wide; it was a truly international meeting and the conference part, in Bonn, was beautifully housed and organised. IS was secretary of the INQUA Loess Commision at that time and had access to a small amount of INQUA funding. ED suggested that this funding should support an applicant from Serbia who deserved some assistance- so INQUA support was provided. This applicant was of course Slobodan. Many years later ED was heard to observe that ' never had INQUA funds been better deployed'  it might be claimed that loess scholarship took a great step forward (or similar extravagant claims may be made). SM participated in the 1999 INQUA LoessFest; it was a memorable occasion..


 

Saturday, 6 August 2022

Windy Day: a once a year discussion of things aeolian; Loess & Dust & Sand Dunes etc

 Once every year (more or less) the Windy Day meeting is held- usually at a university in Middle England. The topics discussed relate to aeolian sediments and aeolian geomorphology. Its a one day meeting and very informal. Here is some history in the form of a list of meetings:

1.   1993   Friday 7th May                University of Oxford

2.   1994   May                                  University College London

3.   1995   Thursday 11th May          University of Sheffield

4.   1996   Wednesday 8th May         Nene College, Northampton

5.   1997   Wednesday 2nd April       Nottingham Trent University

6.   1998   Thursday 14th May          Queen Mary, University of London

7.   1999   Wednesday 23rd June       Cheltenham & Gloucester College

8.   2000   Tuesday 30th May            Anglia Polytechnic University

9.   2001   Tuesday 29th May            University of Luton

10. 2002   Monday 27th May            University of Oxford

11. 2003   Wednesday 14th May        University College Northmapton

12. 2005   Wednesday 2nd February  Geological Society, London  

13. 2007   Wednesday 24th October   University of Northampton

14. 2008   Friday 24th October           Kings College London

15. 2009   Friday 23rd October           Loughborough University

16. 2010   Monday 18th October        Royal Geographical Society, London

17. 2011   Wednesday 19th October    University of Sheffield

18. 2012   Wednesday 17th October    University of Leicester

19. 2013   Wednesday 23rd October      University of Southampton

20. 2014   Wednesday 8th October       University of Oxford

21. 2015   Wednesday 21st October      University of Reading

22. 2016    Wednesday 26th October     Loughborough University

23. 2017    Wednesday 1st November    University of Manchester

24.  2018   Wednesday 7th November    University College London

25.  2019    Wednesday 30th October     University of Northampton



26.  2022     Friday 17th June                  Loughborough University


4 meetings at Northampton, 3 at Loughborough and Oxford, 2 at UCL and Sheffield. Delegates were able to observe the evolution of Nene College as it became University College Northampton and then the University of Northampton.  The Luton meeting took place just before Luton University disappeared. WD just survived the Covid 19 pandemic; its future is under consideration.. there will be a meeting in 2023: Friday 19th May 2023 at the School of Geography and the Environment, University of Oxford.



             

Monday, 18 July 2022

Thermogravimetric Analysis of Essex Loess

 A new review shows the extent and nature of the UK and Irish loess; this note is designed to complement that excellent compiliation- it concerns the loess in south east Essex

C.Bunce, T.Stevens, I.Smalley, A.Assadi-Langroudi  2022   Loess in Britain and Ireland; formation, modification and environmentsl significance, a review in memory of John Catt 1937-2017.  Proceedings of the Geologists Association




The loess is concentrated in the south-east of the county, near to Southend on Sea. The Greater Essex Mineral Resource map shows the location with reasonable precision.



Grenville Lill managed to obtain brickearth samples from the Star Lane and Cherry Orchard Lane brickworks. These were possibly the last two brickearth producers in Essex. As far as we know the only substantial TG analysis on London Brickearth was carried out on these samples.

Monday, 11 July 2022

LL65: Notes for a History of INQUA


 The history of INQUA which was presented in LL65 (April 2011) can be accessed in two places: on the official INQUA website- the LL history has become the official history- go to www.inqua.org>about>history, nicely laid out but lacking pictures. If you want the pictures of the logos etc go to the Michigan State University presentation of the whole collection of LL and call up LL65: loessletter.msu.edu. If you have access to an original hardcopy of LL65 preserve it- no doubt it will become a bibliographical treasure.

Friday, 1 July 2022

The P.D.Tilley map of the loess in southeast England

 Colin Bunce has produced a new version of the map which P.D.Tilley presented at the 1961 INQUA meeting in Poland. Tilley participated in the Loess Symposium organised by Julius Fink. The new map supplements the new paper on the loess in Britain and Ireland by Bunce et al (2022). in Proc.Geol.Assoc- available online- should appear in hard copy in the October issue of PGA.



Thursday, 3 March 2022

Ian Lindsay Freeman b.1927

 Ian Lindsay Freeman, b.1927, probably in Dundee; joined the Building Research Station in Garston, Watford in 1962; retired in 1980s.


 This is the hypothesis: That the ILF paper on the mineralogy of ten British brick clays, published in the Clay Minerals Bulletin in 1964, is the best available listing of the mineralogy of British brick making materials. No other readily available source of mineralogical data is apparent. ILF sample 63AH gives an analysis of a London Stock Brick mixture- one of the very few to give any information on this important source of bricks; bricks made from the loess of south-east England.

The interest in the work of ILF arises because of the connection to the 'Loess in Britain' project. Acknowledgements for assistance go to: Dave Morgan, the Mineralogical Society, Monica Smalley. Picture from the BRE publication Building Magazine 11 June 1971 pp.69-70

I.L.Freeman 1964.  Mineralogy of ten British brick clays. Clay Minerals Bulletin 5, 474-486. 

I.J.Smalley 2021.  London Stock Bricks: from Great Fire to Great Exhibition.  British Brick Society Information 147, 26-34