Estuarine Series Research Articles

Experimental constraints on barium isotope fractionation during adsorption–desorption reactions: Implications for weathering and erosion tracer applications

Constraining the processes that fractionate barium isotopes is essential for utilising barium isotope ratios as environmental tracers. Barium concentration measurements from soils, rivers, and estuaries demonstrate that adsorption–desorption reactions significantly influence the distribution of fluid–mobile barium at the Earth’s surface, potentially driving isotopic fractionation. To quantify the direction and magnitude of isotopic fractionation resulting from these reactions, a riverine and an estuarine series of batch experiments were conducted using environmentally important adsorbent minerals and surface waters. Himalayan river sediment and water samples were used to validate the experimental results.Adsorption–desorption reactions were found to be rapid, relative to the average transit time of sediment and water in catchments, and largely reversible. The direction and magnitude of isotopic fractionation in the riverine experiment series were consistent with the riverine field samples (preferential adsorption of the lighter isotopes). The reaction rate, reversibility, and magnitude of isotopic fractionation were found to depend primarily on the mineral. Experiments performed with iron oxyhydroxides (goethite and ferrihydrite) resulted in a greater degree of fractionation compared to clay minerals (kaolinite and montmorillonite). Estuarine experiments, designed to simulate sediment passage through a salinity gradient, demonstrated a high degree of reversibility, with 77% to 94% of adsorbed barium desorbed upon the addition of seawater to freshwater-equilibrated clay minerals.The results of the estuarine experiments suggest that barium isotope ratios measured in marine paleo-archives (e.g., corals) will reflect both the adsorbed and dissolved freshwater barium inputs to the ocean. The combined findings of this study indicate that the chemical and isotopic behaviour of barium differs from more conventional group 1 and 2 metal isotope systems due to a significant proportion of barium released from bedrock dissolution partitioning to mineral surfaces, rapid reaction rates between fluid–mobile phases, and a high degree of reaction reversibility. Consequently, riverine barium isotope ratios are likely to provide unique insights into the complex array of terrestrial weathering and erosion processes that sustain life on Earth.

Time variability of hydrodynamics and potential use of surface water and ocean topography mission in estuarine macrotidal system: example of Seine estuary

This work was supported by the National Center for Space Studies in the framework of the future mission surface water and ocean topography (SWOT). The estuarine zones with their complex hydrodynamics represent a great challenge for the future SWOT mission. The Seine estuary was selected by the SWOT Science Definition Team for the calibration/validation of the mission. Thus the aim of this study is to investigate the temporal hydrodynamic variability in the Seine estuary and the SWOT ability to reproduce this variability and hydrodynamic phenomena. For this, we used several statistical techniques and frequency analyses applied on the tide-gauge measurements of the Seine estuary and on SWOT simulated data. SWOT samples (SWOT simulated data) have been extracted synthetically from observations using the number of overpasses per repeat cycle [21 days (d)] in order to study the ability of SWOT to reproduce the time variability of the hydrodynamics. Results have demonstrated similar frequencies of multiyear, annual, and intraannual along the estuary from the Seine discharge to the Cherbourg sea level. The 11- to 22-d frequency has been only observed for estuarine and coastal time series suggesting the tide effect in these contexts. The distribution of levels has shown a high influence of tides and discharges at the downstream and the upstream, respectively. Low frequencies of water level are explained by the climate patterns of North Atlantic Oscillation with a mean range of 65%, whereas the high frequencies are associated to the periods of flooding and stormy events. Finally, simulated SWOT samples of water level show a better restitution of observations for high overpasses number. The results have shown a better restitution of hydrodynamic variability by SWOT in the river and upstream of estuary than in the downstream of estuary and coastal zone: in the estuary downstream and the coast, the annual mode is underexpressed while the 3-month (m) mode is overexpressed, which means the annual mode is underestimated and the 3-m mode is amplified by SWOT.

Made in the Nene Valley? Identifying the origins of mortaria using ICP analysis

The Nene Valley, in eastern central England, was a major pottery production centre in the Roman period. Many kiln sites have been identified in the Lower Nene Valley region and, although comparatively less is known about production in the Upper Nene Valley, substantial amounts of mortaria and other coarse wares have been recovered during excavations at Roman sites in the area, and much of it is thought to be locally made. However mortaria made in the Upper and Lower Nene Valley can be difficult to tell apart, and many also have similar forms and fabrics to mortaria produced in Mancetter–Hartshill, Warwickshire. Therefore ICP analysis was used in an attempt to identify the products of different regions. The ICP data showed that the Nene Valley mortaria are compositionally distinct from the Mancetter–Hartshill mortaria in terms of major and trace elements, and the Upper and Lower Nene Valley mortaria could be differentiated from each other using trace elements. Some mortaria were stamped by the potters that made them and so the compositional data could be used to determine where each potter worked. The Nene Valley mortaria were made from the Upper Estuarine Series clay, in common with other types of Roman pottery produced in the Nene Valley, and so the data presented here have also proved useful for investigating the origins of other types of wares.

Photographic Feature The Scarborough Landslide

Early on Friday, 4 June 1993, a large portion of Scarborough's South Cliff collapsed into the sea. The length of the gardens of the Holbeck Hall Hotel, Scarborough's only four star accommodation, had been reduced drastically from 60m to a mere 15 m. The photograph shown in Fig. 1 was taken that morning by an RAF Air Sea Rescue helicopter. Cracks had begun to appear in the Hotel itself and the guests were evacuated during breakfast. Over the following three days, the cliff retreated another 35m, thereby undermining the hotel, which toppled over the cliff piece by piece whilst thousands of onlookers and the media watched in fascination. The police closed off the area to prevent the foolhardy and those interested in antiques from trying to climb the unstable mass. As the hotel gradually collapsed over several days, the national press in their search for new angles on the story, managed to draw parallels between the collapsing Hotel, the state of British sport and that of the Government. Residents of the houses behind the hotel wondered where the slip was going to stop and feared that the value of their properties would plummet. The ground behind the slip was monitored continually for signs of movement. The South Cliff consists mainly of glacial till (boulder clay), which overlies Middle Jurrassic rocks. In the cliff to the left of the landslide (Fig. 1), the Scalby Formation (part of the Upper Estuarine series of the Middle Jurassic Inferior Oolite) crops out and is

The soil clays of Great Britain: I. England and Wales

AbstractThe mineralogy of the clay fractions (<2 µm) of the major soils of England and Wales is reviewed, and the data presented in terms of the 1:250 000 National Soil Map. Most soils developed in pre-Rhaetic sediments are dominated by mica with lesser amounts of chlorite and kaolin. Exceptions are soils developed in calcareous Coal Measure shales which have significant smectite contents, and freely drained soils in Keuper Marl which contain swelling chlorite, sepiolite and palygorskite. Soils developed in post-Triassic sediments are dominated generally by expansible minerals, except for those developed in Lower Lias and Estuarine Series rocks (Jurassic) which are dominated by mica and kaolin respectively. The presence of loess in soils seems to be associated with the occurrence of a complex interstratified mineral with X-ray diffraction properties akin to vermiculite. Weathering of soil clays is most marked in the wetter uplands, but over most of lowland England is detectable only by slight changes in non-exchangeable potassium content and cation-exchange capacity towards the soil surface. Applications of soil clay mineralogy in the fields of plant nutrition and soil mechanics are discussed, in particular the production of maps showing mineralogical provinces.

Isotopic studies on the palaeoecology and diagenesis of the Great Estuarine Series (Jurassic) of Scotland

Synopsis Over 700 carbon and oxygen isotopic analyses of fossils and carbonate rocks refine previous interpretations of the Great Estuarine Series. Many of the fossils are unaltered mineralogically and isotopically. Praemytilus and Liostrea inhabited water of variable isotopic composition and salinity; growth temperatures around 22°C are suggested for Praemytilus . Some Unio inhabited freshwater; other Unio , and Neomiodon , have normal marine δ C 13 and δ O 18 , which is contrary to palaeontological expectation. Fossil-matrix isotopic contrasts show the dominant influence of diagenesis on whole-rock isotopic composition. Early diagenetic carbonates have variable, usually low, δ C 13 (to −29), showing algal and bacterial influence. Sparry calcite cements have low δ O 18 but positive δ C 13 . Isotopic data confirm the solution-reprecipitation mechanism for the replacement of aragonitic shells by calcite. A stratigraphical review shows strongly variable isotopic composition of fossils from the Mytilus Shales, mainly marine values for the middle part of the Series, mainly freshwater for the Ostracod Limestones and Mottled Clays and a transgression in the Staffin Bay Beds.

LITHOSTRATIGRAPHICAL NOMENCLATURE OF THE MIDDLE JURASSIC STRATA OF THE YORKSHIRE BASIN OF NORTH-EAST ENGLAND

Summary Changes in the lithostratigraphical nomenclature of the Middle Jurassic strata of north-east Yorkshire are proposed which avoid the genetic connotations of existing terms such as Estuarine Series and Deltaic Series and which eliminate certain equivocal aspects of previous nomenclatures. A new marine unit has been recognized which is believed to include the beds previously described as the Hydraulic Limestone.

Crustacean faecal pellets, Favreina , from the Middle Jurassic of Eigg, Inner Hebrides

Synopsis Crustacean faecal pellets, Favreina sp. have been found, preserved uncompacted within articulated bivalves, in a thin limestone band of the Estheria Shales of the Bathonian, Great Estuarine Series of Eigg, Inner Hebrides. Though the pellets are well preserved they were not detected without the aid of staining.

The first Jurassic mammal from Scotland

R ecords of mammals in Mesozoic strata are rare: the earliest are of late Triassic age in Wales, S. Africa and China: two primitive mammal families (Eozo-strodontidae and Kuehneotheridae) are represented in these faunas. There then follows a long time gap until Late Jurassic, when mammals are known from the U.S.A., U.K., Portugal and Tanzania: these faunas include pantotheres, the stock from which almost all the later mammals arose. Between the Late Trias and Late Jurassic, the only known fauna is that of the Middle Jurassic of Stonesfield in Oxfordshire. Thus the discovery of a second site is of great importance: it occurs in the Estuarine Series of Skye in Scotland, and contains a fauna of tritylodonts and docodont mammals. The discovery of this fauna was made in August 1971 by Dr. M. Waldman and Mr. J. B. Dobinson during the course of a search for terrestrial vertebrates in the non-marine strata of Skye. Stratigraphy Since Hugh Miller (1858) described the occurrence of Jurassic vertebrate fossils on the Isle of Eigg, further vertebrates of similar age have been found in the Hebridean region. The richest material so far recovered has been from the Bathonian (Middle Jurassic) of Eigg ( Hudson 1966 ), and the most recent find is that of plesiosaur remains from the Bearreraig Sandstone (Bajocian) near Rigg, Isle of Skye ( Hudson & Morton 1969 ). All the Jurassic vertebrate remains known from this area are those of fish and reptiles and occur in a variety of localities. ( Miller 1858 , Peach 1910 , Arkell

Carbon and oxygen isotopic relationships of dolomites and co-existing calcites, Great Estuarine Series (Jurassic), Scotland

The dolomites studied formed during earliest diagenesis in shallow lagoonal environment. In co-existing pairs, O 18 is enriched in dolomite relative to calcite by 0.6–10.1 per mil. From estimates of the isotopic composition of the depositional waters we conclude that one group of dolomites, at least, was precipitated with an oxygen fractionation factor similar to that of calcite. Once formed, dolomite was resistant to subsequent alteration, but calcite exchanged oxygen with groundwaters during diagenesis and, in the Strathaird district of Skye, during a Tertiary heating episode. This explains the range of values of ΔO 18 dol-cal observed. ΔC 13 dol-cal is generally small and positive, but some dolomites are C 13 depleted by 7–10 per mil. These incorporated carbon from the decay of organic matter. δC 13 values were resistant to subsequent alteration.

ALGAL LIMESTONES WITH PSEUDOMORPHS AFTER GYPSUM FROM THE MIDDLE JURASSIC OF SCOTLAND

Hudson, J. D.: Algal limestones with pseudomorphs after gypsum from the Middle Jurassic of Scotland. Lethaia, Vol. 3, pp. 11–40. Oslo, January 15th, 1970. Algal limestones from two horizons within the Great Estuarine Series of the Hebrides are described. That from the Mytilus Shales is a typically stromatolitic limestone formed by algal trapping and binding of micrite pellets. Calcite pseudomorphs after gypsum occur along some of the laminae. The limestones from the Lower Ostrea Beds include less regularly-stromatolitic types, and nodular algal limestones that contain tubes of calcified algae, notably Cayeuxia nodosa Anderson. The algal nodules also yield uncalcified tubes composed of organic material, that are comparable to recent Schizothrix. These algae form inter-growths similar to those recorded from the recent supratidal deposits of the Bahamas. The algal nodules are often coated with microtufa. Pellet- and spheru-lite-limestones are associated with the algae, and pseudomorphs after gypsum are again found. Isotopic data on the carbonate-carbon, and the palaeoecological implications of the algae and the pseudomorphs are discussed.

Echinoid preservation in the Upper Estuarine Limestone of Blisworth, Northamptonshire

SUMMARYThe study of echinoids and their associated limestones in the Upper Estuarine Series of Blisworth has shown that the echinoid tests have been preserved in two ways. (1) Without spines, jaw apparatus or apical disc. When whole, such tests are usually full of sediment. Echinoids of this type are usually associated with clean well-sorted fragmental limestones. (2) Bearing spines and with apical disc and jaw apparatus in place. When whole, the tests are usually full of clear crystalline calcite. Echinoids of this type are usually associated with poorly sorted, complex, muddy limestones with a high proportion of terrigenous material. The sedimentary environment and the relative rate at which the echinoid material passed through the depositional interface appears to have controlled both the limestone lithology and the condition of the echinoid material.

Hugh Miller’s Reptile Bed and the Mytilus Shales, Middle Jurassic, Isle of Eigg, Scotland

Synopsis The type locality of the Mytilus Shales, the lowest division of the Great Estuarine Series on the Isle of Eigg, is described. A map of the exposures is presented, and the detailed stratigraphy of the beds, which include a bed rich in reptilian bones discovered by Hugh Miller, is expounded for the first time. The outcrop is disturbed by small faults and intrusions and partially obscured, so that the succession has to be constructed from five partial sections. The invertebrate faunas, mainly of brackish-water mollusca, are listed. The Reptile Bed itself, a sideritic shelly limestone, is described in detail. Recent work by others on the reptiles, mainly plesiosaurs, is referred to. The conditions of deposition of the Mytilus Shales and especially of the Reptile Bed are considered and analogies are drawn with the bays of the Florida Everglades.

The petrology of the sandstones of the Great Estuarine Series, and the Jurassic Palaeogeography of Scotland

The detrital mineralogy and pebble content of the Middle Jurassic Great Estuarine Series of the Inner Hebrides are described. Pebbles are rare, but are valuable indicators of provenance, and some are described in detail. They include vein quartz, Moine granulite, ?Cambrian quartzite and chert. The light minerals of the sands, which vary considerably in feldspar content, are described with the aid of twenty-three modal analyses. The description of the heavy minerals is based on sixty-five grain-counts of bromoform separations, including some from beds above and below the Great Estuarine Series and from equivalent beds in Sutherland. Removal of hornblende by source weathering, and of kyanite and sphene by interstratal solution, is demonstrated. The evidence for the provenance of the sediment is discussed, and a palaeogeographical map presented. It is concluded that the Scottish mainland, including Moine, Dalradian, Torridonian, Cambrian and Old Red Sandstone, was a major source; a minor Lewisian source is located in the north-west. The history of the Minch Basin is briefly reviewed; there is no evidence of a ‘North Atlantis’.

The stratigraphy of the Great Estuarine Series (Middle Jurassic of the Inner Hebrides)

The successions in the Great Estuarine Series in Northern and Southern Skye, Raasay, Eigg, Muck, Ardnamurchan and Mull are described and correlated. The limits of the Series are defined in each area, and the evidence for its age in the standard zonal scheme is reviewed. It is concluded that the Series is Upper Bajocian to Upper Bathonian; it is the approximate equivalent of the Yorkshire Upper Deltaic Series. Algal beds previously described from Skye have now been recognised in Eigg and Muck. The Series was deposited in brackish-water lagoons; it is not truly estuarine nor truly deltaic.

A marine shell-bed near the base of the Estuarine Series in Raasay

The purpose of this paper is to place on record the discovery of a marine shell-bed near the base of the Estuarine Series of the Jurassic succession in the island of Raasay in the Inner Hebrides. The author acknowledges with thanks the assistance of Dr. Martin Bott, Mr. C. R. Thewlis and Mr. D. Williams who all took part in the discovery. He also records his grateful thanks to Dr. L. R. Cox who identified and commented upon the lamellibranchs and to Dr. F. W. Anderson who identified the ostracods and crinoids collected from the shell-bed. The field work was carried out with the aid of a grant from the Clough Memorial Research Fund, which is gratefully acknowledged. In the Hebridean province of the British Jurassic rocks, the Inferior Oolite Series is followed by strata of estuarine origin known as the Great Estuarine, or simply the Estuarine, Series. This series is regarded as the equivalent of the Great Oolite Series of southern England, but may include at its base strata of inferior Oolite age as well. Arkell (1933, p. 246) noted that the topmost ammonite zones of the Inferior Oolite have not been found in the Hebrides, but the succession upwards from the highest known beds in that Series, namely those of the Garantiana Zone , was believed by Lee to be a conformable one. He stated (1920, p. 53) that in Raasay, “The actual base of the series” (i.e. of the Estuarine Series) “is marked by an oil-shale, 8 to

Frost-heaved soils of Barrow, Rutland

An exposure of disturbed soils occurring upon the Lower Estuarine Series of the Inferior Oolite at Barrow, Rutlandshire, is described. The disturbances are attributed to frost heaving and possible processes leading to their development are discussed.

Edinburgh Geological Society Session CXXV 1958-59. Records of papers read and of exhibits

15th October 1958 The Environment of Fossil Fish . By Dorothy H. Rayner, M.A., Ph.D. 19th November 1958 Mid-Carboniferous Sedimentation in the Midland Valley of Scotland . By G. A. Goodlet, F.G.S. 17th December 1958 The Geology of Kilimanjaro . By W. H. Wilcockson, M.A. 28th January 1959 Diamonds from the East and West . By C. F. Davidson, O.B.E., D.Sc, F.R.S.E., M.I.M.M. 18th February 1959 A Geological Tour of Switzerland . By I. Dalziel. The Geology of Shetland . By J. Phemister, M.A., D.Sc., F.R.S.E. Notes on the Geology of Peru . By J. Chronic, B.S., M.S., Ph.D. Microfossils from the shale underlying the Second Abden Limestone in Fife . By Laing Ferguson, B.Sc. Fossil Fish and Eurypterids from the Hagshaw Hills . By A. Ritchie and Professor F. H. Stewart. Fossils of Eocene Age from the Bournemouth area and the Isle of Wight, and Fossils from the Middle Old Red Sandstone of Caithness . By I. F. Sime. 13th March 1959 The Geology of the Western Alps . By Professor Augustin Lombard. 18th March 1959 Colour Slides taken on recent Field Excursions of the Society . By A. Mackie, Ph.D., D.Sc., F.R.I.C., F.R.S.E. A Marine Fossil Horizon at the base of the Estuarine Series in Raasay . By I. H. Forsyth, B.Sc. Ice-formed Crescentic Markings in Assynt . By R. Sutherland, M.A., LL.B., and C. D. Waterston, B.Sc., Ph.D. A Volcanic Vent in the Bogside Mines, Fife . By E. H. Francis, B.Sc. The Bannockburn Main Coal—A Study in Lateral Variation . By W. A. Read, B.Sc. 6th May 1959 Some Current Problems in

Williamsoniella papillosa, a new species of Bennettitalian flower

Abstract Williamsoniella papillosa sp. nov., from the Jurassic (Lower Estuarine Series) at Whitby is described and compared with W. coronata Thomas.

THE GEOLOGY OF THE YORKSHIRE JURASSIC FLORA

Summary The stratigraphic relations of the flora of the Deltaic rocks of the “Yorkshire Estuarine Series” have remained unsatisfactory because of badly localised collections, ill-defined species and especially because of concentration of effort on the half-dozen best localities. A recent search over nearly the whole outcrop has given several hundred new localities yielding determinable plants (but mostly as small fragments). These show that most species continue through all four divisions of the series. There are however real differences in the floras of successive stages. One group of species is found in a good proportion of the hundred or so localities of the Lower Deltaic, but in the two divisions of the Middle Deltaic it has very few indeed of the numerous available localities and then has a good proportion of localities again in the Upper Deltaic. A contrasted group has numerous localities in the two middle divisions, but is rare in the first and last. This is more like a change in abundance caused by a fluctuation in climate than true zonation. It is to be noted that it is only the proportion of localities where a species is met that changes, not its abundance in a particular locality. Each locality has a flora of special character with a great abundance of certain species, and rarity of others. Even the rarest species may occur locally in millions of specimens and even form a tiny coal seam by itself.