Glacial Beds Research Articles

An upper Paleozoic tillite in the Dry Valleys, south Victoria Land, Antarctica

ABSTRACT A thin pebbly mudstone unit which lies on a Devonian-Permian disconformity at Mount Feather and Mount Fleming in the Dry Valleys of Antarctica is interpreted as a glacial-fluvial deposit and is correlated with Upper Paleozoic tillites farther to the south. These glacial beds are composed of two lithologies: mudstone (till) and channel sandstones (water-laid sands). This marks the northernmost known exposure of Paleozoic tillites in Victoria Land.

Stratigraphy of the Beacon Supergroup between the Olympus and Boomerang Ranges, Victoria Land, Antarctica

IN the summer of 1968–69 a geological expedition from Victoria University of Wellington examined the Beacon supergroup over an area of 3,500 km2 between the Olympus and Boomerang ranges (Fig. 1). In this area the Beacon supergroup comprises as much as 2,300 m of flat-lying non-marine sediments from Devonian or older to Triassic in age. The season's work contributed to the regional geology in two ways: abundant Devonian freshwater fish remains were discovered and collected, thus extending the known geographic distribution and variety of the fossil assemblage; and a thin sequence of glacial beds of Late Palaeozoic age were found to be widespread throughout the area. Data from the measurement of thirty detailed stratigraphic sections have also led to considerable refinement of Beacon supergroup nomenclature (Table 1).

Late glacial marine algae from Greenock and Renfrew

Synopsis Fossil algae attributable to Desmarestia aculeata, Sphacelaria pennata, Sphacelaria plumigera and Laminaria sp. from the late glacial beds of Greenock and Renfrew are described and illustrated. A fossil echinoderm identified as Strongylocentrotus dröbachiensis and found with the algae is also illustrated. The four species of algae are clearly inhabitants of cold seas although they occur through a wide latitudinal range. This is in accord with the view that the beds were laid down under Arctic conditions.

The Eocambrian glaciation in Norway

Traces of the Eocambrian glaciation are found in three district in Norwegian territory, 1) in the south-east, at and north of the lake MjOsa, 2) in north-east, in Finnmark, and 3) in Spitzbergen. The two first districts are connected by a number of localities in Sweden, along the margin of the Caledonian Mountain chain. The glacial beds form the base of the Eocambrian, which is taken as the lowest part of the Cambrian. They generally rests with a more or less pronounced disconformity on dolomitic rocks of the Esmarkian (the upper part of the Riphean system). In some cases they rest directly on the crystalline Precambrian basement. This is due either to Esmarkian tectonic movements, to deep glacial erosion or both. The glacial beds are varied lithologically, but the characteristic rock types are tillites, boulder-shales and varved mudtones. All tillites are not regarded as fossil moraines, formed by ice movement. Some of them are supposed to have been formed by dropping of material from floating ice, either glacier ice or sea ice in a marine or brackish environment. The wide and uniform distribution of the tillite seems to preclude an interpretation as mudflows. Comparison with the Quaternary glacial sediments have given interesting results, and add to the evidence for a glacial origin of the tillites. It is also indicated that the direction of transport will depend on whether the material was rafted with glacial ice, or with drifting sea ice. Much more work has to be done both on the sedimentology, stratigraphy and paleomagnetism of the Norwegian Eocambrian glacial deposits and comparable sediments in order to get a clear and coherent picture of the glaciation, but the present evidence seem to indicate that it was part of a world-wide glaciation of even greater extent than the Permo-Carboniferous and Quarternary ones.

The Cromer Forest Bed: Preglacial or Interglacial?

THE relation of the Cromer Forest Bed Series to the overlying glacial deposits and to the earlier Crag Series has long been a problem, but the recent communication in Nature by Prof. P. G. H. Boswell1 should do much to dispel the idea that the Cromerian stage can be described as an ‘Interglacial’. No glacial tills or similar deposits have ever been seen below this Series, and therefore from the point of view of stratigraphy its description as ‘Interglacial’ can only cause confusion. The very few glacial erratics which have been found in and below the Crag can be attributed to the action of sea-ice, and cannot be counted as representing a ‘glaciation’; these erratics are so rare that in practice unfossiliferous Crag deposits can be distinguished in the field from most glacial beds by the fact that erratics are scarcely ever found in the Crag.

Appendix 2. Glacial erratics from the upper glacial bed at Hoxne

The erratics collected by Dr R. West from the glacial gravel which overlies the interglacial beds at Hoxne have been sent to me for examination, and are identified as shown in the following list. Earlier finds of erratics by Mr R. Moir and by me are included in the list, so that the record may be complete to date. The help of Dr J. V. Harrison and Dr W. S. Kerrow in identifying some of these rocks is gratefully acknowledged.

Permian Glaciation in São Paulo, Brazil

A PAPER by Octavio Barbosa and F. M. de Almeida, which deals with representative beds of the Permian glaciation in the State of São Paulo, Brazil, has appeared in Anais da Academia Brasileira de Ciencial (Rio de Janeiro, 1949) under the title, “Nota Sobre A Estratigrafia Da Série Tubarão Em São Paulo". In 1908 the ‘Tubarão Series’ was shown by I. C. White to exist in the coal measures region of the State of Santa Catarina. This series was composed of lower glacial beds and upper fluvio-glacial, lacustrine and swampy beds with coal. Later on, Euzebio P. de Oliveira separated the lower glacial beds in a new series named Itararé, and detailed research in the Tietê basin, São Paulo, showed that the Itararè–Tubarão Series comprises five formations: (a) Itapetininga formation, probably entirely marine ; (b) Tietê formation—fluvio-glacial, swampy and glacial, with Glossopteris flora and coal ; (c) Gramadinho formation—glacial and fluvio-glacial ; (d) Capivari formation—marine, with invertebrate fauna so far unknown in southern Brazil ; (e) Itú formation—glacial and fluvio-glacial, with Glossopteris flora and coal. The Tatuì beds do not contain coal and are higher in the Itapetininga formation, and Oliveira has shown that the Itarare beds are not a uniform and undividable sequence of glacier sediments.

Pebbles of Regular Shape, and Their Reproduction in Experiment*

MOST pebbles are of irregular shape; for example, in the glacial beds of flint pebbles near my home in Essex, at the most two per cent have any symmetry, and the presumption is that the large majority have not been worn down long enough or far enough to acquire it. We shall leave the irregular majority aside and deal only with those that have symmetry.

THE OCCURRENCE OF A BED CONTAINING MOSS IN THE BOULDER CLAYS OF DIMLINGTON

At the well-known drift section on the Yorkshire coast, at Dimlington in Holderness, silts occur between boulder clays at several horizons. In one exposure about 600 yards north of the summit of the high ground and approximately half-way between the highest point of the cliff and Cliff Farm ( see Bisat, Proc. Yorks. Geol. Soc., vol. xxiv, pl. xvii), in silts capping the Basement Clay and with about 100 feet of glacial beds above them, we were fortunate enough to find recently numerous very thin horizontal pads of moss ( Hypnum sp.). At this particular exposure the following section may be seen :— | Drab Boulder Clay | .. | .. | .. | .. | — | || | Yellow Sand | .. | .. | .. | .. | 4ft | | Grey silty loam with moss beds | .. | .. | .. | .. | 3ft | | Basement Clay | .. | .. | .. | .. | 12ft | | Beach | .. | .. | .. | .. | — | The moss occurs in several thin layers visible in the grey silty loam exposed in the face of the cliff as black lines 1 or 2 mm. in thickness. To trace them horizontally for any distance is difficult owing to the way in which the upper parts of the cliff slide down over the lower. They have, however, been followed, with interruptions due to the above cause, for a distance of rather over 100 feet from the place where they were first seen, rising slightly north and south of this point. Close examination of lumps of the material containing the deposit shows that the main moss-containing layer is overlaid by a bed ...

On the Glacial and Interglacial Marine Beds of Northern Lewis

The Outer Hebrides, lying off the north-west coast of Scotland, are of particular interest to the student of Pleistocene geology, on account of the grand scale on which the results of ice-action are to be seen, and because of the marine shell-beds which are to be found at the northern end of the Isle of Lewis. In the present paper no general survey ofthe glacial deposits of the Outer Hebrides will be attempted; my object is rather to drawattention to certain features of the marine fossils, as a study of the coast sections shows that a faunal sequence can be established in the Pleistocene series.

Pottery in the Palæolithic Period

FURTHER evidence on the disputed question of the occurrence of pottery in the later phases of the palaeolithic period was brought forward by Mr. J. P. T. Burchell at a meeting of the Society of Antiquaries held on October 28. Pottery has now been found by him on several sites in the Thames Valley in circumstances which, he maintains, warrant a dating in Upper Palæolithic times. At a site in the Bean Valley, Kent, which he has excavated recently, pottery occurs between the fourth and the fifth of a series of seven separate deposits of windborne loams. Of these deposits the lowest and oldest is linked with the glacial deposit on which it lies. The first four deposits in the series contain no sign of man, but with the pottery between the fourth and fifth deposits were bones and implements. It has been suggested that the pottery belongs to the bronze age, but Mr. Burchell maintains that the absence of any evidence of a mesolithic culture in the lower beds precludes that view. He relies further on the evidence of the occurrence of the extinct shell Helicella striata in beds 2–4. This shell has not been recognized as occurring after the Upper Palaeolithic period. Collateral evidence which possibly may appear more convincing was obtained at Springhead, in the Ebbsfleet Valley, Kent. Here implements similar to those found in the Bean Valley, as well as those found at Ipswich, with the pottery for which Mr. Reid Moir claims a palaeolithic age, were found in an unworn condition in a gravel bed underlying alluvium and peat and resting on a glacial bed. On top of the gravel occurred a large number of scrapers of a type not hitherto recognized and showing marked eolithic characters. These were striated, presumably by floating ice or the movements of semi-frozen material, indicating that the implements, and therefore, presumably, the pottery, dated from before the last glacial manifestation ; in other words, that both pottery and implements belonged to Upper Palaeolithic times.

Disturbed Glacial Beds in Denmark

Disturbed Glacial Beds in Denmark

Flint Implements from the “Stone Bed” of the North Norfolk Coast

The sub-crag “stone bed” has been described by many writers and there is now a general consensus of opinion that it represents the non-floatable débris of the Tertiary land surface spread out by the advancing Crag sea and sealed in beneath the sands, clays and gravels of the shelly crag. In Norfolk the stone bed rests immediately upon the chalk. At the present time, when most of the formerly numerous chalk pits are no longer worked, sections are scarce. The best available opportunities for examining the stone bed are provided by the cliff section from Weybourne to Sheringham, and the beach and foreshore exposures from Beeston to East Runton.At Weybourne, to the east of the old coast-guard cottages, the chalk rises abruptly from beneath the chalky boulder-clay of the Great Eastern glaciation which cuts down below tide-level to the westward; and soon attains a height of about twenty feet above the pebble-bank. For the first few hundred yards the chalk is very disturbed, flints from the stone bed, patches of very shelly crag and fragments of chalk being inextricably mixed in the upper portion, though the chalk four feet below the surface shows the flint layers apparently undisturbed. In about three hundred yards the stone bed becomes continuous, with varying thicknesses of the crag gravels and sands separating it from the glacial beds above. In thickness the stone bed varies from six to nine inches, occasionally reaching a foot, and tending to become rather thicker as it stretches eastward.

Heavy Minerals of the Pleistocene Beds of the Don Valley, Toronto, Ontario

ABSTRACT A study was made of the heavy minerals from the glacial and interglacial deposits of Pleistocene age exposed in the Don Valley, Toronto, Ontario. The mineral occurrences are listed and special characteristics noted. The actual mineral occurrences are very similar in glacial and interglacial beds but when the relative abundance of certain minerals is plotted as percentage of total heavy minerals present, curves are obtained showing a rather sharp difference between glacial and interglacial beds and a very close resemblance between the various interglacial beds examined. In all cases the mineral assemblage is of typically Pre-Cambrian derivation. It is thought that the materials of the interglacial beds were derived, either from the glaciers and icebergs themselves, or from older boulde clays, and very little from the Paleozoic sediments which underlie the region.

Hand-Axes from Glacial Beds at Ipswich

As is known, there exists a widespread deposit of what I have called the Upper Chalky Boulder Clay, on the high ground in the neighbourhood of Ipswich, Suffolk. This accumulation is especially well developed to the north and east of the town where it forms the more or less flat plateau, the surface of which lies at approximately 150 O.D. I have already recorded the discoveries of flint implements in the Upper Chalky Boulder Clay in the brickfield of Bolton & Co., Ltd., to the north of Ipswich, and elsewhere. From these discoveries, which include that of an Early Mousterian hand-axe, of necessity re-described in this paper, I have concluded that the Upper Chalky Boulder Clay was laid down by an ice-sheet present in East Anglia at the close of Acheulean times, and is to be referred to the 3rd Glacial Period of this area. It is now my purpose to illustrate and describe three further specimens of Acheulean hand-axes derived from a deposit exposed in various sections in the plateau to the east of Ipswich.

Disturbed Glacial Beds in Denmark

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Upper Paleozoic Glaciations of Australia

Introduction In 1919 the authors contributed a paper on the sequence, glaciation and correlation of the Carboniferous rocks of the Hunter River district of New South Wales to the proceedings of the Royal Society of New South Wales (1). In this paper the existence of glacial beds in strata of Carboniferous age in the Hunter River district of New South Wales was described and correlations were suggested with various localities both in Australia and in other parts of the world. The views then put forward have been generally accepted by Australian geologists. Since the publication of that paper, much additional information regarding the Carboniferous and Permo-Carboniferous formations of Australia has become available as a result of the labors of many geologists in the various Australian States, but particularly in Western Australia, Queensland and New South Wales. In 1928 there appeared in these Proceedings (Geological Society of America) a comprehensive paper . . .

Palæobotanica1 Evidence for the Age of the Late Palæozoic Glaciation in South Africa

THE new occurrence recorded by Dr. Walton is of great importance both for showing members of the northern and southern late Palaeozoic floras in association and for indicating the age of this and other deposits. To my mind, the age assigned to the Wankie flora by Dr. Walton cannot be questioned. In one respect I should be even more definite than he. His comparison with South African floras is highly suggestive, but, on the strength of such a correlation, I should consider the Dwyka glacial beds with Gangamopteris to be definitely Upper Carboniferous in age. This gives independent support to the determination obtained in other ways.

Societies and Academies

SYDNEY. Linnean Society of New South Wales, July 28.—C. T. White: On a small collection of plants from the Rigo district, Papua. Two species, one of Plectronia and one Jasminum, are described as new.—C. P. Alexander: The Trichoceridæ (Diptera) of Australia. One genus and four species are described as new. A key is given for the determination of the genera.—R. H. Cambage: Notes on the native flora of New South Wales. Part xi. Moree to Mungindi and Moonie R., with a description of a new species of Eucalyptus. The paper contains notes on the early exploration, topography, etc., and a list of the plants noticed. A comparison of this flora is made with that of Tasmania, in view of the dominating influence of climate on plant distribution.—G. H. Cunningham: Gasteromycetes of Australasia, (v.) The genus Calvatia. The genus may be separated from Lyco-perdon by the method of dehiscence, which is effected in Calvatia by the irregular falling away of the apical portion of the peridium; whereas in Lycoperdon dehiscence is effected by means of a definite apical stoma. The genus contains about eight species, of which four are present in Australia and New Zealand.—G. D. Osborne: Stratigraphical and structural geology of the Carboniferous rocks in the Mt. Mirannie and Mt. Dyrring districts, near Singleton, N.S.W. There are two volcanic series with associated clastic rocks, and separating these series is a set of sediments called the Main Clastic Zone. The major volcanic series comprises andesites, dacites, rhyolites and keratophyres, while the lavas in the other group are chiefly toscanitic and dellenitic. The only glacial beds occur near the top of the Kuttung Series, and Rhacopteris-bearing strata are found on two horizons. The chief tectonic feature is the great Bridgeman Fault which separates the Kuttung Series from the Permian or Permo-Carboniferous Series. This is probably an overthrust. In addition there are many normal faults connected with the late Palasozoic diastrophism which folded the area and produced two basin-structures.

ON THE SUPPOSED RAISED BEACH AT SALTBURN

(Read November 26th 1919.) The supposed presence of a Raised Beach of Post-Glacial age at Saltburn, at 35 feet above high-water mark, has afforded one of the minor problems in the geology of the Yorkshire Coast. The ‘beach’ was first described by Dr. W. Y. Veitch in the Proceedings of our Society for 1883 (N.S. Vol. VIII., pp. 221–6), and was referred to shortly afterwards by Mr. G. Barrow in his memoir, ”The Geology of North Cleveland” (Mem. Geol. Surv., 1888, p. 71). Dr. Veitch describes the ‘beach’ as “a band of alluvial sand containing shells and fragments of shells,” of which six kinds are mentioned, all common on the present shore ( Purpura, Littorina, Trochus, Lachesis minima and Cypraea europaea ); and states that it was exposed in the steep drift-slope below Saltburn in operations by the Saltburn Improvement Company, the deposit “extending 70 or 80 yards from the bridge up Saltburn Beck, where it abruptly comes to an end.” He also found shells at about the same level “south” [east] of the beck, on the seaward slope of Cat Nab, and considered that they indicated a continuation of the beach. Mr. Barrow gives practically the same particulars, and endorses the view that the deposit represents a Raised Beach, though he notices the abnormal circumstance that a beach of this kind should be preserved in a perishing cliff of soft Glacial beds and should be absent from the neighbouring rocky headland of Huntcliff, composed of much more durable Liassic strata.