Fragments Of Chalk Research Articles

Variability and complexity in calcite-based plaster production: A case study from a Pre-Pottery Neolithic B infant burial at Tel Roʻim West and its implications to mortuary practices in the Southern Levant

The production of lime plaster is considered as one of the hallmarks of the Pre-Pottery Neolithic B [PPNB] period in the Southern Levant, where lime plaster has been used not only in architectural but also in mortuary contexts. In this study we investigate the technology used to produce plaster associated with an infant burial found in the PPNB layers at the site of Tel Roʻim West [TRW]. Bulk sediment samples and undisturbed impregnated sediment block samples were studied using Fourier Transform Infrared (FTIR) spectroscopy, micromorphology and micro-FTIR. In addition, we report the results of experimental heating of chalk and marl used as geological reference materials. The results indicate that plaster associated with the burial appears in various compositions, and that none of them is based on pyrogenic production of lime. Rather, these plaster materials are composed of calcite-based crushed/ground local marl and/or chalk that were mixed with anthropogenic remains including fired-clay aggregates, burnt (carbonised) chalk fragments, bones and vegetal matter (the latter clearly used as temper). The case study from TRW provides new insights regarding the production of non-pyrogenic calcite-based plasters in mortuary contexts during the PPNB. This study calls for a re-consideration of archaeological plaster technology: while in the field it is often assumed that PPNB plaster is a product of pyrotechnology our results suggest that in certain cases archaeologists should consider other, non-pyrogenic, technologies of plaster production. We argue for a more widespread use of non-pyrogenic calcite-based plaster than previously suggested, not only in architectural but also in mortuary contexts. We discuss the social, ecological and technological roles plaster production played in PPNB societies in the Southern Levant.

Metalworking at Megiddo during the Late Bronze and Iron Ages

Metalworking at Megiddo during the Late Bronze and Iron Ages

Problems with determining the particle size distribution of chalk soil and some of their implications

Particle size distribution (psd) is one of the most important features of the soil because it affects many of its other properties, and it determines how soil should be managed. To understand the properties of chalk soil, psd analyses should be based on the original material (including carbonates), and not just the acid-resistant fraction. Laser-based methods rather than traditional sedimentation methods are being used increasingly to determine particle size to reduce the cost of analysis. We give an overview of both approaches and the problems associated with them for analyzing the psd of chalk soil. In particular, we show that it is not appropriate to use the widely adopted 8 µm boundary between the clay and silt size fractions for samples determined by laser to estimate proportions of these size fractions that are equivalent to those based on sedimentation. We present data from field and national-scale surveys of soil derived from chalk in England. Results from both types of survey showed that laser methods tend to over-estimate the clay-size fraction compared to sedimentation for the 8 µm clay/silt boundary, and we suggest reasons for this. For soil derived from chalk, either the sedimentation methods need to be modified or it would be more appropriate to use a 4 µm threshold as an interim solution for laser methods. Correlations between the proportions of sand- and clay-sized fractions, and other properties such as organic matter and volumetric water content, were the opposite of what one would expect for soil dominated by silicate minerals. For water content, this appeared to be due to the predominance of porous, chalk fragments in the sand-sized fraction rather than quartz grains, and the abundance of fine (< 2 µm) calcite crystals rather than phyllosilicates in the clay-sized fraction. This was confirmed by scanning electron microscope (SEM) analyses. “Of all the rocks with which I am acquainted, there is none whose formation seems to tax the ingenuity of theorists so severely, as the chalk, in whatever respect we may think fit to consider it”. Thomas Allan, FRS Edinburgh 1823, Transactions of the Royal Society of Edinburgh.

Geoarchaeology of the Kostenki–Borshchevo sites, Don River Valley, Russia

AbstractThe Kostenki–Borshchevo localities include 26 Upper Paleolithic sites on the first and second terraces along the west bank of the Don River, near Voronezh on the central East European Plain. Geoarchaeological research from 2001 through 2004 focused on sites Kostenki 1, 12, and 14, with additional work at Kostenki 11 and 16, and Borshchevo 5. The strata are grouped into three units (bottom up): Unit 1, &gt; 50 ka, consists of coarse alluvium (representing upper terrace 2 deposits) and colluvium, overlain by fine‐grained sediments. Unit 2 includes archaeological horizons sealed within two sets of thin lenses of silt, carbonate, chalk fragments, and organic‐rich soils (termed the Lower Humic Bed and Upper Humic Bed) dating 50–30 ka. Separating the humic beds is a volcanic ash lens identified as the Campanian Ignimbrite Y5 tephra, dated elsewhere by Ar/Ar to ca. 40 ka. The humic beds appear to result from the complex interplay of soil formation, spring deposition, slope action, and other processes. Several horizons buried in the lower part of Unit 2 contain Upper Paleolithic assemblages. The springs and seeps, which are still present in the area today, emanated from the bedrock valley wall. Their presence may account for the unusually high concentration of Upper Paleolithic sites in this part of the central East European Plain. Unit 3, &lt; 30 ka, contains redeposited loess with a buried soil (Gmelin Soil) overlain by a primary full‐glacial loess with an associated Chernozem (Mollisol), forming the surface of the second terrace. © 2007 Wiley Periodicals, Inc.

The depth and productivity of chalky soils

Abstract. In south‐east England, no relation between cereal yield and soil depth is shown by field estimates or harvesting microplots with depths to compact chalk of 23–121 cm. Differences in yield of ryegrass and wheat grown in cylinders containing artificial profiles with different thicknesses of topsoil, subsoil, chalk rubble and clean chalk from the Panholes series on Middle Chalk were attributed almost entirely to different amounts of nutrients. Chalk fragments supplied about 20% by weight of moisture to plants, and topsoil and subsoil about twice as much. Laboratory studies confirmed that fragments of Middle Chalk from near Wye (Kent, UK) hold about 20% water under tensions between 30 and 1500 kPa, but showed that topsoil and subsoil hold slightly less than this. The discrepancy in estimating water holding capacity arises because profiles over compact chalk drain only slowly from saturation. In this wet state they are very vulnerable to water erosion. It was also observed that ryegrass roots under water stress can penetrate well rammed chalk rubble, and that substantial amounts of water can rise 20 cm through solid chalk within a few days. It is concluded that soil losses resulting from erosion over normal porous chalks diminish cereal yields only slightly provided nutrient levels are maintained.

Pockmarks and the Recent geology of the central section of the Norwegian Trench

A small area of 3.1 km 2 in the Norwegian Trench has been selected for a detailed analysis of possible relationships between the Recent geology and the formation of pockmarks. Two sets of side-scan sonar and deep-towed boomer (DTS) data were used for the analysis. The most recent deposit is Unit 1, consisting of finely layered soft, silty clays. Unit 1 has been divided into three seismic subunits (1A, 1B and 1C), based upon the boomer records. The underlying Unit 2 is seismically homogeneous, consisting of stiff, silty, sandy clay with fragments of chalk. Most of the irregularities in the surface of Unit 2 are found to be furrows traversing the study area in a N—S general direction. The seabed is heavily pockmarked (mean density: 30/km 2) and some of the pockmarks are asymmetric with steep ESE walls. The maximum pockmark depth within the study area is 5.8 m, and the maximum wall angle is about 12°. In addition to describing the Recent geology and surface pockmarks the following features are described and their relationship with pockmark formation discussed: (1) “sloping reflectors”, found below some of the pockmarks; (2) “columnar disturbances”, seen under many of the buried pockmarks; and (3) “masked reflectors”, intermittent strong reflectors found within Subunit 1A, which are probably caused by a raised gas concentration in porous layers. Pockmarks and associated features are assumed to be caused by gas escaping through the seabed. A possible gas migration mechanism through the interface between Units 1 and 2 and through Unit 1 is also discussed.

An Insect Fauna of Late Bronze Age Date from Wilsford, Wiltshire

The Wilsford shaft, discovered at Normanton Gorse, Wiltshire, was first described by Ashbee (1963). It is one of the earlier of a series of artificial shafts or ritual wells which are a feature of later prehistoric Europe (Schwarz 1962; Piggott 1965). They are either associated with ceremonial structures and burials, or else are in isolation. Cults centring upon them were current in Roman times. The English examples, their associations and usages, have recently been discussed by Ross (1967 s.v.). Before excavation, the Wilsford shaft was a 'pond-barrow', i.e. a circular dish-like depression surrounded by a bank which had been destroyed by total agriculture. Such 'barrows', some of considerable size, are a regular feature of the barrow cemeteries about Stonehenge (Piggott 1951, Fig. 1) and are found elsewhere in Wiltshire. Excavation of this pond-barrow disclosed an inverted conical cavity which proved to be the weathering cone of a vertical, cylindrical shaft 6 ft in diameter and almost 100 ft (30 m ) deep (Fig. 1). At this depth a fault in the chalk through which water could enter the shaft was encountered and this may have been the reason that the original excavators stopped digging. The shaft had been dug in vertical stages, and checked by plumbing and a template. Deep antler pick marks showed where deviations from the vertical had been corrected and the sides had been dressed with a broad-bladed metal axe. Seams of flint had been broken through. Near the top of the shaft artifacts of Recent, Roman and Iron Age cultures were recovered while at about 60 ft the greater part of a late Bronze Age pot was found. The bottom of the shaft contained a considerable quantity of organic material. This included much wood, both the remains of fabricated containers and also timber, broken branches, twigs and other pieces. Also present were seeds, leaves, cereal straw, moss, possibly fungi and pollen as well as pieces of rope and hide. Artifacts included a shale ring, bone pins and amber beads. Until the time of its excavation by Mr Ashbee and his colleagues the lowest part of the shaft's contents appears to have been more or less continuously waterlogged, thus being preserved in conditions normally only met with in bogs and lakes. This would account for the remarkably fine state of preservation of the insect remains. A sample consisting of pieces of wood collected at depths between 96 ft 6 in. and 97 ft 6 in. (29.4 m and 29*8 m) was submitted to the National Physical Laboratory for radiocarbon dating and an age of 3330 + 90 B.P. was obtained (N.P.L. 74) (Ashbee 1966). It was from this layer that the insect remains described here were obtained. The material examined, which was all recovered from the bottom 6 ft (1 8 m) of the shaft, filled eighteen jars and consisted of a mixture of silt, small fragments of chalk and a mass of comminuted wood and other vegetable matter. It had been mixed with water, alcohol and glycerine to preserve it. It was estimated that the volume of this sludge examined for insects was about 23 1.

Solution of the chalk in the Mimms Valley, Herts

Solution phenomena, consisting of vertical, oblique, and horizontal pipes infilled with Eocene sand, flints, and fragments of chalk are described. Examination of the Mimms Valley has shown that swallow-holes are even more abundant than was formerly supposed. The reasons for the Exceptionally localised solution of the Chalk in the area are briefly discussed.

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.

XXIV.—Chalk Boulders from Aberdeen and Fragments of Chalk from the Sea Floor off the Scottish Coast

In December 1908 I received from Mr A. Earland a fragment of a rock, believed to be chalk, which had been dredged from the bottom of the North Sea. Mr Earland also informed me that he believed boulders of a similar rock occurred in some profusion near what is known as the Kinnaird Deep, off the northern coast of Aberdeenshire. As a result of our correspondence a little later, Professor D'Arcy Thompson asked me to investigate such boulders as might presumably be chalk, dredged from the northern parts of the North Sea during the operations of the s.s. Goldseeker, a vessel employed by the North Sea Fisheries Commission, and he has kindly permitted me to include a description of the boulders found by the Goldseeker in the details of this paper.

Boulder Clay in Essex

THE extensive deep sewerage works now being carried out under Mr. H. Tooley for the Essex County Council at Harlow have disclosed facts of considerable interest to students of glacial geology. The main sewer from Potter Street cuts through the hill of Boulder Clay between that place and Harlow at depths ranging up to 32 ft. The excavations and tunnels are entirely in the Boulder Clay, which assumes here an extraordinary till-like character, more so than in any exposure which has come under my observation in southern England. It is a black (rather slimy) clay, such as may well have been derived from the pounding up of Kimmeridge Clay, or Oxford Clay (as the latter is worked at the extensive works of the London Brick Company at Fletton, near Peterborough). Through this numerous chalk fragments are dispersed, and in the lower portions boulders (rounded, subangular, angular, and often beautifully striated) are met with in great quantity.

Note on Drift-gravels at West Wickham (Kent)

There are two deposits of Drift–gravel at West Wickham upon which I propose to offer a few remarks. The first occupies the bottom of a valley which winds round the southern and western sides of Hayes Common and thence to Bromley. This is shown on the Geological Survey map, but there it appears that the Drift–gravel terminates somewhat abruptly near Keston. The valley itself, however, runs much farther south, extending to the North Downs near Tatsfield and roughly coinciding with the direction of the boundary–line between Kent and Surrey, but following a course varying from 2 miles to ½ mile east of that boundary. A fairly good section of the gravel in the bottom of this valley may be found in a pit at Gates Green, a point near the junction of the three parishes of West Wickham, Hayes, and Keston. The beds exposed consist of rolled flints, fragments of Chalk, and bands of sand containing minute fragments of flint and portions of Chalk–fossils, including a large proportion of foraminifera. The beds also contain a few rolled fragments of ferruginous sandstone, probably derived from the Lower Greensand. The character of these beds is precisely what might be expected from the destruction of Chalkbeds. The fragments from the Lower Greensand also go to show that these gravels have a definite, although perhaps not direct, relation to the forces which excavated and denuded the Wealden area. The bands of sand indicate, I would submit, periods of comparative tranquillity

VI.—The Chalky and other Post-Tertiary Clays of Eastern England

Among the so-called Glacial beds, none fills a larger place in geological literature than the Chalky Clay of Eastern England. I prefer to call it the Chalky Clay, as Searles Wood named it, rather than the Chalky Boulder-clay, because boulders in the true sense of the word, such as characterize the genuine Boulder-clays of North Britain, are infrequent in it. The term Chalky applied to this clay depends on the fact that it is more or less crowded with chalk rubble and chalk fragments of various sizes, and that it has also incorporated in it a considerable quantity of chalk dust, whence its colour and superficial appearance. These peculiarities, which mark it over a wide area from Yorkshire to Finchley, and from Southwold to Warwickshire, are, nevertheless, a secondary, and not a primary, feature of the clay, and have disguised and confused the problem of its explanation.

Notes on Field Excursion for the Examination of the Coast between Bridlington and Filey

In connection with the General Meeting at Bridlington a Two-day’s Field Excursion was arranged for the examination of the coast sections between Bridlington and Filey, on Friday and Saturday, June 8th and 9th. The party was under the leadership of the Rev. E. Maule Cole, M.A., F.G.S., and Messrs. P. F. Kendall, F.G.S., and J. W. Stather, F.G.S. On the arrival at Bridlington of the trains from Hull and Scarborough, a start was made along the beach, and the Glacial and Chalk beds up to the South Landing were examined. A special halt was made there in order to allow of a search for the bed containing arctic shells, identifiable fragments of which were obtained. The road was then taken to Flamborough where a West Riding contingent was added to the party, and, after luncheon, the journey was resumed to the Lighthouse in wagonettes. There a prolonged examination of the large boulders of Speeton and Kimeridge Clay, and Red Chalk, was made, and the remarkable crater-like hollows, formed by the falling-in of sea-caves, were duly admired. A rapid walk was then taken along the cliffs to Bempton, the notable example of denudation at North Landing being of special interest. Fragments of chalk were found along the cliff top, having been torn off and carried up by the wind in recent heavy gales and strewn over the fields for considerable distances inland. After a rest to view the contortions of the Chalk at Old Dor, and the pranks of thousands of ...

On some recent Discoveries of Flint Implements of the Drift in Norfolk and Suffolk with observations on the Theories accounting for their Distribution

I n June 1866 I had the honour to lay before the Society a paper upon some flint implements then lately found at Thetford in the valley of the Little Ouse river†; I have lately occupied myself with further investigations of the same district, the results of which, are, I trust, of sufficient interest to justify me in bringing them to the notice of the Society. The localities which I have now examined are four in number. In each of these flint implements have been found, and in several of them in great abundance, corresponding in the main, as well in fashion as in material, with those of St. Acheul, Thetford, Salisbury, and Icklingham, which are now so well known. Broomhill .—The first deposit which I have to notice is found at Broomhill, on the north bank of the river, about five miles from Thetford, and two from Santon Downham mentioned in my former paper. The implements, which are usually much rolled and worn, and are often stained to a chocolate-colour, are here found in a gravel-pit about 350 feet from the river-bank. They are usually met with in a bed of ferruginous flint-gravel about 2 feet thick, resting immediately on the surface of the chalk, and 5 or 6 feet above the level of the river. This gravel, which is very coarse and not much rolled, contains large flint nodules, some of them weighing over a hundredweight, and is mixed with rounded quartzite pebbles and rolled fragments of chalk. It is

V.—Notes on the Geology of South Beds

Since my former communication on this subject, which appeared in the Geological Magazine for April last, (p. 154) I have had several opportunities of re-visiting some of the cuttings, on the Midland Railway, therein referred to, respecting which some doubts were expressed in reference to the age of the deposits exposed to view, and, as they are now completed, more precise observations can be made than when they were only just commenced. The cutting, south-east from Westoning, (which, in an Editorial note, was suggested might be of Tertiary age) exposes a dark heavy clay, which, upon the most rigid examination, furnished not the least trace of rolled fragments of Chalk or flints, or any other substance so frequent in the Tertiary clays of this neighbourhood, which would lead to the inference that it had been deposited subsequently to the Cretaceous era. It, however, contains what would strongly indicate that it is coæval with the Greensand, namely, a continuous band of coprolitic nodules, averaging about a foot in thickness. This layer passes through about one-third of the cutting, and may be traced from its commencement on the north-west side of the hill, passing along the face of the cutting with a gentle dip, until it reaches the level of the line, when it passes out of sight, nor does it re-appear on the south-east side of the excavation. The fossils associated with the nodules are Lamna, Belemnites, Parasmilia, and Terebratulœ, all of which are abundant in the coprolite beds at Hexton and other places in the immediate vicinity. Both above and below the coprolites the caly is identical in character, and must have been deposited eontemporaneously with its associated nodules, and, as far as I can judge, it is the equivalent of the bed h of the section given by Mr. W. Whitaker, in the Quart. Journ. Geol. Soc., vol. xxi., 1865, pp. 399, “On the Chalk of Bucks.” About the middle of the cutting is a considerable accumulation of light-brown coloured drift-sands, that lie in a basin-like hollow, that has been eroded from the summit of the hill.

On the Drift at Sangatte Cliff, near Calais

The flat and extensive plain around Calais is composed of Tertiary strata (bearing a close resemblance to the London series), reposing on Chalk and overlaid by a thick covering of flint-gravel. At the small village of Sangatte, three miles W.S.W. from Calais, and immediately opposite to Dover, the chalk rises to the surface, forming the well-known promontory of Blanc-nez. These chalk cliffs were described in the Transactions of the Geological Society for 1820* by Mr. W. Phillips, who alludes briefly to the large accumulation of flint-gravel, and observes “that this kind of deposit is confined to the summit of the rising cliff, which consists beneath of sand lying in thin beds of different colours”......“but the general tint of the mass is greenish.” He continues—“the probability that this sand may belong to the Plastic Clay formation occurred to me, but I discovered nothing beyond the general appearance of the sand to strengthen the suspicion.” He correctly notices that this newer deposit abuts against the Chalk. In 1839, M. D'Archiac also noticed these cliffs, and stated that they exhibited a flint-gravel 8 metres thick, overlying 3 metres of a yellowish sandy clay with fragments of chalk—the whole reposing on a bed of deep greenish coloured sand about 3 metres in thickness, unconformable to the Drift above†, and apparently belonging to the Sables Inferieurs, but without fossils to prove it. When passing through Calais last autumn, I visited Sangatte, for the purpose of examining these erupted Tertiary strata; but either they have been