Clay Base Research Articles

Palynology and Paleoecology of Postglacial Sediments from the Lower Fraser River Canyon of British Columbia

The postglacial history of vegetation in the Yale area of the lower Fraser River Canyon is described from sediments of two lakes using percentage pollen analysis supplemented with macrofossil evidence and radiocarbon dating. Deposition of postglacial sediments, ranging from basal clays to gyttjas, began about 11 500 y B.P. Three distinct pollen assemblage zones are distinguished, reflecting in part the main climatic conditions for the intervals. The oldest zone, with high percentages of pine (Pinus) and alder (Alnus) pollen, suggests cool and moist conditions following withdrawal of glacial ice. This is followed by marked increases in Douglas-fir (Pseudotsuga), grasses and other nonarboreal pollen, suggesting in part, warmer and drier conditions. The third zone, ranging from about the Mt. Mazama ash at 6600 y B.P. to the present, is marked by high alder and Douglas-fir, and increasing cedar (Thuja-Chamaecyparis type), western hemlock (Tsuga heterophylla), fir (Abies) and birch; an assemblage indicating a return to wetter conditions. This sequence contrasts with previously described successions that recognized the classical Hypsithermal in adjacent areas. The sequence of inferred vegetational changes, although similar to those described for the Haney area to the west, suggests that the Yale area has been a biogeoclimatically transitional area for much of postglacial time.

New Component of Braided River Model: ABSTRACT

During the late Wisconsin glacial retreat in southern Ontario, extensive sheets of braided gravelly and sandy outwash were deposited. In the Credit River valley, near Toronto, there are 2 overall fining-upward sequences of braided deposits, with gravels passing upward into sands. The gravels contain large-scale (up to 3 m) crossbedding and abundant channeling, suggesting deposition from migrating mid-channel braid bars. The sands contain some tabular crossbedding (sets up to 1 m), and also a distinctive, newly defined coarsening-upward lithofacies sequence. The sequence begins with a thin (3-6 cm) layer of clay, which overlies abruptly on rippled sand. The clay grades upward into silty clay with faint wavy laminations, and some cross-lamination with preserved stoss sides. The silty clay grades upward into cross-laminated silt, and then ripple-drift cross-laminated sand with eroded stoss sides. The rippled sand is followed erosionally by trough crossbedded sands (sets up to 40 cm) resting in channels up to 1 m deep and 3 m wide. In places, these channels cut down to the basal clay layer. The uppermost part of the sequence consists of tabular and trough crossbedded coarse sands and gravels. The coarsening-upward sequence is interpreted as the fill of an abandoned channel. The clay represents fines washed over a levee from an active channel in flood. As more material was washed in, gentle flow began and ripples were formed in silt and fine sand. Levee breaching introduced bed load material into the new channel, forming the crossbedded gravels and sands. End_of_Article - Last_Page 610------------

On the characterization of ceramic clays

AbstractCeramic clays are characterized by a method that stems from the IL/MA procedure proposed by Keeling (1958a, b) but which is more rapid to perform and more basic in concept. By thermogravimetric methods an estimate is made of both OH water and interlayer plus physically adsorbed water. These are plotted against each other in a manner similar to the IL/MA plot. The composition of the clay can be characterized uniquely on such a diagram by estimating either the quartz or the free silica contents of a sample, its silt, and < 2μ fraction, and plotting for each on a 100% clay basis their OH water, and interlayer and physically adsorbed water. Simple methods are given for assessing these factors. The determination of interlayer water content could form the basis of a method of plant control of clay composition in a way similar to that proposed by Keeling using moisture adsorption determinations.

Possible methods of preventing groundwater contamination at landfill sites; case studies from Nepal

Significant increase in municipal solid waste in Nepal has led to build up of few landfill sites in urban areas. Among several problems existing in the landfill sites, groundwater and soil contamination are the major problems. The major causes of contamination are generation of leachate, improper design and selection of materials in the landfill sites. Therefore, understanding on physical and chemical behavior of the leachate with the fill material, and the landfill site design parameters is required to solve the problem. Three landfill sites (Gokarna, Sisdol and Pokhara) were studied as case studied to identify leakage problems in view of controlling leachate migration. Hydraulic conductivity, particle size distribution and shape of basement material were studied. Gokarna Landfill Site did not have proper clay lining or other technology that prevents groundwater contamination. The Sisdol and the Pokhara landfill sites were improved sites but were devoid of clay lining. To control leachate migration, proper basement and other design is required. The slope of the basement clay liner should be adjusted properly according to the hydraulic conductivity of the clay to prevent leachate movement downward. Similarly, selection of shape and size of drainage material is important for aeration, and to prevent from leachate clogging and puncturing the basal clay or geo-membrane. The case studies suggested need of some improvements for basal design of landfill sites for future. Besides the basement design, design of leachate suction well and vegetative technology for leachate treatment are necessary. A basement design is proposed that will be economic and suitable for developing countries. This paper discusses about some drawbacks in technical practices in some landfill sites in Nepal and suggests possible methods that can be applied in constructing landfill sites for reducing contamination. doi: 10.3126/bdg.v11i0.1542 Bulletin of the Department of Geology, Tribhuvan University, Kathmandu, Nepal, Vol. 11, 2008, pp. 51-60

Borden Delta (Lower Mississippian) in North-Central Kentucky: ABSTRACT

The Borden Formation in north-central Kentucky consists of 4 widespread units--a basal clay shale, a middle siltstone and silty shale, a glauconite-rich marker bed, and an upper siliceous silty carbonate. The lower 2 units are a clastic deltaic wedge, the upper limit of which is defined by the marker bed. The wedge thins gradually westward at a few feet per mile to the vicinity of Elizabethtown, where it was found by areal geologic mapping to pinch abruptly from 260 to 50 ft southwestward across a zone about 2 mi wide. This more steeply sloping surface represents the clinoform or foreset front of the Borden delta. Recognition of this part of the fossil delta is an important adjunct to reconstructing the Late Devonian and Early Mississippian geography of the Illinois basin. Within this framework, several extrapolations are possible: (1) time planes within the delta parallel the delta front; (2) the water into which the delta prograded was at least 200 ft deep in this area; (3) the basal clay shale represents prodelta fondoform sediments; (4) the middle siltstone and silty shale represent the clinoform sediments of the delta proper; and (5) the upper silty carbonate represents resumption of sedimentation under somewhat different conditions following a period characterized by thin glauconite-rich sediment of possible nondeltaic origin. End_of_Article - Last_Page 855------------

Mechanisms of clay stabilization with inorganic acids and alkalis

A series of mono- and di-valent cation hydroxides, and certain strong acids, were allowed to react with a two- and a three-layer clay mineral (kaolin and montmorillonite) under conditions simulating those for normal soil stabilization in field practice, i.e. mixed, remoulded, and moist-cured at a moisture content and density approximating optimum compaction conditions. The progress of reaction was followed over extended periods of time, up to two years. Changes in strength and volume were correlated with chemical and mineralogical changes in order to identify those bonding mechanisms which contribute to inorganic soil stabilization. For an additive level of 10% by weight dry clay basis (9.1% total dry solids basis) it was shown that several distinct stabilization mechanisms exist. One major mechanism is the surface coating of fabric units, and another the reinforcement of the soil by product formation in crevices, angularities, pore constrictions, and similar defects which influence the mechanical properties of the whole sample. The importance of these reactions to practical soil stabilization is thus demonstrated.

Further Notes on the Hittite Laws

Previous articleNext article No AccessFurther Notes on the Hittite LawsHans G. GüterbockHans G. Güterbock Search for more articles by this author PDFPDF PLUS Add to favoritesDownload CitationTrack CitationsPermissionsReprints Share onFacebookTwitterLinkedInRedditEmail SectionsMoreDetailsFiguresReferencesCited by Journal of Cuneiform Studies Volume 16, Number 11962 A journal of ASOR Article DOIhttps://doi.org/10.2307/1359428 Views: 2Total views on this site PDF download Crossref reports no articles citing this article.

Geological Age of the Lehner Mammoth Site

AbstractThe late Pliocene basal clay of the region and remnants of later deposits are cut by a perennial stream of pluvial age. Bones and artifacts, including Clovis- fluted points, occur in gravel and other channel deposits in a meander bow of this stream. The bone bed is overlain by a black swamp deposit indicating a subhumid climate and by calichified silts indicating arid conditions, both cut by an Altithermal channel. The hunt, stratigraphically pre- Altithermal, is dated by the equation of the relatively warm and dry 14-to-12 foot level in the San Augustin Plains profile with the Allerod of northern Europe (12,500-10,800 B.P.). This semi-arid period, called the Datil Interval or Datil Drought, is believed to have caused the extinction of the mammoth in both the Southwest and the High Plains by 11,500 B.P. The Sulphur Spring stage Cochise deposit at Double Adobe, which is overlain by a bed containing a mammoth skull, is dated at more than 12,500 B.P. The mammoth hunts of the Lehner and Naco sites are assigned an age of 13,000 or more years.

Clay Mineralogy of Some Basal Pennsylvanian Sandstones, Clays, and Shales: GEOLOGICAL NOTES

Clay Mineralogy of Some Basal Pennsylvanian Sandstones, Clays, and Shales: GEOLOGICAL NOTES

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 ...

The Age of the Norwich Brickearth

Following the original suggestion of Searles Wood, the Norwich Brickearth has been referred to the same phase of glaciation as the Basement clay of Holderness, which in turn has been correlated with the Scandinavian Drift of Durham. Recent work by Stather (1929) and by Bisat (1932, 1935) shows, however, that the Basement clay of previous authors (Wood, Lamplugh, Reid, and others) may be resolved into a drift (a) of Scandinavianorigin, together with (b) deposits of separate derivation; and the time now seems appropriate for a critical examination of the position of the Norwich Brickearth in the glacial sequence.

The Glacial Gravels of the Market Weighton Area and Related Deposits

I. Introduction The conditions obtaining in the Vale of York during the Glacial Period are generally considered to have been as follows. A glacier from the Lake District passed over Stain-more and continued to flow eastward until such time as the Scandinavian ice impinged upon the coast. The estuaries of the Tees and Humber then became blocked, forcing the Stainmore glacier down the Vale of York and simultaneously giving rise to a “Lake Humber” south of York and a “Lake Pickering” east of Malton. These events must have occurred during the period of deposition of the Basement Clay of Holderness. The Scandinavian ice then retreated sufficiently to allow Scottish ice to pass down the coast. Finally, during the Hessle Clay period, the ice reached as far south as York, and in Holderness as far west as Driffield and Kipling Cotes. Unless, therefore, the Basement Clay blockage had a permanent effect, there would be a return to the old directions of drainage until a second closure caused a repetition of lacustrine conditions. In brief, there must have been a “Lake Humber” on at least two separate occasions, but direct evidence has never been forthcoming of the existence of more than one. Moreover, in the Vale of York, the recognition of boulder-clays of different ages is difficult, since each glaciation would produce the same conditions; glaciers would travel along the same courses as before, giving rise to boulder-clays lithologically identical. There would be no means of separating them except by an appeal

Upper and Lower Palaeolithic Man in East Yorkshire

The most complete section of the glacial series of deposits described and illustrated in Lamplugh's classic paper entitled “On the drifts of Flamborough Head” is that which is located at Danes' Dyke.Referring to this section Lamplugh says:—“I have spent much time in exploring this section, and consider that the beds up to this horizon represent the Basement Clay, while the persistent upper band of brown Boulder-clay (3) is all that remains of the upper Clay of Sewerby, this bed and the underlying sand and gravel (3b) together taking the place of the Purple Clays of Bridlington and Holderness. Above this clay lie the Sewerby Gravels (2b), the lower part chalkless and the upper layers composed chiefly of chalk-pebbles, as noticed farther west. A few feet of loamy stuff overlies these gravels at the cliff top (2c), resembling a weathered Boulder-clay, and a little farther east (near Hartindale Gutter) a seam of Boulder-clay certainly appears in these gravels, their contemporaneity with the uppermost part of the Boulder-clay, and consequently their Glacial age, being thus fully established.”

The Petrology of some Yorkshire Boulder Clays

One of the most imposing and best known exposures of glacial deposits in the north of England is the line of high cliffs along the Yorkshire coast, between Patrington and Withernsea, the highest point of the cliffs being at Dimlington Beacon. Here 140 feet of glacial material is exposed in the cliff face and the foreshore is entirely of boulder clay, the base of the deposits being a long way below sea-level. The work of this paper relates to the clays and sands in this cliff exposure. The deposits are easily distinguished as being of three varieties; at the base and along the foreshore, a dark leaden grey to black, tough boulder clay, including lenticles of sand frequently containing shell fragments; this is succeeded by a thick clay of rich purple or red colour, with noticeably more contained boulders, and near the top, much included sand in lenticles, passing into a bed of pure sand; the highest part of the cliff is of earthy clay, foxy red in colour, and with relatively few boulders. These are respectively the Basement clay, the Purple clay, and the Hessle clay. Between the Basement clay and the Purple, and at the top of the Purple clay, there are beds of sand a few feet thick; these are not to be seen at all parts of the coast, but are generally present in the highest sections. Fig. 1 is a vertical section of the Dimlington cliff, and the Roman numerals indicate the specimens petrologically examined.

VERTICAL DISTRIBUTION OF EAST YORKSHIRE ERRATICS

Clement Reid’s Geology of Holderness was published in 1885, forty-three years ago, and following the lead of Wood and Rome, who preceded him by seventeen years, he recognised three or four distinct boulder clays, in the Coast sections, and adopted the same names for them that they had applied, viz: — Hessle Clay. Upper Purple Clay. Lower Purple Clay. Basement Clay. Reid went into some details regarding the position, colour and texture of these clays, but said comparatively little about the boulders which they contain. Reid returned to Yorkshire in 1888 to superintend the excavations which were at that time being carried along the line of buried cliff at Sewerby. This was a chance not to be missed. We told him that a Geological Society had been formed in Hull, and that the members were studying the Holderness Drifts, but were finding some difficulty in recognising with certainty the different boulder clays described in his book. In reply, he said that at first the tracing of the divisions might not be easy, but they were really there and a little more experience would make all clear. The best sections were in South Holderness, in the neighbourhood of Dimlington where the complete series occurred. “But go,” he said, “during Spring tides, and if possible after a period of north-east winds, which will probably clear the sand and shingle from the base of the cliffs and beach, when you will see a great spread of Basement Clay on the beach, and plenty of …

The Bagshot Beds of Bagshot Heath (a Rejoinder)

The Author maintains that the northerly attenuation of the Lower Sands and of the ‘green-earth series’ between the two principal brick-clays of the district is an established fact. He insists on the value of the Wellington College well-section as a vertical datumline, on account of its proximity to the northern outcrop (which is not the case with the Goldsworthy section), and criticizes the arguments recently put forward in favour of an alternative and very doubtful sectional reading. But it does not stand alone, for the well-section at the Bagshot Orphan Asylum gives practically the same sequence, and affords strong evidence of the thinning northward of the above-named deposits. (Other instances cited by the Author in ‘Recent Contributions’ &c., corroborate the reading he has adopted.) The Goldsworthy section itself lends strong corroborative evidence as to the value of the College well-section. The evidence of attenuation in the direction of Bracknell the Author reserves for the present. In his paper published in the February number of the Society's Journal for the current year, Mr. Monckton ignores the determinative value of stratigraphical alignment of the clays claimed as the basal clays of the Middle group with clays of the same character seen cropping out from below the ‘green-earth series’ at no great distance. This evidence of stratigraphical alignment must be allowed due weight when set against evidence derived from such lithological characters as the presence of pipe-clay, mica, and false-bedding. The Author considers that the argument as to the fossil evidence is over-stated

Bored Stones in Boulder Clays

STONES bored by Pholas and Saxicava are by no means rare in the shelly “Basement clay” of East Yorkshire, and I have occasionally found examples in which the shells remained in the borings surrounded by fossiliferous sand, just as described by Mr. T. Mellard Reade from the Lancashire area. These stones are generally limestones of various kinds—Carboniferous, Magnesian, Jurassic, or Cretaceous—and the diversity of their origin seems to show that they have first been scattered over a shallow sea-bottom by floating ice, and afterwards perforated, but I do not think that they can be taken as proof of the marine origin of the boulder clay in which they now lie.

Petrological Notes on some Boulders from the Boulder-clays of East Yorkshire. (An Appendix to Mr. Lamplugh’s Paper.)

[NOTE.—The numbers in brackets refer to slides in the Woodwardian Museum Cabinet at Cambridge.] [929] From the Lower Purple Clay, South of Withernsea. A conglomerate including small rounded pebbles, some of dark limestone, about one-fifth of an inch long, and grains of quartz in a compact ground. Under the Microscope a slice shows abundant rounded grains of quartz, with rolled pebbles of (probably dolomitized) limestone, imbedded in a mass of carbonate of lime. This calcareous matrix often shows the characteristic cleavage of crystalline calcite; but in other places are little ellipsoidal concretions with both concentric and radial structures, and showing the black cross in polarized light. Though less coarse than the usual type, there can be no doubt that this rock is the “Brockram,” which forms the basement of the Permians in the Eden Valley. A slide [514] from near Appleby shows precisely the same characters, including the little oolitic concretions. Brockram boulders were long ago recorded by Phillips from the Yorkshire coast, where they are not at all uncommon. [930] From the Basement Clay at Bridlington Quay. A dark grey doleritic rock, showing little glistening felspars in a dark compact ground-mass. Micro. The porphyritic felspars, about one-eighth of an inch long, are rather rounded, as if by corrosion, and sometimes enclose portions of the ground-mass. They are very clear, and show Carls-bad-twinning, but the finer twin-lamellation is very difficult to detect. This is owing to the nearly straight extinction of the crystals, which must belong to a variety ...