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A considerable amount of interest has been taken in the coast and adjacent sea-floor of Great Britain s c the w r. It seems therefore worthwhile to call attention to papers concerned more particularly with the geographical and geological aspects of coastal morphology, which are scattered through very different types of journals, and so may easily escape the notice of those for whom they are intended. In our own Journal Miss M. A. Arber gave an account of the cliff profiles in Devon and Cornwall,1 and thus extended the observa? tions made known by her father in fThe Coast Scenery of North Devon' (1911). Recently W. G. V. Balchin, continuing his work on Cornwall has given us a paper on the high level surfaces and their relation to the coast of North Devon. J. Challinor added a chapter to his earlier work on the Cardigan coast in the form of a note on convex erosion slopes in North Cardiganshire,2 and E. H. Brown 3 has analysed comprehensively the erosion surfaces of the same area. These three papers are however only incidentally concerned with the coast. C. A. Cotton 4 discusses our south-western coasts, and thinks the morvan theory, slightly modified, explains their structure better than the fault theory outlined by Suess. He regards the English and St. George's Channels as old features. The deepening of the valleys, later drowned by the Flandrian transgression, took place in times of glaciation. He thinks the tempo of coastal erosion has been slow owing to the great width of the continental shelf. Thus shoreline details survive from an interglacial age. His explanation of the bevelled form of some of the cliffs depends on two cycles of erosion, and so differs from Miss Arber who regards the distribution of bevelled cliffs as being controlled by structure, especially jointing. Other differences of opinion arise over the rate of cliff retreat in relation to valley truncation and the preservation of raised beaches.5 Cotton also alludes to The Needles of the Isle of Wight 6 and regards them as the surviving remnants of a plunging cliff which has been subjected to lateral erosion by the sea. Cotton's treatment of these two problems is theoretical, and scarcely takes local details sufficiently into consideration.

In recent years significant interest has emerged regarding bottom currents and sediment dispersal over continental shelves and shallow marine waters. Although many papers have been written on sediment dispersal mechanisms, they include relatively few long-term observations of bottom currents and/or sediment transport. Lack of observational data is related to the hostile nature of the environment, and the difficulty associated with placing and retrieving instruments on the floor of the continental shelf during some seasons and environmental conditions. This paper describes an instrumentation system designed for use on the floor of the continental shelf. It can remain submerged for periods of one month continuously recording water speed and direction 1 m from the sea bed, differential pressure, and bed nature by means of half-hourly photographs. Four of these systems are presently in use in arrays across the continental shelf of Washington.

OF all the groups of organisms which recent investigations have discovered in the deep oceans, probably none have become more widely divergent from their littoral relatives and more particularly adapted for a free-swimrning life far beneath the surface of the water than have the nernerteans. The object of this paper is to call attention to some of these special adaptations, but with particular reference to the material collected by the U. S. F. C. S. Albatrsoss in various parts of the Pacific Ocean. The results of a detailed study of this material have been published in monograph form during the past year (Coe, '26). Although the total number of described species of neMerteans is less than six hundred, they are very widely distributed, being found on the bottoms and along, the shores of all the oceans, less commonly in fresh water, and occasionally in moist earth and even in moist cavities on trees. They are most numerous along the sea-coasts of Europe and North America, but relatively few species extend along the bottom into the deep oceans whllich lie beyond the continental shelves. In the open oceans they are represented by a highly specialized group of the Hoplonemertea, constituting the tribe Pelagica, with peculiar adaptations for slowly swimming or floating idly in particular water layers which lie at considerable depths. It is with this bathypelagic group that this paper deals. Forty-seven species 'of these highly modified forms have been described. These have been grouped in nine families and twenty-five genera. The members of each

This paper was prepared for the 44th Annual California Regional Meeting of the Society of Petroleum Engineers of AIME, to be held in San Francisco, Calif., April 4–5, 1974. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. Abstract California's Continental Shelf is about one-fifth as large as the State's mainland area; however, the onshore and offshore areas favorable for oil and gas exploration are about equal in extent. The offshore province of California is estimated to contain province of California is estimated to contain 100 billion barrels of petroleum including 6 billion within producing fields, 5 billion within discovered but unproduced fields, and 89 billion within fields yet to be discovered. The two factors which will have the most influence on ultimate recovery of offshore petroleum are water depth and legislation. petroleum are water depth and legislation. The petroleum industry now has the capability for drilling and completing wells in moderately deep water and research is being conducted on techniques and equipment to operate in even greater depths. Prior to the 1969 blowout in the Santa Barbara Channel, nearly all legislation involving oil in California's Continental Shelf was primarily concerned with ownership and management of leases in contrast to after the blowout, when most actions have either restricted or prohibited offshore petroleum operations. prohibited offshore petroleum operations. Recent developments, aided by the energy shortage, have resulted in lifting the State moratorium on drilling and opening 7.7 million acres of Federal submerged land for leasing. It is estimated that at the present rate of development, less than 1 billion barrels of petroleum will be recovered from California's petroleum will be recovered from California's offshore fields, but under full-scale operations, over 23 billion barrels could ultimately be recovered. Introduction California's Continental Shelf consists of 35 thousand square miles and contains an estimated 100 billion barrels of petroleum, including natural gas at 10 Mcf. per barrel of oil. Although the Shelf area is only about one-fifth the size of California's mainland, the onshore and offshore areas underlain by Cretaceous, Tertiary and Quaternary marine sediments are about equal in extent (Figure 1). All known California oil and gas fields are located within these areas. In this report, the Shelf has been divided into three offshore regions corresponding to the subdivisions used by the American Association of Petroleum Geologists in their report on "Future Petroleum Provinces of the United States".

This paper was prepared for the Second Annual European Meeting of the Society of Petroleum Engineers of AIME, to be held in London, England, April 2–3, 1973. Permission to copy is restricted to an abstract of not more than 300 words. Illustrations may not be copied. The abstract should contain conspicuous acknowledgment of where and by whom the paper is presented. Publication elsewhere after publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF publication in the JOURNAL OF PETROLEUM TECHNOLOGY or the SOCIETY OF PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor PETROLEUM ENGINEERS JOURNAL is usually granted upon request to the Editor of the appropriate journal provided agreement to give proper credit is made. Discussion of this paper is invited. Three copies of any discussion should be sent to the Society of Petroleum Engineers office. Such discussion may be presented at the above meeting and, with the paper, may be considered for publication in one of the two SPE magazines. ABSTRACT: Well stimulation practices in the North Sea have been surveyed. Matrix acidizing and fracturing with a seawater based fluid are discussed and results presented. INTRODUCTION: In the past six years widespread use of well stimulation techniques has been made in the gas wells of the southern North Sea Basin. Generally speaking, wells in the Indefatigable and Leman Fields (Rotliegendes formation) require a treatment for formation damage removal only, West Sole Field (Rotliegendes formation) wells require fracture stimulation, and Hewett (Bunter and Hewett Sandstone) and Viking Field (Rotliegendes formation) wells achieve optimum production without stimulation or a treatment for damage removal. Since the majority of these treatments have been performed in the Rotliegendes (Basal Permian) sandstone formation, a survey has Permian) sandstone formation, a survey has been made of all available data in an attempt to determine which particular treatment designs have been most successfully applied. Net pay in the Rotliegendes formation is typically 100 to 300 feet with an average porosity of 15 to 20 percent. Permeabilities vary widely. Pressure build-up and draw-down tests of the Pressure build-up and draw-down tests of the gas wells completed in the Rotliegendes formation show high formation damage in wells of higher permeability following initial completion. Those wells of low permeability generally do not show very high damage, although production is often below what is considered economically acceptable. Generally, the wells having higher permeability have responded to acid stimulation permeability have responded to acid stimulation while those of lower permeability have required fracture treatment. ACIDIZATION: Most of the data available on acidization has been drawn from the Rotliegendes formation in the Indefatigable and Leman fields. Whether intentionally or not, all wells investigated were matrix acidized rather than fracture acidized. Matrix acidization uses the technique of treating a formation at pressures below that required to initiate a fracture, i.e. at pressures below the bottom hole fracture pressures below the bottom hole fracture pressure (BHFP). pressure (BHFP). Fracture acidizing is the technique whereby acid is used to hydraulically induce a fracture, then give that fracture conductivity by the dissolving reaction of the acid with the fracture face.

In the following, some selected modern beachshelf profiles are described and discussed. Despite numerous papers on the coastal and continental shelf sediments of modern environments, there are only a few systematic detailed descriptions of such regions which can be used to make models for the environmental interpretation of ancient sediments. Particularly rare are papers giving systematic descriptions of sedimentary structures, i. e., primary bedding and bioturbation structures.

Subsea sedimentary rocks favorable for petroleum are confined largely to the continental shelves and adjacent offshore areas. The total world offshore area out to 1,000 feet of water depth is 10,763,000 square miles. This area may be classified as follows. Table The foregoing figures are broken down in Tables I, II, and III by 10 continent or major world subdivisions. The only sound basis for rating sedimentary areas is geologic understanding of the factors that control oil occurrence. Such understanding can be attained only through intensive analysis of the vast quantity of facts concerning oil occurrence that is available from industry experience in thousands of instances worldwide. From these analyses, world averages have been derived for such basic parameters for each category or subcategory of basin or basin area as: the percentage of total area that will prove productive, the yield per unit of productive area, the yield per square mile or per cubic mile of basin sediments. Still other parameters provide various means of cross-checking. After applying the world averages to the total world offshore basin areas of categories A and B, the following conservative estimates of potential offshore liquid petroleum resources recoverable by primary production methods are derived. Barrels Total A area 168,450,000,000 Total B area 530,240,000,000 --------------- Total 698,690,000,000 or, say, 700 billion barrels of petroleum liquids. Other subsea sources of hydrocarbons are available. Their volumes are similarly estimated. The grand total of all of the offshore hydrocarbon resources of the world (not including the large amounts of additional hydrocarbons which may be derived from coal) is indicated as follows. Table For reasons that are explained in the paper, the comparative economic disadvantage of offshore hydrocarbons, which results from the somewhat greater average operating costs, will be more than offset by a greater incidence of oil occurrence and resulting productivities to be expected offshore. The paper concludes with a review of the principal current happenings in world-wide exploration.

Before the last meeting of the British Association, held in Liverpool, Professor Edward Hull presented a paper upon “Another Possible Cause of the Glacial Epoch.”inthat paper, Professor Hull applied the writer's work on the “Reconstruction of the Antillean Continent,” which brought together evidence of great continental elevation. This elevation and its effects upon the ocean-currents, in diverting them from the West Indian regions, with the consequent reduction of their temperature as they reach the northern latitudes in conjunction with the elevation of the land, were thought by Professor Hull to be sufficient causes for the production of the glacial climate over temperate regions in late geological times. The writer has hitherto never applied his observations on high continental elevation to climatic changes; but in this paper he proposes to extend briefly his researches from the Antillean region to the higher latitudes of America and the North Atlantic regions. Something has also been learned of the date of the great elevation; consequently inferences may be drawn as to climatic changes.

This paper is a reply to the critique by David G. Moore and Joseph R. Curray (1964) of my paper “Wave-base, marine profile of equilibrium, and wave-built terraces: A critical appraisal.” Our points of difference seem only to involve minor aspects and emphasis. In contrast to Moore and Curray, I doubt the importance of continental terrace prograding. Even for the example they cite off Norfolk, Virginia, this extension of the terrace is shown to be only slight. Although I do not deny the existence of some open-shelf and continental-slope deposition, I consider their volume to be greatly less than either paralic or continental-rise deposition. I re-emphasize that wave-base can only be of minor and subtle geologic importance and does not control the building of the continental terrace. In contrast, surf-base exerts a strong influence. In common with earlier writers, Moore and Curray fail to specify the depth of wave-base or its exact position on the self profile; therefore their concept of wave-base remains vague. I suggest placing wave-base at the shelf break, regardless of its depth. Actually the realm of sea-water agitation extends deeper than shelf depths everywhere, hence shelf deposits tend to be sorted or “above wave-base” as this term is used by stratigraphers. Beyond the shelf break the gradient of the continental slope probably exerts a stronger influence on sediment facies than does the degree of water agitation. In this context, wave-base is controlled by topography and not topography by wave-base.

IRELAND'S location near the edge of the European continental shelf predestined it to be strongly affected by the eustatic changes of sea-level so characteristic of Quaternary times. Furthermore Ireland has experienced at least two major Pleistocene glaciations, one consequence of which was to superimpose isostatic adjustments due to ice-loading and ice-melt upon the already complex eustatic changes. The coastal margins clearly exhibit both raised and submerged shoreforms attributable generally to these complex oscillations of Quaternary sea-level. Our knowledge of these oscillations is unfortunately incomplete, since comparatively few persons have worked in this field. This paper discusses the nature of the evidence now used to demonstrate past changes of sea-level and their correlation within the Quaternary timescale. The paper will argue for the comparative antiquity of the coastal zone while allowing for marginal marine oscillations and complementary subaerial base levelling farther inland. Raised strandlines just above present high water have long been recognized in Ireland, owing partly to their comparative freshness and partly to their suprajacent beach deposits. For example, E. Hull described the wave-cut rock platform in north-east Ireland as early as 1872, but was misled by the suprajacent Post-glacial raised beach into assuming, incorrectly, that the platform and beach were contemporaneous. In 1881, he described multiple marine terraces cut in drift at 5o, 75, and ISo feet on the Down coast. Where beach deposits were absent, the origin of the old shore-platforms was, at first, less easily assessed, and confusion as to age and origin persisted in some localities for many years. However, by I904 the nature and extent of the so-called pre-glacial raised beach along the south coast (W. B. Wright and H. B. Muff, I904) and of post-glacial changes of sea level were largely appreciated. Subsequent research has recognized several Quaternary strandlines just above and below present sea-level but controversy still surrounds their precise dating.

7 pages, [EN] This paper deals with the marine fisheries off the West African coast, between the Straits of Gibraltar and Mauritania, an area which is characterized by its relatively narrow continental shelf, the presence of the Canary Current, and intensive upwelling resulting in very high primary production and rich bottom fauna.The main fisheries (for sardines, sardinellas, hakes, sparids, cephalopods, and demersal crustaceans) are analyzed with regard to their evolution, species composition, fishing areas and seasons, the biological characteristics of the exploited stocks, and the effect of fishing on them.The criteria to be considered when planning the control and regulation of these fisheries are also analysed. [...] Sardinella aurita, Sardinella eba, Sardinella maderensis, Clupeidae, Engraulidae, Merluccius merluccius, M. senegalensis, Dentex macrophthamus, D. dentex, D. canariensis, Spondioliosoma cantharus, Pagellus belloti, P. acarne, Octopus vulgaris, Sepia officinalis var. hierredda, Loligo vulgaris, Panulirus regius, Palinurus mauritanicus, Palinurus vulgaris, Aristeus antennatus, Aristeomorpha foliacea, Plesiopenaeus edwarsianus, Penaeus duorarum, Corvina sp., Scomber japonicus, Trachurus trachurus, Decapterus ronchus, [ES] Este trabajo se ocupa de la pesca en aguas marinas frente a las costas del Africa occidental, entre el estrecho de Gibraltar y Mauritania, zona que se caracteriza por la relativa estrechez de su plataforma continental, la presencia de la corriente de las Canarias y la intensidad de los afloramientos, que da lugar a una producción primaria elevadisima y una notable abundancia de fauna bentónica. El autor estudia las principales pesquerías (de sardina, machuelo y alacha, merluza, espáridos, cefalópodos y crustáceos demersales) y analiza su evolucion, la composición por especies, los caladeros y estaciones de pesca, las caracteristicas biológicas de las poblaciones explotadas y los efectos de la pesca. Se analizan también los criterios que han de tenerse en cuenta a la hora de planificar la inspección y regulación de estas pesquerías. [...] Alacha, merluza, espáridos, pulpos, sepia, calamar, langostas, peneidos, corvinas, caballa, chicharro, jurel [...], [FR] Le présente document traite des pêcheries maritimes opérant au large des côtes de l'Afrique de I'Ouest, entre le détroit de Gibraltar et la Mauritanie. Cetee zone est caractérisée par la relative étroitesse du plateau continental, par la présence du courant des Canaries et par l'intensité de l'upwelling, facteurs qui expliquent I'importance de la production primaire et la richesse de la faune benthique. L'auteur analyse les principales pkheries (sardines, sardinelles, merlus, sparjdés, cephalopodes et crustacés démersaux) sous divers aspects: évolution, composition par espèces, zaones et époques de pêche, caractéristiques biologiques des stocks exploités et incidences de la peche sur ces stocks. Sont également examinés les criteres i appliquer dans la planification du controle et de la réglementation de ces pêcheries

The continental margin reviewed in this paper corresponds in almost all its parts to a Hercynian platform which was more or less structured during the Mesozoic and Cenozoic in association with the formation of the Atlantic Ocean. In the areas above water and the continental shelves, this Hercynian platform either has a thin sedimentary covering (Galicia, Armorica, West Ireland, Porcupine Bank) or, on the contrary, has been extensively depressed by distension movements accompanied with the formation of thick Mesozoic and Cenozoic basins connected with the oceanic domain (West Portugal, Basco-Cantabrian zone, Adour Basin, Parentis Basin, Western Approaches Basin, North Celtic Sea Basin, Porcupine Seabight Basin). In addition, the Early Cenozoic Pyrenean-Alpine compression movements had repercussions on the structure of the north Spanish margin. From the structural standpoint, the main features of the margin are linked both to the deep indentation of the Bay of Biscay and to the existence of more or less collapsed blocks prolonging the continental domain. These blocks are visible either in the topography (Porto and Vigo seamounts, Galicia Banks, Asturian marginal shelf, Porcupine Bank) or solely by seismic reflection (Trevelyan Escarpment). Thick marginal sedimentary basins exist at the foot of the slope.

This paper gives a theoretical analysis of storm surges generated on a continental shelf by moving wind fields; surges generated in the ocean and propagated on to the shelf are also investigated. A continental shelf of uniform depth and width, bounded by a long straight coast and connected with an infinitely deep ocean, is considered. In studying the motion of the shelf sea, bottom friction and Coriolis force are taken into account, and it is supposed that conditions are the same in all vertical sections normal to the coast. The theory is applied to the problem of storm surges on the west coast of the British Isles. It is shown that these surges are generated by wind fields, associated with moving depressions, acting over the sea of the continental shelf to the south of Ireland. In two cases the observed surge at Milford Haven has been reproduced satisfactorily by the theory.

The genus Chiridotea. is unique to the eastern coastal region of the United States and southeastern Canada. Members of this genus are small (usually < 1 cm. ) , broad, depressed valviferous forms that inhabit sandy areas and charac teristically burrow just beneath the sediment surface. The species described herein constitutes the fourth known species of this genus. Those previously described are : C. coeca (Say, 1818) ; C. tuftsi ( Stimpson, 1853) ; and C. a/myra Bowman, 1955. Included in Bowman's paper is a revision of the generic characteristics of this group. The description of this new form is based on specimens collected on Georges Bank, a relatively shallow portion of the continental shelf east of Massa chusetts, U. S. A. These specimens were encountered while processing collections of benthic invertebrates taken by the R/V Albatross III and the R/V Delaware for the Woods Hole Laboratory, Bureau of Commercial Fisheries, U. S. Fish and Wildlife Service. Material Exa@nined.—Holotype, adult female with oostegites developed, 7.5 mni. in length, deposited in the U. S. National Museum (Catalogue No. 104282); allotype, adult male 6.0 trim. in length (U.S.N.M. Catalogue No. 104280) ; para types, 1 male 5.0 mm. in length and 1 ovigerous female 6.5 mm. in length (U.S.N.M. Catalogue No. 104281) ; all type specimens were collected August 6, 1959, by means of a grab-type bottom sampler on Georges Bank at lat. 41°48' N., long. 67° 53' W. ; water depth 15 fathoms, sand substrate, bottom water tempera ture 57.0°F. (R/V Delaware, cruise number 59-9, station 21). One female, 7.5 mm. in length, collected December 7, 1955, at lat. 40° 51' N., long. 68° 55' W.; substrate coarse sand, water depth 36 fathoms, bottom water temperature 47.2° F. (R/V Albatross III, cruise number 70, collection 3). One male, 6.5 mm. in length, collected December 14, 1955, at lat. 41°40' N., long. 67°36' W.; substrate gravelly sand, water depth 28 fathoms, bottom water temperature 45.7° F. (R/V Albatross III, cruise number 70, collection 38). Five females, body lengths 4.0, 5.0, 6.5, 7.5, 7.5 nim., and two males, body lengths 7.0 and 7.0, collected August 24, 1957, at lat. 41°22' N., long. 68°20' W.; substrate coarse sand, water depth 24 fathoms (R/V Albatross III, cruise number 101, station 64). Three specimens, 4.0, 4.5, 4.5 mm. in length, collected August 24, 1957, at lat. 41° 34' N., long., 67° 28' W.; substrate coarse sand, water depth 23 fathoms (R/V AlbatrossIII,cruisenumber 101,station90). Diagnosis.—Medium-sized Chiridotea with short antennae; flagellum of antenna 2 is much shorter than the peduncle; antenna 1 usually not reaching beyond the peduncle of antenna 2; outer margin of pereion epinieral plates 5—7

Summary. An analysis is presented for the propagation of Rayleigh waves in a multi-layered medium with water as the uppermost layer from which it is possible to obtain the group velocity as well as the phase velocity for the Rayleigh waves in an oceanic path with the ocean bed consisting of two upper layers each of uniform composition and finite thickness, underlain by ultrabasic rock extended to large depths. The results have been applied in the analysis of microseisms associated with cyclones and “norwesters”. It has been shown that the period of the microseisms recorded at different stations depends critically on the structure of the continental shelf. The results obtained in the present paper, when compared with the nature of the recorded microseisms associated with cyclones, and their variations, give useful information about the depth and structure of the ocean beds.

Phosphatic concretions and nodules, some of which are coated with goethite, have been dredged at depths between 210 and 385 m from the upper continental slope off northern New South Wales. Some of these appear to have been concentrated on a low sea level terrace at a depth of about 210 m by wave action, while deeper‐water non‐abraded examples may have been winnowed from host sediments by relatively gentle current activity. Similarities in structure, mineralogy and age of contained fauna are noted between nodules described in this paper and phosphatic nodules from the California Continental Borderland, the Chatham Rise off New Zealand and Cainozoic sediments outcropping in Victoria. It is proposed that the Eastern Australian material formed as phosphatic concretions within phosphorus‐enriched slope sediments during diagenesis and that they have since been winnowed, exposed and in some cases re‐cemented into agglomerations on the sea floor in areas of low sedimentation rate.

In this paper the palaeomagnetic polar wandering curves of Europe and North America are discussed in the light of the latest available palaeomagnetic data. First the criteria are described by which the data are selected on which the calculation of new palaeomagnetic mean pole positions is based. The prime concern in this selection is to use only data pertaining to rocks which have been subjected to demagnetization tests, though a number of other considerations are also relevant. Subsequently, these data are used to construct new polar wandering curves for Europe and North America. The results confirm Runcorn's (1956b) interpretation in that two significantly different polar wandering curves are found which clearly favour the concept of continental drift. Finally, the palaeomagnetic results are compared with those obtained by Bullard et al. (1965) by the fitting of Atlantic continental slope topography. It is found that the palaeomagnetic data confirm the fit found by Bullard et al. on the basis of topography. The palaeomagnetic data are insufficient to determine the exact moment in geological history when the opening of the North Atlantic Ocean began. The opening movement may have started in late Permian time or in Mesozoic times.

Botanical interest in the islands of the southern ocean has centred largely on the geographical relationships of their floras, problems of long-distance dispersal, and on the larger questions which their floras raise concerning the past distribution of land and sea in the southern hemisphere and the origins and migration-routes of the continental floras (references in Turrill 1953, pp. 184-88). This paper will deal with the vegetation types of the southern islands. The major types of native vegetation on the islands are compared with one another, and with similar types on the southern continents, and some of the ecological consequences of their insularity are discussed. Geographically, the islands considered all lie between the Tropic of Capricorn and the Antarctic Circle (figure 10). With the exception of the mid-Atlantic and mid-Indian Ocean groups, all he within about a thousand kilometres of the nearest continental shelves. Most of them consist wholly or partly of volcanic material. Islands of both continental and oceanic origin (Wallace 1895) are included. Their climates are all extremely oceanic, with small temperature ranges, evenly distributed rainfall, constantly high humidities, and strong westerly winds. Air temperatures at sea level closely follow those of the surrounding seas (figure 11).

The principle of isobaric equilibrium is quantitatively applied to a strong lithosphere near a continental boundary. Following methods outlined in earlier papers, the deformation of the lithosphere near Cape Henry is determined from the magnitude and distribution of the sedimentary and fluid load superimposed on the original crystalline basement. From the calculated figure and the equivalent load, the resulting distribution of vertical stress and gravity defect are estimated. Except for the prediction of appreciable positive gravity defects at the continental shelf the calculated and observed gravity distributions are quite similar. The fibre stress due to the deformation is evaluated and it is shown that the position of the calculated maximum stress in tension on the landward side coincides with the observed position of lithospheric failure or the Fall Line. The strength in tension of the upper lithosphere here is shown to be less than 8.5 X 108 dynes/cm2. The simultaneous prediction of the approximate magnitudes of the gravity anomalies, their distribution and the location of the Fall line appears to show that a strong elastic lithosphere characterized by the constant b = 8.4 ± 2 × 10−8 cm−1 has a real and important geological existence.The investigation shows that due to the finite strength of the lithosphere, long linear areas parallel to continental coast lines are usually regions of disturbed gravity.

This paper presents a model of geological interpretation of gravity observations along the profile across the Pacific Ocean from the Japan trench across the Hawaiian ridge to the Middle America trench crossing eleven geological regions (the total length of the profile is about 14,000 km). The interpretation was made by comparing the gravitational attractions of the combined layer of the hydrosphere and the crust and upper mantle from sea level to the depth of isostatic compensation by using the fundamental principles of the theory of isostasy. The density of the crust and mantle beneath the M discontinuity was determined from the results of deep seismic sounding (DSS) and the correlation between compressional velocities and densities of rocks. A statistical analysis was made of the data obtained by many scientists to improve the correlation for different rocks at pressures of 0.001–10 kb. Density distribution curves are presented for different rocks and different velocity intervals. The lateral density inhomogeneities in the lower part of the combined layer from a depth of 50 km to the depth of isostatic compensation are supposed to cause regional gravity anomalies of the first order determined from satellite observations, whereas density inhomogeneities of the combined layer of the hydrosphere and the crust and upper mantle to a depth of 50 km account for residual gravity anomalies obtained from free-air anomalies (the normal gravity formula derived by Helmert (1901–1909)) after the regional first-order anomalies are subtracted from the satellite data. For the profile across the Pacific Ocean we obtained curves of regional gravity anomalies of the first order, residual gravity anomalies, ocean-floor topography, variations of the apparent density of the combined layer of the crust and mantle to a depth of 50 km below sea level, variations of the apparent density of the upper-mantle layer to the same depth, variations of heat flow, and a model of a density section to a depth of 50 km below sea level. The density of the crustal rocks varies from 2.7 to 3.0 g/cm3. The upper-mantle layer has its highest density (3.42 g/cm3) directly beneath the M discontinuity under the Hawaiian ridge (from DSS) and under the Japan trench (under the continental slope). Compact rocks lie beneath the northwest Pacific basin and the mid-Pacific mountains and also in fracture zones. The upper-mantle rocks of the lowest density (3.13 g/cm3) lie beneath the east Pacific ridge, the Hawaiian ridge (at a greater depth), and in the form of isolated horizontal lenses beneath the mountains of the Darwin uplift. Anomalously high values of the heat-flow intensity were found. A suggestion is made that the upper-mantle rocks with a density of 3.13 g/cm3 west of the Hawaiian ridge are genetically related to the rocks of about the same density lying at the base of the third crustal layer (density obtained from DSS data). This interesting region requires geophysical investigation and deep drilling to reach the rocks with a 3.13-g/cm3 density at a depth of about 3 km. These studies will throw light on the processes of transformation of rocks in the crust and upper mantle.

The principal cause of submarine telephone cable failures has been fishing activities on the continental shelf, particularly in the Western Atlantic area. The Bell System has conducted extensive investigation of methods of burying these cables in the affected area to eliminate this hazard. This has culminated in the development of a unique underwater plow which was used successfully in July 1967 to bury about 100 miles of cable on two transatlantic cables off the coast of New Jersey in water depths up to 100 fathoms and 40 miles of the 720-circuit Florida-St. Thomas cable. This paper covers the problems involved, the extensive exploration of the sea bottom, and the development of the sea plow. It also discusses the improvements that are expected in submarine cable reliability and the affect on selection of future submarine cable routes.

1. A study was made with the aid of closing nets of the diurnal vertical migrations of bathypelagic organisms at a station in continental slope water of the western North Atlantic.2. While the hauls were being made a continuous record of the light intensity at the surface was kept.3. The penetration of light into the upper 84 m. of water was directly measured photometrically; the average extinction coefficient for green light was κ = 0.092.4. All of the malacostracan Crustacea (to which the detailed results presented in this paper are limited) which occurred in sufficient numbers for analysis exhibited diurnal migrations 200 to possibly 600 m. in vertical extent.5. The speed of vertical movement in these migrations varied from 24 to 125 m. per hour among the various crustaceans.6. A considerable part of the migrations took place while the light intensity even at the surface was no greater than starlight.7. Several Crustacea living at 800m. during the day showed extensive diurnal vertical migrations.8. It ...

This paper reports the species of Macrochiridothea occurring up to now on the continental shelf of southern Brazil. Two species are new to science: M. marcusi sp. n. and M. lilianae sp. n.. M. stebbingi Ohlin, 1901, is the third species reported for the area. The genus now comprises 8 species. A diagnosis for the genus, as well as for alI the species is given, together with comprehensive illustrations to permit prompt recognition of the species. Secondary sexual dimorphism is reported for the first time in the genus. A elassification key based on adults is furnished, and remarks or eomments for eaeh speeies are made. The geographie range for the genus has been considerably extended to the north, to about Lat. 23º07'S. General ecological and zoogeographieal remarks are made.Três espécies do gênero Macrochiridothea (Crustacea, Isopoda, Valvifera), são registradas na plataforma continental centro-sul do Brasil. Duas espécies são novas para a ciência: M. marcusi sp. n. e Af. lilianae sp. n.; Af. stebbingi Ohlin, 1901, e ocorrência nova para o Brasil. O limite N de distribuição do gênero é consideravelmente ampliado. São fornecidas diagnoses para o gênero e para todas as espécies que atualmente o compõem, juntamente com ilustrações que possibilitam seu pronto reconhecimento. Dimorfismo sexual secundário e relatado pela primeira vez no gênero. É dada uma chave de identificação para todas as espécies do gênero. Considerações ecológicas e zoogeográficas gerais completam o trabalho.

Three exceptionally large and long submarine canyons — Bering, Pribilof, and Zhemchug — incise the continental slope underlying the southeastern Bering Sea. Bering Canyon, the world's longest known slope valley, is approximately 400 km long and has a volume of 4,300 km 3 . The volume of Pribilof Canyon is 1,300 km 3 and that of Zhemchug is 8,500 km 3 ; Zhemchug Canyon may well be the world's largest slope valley; most other large submarine canyons have volumes less than 500 km 3 . Pribilof and Zhemchug canyons are further distinguished by the headward bifurcation of their slope axes to form elongated trough-shaped basins behind the regionally projected position of the shelf edge. These troughs are superimposed over structural depressions formed by down-faulted basement rocks of Mesozoic and older ages. Prior to canyon cutting these depressions were filled with as much as 2,600 m of shallow-water diatomaceous, tuffaceous, and detrital sediments largely of Tertiary age. Deposition of these sediments took place concurrently with general margin subsidence of at least 2,000 m. The data and conclusions presented in this paper stress that the location, trend, and shape of the enormous submarine canyons cutting the Bering margin are structurally determined. However, axial cutting and headward erosion within the relatively unconsolidated Tertiary strata and the older, lithified basement rock is thought to have been caused by basinward-sliding masses of sediment; these unstable sediment bodies accumulated on the upper continental slope and outer shelf, probably near the mouths of major Alaskan rivers. Bering Canyon was periodically cut and filled by axial sedimentation during Late Tertiary and Quaternary time. Pribilof and Zhemchug canyons, however, are thought to have been excavated entirely during the Pleistocene. It is presumed that, during one or more periods of glacially lowered sea level, the Kuskokwim and Yukon rivers emptied into or near the heads of Pribilof and Zhemchug canyons. The enormous size and unusual shape of Zhemchug Canyon resulted from the breaching of the seaward wall of an outer-shelf basement depression and the subsequent removal of nearly 4,500 km 3 of Tertiary deposits filling it.

Sediment patterns on the ocean floor of the continental shelf can be studied using ultrasonic sonar systems, in which the geophysical patterns are mapped on a permanent paper record. Housed within a streamlined fish-like towed body, a transmitter sends an ultrasonic acoustic beam towards the sea bed, illuminating a path of the sea floor of width 1 km parallel to the track of the ship. The strength of the echo reverberation signals increases progressively through the sediment series soft mud, sands, cobbles, rocks and corals, so some measure of sediment identification is possible.

INTRODUCTION The material from Georges Bank, described in this paper, was submitted to John B. Reeside, jr., Chief of the Section of Paleontology of the United States Geological Survey, by Henry C. Stetson, Assistant Curator of Paleontology, Museum of Comparative Zoology, and Research Associate in Submarine Geology, and was subsequently placed in the writer’s hands for identification and description. The material was dredged by the ketch Atlantis on August 8, 1934, under the direction of Stetson, who, under the auspices of the Woods Hole Oceanographic Institution, is in charge of their studies of sediments, past and present, on the Continental Shelf off the eastern coast of the United States. Stetson was assisted by Marshall Schalk. Most of the material submitted consists of coarse, gray, conglomeratic, calcareous, fossiliferous sandstone. The fossils are preserved mainly in the form of molds, but the shells of Exogyra and a few other shells found in, . . .

For the experiments described in this paper a new method of seismic refraction shooting was developed. With this method hydrophones suspended at a depth of about 100 ft. below the surface of the sea acted as receivers for the compressional waves developed by depth charges exploding at a depth of approximately 900 ft. The hydrophones were connected with sono-radio buoys which radio-transmitted the electrical signals to a recording system in the ship from which the charges were dropped. Four buoys were in use simultaneously, distributed at differing ranges from the ship. The experiments were carried out at three positions in an area of the eastern Atlantic around the point 53° 50' N, 18° 40' W, where the water depth is approximately 1300 fm. (2400 m). The results showed that the uncrystalline sedimentary layer in this area varied in thickness from 6200 ft. to 9700 ft. (1900 to 3000 m), and that the velocity of compressional waves in it increased from the value for sea water, 4900 ft./s (1.5 km/s), at the surface with an approximately constant gradient of 2.5/s to a limiting value of 8200 ft./s (2.5 km/s). Below the sedimentary layer there was a crystalline rock with compressional wave velocity of approximately 16500 ft./s (5.0 km/s) and of thickness varying between 8800 ft. (2700 m) and 11100 ft. (3400 m). The base of this layer was in both determinations at approximately 25500 ft. (7800 m) below sea-level. The lowest layer concerning which information was obtained gave a value for the compressional wave velocity of about 20500 ft./s (6.3 km/s), but was of undetermined thickness. The characteristics of the sedimentary layer were such as might be expected for a continuous succession of deep-sea sediments, the thickness on this basis being such as to indicate the long existence of the ocean in this area. On the other hand, it is possible that it represents a downwarped continental shelf. The layer below the sedimentary layer has a compressional wave velocity which is low for an igneous rock at this depth, and it is probable that it represents a crystalline sedimentary rock. From the evidence it is not possible to determine whether this rock is of continental or deep-sea origin. The lowest layer of these experiments is unlikely to have a constitution similar to that of the European granitic layer, since the compressional wave velocity in it would, on this hypothesis, be exceptionally high. The value is, however, close to that calculated by Jeffreys for the intermediate layer.

For 3 years, the Institute of Oceanographic Sciences has operated a long-range side-scan sonar for viewing the texture and topography of the ocean floor (project G.L.O.R.I.A., Geological Long Range Inclined Asdic). It was recommended that an experiment should be arranged to discover if such a device could detect commercial pelagic fish on the Continental Shelf at long ranges and, if so, to determine any research on commercial applications. This paper describes such a trial, carried out on a Scottish inshore herring fishery in the Sea of the Hebrides, during late September,1971. A survey was first made in the area by echosounder and short-range side-scan sonar to confirm the bathymetry, to locate false targets, and to observe the distribution and diurnal vertical movement of the herring. During the subsequent G.L.O.R.I.A. runs, up to 9kW of acoustic power was transmitted at 6.4 kHz, with the signal returns processed by a linear correlator with a time-bandwidth product of 400, so that signal/noise ratios obtained were equivalent to a short-pulse sonar with peak powers in excess of 1 mW. Due to the summer water-conditions, it was found that the propagation depended critically on the position of the source in the water column. Under the best conditions, with the source towed at 33 m in an isothermal surface layer, herring were detected to a range of 15 km in a water depth of 120 to 170 m. For a period of 3 days, a fishery area of 170 km2 was kept under surveillance by steaming up and down 13 km-long base lines at a speed of 13 km/h facing SE towards Hawes Bank and the islands of Tiree and Coll. As a result, a plan view of the area, including both fish and the geological features of the bank, was generated every 1 1/4 h. It was found possible to track certain aggregations of herring using these records for periods up to 5 h. On the final might, remotely directed catches were made on 3 aggregations by guiding a purse-seine vessel to within 1 km of each target. The internal composition of the aggregations detected by G.L.O.R.I.A. is discussed in terms of both the echosounding data and expanded A-scan excerpts from the recorded G.L.O.R.I.A. target signals. Possible research and commercial applications for the long-range detection of pelagic fish by low-frequency towed or fixed sonar systems are briefly discussed.

This paper describes an aeromagnetic profile from Prince Edward Island, through the Cabot Strait to the Tail of the Grand Banks of Newfoundland, and subsequently over the Flemish Cap. It is inferred that Burgeo Bank off the southwest coast of Newfoundland is possibly a granite intrusion of Devonian age. A distinct magnetic anomaly, approximately 400 gammas in amplitude, appears to be associated with the edge of the continental shelf at the Tail of the Bank. A series of sharp shallow-source magnetic anomalies was recorded over the Flemish Cap, and this feature appears to have a negatively polarized core whose long dimension is oriented in a NNW.-SSE. direction.

INTRODUCTION Numerous investigators in recent years have called attention to regularly recurrent sequences in the strata of the Pennsylvanian system in the eastern and central parts of the United States. Wanless, in association with J. M. Weller, has been engaged for several years in field studies of the Pennsylvanian in Illinois and surrounding states, for the Illinois State Geological Survey, and has traced many of the recurrent sequences or cyclothems[1][1] over wide areas, using them as an aid in correlation. Reconnaissance studies have also been made by him in Ohio, Kentucky, Indiana, and the northern mid-continent and Rocky Mountain regions. Shepard has suggested the basic idea as to the cause of the cycles developed in this paper and has contributed information from studies of recent sea level oscillations and the influence of these changes on continental shelf sediments. The authors have attempted to determine whether this peculiar type of sedimentation . . . [1]: #fn-3

This paper is the introduction to a long-term, detailed study of open ocean, benthic assemblages. Attention will be paid to taxonomy, community structure, physiology, recruitment, patchiness, modes of feeding, zoogeography, and many other related topics. The major area of study is a transect between Massachusetts, U.S.A., and Bermuda, in the North Atlantic Ocean. Quantitative samples were taken with an anchor dredge and were washed through a 0·42-millimeter-aperture screen. The sediments along the transect range from fine sands of terrigenous origin on the upper continental slope, to silty clays and clays composed primarily of pelagically derived calcium carbonate in the Sargasso Sea. With increasing depth. temperature at the stations not only decreases, but shows more restricted fluctuation. Analysis of results shows much greater faunal densities than those reported from previous studies; this probably results from our using a smaller screen aperture. Each region of the transect supports a characteristic number of animals per square meter in a general trend of decreasing density with increasing depth and distance from the continent: outer continental shelf, 6,000–13,000; upper continental slope, 6,000–23,000; lower continental slope, 1,500–3,000; abyssal rise, 500–1,200; abyss under the Gulf Stream, 150–270; abyss in the Sargasso Sea, 31–130; lower Bermuda Slope, 140–300; upper Bermuda Slope, 500–850. From all but three stations, Polychaeta, Crustacea, Pelecypoda and Sipunculoidea combined comprised 85–100% of the fauna, with the former group being particularly important. Pogonophorans, ophiuroids, anemones, solenogastres, gastrods, and scaphopods were also important, but less abundant. The dominance of polychaetes tended to decrease with distance from the continent, while the crustaceans correspondingly increased in importance. Attempts to relate the density of animals to the amount of organics in the sediment provided no clear correlation. It is suggested that this results from the fact that the analytical techniques do not differentiate between labile and more refractory organic compounds.

In this paper are summarized the findings of the bathymetric survey carried out off the Pacific coast of the southern part of Tohoku (Sanriku) District of Honshu, Japan.Significant topographic features of the continental shelf, continental slope, deep sea terrace and the Japan Trench are illustrated on Profiles I to XII.

This paper deals with the bionomy of the sea bottoms of the N-NE Brazilian continental shelf, between Cape Orange and the State of Sergipe, south of Sao. Francisco River. It is based on data collected by the Instituto Oceanografico, Recife, Brazil, during several surveys conducted in that area. Special emphasis is placed on the characteristics of the bottom, chiefly surveyed by means of dredging, as well as on the biological populations living on the different substrata. The sector of Recife, investigated in more detail, provides a general scheme of population delimitation. The study is applicable to the rest of the N-NE Brazilian region. The great extent of the mud or muddy sand bottoms gives the Amazonian coasts a very typical aspect. The rest of the area is remarkable for the predominance of calcareous algae of the Melobesiae group. Some biogeographical considerations are presented regarding the northern and southern limits of the NE Brazilian region. Finally, it is attempted to define the bionomical significance of the bottoms studied, comparing them with similar and better knwon biotopes from the Mediterranean Sea and SW Indian Ocean.

Abstract A plausible method of drilling beyond the continental shelves is set forth withlimitations of the method. The continental shelves comprise the water-coveredportions of land masses out to 600'Ft. of water, or 100'Fathoms. The problemsand possibilities of drilling beyond this depth are discussed in thispaper. Introduction Much attention is being given the problem of developing petroleum beneath theopen sea. Geophysical surveys have been made 26 miles offshore from thecontinental United States, and once offshore ownership is established it islikely that there will be drilling for oil on the continental shelves. More than two? years ago the author presented the means for drilling in deepwater. at the fall meeting of the Petroleum Division of the AIME at LosAngeles. His concepts then were based on the use of rigid foundations suitablefor drilling in water up to 600'Ft. deep. The present paper suggests a methodfor drilling in deeper water. Possibilities and Problems of Drilling Beyond the Continental Shelves It being conceded that because restricted deep-water portions of thehydrosphere might contain oil in commercial quantities, and that at any rate itis pertinent to know more of the nature of the lithosphere beneath thehydrosphere, the possibilities and problems of drilling beyond the continentalshelves should be set forth. Drilling in open water would offer few if any advantages over drilling on land.These are:The ocean transportation is available to deep-water drilling sites, andextensive pipe lines and roads are unnecessary.Refinery facilities and markets perhaps are established on the near-by shorewhere adjacent fields on land are nearing depletion.There is freedom from jungle pests and tropical diseases.Competitive drilling is less likely.Extensive areas attractive for development are not yet under lease orconcession. Disadvantages are great and numerous:Storm hazards from wind and wave.Expensive foundations, either rigid or floating.Shutdown times because of weather.Marine Regulations of Federal Bureaus in addition to customary regulationson land.Frequent difficulty in moving men and materials to and from drillingplatforms.Extra precautions required in open sea. T.P. 2095

Among the Applications Activities (the application of NASA technological expertise to civil sector problems) at the Langley Research Center are the study of pollution transport in the Coastal Zone and coastal wave conditions. This paper describes the Coastal Zone modeling work being undertaken in support of these Applications Activities. The analytical models described are being developed to provide a predictive capability for pollution transport and wave conditions in the Coastal Zone. The models include: (1) a Continental Shelf circulation model, (2) a North Atlantic circulation model intended for validation of the general ocean circulation models, (3) two pollution dispersal models, and (4) a first-order coastal wave refraction model.

During the past two years it has been determined that submersibles can be used for cable burying work. The submersible mounted jet system has been used to bury cable and repeaters in a variety of bottom conditions and in water depths exceeding 600 meters. The purpose of this paper is to report on cable burying operations carried out by International Hydrodynamics, on the Canadian Continental Shelf off Nova Scotia during the Summer of 1973, using the manned submersible, PISCES V. The submersible support vessel MV HUDSON HANDLER is also described.