470 



NA TURE 



[February i8, 1909 



REGIONAL AND STRATIGRAfHICAL 

 GEOLOGY. 



A MOXG the latest memoirs published by the Geo- 

 logical Survey of Great Britain in 1908 are three 

 dealing with familiar ground. Mr. C. Fox-Strangways 

 writes on " The Geology of the Country North and East 

 of Harrogate " (price 2s. 6d.), in explanation of Sheet b2. 

 A geological map of the district round Harrogate is in- 

 serted as a plate in the memoir, and the photographic 

 views, including the famous dropping well of Knares- 

 borough, will interest visitors who may not be specialists. 

 There is a chapter on the history and origin of the Harro- 

 gate springs, \vhich are held to arise from independent 

 sources in the hills west of the town, obtaining their 

 chemical ingredients as they pass through the Lower 

 Carboniferous strata towards the spots where they emerge. 

 These strata are provisionally retained as Voredale beds. 



-Messrs. A. J. Jukes-Browne and H. J. Osborne White, 

 in explanation of- Sheet 254, write of " The Country 

 around Henley-on-Thames and Wallingford " (price 2S.). 

 'Ihc colour-printed map (price is. bd.) was issued in 1905, 

 and a slight correction of it, as regards the zones of the 

 chalk north of Henley, is given, on a somewhat reduced 

 scale, in the memoir. The country depicted includes the 

 well-known road that climbs from Henley to the woods of 

 Ncttlebed, and drops again over the face of the Chalk 

 to the Thames alluvium at Benson. From Dorchester, one 

 of the pleasantest of Oxford villages, we look back at the 

 fine Chiltern scarp, through which the Thames cuts deeplv. 

 .A map like this, with the section at its foot, explains a 

 delightfully varied piece of country. The memoir hardlv 

 directs suflicient attention to the interest of the various 

 gravels and to the problems of pebble-distribution in con- 

 nection with the present valley, but the facts can, of course, 

 ail be found in Mr. White's chapters on the superficial 

 deposits, where numerous references to other works are 

 given. Mr. White shows how subaerial w'asting (p. yq) 

 has been going on here since Oligocene times, so that the 

 pebble gravel of the Chiltern slope can have no definite 

 age assigned to it. He regards the exotic pebbles, such 

 as those of quartzite, that occur in the " plateau gravel " 

 (p. S5I, as derived from the older " pebble gravel," and 

 as ■' carried into the region of the Upper Thames basin 

 long before the commencement of the Pleistocene ' Ice 

 Age.' " 



That energetic writer, Mr. A. J. Jukes-Browne, has also 

 prepared the memoir on " The Country around Andover " 

 (price IS. (id.), accompanying Sheet 283. The map (also 

 price IS. 6d.) was issued in 1905. In this area we are 

 on the great undulating plateau of chalk, over which men 

 still travel fast — often far too fast — on the way from 

 Basingstoke to Bath. The beautiful little vallev of Kings- 

 clerc adds variety in the north-east, where a breached 

 anticline exposes Selbornian Upper Grcensand. This fold 

 is illustrated by a section on the map itself. The un- 

 initiated, however, must remember that the exaggeration 

 of the vertical scale, harmless enough in the right-hand 

 portion, produces an unfortunate effect where the dip 

 changes rapidly on the left, the Chalk appearing as if 

 compressed to one-third of its thickness at the outcrop. 

 The memoir deals with the Cretaceous zones in a manner 

 that was impossible when the area was first surveyed in 

 1857. In conclusion, it touches on springs and water- 

 supply, questions of special importance in such a region. 



.A fourth memoir, on " The Country between Newark 

 and Nottingham," by .Messrs. Lamplugh, Gibson, Sher- 

 lock, and Wright (price 2s. 3<i.), describes Sheet 126, pub- 

 lished in iqoS. There is very little glacial drift in this 

 part of the Trent valley, and the surface is niainlv occupied 

 by Triassic strata. The chief point of interest for the 

 dwellers in this agricultural country lies in the fact that 

 the Coa'.-measures, which crop out west of Nottingham, 

 probably underlie the whole of it. Indications of concealed 

 .aults, known already from subterranean workings, are 

 .shown by orange lines upon the map. The longitudinal 

 section below it is properly non-committal as to the con- 

 cealed coalfield; but the' Clifton Colliery has already 

 burrowed under the Trent, and the whole' land eastward 

 may yet become a "black country," with the Trent as 



NO. 2051, VOL. jq] 



its convenient waterway. The soils of the district an; 

 interestingly referred to on pp. 96-7. 



In the Proceedings of the Geologists' .Association, vol. 

 XX. (1908), p. 390, Messrs. C. P. Chatwin and T. H. 

 Withers describe the zones of the Chalk in the Thames 

 valley between Goring and Shiplake, a district bearing 

 on those recently examined by the survey. The work of 

 these authors is, in fact, referred to in the Andover memoir. 

 The united evidence shows that the higher zones of the 

 Senonian were denuded away over a wide area in our 

 -Midlands before the deposition of the Eocene strata. 



-\ special character was imparted to the later work of 

 Mr. J. Lomas by the broad geographical outlook of the 

 author. This is apparent in his description of the geology 

 of the Berwyn Hills (Proc. Geol. -Assoc, vol. xx., 1908, 

 P- 477)1 which serves as a useful companion for any visitor 

 to Llangollen. We may mention the account (p. 488) of 

 the walls of the Dee valley, and their relation to former 

 glaciers, as an example of the features here clearly brought 

 before the reader. 



In the Jakrbnch d. k.k. geol. Reichsanslalt for 190S, 

 pp. 469-520, Dr. H. Reininger furnishes an interesting 

 study of the Tertiary basin of Budwcis, near the southern 

 Bohemian border. He concludes that the plant-bearing 

 beds were laid down in a considerable lake in Middle 

 Miocene times between steeply falling walls of crystalline 

 rock. The .Alpine movements (p. 511) gave rise to the 

 hollow in which the water gathered, despite the general 

 resistance of the old Bohemian mass that surrounds the 

 basin. Dr. Reininger points out that numerous fissures 

 were produced in Bohemia by pressures of even later date, 

 and that the basin of Budweis was probably uplifted with 

 the southern Bohmerwald at some time later than the 

 Miocene. Here w'e approach the edge of controversy, and 

 once more look towards the Alps. 



It is impossible to do justice, however, either in the 

 study or the field, to the successive memoirs that appear 

 on the tectonics of the -Alps. In three numbers of Peter- 

 inann's Milleiluiigen (Bd. liv., 190S, Nos. 10, 11, and 12I 

 Prof. Fritz Freeh, of Breslau, has furnished a summary 

 occupying forty-two pages, in which he endeavours to 

 harmonise the views of various writers. Profs. Diener, 

 Kilian, and Schardt have supplied descriptions of special 

 districts, and Prof. Freeh shows his fairness by a kindly 

 reference (p. 223) to the gravitational theory of folding 

 urged by Reyer. Emphasis is laid on the great faults that 

 accompanied the folding in the eastern .Alps (p. 256), such 

 as the "Gailbruch," which manifested itself as late as 

 1346 in a terrific earthquake and a landslide, the huge 

 scars of which can still be seen on the precipice of the 

 Dobratsch as one leaves Villach for the south. Close at 

 hand we find the region of the south Alpine Trias, a 

 plateau-country cut up by vertical faulting. In his con- 

 cluding sentences. Prof. Freeh shows how the overfolded 

 structure of the western Alps is connected with the dis- 

 similar and broken structure of the cast by districts, like 

 the Brenner or the Radstadter Tauern, where both types 

 lie near one another. This gives the .Alpine chain an 

 advantage over many other mountain regions ; but the 

 author points out (p. 282) that we may be led on from it 

 to connect the folded ridges of Mexico with the faulted 

 plateaus of .Arizona and Utah, as manifestations of one 

 and the same mountain-building process. The memoir is 

 illustrated by photographic plates and sections. 



Dr. .Ampferer's paper on the Sonnwendgebirge, re- 

 ferred to by Prof. Freeh in a footnote, appears in the 

 Jahrbuch der k.k. geologischen Reichsanstalt, Band Iviii. 

 (1908), p. 281. Wahner has recognised certain " hornstone- 

 breccias " intercalated among Jurassic radiolarian marls 

 as evidences of overlhrusts. -Ampferer regards them as 

 truly and evenly interbedded, and as resulting from the 

 uplift of an eastern part of the sea-floor ; the sediments 

 already formed slipped down over the underlying slope of 

 the Kossen beds, wrinkling themselves during this gravita- 

 tional sliding. Denudation of the uplifted part by sub- 

 aerial agencies set in, and the hornstone-breccias are 

 evidences of this decay. The large blocks foiind in them 

 may record actual landslips. Where the breccias are re- 

 peated, elevation and depression must have alternated. 

 The Gosau beds were laid down unconformably on the 

 surface due to this epoch of denudation. Features of this 



