The Hoxnian Interglacial deposits at Woodston, Peterborough

1992 ◽  
Vol 338 (1284) ◽  
pp. 131-164 ◽  
Keyword(s):  
Sedimentary Environment ◽  
Plant Macrofossils ◽  
Estuarine Environment ◽  
Middle Pleistocene ◽  
Marine Transgression ◽  
South Side ◽  
Broad Agreement ◽  
Plant Remains ◽  
Closed Canopy ◽  
The Individual

Interglacial deposits on the south side of Peterborough have yielded a diverse flora and fauna which lived in an estuarine environment that was affected by marine transgression and regression. Fossils described from six sequences indicate that the deposits accumulated under fully temperate conditions. The Woodston Beds have a diversity of fossils (pollen, plant macrofossils, molluscs, ostracods, insects and mammals) which allows their palaeoecological relationships to be examined, and compared with those of other sites of similar age. The environmental reconstructions based on the individual taxa, although emphasising differing facets of the habitat, are in broad agreement. Some slight discrepancies arise from the assumption that the organisms are characteristic of the sedimentary environment in which they are found. In fact many of the fossils have been transported to the site of deposition from nearby habitats. Evidence of a closed canopy forest with associated land environments, is provided by the plant remains and the land molluscs, and to a lesser extent by the insects and the mammals. A large, slow- flowing river, with adjacent marsh and meadow areas is also suggested by the taxa of molluscs, ostracods and insects present. Molluscs and ostracods show clearly the presence of marine influences between 11 and 14 m Ordnance Datum . The climate under which the Woodston Beds were deposited was slightly warmer than the present. An age in the Hoxnian Interglacial of the Middle Pleistocene is proposed.

Comparative geochemistry of pelites from the Moinian and Appin Group (Dalradian) of Scotland

1981 ◽  
Vol 118 (5) ◽  
pp. 477-490 ◽  
Author(s):  
R. St. J. Lambert ◽  
J. A. Winchester ◽  
J. G. Holland
Keyword(s):  
Trace Element ◽  
Sedimentary Environment ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
Central Highlands ◽  
The Individual

SummaryPelitic schists from the Appin Group of the Dalradian Supergroup are all chemically distinct from pelitic schists in the older Moinian Supergroup. In addition, trace-element geochemistry can also discriminate between the individual pelitic schists within the Appin Group, especially those within the Lochaber Subgroup. These differences apparently relate mainly to differences in provenance rather than differences of sedimentary environment, and are sufficiently consistent to offer a means for correlation or identification of pelitic units in areas of the Central Highlands where the stratigraphy is still in dispute.

The Icenian Crag of southeast Suffolk

1974 ◽  
Vol 269 (895) ◽  
pp. 1-28 ◽  
Keyword(s):  
The Netherlands ◽  
Deciduous Forest ◽  
Middle Pleistocene ◽  
Pollen Assemblage ◽  
Marine Transgression ◽  
Open Coast ◽  
Lower Pleistocene ◽  
Mollusc Assemblages ◽  
Deep Boreholes ◽  
Beach Plain

Sections in the Icenian Crag at Chillesford, Aldeburgh, Thorpe Aldringham, Sizewell, Dunwich, Wangford and Southwold are described. Pollen and mollusc assemblages from these sites are tabled. The Icenian Crag is shown to contain a temperate pollen assemblage, resulting from a regional deciduous forest of the time. The assemblage is provisionally correlated with the Pastonian stage of the Middle Pleistocene, as Tsuga is very poorly represented and Abies is absent. The mollusc assemblages are divided into a sublittoral or infralittoral facies, a sheltered estuarine or wadden area facies, an open coast facies and a high-boreal or sub-arctic silty deposit facies, probably infralittoral. The unconformable relation of the Icenian Crag to Red and Coralline Crags at Chillesford and Aldeburgh and to Baventian sediments at Easton Bavents indicates a strong marine transgression over Lower Pleistocene deposits in Pastonian times. The beach plain of the Westleton Beds is included within this transgressive phase. Pollen assemblages from deep boreholes at Sizewell and Southwold show that the transgression deposits overlie Lower Pleistocene sediments correlated with the PreLudhamian, Thurnian and Baventian stages. A correlation is suggested between the Pastonian and the Cromerian III Interglacial of the Netherlands.

A Clinical Grading System for Dupuytren’s Contracture

1998 ◽  
Vol 23 (3) ◽  
pp. 303-305 ◽  
Author(s):  
M. J. WOODRUFF ◽  
M. A. WALDRAM
Keyword(s):  
Operation Time ◽  
Dupuytren’S Contracture ◽  
Clinical Classification ◽  
Surgical Experience ◽  
Broad Agreement ◽  
Dupuytren's Contracture ◽  
Actual Operating ◽  
Significant Difference ◽  
The Individual ◽  
Clinical Grading

A clinical classification for Dupuytren’s contracture of the hand is described. The classification system has been used to sort patients with Dupuytren’s contracture into five broad surgical categories and takes into account predisposing factors, risk of recurrence and sympathetic tone in the individual patient. The system has many advantages in determining the approximate operation time and surgical experience required to treat patients. One hundred and four patients graded by this system have been analysed. There was a broad agreement between expected and actual operating times, with no significant difference between them.

scholarly journals Dominant Role of Sea Level on the Sedimentary Environmental Evolution in the Bohai and Yellow Seas Over the Last 1 Million Years

2021 ◽  
Vol 9 ◽  
Author(s):  
Xuefa Shi ◽  
Zhengquan Yao ◽  
Jianxing Liu ◽  
Shuqing Qiao ◽  
Yanguang Liu ◽  
...  
Keyword(s):  
High Resolution ◽  
Sea Level ◽  
Yellow Sea ◽  
Bohai Sea ◽  
Dominant Role ◽  
Sedimentary Environment ◽  
Middle Pleistocene ◽  
Southern Yellow Sea ◽  
Sea Level Fluctuations ◽  
The Southern Yellow Sea

Transgression and regression deposits from the shallow continental margin provide information on orbital-scale variations in sea level, climate change, and local tectonics. In this study, we conduct a high-resolution chronological and sedimentological analysis of a 125-m core (NHH01) drilled in the southern Yellow Sea. We developed a high-resolution age model at the orbital timescale over the last ∼1 Myr by the astronomical tuning of the sediment grain size. Sedimentological analysis and environmental proxies reveal that the study area is characterized by cyclic alternations of neritic and littoral/fluvial deposits controlled by glacial–interglacial sea-level changes. These results confirm the earlier assumption that sea-level fluctuations play a dominant role in the sedimentary architecture of the southern Yellow Sea. Moreover, only low-frequency sea-level fluctuations (∼100 kyr) were preserved in the NHH01 sequence; however, additional high-frequency (∼40 kyr) sea-level variations were also present in the sediments of the shallower Bohai Sea. Despite the large spatial difference, this finding implies that the sedimentary environment in the eastern marginal seas of China had been influenced by the sea level as a whole over the last 1 Myr. The comparison of the sedimentary environment with other cores from the Bohai Sea, Yellow Sea, and coastal region, as well as records from Indonesia and Japan, reveals that a consistent initiation of large-scale marine transgression occurred at ∼0.8–1 Ma. This phenomenon was likely caused by the long duration of glacio-eustatic high sea-level stands following the Middle Pleistocene transition, which is characterized by a shift in glacial cycles from 40 to 100 kyr.

scholarly journals Historia de la vegetación del sitio Huapilacuy II durante el Holoceno Medio a partir del análisis polínico y de macrofósiles vegetales, Isla Grande de Chiloé, Chile

2021 ◽  
Vol 49 (1) ◽  
Author(s):  
Liliana Londoño Ortiz ◽  
Carolina Villagrán ◽  
Ismael Rincón ◽  
Luis Felipe Hinojosa ◽  
Giselle Andrea Astorga
Keyword(s):  
Pollen Analysis ◽  
Local Development ◽  
Plant Macrofossils ◽  
Plant Colonization ◽  
Sedimentary Sequence ◽  
Lake District ◽  
Closed Canopy ◽  
Northwestern Coast ◽  
Temperate Rainforests ◽  
Tree Composition

This study examines the new fossiliferous site Huapilacuy II of Mid-Holocene age (7,344±51-6,865±58 cal years BP.) located in the northwestern coast of the Isla Grande de Chiloé. This area was not affected by the successive Pleistocene glaciations, and therefore it presents a biogeographic relevance as a potential area of refugia and stability for the vegetation. The presence of plant macrofossils contained in a sedimentary sequence of ca. 300 cm thick, confers a special interest to the site, due to the scarce information available on this type of indicator in paleoenvironmental studies of southern Chile. Additionally, several pollen-based reconstructions from the southern Lake District of Chile (40-44˚ S), document the Holocene sequence of recolonization by the different temperate rainforests types that today occupy this region, although there are non-Holocene records for the Pacific coast of the region. The aim of this study is to reconstruct the local environmental conditions and paleoecology based on the stratigraphic context and the analysis of plant macrofossils at the site Huapilacuy II. In addition, based on the pollen analysis of the deposit, we provide new information to reconstruct the regional characteristics of the vegetation during the Middle-Holocene. In particular, the plant macrofossil record of marsh species contained in the sediments of the lower section of the studied sedimentary sequence, together with the pollen analysis of the same sequence, document a first phase of plant colonization at 7,344±51 cal yrs. BP, with predominance of Poaceae, ferns, and trees with regeneration capacity in open areas, such as Embothrium coccineum and Drimys winteri. The analysis of leaf macrofossils and palynomorphs recovered from several intercalated layers, from the middle section of the sedimentary sequence, show the local and regional development of dense and very humid forests dominated by Aextoxicon punctatum, associated with several species of Myrtaceae. The presence of soil moisture indicator species, such as Luma chequen, Myrceugenia sp. and Myrtaceae Blepharocalyx-type is consistent with the sedimentary environment and the local development of swamp or riverine forests. This hygrophile forest environment is also consistent with the assemblage of fossil mosses, dominated by species that grow today in dense closed-canopy forests, such as Weymouthia, Ptychomnium, Rigodium, Porothamnium and Eucamptodon. The regional correlation of the pollen spectra from Huapilacuy II and other records from the Lake District allows us to establish latitudinal and longitudinal differences of tree composition in the temperate-rainforests that expanded during the Early to Mid-Holocene. In particular, this study established for the northwestern coast of the Isla Grande de Chiloé the presence of the coastal association of the valdivian forest (As. Lapagerio-Aextoxiconetum), currently distributed along the Chilean coastline between 30˚- 43˚S. In contrast, the Valdivian associations recorded in other areas of the region exhibit the dominance of Eucryphia cordifolia, Caldcluvia paniculata, Weinmannia trichosperma and different species of Nothofagus. Despite the differences in tree composition, the fossil bryophyte species recorded in several of the sites compared are common with those reported for Huapilacuy II, thus showing the wide ecological range of Chilean bryophytes associated with closed-canopy temperate-rainforests.

The volcano sedimentary sequence in the Upper Awash valley (Ethiopia): a type case of volcanoclastic sedimentation in a peripheral rift environment 

2021 ◽  
Author(s):  
Laura Pioli ◽  
Margherita Mussi ◽  
Rita T. Melis
Keyword(s):  
Volcanic Activity ◽  
Sedimentary Environment ◽  
Drainage System ◽  
Middle Pleistocene ◽  
Ethiopian Rift ◽  
Stratigraphic Correlation ◽  
Sedimentary Sequence ◽  
Main Ethiopian Rift ◽  
Ignimbrite Sheet ◽  
Volcanic Facies

<p>The Upper Awash valley runs across a volcano-sedimentary sequence dated from Late Miocene to about 500 my ago. The volcano sedimentary sequence in the Upper Awash valley developed within a closed basin at the western margin of the Main Ethiopian Rift branch and was affected by tephra sedimentation from nearby sources but also from volcanoes from the rift floor, and local fissural/dome eruptions. Dynamic interaction between rift tectonics, volcanic activity, tephra erosion and redeposition created a complex sedimentary environment constituting an exceptional fossil trap. In the area of Melka Kunture, the sediments host numerous fossils and archeological remains of Early-Middle Pleistocene (Oldowan and Acheulean) and Upper Pleistocene age. This is one of the most relevant African locations for researching human evolution.</p><p>The valley sequence formed after deposition of the large ignimbrite sheet of the Munesa tuff, within a paleo fluvial system which developed within lateral rift faults. Sedimentation rates significantly decreased after 500 my ago, probably due to decline of the volcanic activity in the area.</p><p>The basin stratigraphy consists of a composite sequence of primary (fall and flow) volcanic facies interbedded with reworked sediments emplaced in a low energy floodplain environment. The sequence is dominated by the deposit of one large pyroclastic density current (Kella Tuff) which is a main marker layer dated at 1.2 My. Deposition of the Kella Tuff had deep impact on the area leading to a complete reorganization of the drainage system and river channel migration and development of a disconformity in the southern Melka Kunture area.</p><p>Stratigraphic correlation is based on the interpretation of the basin history and evolution and has a crucial relevance not only for the reconstruction of the paleoenvironment but also for the interpretation of the paleontological and archeological data.</p><p> </p>

Pliocene-Quaternary river-terrace sequences in intramontane basins in the south-eastern Alpine foreland (Slovenia): characterization of morphostratigraphy and provenance

2021 ◽  
Author(s):  
Eva Mencin Gale ◽  
Petra Jamšek Rupnik ◽  
Miloš Bavec ◽  
Mirka Trajanova ◽  
Luka Gale ◽  
...  
Keyword(s):  
Sedimentary Environment ◽  
Early Pleistocene ◽  
Tectonic Activity ◽  
Middle Pleistocene ◽  
Published Data ◽  
Drainage Network ◽  
The South ◽  
South Eastern ◽  
Alpine Foreland ◽  
Intramontane Basins

<p>This study focuses on the Pliocene-Quaternary sedimentary evolution of the fluvial systems in the Slovenj Gradec, Nazarje, Velenje, Celje, Drava-Ptuj and Krško Basins in the south-eastern Alpine foreland, Slovenia. The main aim was to determine the composition, morphostratigraphy, provenance, sedimentary environment and age of the deposits using geomorphological, sedimentological, geochemical, mineralogical and biostratigraphical methods. Pliocene-Quaternary sediments were deposited in fluvial (braided and wandering river systems) and alluvial/colluvial fan environments. The sediments are preserved in the terrace staircase sequences, formation of which is strongly controlled by tectonic activity. Based on geomorphological analyses, low-, middle- and high-level terrace groups were constrained and tentatively attributed to Late Pleistocene, Middle Pleistocene, and Plio-Early Pleistocene, respectively. The provenance analyses focused on the Plio-Early Pleistocene sediments and included lithological and microfacies analyses of the clasts. Based on the provenance analyses and published data, the long-term development of the drainage network was interpreted. Major changes occurred during the transition from Miocene-Pliocene and at the latest at Plio-Early Pleistocene the drainage network reached conformity with the present one. Overall, the spatial distribution of the Pliocene-Quaternary landforms revealed tectonic activity in intramontane basins during their development, from which the landscape evolution was deduced. </p>

Coastal interglacial deposits of the English Channel

1960 ◽  
Vol 243 (701) ◽  
pp. 95-133 ◽  
Keyword(s):  
Sea Level ◽  
Pollen Analysis ◽  
Brackish Water ◽  
High Tide ◽  
English Channel ◽  
Sea Level Changes ◽  
Last Interglacial ◽  
Marine Transgression ◽  
Plant Remains ◽  
Eemian Interglacial

Fossiliferous Late-Pleistocene deposits on the foreshore of the English Channel at Selsey (Sussex), Stone (Hampshire), and near Arromanches (Calvados), have been investigated. At each site analyses of pollen, macroscopic plant remains and Mollusca have been made and from these vegetational, faunal, environmental and climatic conditions have been reconstructed. At Selsey, it is shown that the deposits, which lie in a channel cut in Eocene rocks, are of Ipswichian (Eemian or Last) Interglacial age. Pollen analysis of the sediments of the channel filling show they were formed during zones b , c , d , e and f of this interglacial from open parkland vegetation to birch-, to pine-, to oak-dominated forests. Analysis of the macroscopic plant remains and of the molluscs suggests a rapid climatic amelioration at the beginning of the interglacial, so that by the beginning of zone f there are indications of summer warmth exceeding that of the present day in the area. In the upper part of the channel filling, estuarine deposits overlie freshwater deposits. It is shown that the marine transgression causing the change was taking place in zone f and was probably responsible later for the raised beach deposits which overlie the channel deposits and which form the cliffs at Selsey Bill. At Stone pollen analysis shows that brackish water deposits, below present high tide level, were formed in zone f of the Ipswichian Interglacial. At that time Quercus , Pinus and Acer were the chief trees forming the forest in the region. The macroscopic plant remains and the Mollusca indicate that the deposit was formed under saltmarsh conditions. As at Selsey, the raised beach gravel found overlying the interglacial deposit is related to the same marine transgression that produced the brackish water conditions. Near Arromanches, at St Côme de Fresne and Asnelles-Belle-Plage, two deposits showing a change from marine to freshwater sediments were investigated. The analysis of pollen and the Mollusca showed the prevalence of pine forest and its replacement by open steppe-like conditions as the marine regression occurred. After the regression, limon covered the freshwater deposits. The fossiliferous deposits are tentatively correlated with zone i of the Eemian Interglacial. The relative land- and sea-level changes indicated by all the deposits are considered. It is concluded that in the English Channel, during the Ipswichian (Eemian) Interglacial, sea level rose above its present height in zone f and fell below it during zone i . The Selsey-Brighton raised beach and the Normannien II raised beach are correlated with the same marine transgression. It is pointed out that if the Selsey-Brighton raised beach is to be correlated with the Monastirian II level of 7—8 m, then this level should be correlated with the Ipswichian (Eemian) Interglacial.

scholarly journals Palaeobotanical evidence for warm summers in the East Siberian Arctic during the last cold stage

2005 ◽  
Vol 63 (3) ◽  
pp. 283-300 ◽  
Author(s):  
Frank Kienast ◽  
Lutz Schirrmeister ◽  
Christine Siegert ◽  
Pavel Tarasov
Keyword(s):  
Sediment Accumulation ◽  
Food Resource ◽  
Floristic Composition ◽  
Plant Macrofossils ◽  
Arctic Vegetation ◽  
Cold Stage ◽  
Plant Remains ◽  
Siberian Arctic ◽  
Large Populations ◽  
Steppe Communities

Plant macrofossils from the “Mamontovy Khayata” permafrost sequence (71°60′N, 129°25′E) on the Bykovsky Peninsula reflect climate and plant biodiversity in west Beringia during the last cold stage. 70 AMS and 20 conventional14C dates suggest sediment accumulation between about 60,000 and 750014C yr B.P. The plant remains prove that during the last cold-stage arctic species (Minuartia arctica,Drabaspp.,Kobresia myosuroides) coexisted with aquatic (Potamogeton vaginatus,Callitriche hermaphroditica), littoral (Ranunculus reptans,Rumex maritimus), meadow (Hordeum brevisubulatum,Puccinellia tenuiflora) and steppe taxa (Alyssum obovatum,Silene repens,Koeleria cristata,Linum perenne). The reconstructed vegetation composition is similar to modern vegetation mosaics in central and northeast Yakutian relict steppe areas. Thus, productive meadow and steppe communities played an important role in the Siberian Arctic vegetation during the late Pleistocene and could have served as food resource for large populations of herbivores. The floristic composition reflects an extremely continental, arid climate with winters colder and summers distinctly warmer than at present. Holocene macrofossil assemblages indicate a successive paludification possibly connected with marine transgression, increased oceanic influence and atmospheric humidity. Although some steppe taxa were still present in the early Holocene, they disappeared completely before ∼290014C yr B.P.

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