Institute Of Geological Sciences Research Articles

Generation of Pi2 pulsations by bursty bulk flows

We present the first observations directly relating bursty bulk flows (BBFs) to Pi2 pulsations. At ISEE 2, a large earthward flow was observed. The Institute of Geological Sciences (IGS) magnetometer chain located at the same local time as ISEE 2 recorded Pi2 pulsations, slightly delayed relative to flow onset, consisting of a long‐period (7–8 mHz) component associated with oscillations of the substorm current wedge. We demonstrate that the ionospheric current began to increase 90 s before the arrival of these Pi2 pulsations. We argue that this precursor was generated by earthward convection of plasma sheet plasma. Phase skips at midlatitudes on the nightside are associated with new flow bursts at ISEE 2. The Air Force Geophysics Laboratory (AFGL) magnetometer chain, which was located on the dusk flank, measured Pi2 pulsations that started ∼90 s after the flow bursts. We demonstrate that there is a one‐to‐one correlation between impulsive flow onset in the tail and Pi2 pulsations. We also show that oscillations at AFGL are directly related to temporal variations of the flow. Thus we suggest that the characteristic frequencies of low‐latitude Pi2 pulsations are established by the temporal structure of processes in the near‐Earth magnetotail.

Radiocarbon Distribution in Northwest Belarus Near the Ignalina Nuclear Power Plant

Since 1994, the Institute of Geological Sciences has undertaken an environmental monitoring program to measure radiocarbon levels in territory adjacent to active nuclear power plants (NPP). We determined 14C concentrations in natural objects from areas contiguous to Ignalina NPP as well as 14C background concentration in areas remote from the NPP. In the environs of the Ignalina station comparatively elevated levels of 14C were observed in vegetation and waters of Lake Drisvyaty. This appears to be a consequence of release of carbon radioisotope into the atmosphere and probably into waters of the lake during operation of the nuclear reactor.

Petrology and Schedules of Stone Artefacts

The worked stone, other than sarsen, was kindly examined macroscopically by Mr R W Sanderson of the Petrological Department of the Institute of Geological Sciences, and the following notes were compiled from his verbal comments. Apart from the polished stone axes, the majority of the rocks are not very distinctive in type, and except for a few specimens (eg S2, S15, and S20 and possibly S3, S6, and S5), it has not been possible to identify their sources.

The Geology of the Area

Mr B W Conway of the Institute of Geological Sciences has kindly made the following comments on the geology of the site:“The causewayed enclosure is sited on the eroded terminal surface of the gravel train of the Upper Floor Plain Terrace at the junction of the Coinè and Thames river valleys (see OS 6 inch geological maps Buckinghamshire 56 SE, 58 NE and Middlesex 19 NE and SE (and Fig 2)). The late Professor Zeuner traced the profile of this terrace and claimed that it grades into the Late Monasirian sea level (7.5 metres) of the latter part of the last interglacial. The Coinè valley Flood Plain joins that of the Thames at Wraysbury and projects into the Thames as a distinct, slightly raised, delta. This delta was formed by the piling up of aggradation by the Coinè beyond the capacity of the Thames to remove it. The presence of this delta was the cause of the breaking up of the Coinè into a series of distributory channels: mainly those of the River Coinè, the Coinè Brook and Wyrardisbury River. These in turn eroded the Cclne delta and the Flood Plain gravel train. Erosion by the several distributory channels left slightly elevated gravel ridges between their valleys and clays, peats, and silts accumulated in these valleys. The eroded remnants of the delta and the Flood Plain Terrace appear as low “islands” of gravel between marshy stream valleys. The Staines causewayed enclosure is sited on the southern tip of the largest of these islands, which is approximately 4km long, has an average width of about 0.4km, and an area of approximately 182.lha.”

Re‐evaluation of Reference Materials, IGS 21‐39

The 20 ore and concentrate reference materials originally issued by the Institute of Geological Sciences (as it then was) in 1977 have been reevaluated using robust as opposed to classical statistical techniques. The opportunity has also been taken to correct minor errors and to incorporate any new data. One material, the nickel concentrate, IGS 20, has been withdrawn due to incipient oxidation. A total of 24 elemental concentrations in the remaining 19 samples have received revised values.

Anthracitization of coals in the South Wales coalfield

Investigations by the Institute of Geological Sciences on potential geothermal water sites in the coalfield of South Wales have been reported. They are of considerable interest and revive the controversy about the nature of the heat-source responsible for the anthracitization of some coals in this classic area. In the absence of exposed post-Carboniferous igneous rocks in the coalfield, general opinion has favoured heat generation by friction along faults or “disturbances”. We re-examine the evidence in the light of more recent geophysical and geochemical investigations which suggest the possibility of igneous intrusions at a depth of about 3.5 km or shallower. The likely age of such intrusions is also considered. High seismic velocity basement rocks rise to only 2.5 km beneath the surface of the Carboniferous in the northwestern anthracitized zone of the coalfield and we suggest that anthracitization in South Wales is not the result of depth of burial nor of frictional heat but of proximity to a magmatic heat source associated with crystalline rocks of the basement.

Sources of Tin and the Beginnings of Bronze Metallurgy

Recent discoveries of Bronze Age tin ingots and tin artifacts, together with new geological evidence on tin deposits in Europe, the Mediterranean and Western Asia, provide the opportunity to survey the evidence for possible sources of tin and the first use of bronze in the eastern Mediterranean and in Western Asia. Afghanistan now emerges as the most promising eastern source of tin, with western sources most likely located in southern England and Brittany. Central European tin sources still provide serious problems within the context of the nature of Bronze Age mining technology and the type of cassiterite being utilized at that time. During the past ten years there has been an enormous increase in the degree of interest and the quantity of publication on all aspects of ancient metallurgy.' The field has acquired a new name, archaeometallurgy, used by at least one Institute for ArchaeoMetallurgical Studies, with several other programs devoted to research in the field.2 The discipline now has its own journal,3 a sure sign of status in the research climate of today. It is obvious that our understanding of many basic aspects of the field has been transformed and also-an inevitable corollary-that there are at present no up-to-date surveys or works of synthesis.4 Many basic problems remain and, in certain areas, we have yet to see a major breakthrough or significant change in traditional confusion. Foremost in the latter category must be the problem of ancient sources of tin. It is remarkable that, after twenty years of intensive scholarly investigation and fieldwork, we still have no hard evidence regarding the sources of tin being exploited by the numerous and widespread bronze industries of antiquity.5 The main sources of tin exploited by the industrialized countries of the world since at least the sixteenth century are located either on the fringes of the ancient world-in southern England (Cornwall and Devon) and in Burma, Thailand and Malaysia-or in places such as Bolivia, Kazakhstan and China that were far beyond the reaches of a world centered on the Mediterranean.6 What contact there was with countries such as China was only of a most exotic nature and virtually non-existent in any form prior to the time of the Roman Empire (ill. 1).7 * This article is based upon the paper delivered at the Chronologies in Old World Archaeology Seminar, Columbia University, on 9 December 1982, at the kind invitation of Professor Edith Porada. The author would like to take this opportunity to thank his colleagues throughout the world for providing him with copies of their publications. Special thanks are due to Professor Tamara Stech (University of Pennsylvania) and Professor Robert Maddin (Harvard University) for their advice and constructive criticism. 1 The interval is, with no little arrogance and, I hope, some small justification, based upon the publication, in 1973, of my book on Copper and Tin. The Distribution of Mineral Resources and the Nature of the Metals Trade in the Bronze Age (Transactions of the Connecticut Academy of Arts and Sciences 43; Hamden, Conn. 1973, issued in 2nd ed., with Supplement, in 1976). 2 The Institute for Archaeo-Metallurgical Studies (IAMS) is at the University of London. At the University of Pennsylvania we have established the Program for Ancient Metallurgy, while another program on archaeometallurgy is part of MASCA at the University Museum. For the various groups now conducting research in the field, see the special series of articles in T. Berthoud et al., Production, c also Evidence for Sources of and Trade in Bronze Age Tin, in A.D. Franklin, J.S. Olin and T.A. Wertime eds., The Search for Ancient (Washington, D.C., 1978) 43-48; R. Maddin, T.S. Wheeler and J.D. Muhly, Tin in the Ancient Near East: Old Questions and New Finds, Expedition 19.2 (1977) 35-47. 6 For world tin resources, see World Mineral Statistics (Institute of Geological Sciences, London 1979). Total world production in 1976 was 197,000 tons. Of this Malaysia, Thailand and Indonesia produced 107,271, China, 20,000 and Bolivia, 30,355. This accounts for 80% of the world total. See also P.J.H. Rich, Future of as a Tonnage Commodity, Transactions, Institution of Mining and Metallurgy 89A (1980) 8-17 (with correction on p. 106 and discussion on pp. 157-64). Rich estimates that, between 1851 and 1976, Malaysia produced 4,817,500 tons of tin. 7 The discovery of Chinese silk in an early 6th c. B.C. grave near the Heuneburg fort in South Germany is hardly sufficient evidence 275 American Journal of Archaeology 89 (1985) This content downloaded from 207.46.13.128 on Tue, 06 Sep 2016 05:54:46 UTC All use subject to http://about.jstor.org/terms 276 JAMES D. MUHLY [AJA 89 PENINSULAA I LAOEAA-LIA TRA~SBAIKAL MA SA C % ERZGEIRGE CHANG NEW RunswC c NAssI CENTRAL-SRI TANS ZTL A SOUTTHERN MARITIME I TS R REITORALR ASA

The Quaternary history of the central and southwestern Celtic Sea

The British sector of the Celtic Sea, south of the Isles of Scilly, has recently been investigated by the Institute of Geological Sciences (IGS), using several types of bottom sampler and several types of acoustic device. By this means, the bathymetry has been improved, a surface sediment chart constructed, and the stratigraphy established by comparison of boreholes with seismic sections. A great deal of new information has emerged regarding the late Pliocene/Quaternary history of the area. The Celtic Sea shelf is very wide, with a low general gradient and a relatively deep shelf edge. The inner shelf is topographically almost featureless, whereas the middle and outer shelf are diversified by a series of large tidal sand ridges (TSR), running approximately normal to the shelf edge. The late Pliocene/Quaternary sediments in the area consist of two main formations, the late Pliocene/early Pleistocene upper part of the Little Sole Formation, and the late Devensian/early Flandrian Melville Formation. Both formations appear to be composed predominantly of sand, with subordinate gravel and a minor proportion of mud; the upper Little Sole probably consists mainly of fluvial deposits, accompanied by subordinate shallow marine deposits in its upper part, whereas the Melville consists essentially of tidal deposits, which have been fashioned (probably by the Huthnance mechanism) into the tidal sand ridges. Later erosion has developed a gravelly lag pavement (Layer B) across the top of the Melville Formation (and across exposures of upper Little Sole or older formations between the ridges). Above this comes a layer of mobile sandy sediment (Layer A), never more than a few metres thick, but fashioned in most places into bedforms appropriate to the local current regime; these include ripples, megaripples, sand waves and sand ribbons. Ice-rafting has evidently been responsible for depositing (1) occasional small mounds of material (revealed by side-scan sonar) which are found on the sea bed, between the TSR; (2) scattered boulders which occur in the normally pebbly lag pavement; and (3) scattered outcrops of till (revealed by sampling), some of which may represent mounds. Massive marine planation has occurred in the Celtic Sea shelf area, prior to the upper Little Sole, following the deposition of that formation, and probably many times during the Pleistocene. Depths of deposition of samples from the upper Little Sole, together with similar data from the almost coeval St. Erth Beds on the Cornish mainland, indicate that the area has been tilted oceanwards. Subsidence of the outer shelf area is confirmed by the relatively deep shell edge. The most likely mechanism for these displacements appears to be the resolution of large-scale gravity anomalies in the asthenosphere.

Deep Seismic Reflection Profiling Onshore United Kingdom

Over the last few years the Deep Geology Unit of the Institute of Geological Sciences (IGS), with the support of the Natural Environment Research Council's (NERC) Deep Geology Committee, has been acquiring and interpreting seismic reflection data of six seconds, or greater, two-way travel time (TWTI). The purpose of the work is to study the continental crust beneath the UK landmass particularly at levels deeper than those examined on a routine basis by exploration companies. This account discusses some details of individual surveys and presents notes on field parameters, data quality and factors affecting data quality, and interpretation. In general, interpretation work, supplemented by data from relatively shallow reflection surveys and borehole information is showing a consistency of seismic structure of the Earth's crust beneath Britain despite the relatively scattered nature of the data points. The seismic lines themselves, ranging in length from 1.5 to 30 km, have been shot in various, widely separated parts of the country. Not all of the data available to the Unit is discussed in this paper for reasons of confidentiality, but all data has been taken into account in discussion of recommendations for deep data acquisition. Three principal approaches have been used to acquire data: (1) Lines commissioned by IGS, some on behalf of NERC, and shot by a commercial seismic prospecting company. (2) Lines shot by IGS using in-house equipment but processed commercially. (3) Lines shot as commercial hydrocarbons surveys but with record length increased using funds provided by IGS and NERC. The first approach is the most effective in that choice of location and energy source are determined by Deep Geology Unit; speed of data acquisition is a great advantage but the method is expensive (the cost is variable depending on the energy souree used). The second approach is less expensive and allows choice of location, but an explosive energy source is necessary at present; this involves drilling shotholes and therefore a relatively slow rate of data acquisition. The third approach is relatively inexpensive because the cost is limited virtually to the extra processing required. Disadvantages are that there is no control by Deep Geology Unit over acquisition techniques and location. The individual surveys are not illustrated by seismic sections. However, the Deep Geology Unit will inform enquirers which surveys are on open file.

Lost & Found: 129. Colenutt, George William (c.1862-1944)

Mike Crane has drawn attention to the entry in R.J. Cleevely, 1983, p.85, which states that the Tertiary fish from the Osborne Beds and Bembridge Marls described by E.T. Newton (1899) are now to be found in the Institute of Geological Sciences. The British Museum (Natural History) is also stated to have received donations of Tertiary fish and Crustacea in 1899 and 1903. A number of other Colenutt donations are also recorded here. To avoid any confusion in the future, it should be noted that entry 4852 in the Bristol Institution 'Rough Present Book', reproduced in The Geological Curator 3(6): 397, is correctly dated 1895. This volume...

A new look at the type Wolstonian glacial deposits of Central England

The Institute of Geological Sciences has completed a geological survey of an area which includes the stratotype of the Wolstonian Stage of the British Quaternary. The stratigraphy of the glacial deposits is described, and some modifications to previous nomenclature are suggested. The sequence includes several formations not previously described in this area. Depositional environments are briefly discussed. The evidence for the age of the deposits is reviewed, and it is suggested that the type Wolstonian and type Anglian sequences may be equivalent.

A Versatile XRF Analytical System for Geochemical Exploration and Other Applications

For more than a decade the Institute of Geological Sciences has carried out large-scale geochemical analysis in pursuit of mineral exploration and regional geochemical reconnaissance programmes for the Department of Industry. Over this period an XRF analytical system has been developed to meet part of this requirement for multielement data. The elements of interest range from the fourth period to uranium, and have become more numerous as exploration and analytical techniques have expanded. In particular, additions have been made of those elements such as arsenic, molybdenum and tungsten which are more difficult of determination by conventional methods.

Deep structure of the Scottish Caledonides revealed by the MOIST reflection profile

The Moine and Outer Isles Seismic Traverse (MOIST) is a deep crustal reflection profile shot at sea off the north coast of Scotland in 1981. Spectacular reflections are observed from the Moho and from thrust zones within the Caledonian fold belt and foreland. Deep reflection profiling of the continental crust of the United States under the direction of the COCORP group, has amply demonstrated the value of this technique when applied to suitable geological problems (see, for example, refs 1,2). A similar group, the British Institutes Reflection Profiling Syndicate (BIRPS), has now been set up in the UK to organize such projects. Funds are provided by the Natural Environment Research Council (NERC) through the core group based at Cambridge University. However, a preliminary experiment, of which MOIST is the result, was organized through the Institute of Geological Sciences (IGS).

D. V. Frost and D. W. Holliday 1980. Geology of the country around Bellingham. Memoir for 1:50,000 geological sheet 13. Institute of Geological Sciences, Natural Environment Research Council, H.M.S.O., London, viii + 112 pp. Price £14.00.

D. V. Frost and D. W. Holliday 1980. Geology of the country around Bellingham. Memoir for 1:50,000 geological sheet 13. Institute of Geological Sciences, Natural Environment Research Council, H.M.S.O., London, viii + 112 pp. Price £14.00. - Volume 119 Issue 4

A deep seismic reflection profile over a Caledonian granite in central England

In 1980, a short, deep reflection profile, undertaken jointly by the University of Leicester and the Institute of Geological Sciences, crossed a buried Caledonian granite to the south-west of Melton Mowbray in Leicestershire. Little structure is seen in the section between the top of the granite at 0.25 s two-way time (sTWT), and a zone of very strong sub-horizontal reflections at 6 s TWT. A further reflection zone is identified at 7.2s TWT below which there are a series of strong but impersistent reflections to the full reording time of 12 s TWT. The data indicate that the granite must be relatively homogeneous and underlain by several marked sub-horizontal boundaries at mid- to lower-crustal levels. This suggests that, during emplacement, either the granite must have had little effect on the lower crust sampled by the profile, or the lower crust was mobile enough to have developed layering since the granite was emplaced during the Caledonian orogeny.

Sir Peter Kent. Eastern England from the Tees to the Wash. British Regional Geology. Institute of Geological Sciences, NERC. 2nd edition, 1980. vii + 155 pp. 30 text-figs, 21 plates. Price £4.50. London: HMSO.

Sir Peter Kent. Eastern England from the Tees to the Wash. British Regional Geology. Institute of Geological Sciences, NERC. 2nd edition, 1980. vii + 155 pp. 30 text-figs, 21 plates. Price £4.50. London: HMSO. - Volume 119 Issue 2

Childrenite in South-West England

SynopsisChildrenite (Fe,Mn)AlPO4,(OH)2.2H2O, the iron-rich end-member of the childrenite-eosphorite diadochic series, was first discovered by Brooke (1823) on specimens from near Tavistock in Devon. Subsequently it has been recorded from a small number of other British localities, mostly in the Tavistock area, and also from near St. Austell in Cornwall, and from one locality in Cumbria. The Sir Arthur Russell collection, now in the British Museum (Nat. Hist.), has specimens from a few additional localities, all near Tavistock, and the Geological Museum, Institute of Geological Sciences, has a specimen from Wheal Jane, near Truro.

Assessment of models proposed for the 1981 revision of the IGRF.

For the second revision of the International Geomagnetic Reference Field (IGRF), the U. S. National Aeronautics and Space Administration (NASA), the U. K. Institute of Geological Sciences (IGS), and the U. S. Geological Survey (USGS) submitted proposed models of the Earth's main magnetic field at 1965.0, 1970.0, 1975.0, and 1980.0, and its secular variation during 1980-1985. We assessed the proposed models by comparing them with annual mean values from worldwide magnetic observatories, data for 1978-1980 from 63 U. S. magnetic repeat stations, and rates-of-change values for worldwide magnetic observatories for 1965-1985 that were derived from straight lines fitted to annual means for five-year intervals. We also mutually compared the 1980 models.For the observatory data, the IGS 1980 model yields an absolute mean residual in X that is more than twice as great as that for any other model for any year, and that model yields an RMS residual in Z of 246nT, compared with less than 193nT for the other two 1980 models. For the repeat station data, the IGS 1980 model yields an absolute mean residual in F of 113nT, compared with about 30nT for the other two. The secular variation of Z for 1975-1980 deduced from the IGS models, and for 1980-1985 from the NASA secular variation model, yield RMS residuals of 32 and 21nT/yr, respectively, when compared with the observatory rates-of-change values. The NASA and USGS 1980 models, both based on MAGSAT data, differ by no more than about 70nT, but the IGS 1980 model differs from the other two by more than 600nT in some places. This study suggests that the second revision of the IGRF should consist of means of the proposed models, with the exceptions of the IGS 1980 and the NASA 1980-1985 models.

Hydrogeology of the Kufra and Sirte Basins, Eastern Libya. By E. P. Wright, A. C. Benfield, W. M. Edmunds and R. Kitching. 35 pages, including 10 maps and diagrams. Geophysics and Hydrogeology Division, Institute of Geological Sciences, Wallingford, England1981.

Hydrogeology of the Kufra and Sirte Basins, Eastern Libya. By E. P. Wright, A. C. Benfield, W. M. Edmunds and R. Kitching. 35 pages, including 10 maps and diagrams. Geophysics and Hydrogeology Division, Institute of Geological Sciences, Wallingford, England1981.

GEOTHERMAL ENERGY: REPORT OF A SYMPOSIUM

( Symposium held at the University of Durham on 15 th November, 1980) I. INTRODUCTION The aims of the symposium were to summarise the current state of knowledge concerning geothermal energy and the possibilities for its economic extraction in the United Kingdom. The interpretation of geochemical data on the thermal fluids in certain prospective areas was also discussed. The President, Dr G. A. L. JOHNSON, opened the meeting and presented an introductory contribution on behalf of Professor SIR KINGSLEY DUNHAM who was indisposed and unable to be present. Professor M. H. P. BOTT (University of Durham) gave details of the origins of the escaping heat in the earth and of the possible reasons for the differences in heat flow in various parts of the crust. He made particular reference to heat flow over the Alston Block originating in the Weardale Granite. Dr R. A. DOWNING (Institute of Geological Sciences) discussed the potential geothermal systems in the United Kingdom and referred to the results of drilling the first geothermal test well at Marchwood, near Southampton. Dr W. M. EDMUNDS (Institute of Geological Sciences) explained how geochemical techniques gave important information on likely reservoir temperatures at depth, the source of the thermal fluids and highlighted problems such as corrosion and difficulties in disposing of the fluids once they had reached the surface. II. THE EXPLOITATION OF THE EARTH’S CRUSTAL HEAT FLOW In giving Professor Sir Kingsley Dunham’s introductory contribution the President explained the differences between high- and low-enthalpy geothermal energy. In the former case, ...