Wealden research—ways ahead

Allen, P.

doi:10.1016/s0016-7878(89)80026-4

Cited by 43 publications

(27 citation statements)

References 133 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Though the sediments within the Ashdown and Wadhurst Clay formations were deposited in predominantly freshwater environments, tidal and lagoonal influences have been previously noted (e.g. Stewart, ; Lake and Shephard‐Thorn, ; Allen, ; Radley and Allen, ). In this current study, the abundance of ripple marks, rhythmic bedding, flaser bedding and wavy bedding suggests tidal influences during deposition.…”

Section: Discussionmentioning

confidence: 99%

Multi‐proxy approach to palaeoenvironmental modelling: the English Lower Cretaceous Weald Basin

Akinlotan

2017

Geological Journal

View full text Add to dashboard Cite

Palaeoenvironmental reconstructions of the Wealden (Lower Cretaceous) in southeast England have been previously based mainly on field and fossil data. This study presents new interpretations of multi-proxy data sets such as sandstone petrography, elemental geochemistry and sideritic ironstones, supplemented by outcrop and clay mineralogical data. The dominance of quartz arenites, kaolinite and thorium and the presence of Zr in the sediments suggest that they were sourced mainly from granitic and/or gneissic rocks. Materials from metamorphic sources are secondary in abundance. The mineral and textural maturity of the sediments coupled with inferred short transport distances suggests reworking from older sources. Palaeoclimatic conditions in the source areas were generally warm and humid in nature, which supported an intensive weathering regime. The nature of the sediments suggests they may have been sourced directly or indirectly from a stable craton. The lithology, facies, sedimentary structures, architecture and gamma ray data confirm the freshwater origin of the sediments. Redox-sensitive trace elements such as Mo, U, V and Co suggest anoxic conditions in the basin. The results presented in this paper reinforce the importance of integrating multi-proxy data sets for interpreting the palaeoenvironmental conditions of sedimentary basins: when traditional data sets such as field and fossil data are not readily available or insufficient to enable adequate interpretations, the integration of petrographic, mineralogical and geochemical data sets may prove to be useful in similar palaeoenvironmental studies.

show abstract

Section: Discussionmentioning

confidence: 99%

Multi‐proxy approach to palaeoenvironmental modelling: the English Lower Cretaceous Weald Basin

Akinlotan

2017

Geological Journal

View full text Add to dashboard Cite

show abstract

“…Relative distribution of mudflats and shallow water bodies was strongly influenced by prevailing barometrics, wind effects, coastal storms and possibly eustatic effects. In this respect these beds are closely comparable to the Purbeck-Wealden clay formations of the Weald subbasin, southeast England (Allen, 1975(Allen, , 1981(Allen, , 1989. Significantly these successions also include coquinas of possible storm origin, such as certain Neomiodon limestones within the Berriasian (Upper Purbeck) Greys Limestones of the River Line section, East Sussex [TQ 715 191] (Radley, 1999).…”

Section: Discussionmentioning

confidence: 81%

“…Minor fluctuations in water level, and thus the relative extent of marginal mudflats, were probably partly controlled by wind-driven and barometric 'seiches' . Stewart et al (1991) postulated north-south-trending barrier islands to the east of the Isle of Wight area, protecting the Vectis lagoon from marine influxes via the Paris Basin or the Southwestern Approaches (Allen, 1989;. Partial breaching of these may have facilitated a weak tidal influence (Allen, 1981;.…”

Section: Stratigraphy and Palaeoenvironmental Settingmentioning

confidence: 99%

“…Partial breaching of these may have facilitated a weak tidal influence (Allen, 1981;. Micropalaeontological evidence (ostracods, dinocysts) additionally indicates a northern marine influence (Anderson, 1967;Harding & Allen, 1995), possibly via a barrier coastline in the CornubiaLondinia gap (Allen, 1981(Allen, , 1989. Belemnites in the upper part of the Vectis Formation (Ruffell & Radley in Harding & Allen, 1995) are probably reworked Jurassic bioclasts (Radley, Gale & Barker, 1998), rather than of contemporaneous marine origin.…”

Section: Stratigraphy and Palaeoenvironmental Settingmentioning

confidence: 99%

“…Wealden climates are inferred to have been warm to very hot and of annually seasonal 'Mediterranean' type (Allen, 1989(Allen, , 1998. The Cowleaze Chine and Shepherd's Chine members of the Vectis Formation ( Fig.…”

Section: Stratigraphy and Palaeoenvironmental Settingmentioning

confidence: 99%

See 2 more Smart Citations

Palaeoenvironmental significance of storm coquinas in a Lower Cretaceous coastal lagoonal succession (Vectis Formation, Isle of Wight, southern England)

Radley

Barker

2000

Geol. Mag.

View full text Add to dashboard Cite

Thin bioclastic limestone beds ('coquinas') in the Vectis Formation (Wealden Group, Lower Cretaceous) of the Isle of Wight, southern England, exhibit a range of biofabrics and internal stratigraphies. These features are attributed to both simple and complex storm deposition of allochthonous biogenic and siliciclastic materials in coastal lagoons and on adjacent mudflats. These modes of deposition facilitated preservation of dinosaur trackways, desiccation cracks, shallow-tier trace fossils and in situ bivalve colonies through rapid burial. The coquinas thus preserve a record of surficial muds, commonly lost through reworking. The principal components of the coquinas comprise dispersed elements from within the argillaceous 'background' facies. Some of these beds are laterally traceable for up to 27 km, providing the foundations for a high-resolution event-stratigraphic framework.

show abstract

Sphaerosiderites as sensitive recorders of non‐marine depositional and diagenetic history: Insights from the Lower Cretaceous Wealden Supergroup

Sengupta

Robinson

Tosca

2021

The Depositional Record

View full text Add to dashboard Cite

Waterlogged, reducing soils in modern and ancient wetlands feature distinctive syndepositional to early diagenetic spherical iron carbonate concretions, known as sphaerosiderites. Sphaerosiderites are thought to record pore water elemental chemistry and local palaeoenvironmental conditions, and are widely used in palaeohydrological reconstructions throughout the Phanerozoic. The Lower Cretaceous non‐marine Wealden Supergroup of Southern England, deposited in fluvio‐lacustrine settings, contains abundant well‐preserved sphaerosiderites offering an ideal archive for unravelling the geochemistry of ancient non‐marine environments. Sphaerosiderites were characterised via multiple microanalytical techniques (SEM‐EDS, EPMA, XRD, SIMS), and show morphological and compositional heterogeneity (e.g. concentric zones of variably enriched Mn, Ca or Mg, elemental differences between cores and rims) in well‐preserved sphaerosiderites from the Ashdown and Tunbridge Wells Sand formations. The preservation of primary fabrics, lack of post‐burial cements or extensive alteration suggests these sphaerosiderites record primary palaeoenvironmental conditions. By contrast, in the Wadhurst Clay Formation, sphaerosiderites are recrystallised, potentially reflecting wide scale palaeoenvironmental changes (e.g. marine incursions). New experimental constraints on elemental uptake during siderite growth suggests that rather than reflecting pore water elemental chemistry, the elemental heterogeneity in the Wealden sphaerosiderites reflects complex parameters; variations in pH, cation concentrations, DIC, growth rate and siderite saturation state in groundwaters. At a larger scale, morphological and compositional differences between sphaerosiderites from distinct palaeosol horizons record spatial and temporal variability in local hydrogeochemistry. This suggests that the Weald Basin wetlands of the Lower Cretaceous featured a dynamic and periodically fluctuating groundwater table, where sphaerosiderites growing close to the soil surface responded rapidly to variability in physiochemical conditions, consistent with wet and warm conditions suggested by sedimentological evidence and climate model simulations. Similar morphological and compositional variability noted in other Phanerozoic sphaerosiderites suggests analogous processes operated in ancient wetlands, and that sphaerosiderites could provide a crucial tool to understand wetland dynamics in deep time.

show abstract

Wealden research—ways ahead

Cited by 43 publications

References 133 publications

Multi‐proxy approach to palaeoenvironmental modelling: the English Lower Cretaceous Weald Basin

Multi‐proxy approach to palaeoenvironmental modelling: the English Lower Cretaceous Weald Basin

Palaeoenvironmental significance of storm coquinas in a Lower Cretaceous coastal lagoonal succession (Vectis Formation, Isle of Wight, southern England)

Sphaerosiderites as sensitive recorders of non‐marine depositional and diagenetic history: Insights from the Lower Cretaceous Wealden Supergroup

Contact Info

Product

Resources

About