Sand Martins favour loess; thoughts & comments relating to Gilbert White

Smalley, I.J., Smalley, G.J., O'Hara-Dhand, K., Jary, Z.  2013.  Sand martins favour loess: how the properties of loess ground facilitate the nesting of Sand Martins/ Bank Swallows/ Uferschwalben (Riparia riparia Linnaeus 1758).  Quaternary International 296, 216-219.

Gilbert White:  The Natural History of Selborne. 1st publ. Ben.White London 1789. Penguin Classics edition, ed. Richard Mabey 1987.  283p.

"The sand-martin, or bank-martin, is by much the least of any of the British hirundines; and, as far as we have ever seen, the smallest known hirondo; though Brisson asserts that there is one much smaller, and that is the hirundo esculenta."

Here are in this parish, in the sand-pits and banks of the lakes of the Wolmer-forest, several colonies of these birds; and yet they are never seen in the village; nor do they at all frequent the cottages that are scattered about in that wild district..
..this species seems so to delight in large waters, that no instance occurs of their abounding, but near vast pools or rivers: and in particular it has been remarked that they swarm in the banks of the Thames in some places below London-bridge."

"The parish of Selborne lies in the extreme eastern corner of the county of Hampshire, bordering the county of Sussex, and not far from the county of Surrey; is about fifty miles south-west of London, in latitude 51, and near midway between the towns of Alton and Petersfield...
The soils of this district are almost as various and diversified as the views and aspects. The high part to the south-west consists of a vast hill of chalk, rising three hundred feet above the village; and divided into a sheep down, the high wood, and a long hanging wood called the Hanger...  The prospect is bounded to the south-east and east by the vast range of mountains called the Sussex-downs, by Guild-down near Guildford, and by the Downs round Dorking.."

Sand martin distribution: Selborne is in the south of England close to Southampton and the Isle of Wight, in the region where loess material was deposited. The South Downs are covered by loess. The map shows sand martins favouring river regions and loessic regions. "The vast range of mountains called the Sussex Downs" is covered by loess.

Loess in Britain XVIII: PTDC chart for S.E.England

The actions/events forming a loess deposit can be charted via the PTDC chart; it shows a fairly complex arrangement for the small loess deposits in S.E.England.  But, as John Catt said, the modest English loess may have messages for the wider loess community.
Chart by Colin Bunce.

Nature (1869) and Loess History

 

The scientific journal Nature, having reached its 150th birthday, is celebrating and promoting history. We think that history is important in the study of loess; loess scholarship is a very cumulative topic and it moves quite slowly; we have come a long way since 1869. Its worth quoting some bits from the Nature editorial of 26 September 2019:

"To count the handful of years between the newest and oldest paper on many a citation list is to know that scientists rarely have cause to look back very far. That's a problem. Research is not just about placing one new brick on top of- or instead of- the last. It is a product, and a shaper, of people, place and society. To navigate that context wisely, the long view is essential."

The long view is essential. The topic was born in 1824 and was growing and developing by 1869. Successive editions of the Principles of Geology were continuing to spread the word and Lyell's adventures in North America were popularising the idea on that continent. The default theory of loess formation was Lyell's idea of deposition from a lake or perhaps flowing water. The best, and perhaps the only, comprehensive history of loess investigation is that by S.Z.Rozycki (1986 Polish, 1991 English) and he covers the period from 1869 onwards:

"Not everyone, however, supported the view of the fluvial genesis of loess. In 1857, Benningsen- Forder, putting forward a thesis of three marine transgressions during the Diluvial flood, maintained that the deposits associated with those transgressions were nothing else but loess, in which, in the vicinity of Siedenburg, he had apparently found marine fauna. Thus he became the forerunner of the marine theory of the origin of loess. In spite of the lack of factual evidence and the presence in the theory of elements which contradicted already known facts (terrestrial and fresh-water fauna within the loess, altitude etc.) it was accepted by many research workers in western Europe, For example Fallou (1867) regarded the limy loess of Saxonia as form of marl, and maintained that it was a marine sediment which had also been absorbing glaciofluvial material. Kingsmill (1869, 1870) carried this theory to China, where it was still defended by Prestwich in 1894."

CR, MR & MRD; a new loess classification

Li Yanrong,  Shi Wenhui,  Aydin, A.,  Beroya-Eitner, M.A.,  Gao Guohong.  2019  Loess Geneisis and Worldwide Distribution.   Earth Science Reviews https://doi.org/10.1016/j.earscirev.2019.102947

 

Charles Lyell interacts with the Loess in North America

Charles Lyell made four visits to North America, and wrote two books about his observations and experiences. His adventures have been recorded and discussed by Wilson (1998).

Wilson, L.G.  1998.  Lyell in America: Transatlantic geology, 1841-1853.  Johns Hopkins University Press, Baltimore. 429p.

 

 

"At Natchez .. there is a fine range of bluffs-  several miles long, and more than 200 feet in perpendicular height, the base of which is washed by the river. The lower strata, laid open to view, onsist of gravel and sand, destitute of organic remains, except for some wood and silicified corals, asnd other fossils, which have been derived from older rocks; while the upper sixty feet are composed of yellow loam, presenting, as it wastes away, a vertical face towards the river. From the surface of this clayey precipice are seen, projecting in relief, the whitened and perfect shells of land-snails of the genera Helix, Helicina, Pupa, Cyclostoma, Achatina, and Succinea.  These shells, of which we collected twenty species, are all specifically identical with those now inhabiting the valley of the Mississippi."  ( 1849, A Second Visit, v.2, p.194)

Lyell, C.  1849.  A second visit to the United States of North America.  Murray London 2 vols.

Dott, R.H.  1996.  Lyell in America- his lectures, field work and mutual influences 1841-1852. Earth Sciences History 15, 101-140.

Skinner, H.C. ed.  1978.  Charles Lyell on North American geology; an original anthology.  Ayer New York. 226p.

"The resemblance of this loam to that fluviatile silt of the valley of the Rhine, between Cologne and Basle, which is generally called 'loess' or 'lehm' in Alsace, is most perfect. In both countries the genera of shells are the same, and as, in the ancient alluviums of the Rhine, the loam sometimes passes into a lacustrine deposit containing shells of the genera Lymnea, Planorbis and Cyclas, so I found at Washington, about seven miles inland, or eastwards from Natchez, a similar passage of the American loam into a deposit evidently formed in a pond or lake.  It consisted of marl containing shells of Lymnea, Planorbis, Paludina, Physa, and Cyclas, specifically agreeing with testacea now inhabiting the United States."

"With the land shells before mentioned are found, at different depths in the loam, the remains of the mastodon; and in the clay, immediately under the loam, and above the sand and gravel, entire skeletons have been met with of the megalonyx, associated with the bones of the horse, bear, stag, ox, and other quadrupeds, for the most part, if not all, of extinct species. This great loamy formation, with terrestrial and fresh-water shells, extends horizontally for about twelve miles inland, or eastward from the river, forming a platform about 200 feet high above the great plain of the Mississippi."

Lyell & Mrs Lyell left Liverpool on 20 July 1841 and returned 27 Aug 1842; that was the first visit. They left Liverpool again on 4 Sept 1845 and returned on 13 June 1846. That was the second visit; the visit of some consequence for loess scholarship; on 13 March 1846 Lyell was at Natchez. The second visit was reported in 'A second visit to the United States of North America' published in 1849. It is said that there was some delay in publication to allow for the publication of scientific results in various journals. In vol.2 are the first(?) descriptions of loess in the USA.

p.208: "Leaving my wife at rest at the hotel, I made a rapid trip by railway, fifty-five miles eastwards, to Jackson, the capital of the State of Mississippi. For the first ten miles, the cars traversed a table-land, corresponding in height with the summit of the bluff at Vicksburg, and preserving an even surface, except where gullies had been hollowed out in the soft shelly loam or loess. These are numerous, and it had been necessary to throw bridges over many of them so as to preserve the level of the road. It was curious to observe, in the cuttings made through the loam, that each precipitous face retained its perpendicularity, as in natural sections, although composed of materials wholly unconsolidated."

p.276. "The distance from Evansville (Indiana) to Louisvill (Kentucky) was 205 miles, and on both sides of the (Ohio) river were hills of liomestone or sandstone, of the coal formation., 300 feet high, frequently presenting steep and picturesque cliffs. Everywhere I observed a flat terrace of loam, or loess, bordering the river, sometimes on the side of Kentucky, sometimes on that of Indiana."

Charlotte Hibbert 1832 Map (first loess map)

Sam.Hibbert's book on the volcanos(sic) of the Eifel region was published in 1832; it contained some interesting discussion on loess and loess deposits (see Loess Letter 67 at www.loessletter.msu.edu).
Attached was a remarkable map, drawn by Charlotte Hibbert- which deserves to be better known and appreciated. We reproduce some parts; what is needed is a full scale republication- the map's full title is:  The volcanic district bounded by the rivers Nette & Bruhl on the Lower Rhine-(for some discussion see Fitzsimmons et al 2019).

Fitzsimmons, K., McLaren, S., Smalley, I.J. 2018.  The first loess maps and related matters; contributions by twenty significant women loess scholars.  Open Geosciences 10, 311-322.

Smalley, I.J. 2019.  Samuel Hibbert in Edinburgh; early studies on loess deposits- connecting Leonard and Lyell.  Quaternary International 502A, 165-172.

 

Loess in Britain XVII: Sir Joseph Prestwich [1812-1896]

Prestwich, J.  1864. (a) Theoretical considerations on the conditions under which the (drift) deposits
containing the remains of extinct mammalia and flint implements were accumulated and their geological age  (b) On the Loess of the valleys of the south of England, and of the Somme and the Seine.  Philosophical Transactions of the Royal Society of London 12, 154,  247-309.

Prestwich wrote on loess and published a significant paper in the Roy.Soc. transactions of 1864. Actually the loess material appeared as part of a two-section paper- which has caused some confusion

There is some bibliographical muddle and this may have prevented him from receiving the loessic credit which is is due.
 

 

Sedgwick & Murchison: early observations on Loess in the Danube valley

Sedgwick, A., Murchison, R.I.  1832.  A sketch of the structure of the eastern Alps, with sections from the newer formations on the northern flanks of the chain, and through the Tertiary deposits of Styria etc. etc.   Transactions of the Geological Society of London (s2) 3, 301-420
with supplementary observations, sections, and a map by R.I.Murchison.

An enormous paper, and difficult to reference; we approach it via the writings of Horner and Lyell.
Horner (1836, p.460): " In the synopsis of the successive deposits in the basin of Vienna, given by Mr.Murchison, the uppermost is described to be 'Alluvial loam, called Loess, with terrestrial shells of existing species.. mixed with bones of elephants of extinct species. The average thickness of this deposit is about 60ft but at some places the thickness is much greater. Further, it is greatly expanded near Krems and St.Polten, reaching occasionally the thickness of 140ft, and having, near these places, the exact appearance of the old alluvial hillocks in the valley of the Rhine, which have been described by M.Voltz.." 
We appear to have early references to the loess in the Danube basin; in fact these might be among the earliest references to loess in the Danube basin..

Charles Lyell is in Europe in July 1835, he writes to Sedgwick: " I am reading you and Murchison on the Eastern Alps, as I am going so near your section. Your elaborate joint paper is now quite a treat. Boue has given me many Gosau fossils. He is going to live four years in Vienna, and next year to do the Balkan. My wife says, 'Give my kind regards to Mr.Sedgwick, and tell him it is dreadfully hot.'
Lyell deploys a well chosen phrase-'your elaborate joint paper; its impressive that he carried so much paper with him.  This elaborate joint paper appears to have been a bit neglected subsequently; no mention in the detailed history of Danube loess research by Markovic et al (2016)- not surprising, the material is well hidden but the 140ft thick loess at Krems deserves a mention.

The history of Danube loess research 2016.  Markovic, S.B., Fitzsimmons, K.E., Sprafke, T., Gavrilovic, D., Smalley, I.J., Jovic, V., Svircev, Z., Gavrilov, M.B., Beslin, M.  Quaternary International 399, 76-89.

Zalasiewicz on Geology

Jan Zalasiewicz  2018.  Geology: A Very Short Introduction.  Oxford University Press 145p.

JZ presents the story of geology in the compact format of the 'Very Short Introduction' series by OUP.  There are over 550 titles in the VSI series and 'Geology' is a welcome addition.

Earth history from the very beginning to the Anthropocene- neatly illustrated; -and properly indexed. Go to L in the index, look for Loess- we have an entry- p.83. We will have to quote- the temptation is too great:
"These are still widely called 'drift' deposits (from the old idea that many formed from drifting icebergs), but are more technically referred to as 'superficial' or 'surficial' deposits. Not all relate to glaciation, by any means. In low latitude parts of the world they can include thick windblown sand deposits, as in parts of the Sahara, or the thick windblown silt or loess that covers much of Central China, having been blown there during the past two and a half million years from the Himalayas, and peat bog deposits. Where large rivers such as the Mississippi or Ganges-Brahmaputra meet the sea, huge deltas build out. "
Good to see the Himalayas acknowledged as the source of loess material; and two and a half million years of loess deposition. Is Central China the place or would the loess region be better described as northern China? and where do the peat bog deposits contribute? 

Another relevant VSI book is The Ice Age by Jamie Woodward:
Jamie Woodward 2014.  The Ice Age: A Very Short Introduction.  Oxford University Press 163p.

This is in many ways an excellent study of Quaternary matters- but there is one terrible short-coming.
Look in the index, go to L- where is Loess?  Why does JW not mention loess? surely Loess is one of the most interesting and significant of the Ice Age deposits.

Adobe as Loess (Why not?)

Alfred Scheidig (1934) in his classic book 'Der Loess und seine geotechnischen Eigenschaften' stated that:  In addition to the aforementioned loesses, which are mainly of glacial origin, there are continental loesses in the fringe regions around desert and steppe zones. Keilhack (1920) mentions this in Texas, Shaler (1899) in Montana, Henning (1911) in Colorado, New Mexico and Arizona. In the latter two areas, the loess is closely related to the formation known as 'adobe' (pronounced adobi) in fact, in most cases it is identical to adobe (translated by LL).

Adobe is widely used as a building material in Africa- in and around the 15N region; it is also used in the S.W.USA; these are probably the best known adobe regions. The sources of adobe material in Africa can perhaps be demarcated.

On the map <<<  FJ is the Fonta-Djalon highlands; BD is the Bodele depression; EH is the Ethiopian highlands. Also indicated- the catchment of the River Niger.  The highlands can be seen as particle-source regions- possibly for loess sized particles. The Bodele depression is the classic source region for small dust particles- derived from deposits in ancient Lake Chad. This can deliver clay-mineral material and silica diatoms. A lot of interesting particulate material is available in the 15N region. For the adobe reaction to function effectively there needs to be some carbonates in the system. The Ethiopian Highlands deliver large amounts of silt-sized material for the Nile Valley deposits and also makes material available for the eastern parts of the adobe region. There are actually few well defined loess deposits in Africa- but there must be a large amount of usable material in accessible regions.

 

Onn Crouvi and associates have provided a neat map of Africa showing loess deposits and the critical regions. The countries of Mauritania, Mali, Niger and Chad cover much of this region; classic adobe buildings are found in this zone.

Crouvi, O., Amit, R., Enzel, Y., Gillespie, A.Ar. 2010.  Active sand seas and the formation of desert loess.  Quaternary Science Reviews 29, 2087-2098.

 

Brickmakers at Mohenjo Daro

Bricks are ubiquitous at Mohenjo Daro and Harappa. Bricks were important in the Indus Valley settlements. The ancient Chinese society left us many objects and much writing; the ancient Egyptians left us an entire academic discipline; the Indus Valley people mostly left us bricks.

Very few artefacts- most famously the bronze statuette of the young woman dancer and the 'Priest/King' stone bust; but very many bricks- good quality fired bricks in enormous numbers. Can we study the Indus Valley people more closely via their bricks? Can we mobilize brick specialists to tell us more?- via a study of bricks.
We propose that these were loess bricks. Loess is known as excellent brickearth; the positioning of the loess deposits may have influenced the location of the brick built cities. Great brick buildings extend beyond Hampton Court Palace and St.Pancras station, they include the city structures at Mohenjo Daro and Harappa. The loess deposits in Kent & Essex supplied the bricks for Victorian London; the Indus Valley loess supplied the bricks for Mohenjo Daro.

The bricks at Harappa were discovered before the city (can we say that?). When the Lahore -Karachi railway was being constructed in 1856 the constructors discovered large deposits of hard, strong bricks which they used to construct the trackbed foundations for many miles of track (about 100 miles). These four thousand year old bricks provided excellent ballast material. The old Harappans made amazingly good bricks- possibly because they had the best available brickearth. Perhaps the brickmakers were important people in Indus Valley societies; perhaps the priest/king is really a brickmaker.

Figures from:
J.M.Kenoyer 1991. The Indus Valley traditions of Pakistan and western India. Journal of World Prehistory 5 (4)  331-385