scholarly journals Early Ordovician acritarchs of the Lierneux Member (Stavelot Inlier, Belgium): stratigraphy and palaeobiogeography

2002 ◽  
Vol 173 (6) ◽  
pp. 561-568 ◽  
Author(s):  
Michel Vanguestaine ◽  
Thomas Servais
Keyword(s):  
Cold Water ◽  
Southern China ◽  
High Latitudes ◽  
Lake District ◽  
Northern Germany ◽  
The Czech Republic ◽  
Prague Basin ◽  
Sierra Morena ◽  
Northern Border ◽  
Northwestern Russia

Abstract The messaoudensis-trifidum acritarch microflora is currently considered to be characteristic of latest Tremadocian-earliest Arenigian cold-water environments on the periphery of Gondwana, at high latitudes in the southern hemisphere. Integrated biostratigraphical studies on both acritarchs and graptolites are available from two areas of peri-Gondwana, the Lake District (northwestern England) and the Sierra Morena (southwestern Spain). The assemblage was also recorded from other areas on the northern border of the Gondwana continent where macrofossils are generally not available: from southern Ireland, the Isle of Man, southern Wales, the island of Rügen in northern Germany, the Prague Basin in the Czech Republic, and southern Turkey. While it appears that the messaoudensis-trifidum acritarch assemblage is limited to cold-water environments in localities on the periphery of Gondwana, some of its elements can be found in other areas. Some taxa, but not the complete assemblage, have been identified in the eastern Cordillera of Argentina, and some species of the assemblage are cited from continents which were situated at intermediate latitudes in warmer waters: some elements of the assemblage are described from localities of Baltica (from Norway, Estonia and the St. Petersburg area in northwestern Russia) and from the Yangzte Platform in southern China. In these regions, typical representatives of the messaoudensis-trifidum assemblage co-occur with taxa typical of temperate and warm-water areas. The present paper reports the discovery of the messaoudensis-trifidum acritarch assemblage in the Lierneux Member (Stavelot Inlier, Belgium). The Lierneux Member, which constitutes the uppermost part of the Jalhay Formation (formerly Salmian 1c) in the Stavelot Inlier, was first dated as late Tremadocian by Vanguestaine [1992a]. Following recent stratigraphical conclusions based on the detailed investigations of the messaoudensis-trifidum assemblage from different sequences of peri-Gondwana, the age of the Lierneux Member recovered from the Chevron borehole in the Stavelot Massif can now be confirmed as being probably latest Tremadocian. The discovery of the messaoudensis-trifidum assemblage in the Stavelot Inlier provides further evidence for the palaeogeographical distribution of the assemblage on the northern border of Gondwana and allows tentative correlations between eastern Belgium and northern Germany.

scholarly journals Ordovician acritarchs of China and their utility for global palaeobiogeography

2002 ◽  
Vol 173 (5) ◽  
pp. 399-406 ◽  
Author(s):  
Jun Li ◽  
Thomas Servais
Keyword(s):  
Cold Water ◽  
Southern China ◽  
Warm Water ◽  
High Latitudes ◽  
Latitudinal Distribution ◽  
Low Latitude ◽  
Middle Ordovician ◽  
Tentative Model ◽  
Latitudinal Position ◽  
Oceanic Currents

Abstract Since the 1970s, acritarch workers have recognized two distinct geographic acritarch assemblages in the Ordovician. The first assemblage occurs in the late Tremadoc in low latitude areas. This assemblage, recently redefined by Volkova [1997], has been attributed to warm-water environments. A second “Mediterranean” or “peri-Gondwanan” province, attributed to high latitudes in the southern hemisphere, can easily be recognized in late Tremadoc to Arenig acritarch assemblages. This second palaeogeographic “province”, defined by Li [1989] is distributed around the border of Gondwana in a zone reaching from Argentina through northern Africa and peri-Gondwana up to Iran, Pakistan and southern China. In the present work we propose an initial simplified, tentative model of the latitudinal distribution of selected early to middle Ordovician acritarchs. Both “provinces” are plotted on the recent palaeogeographical reconstruction of the early Ordovician of Li and Powell [2001]. It appears that the first “province” is limited to low and intermediate latitudes, i.e., to warmer water environments. However, the generally adopted interpretation that the so called “Mediterranean” or “peri-Gondwanan” geographical assemblage is principally controlled by palaeolatitudes and is considered to be typically “cold-water” has to be revised, because the distribution of this “province” appears related more to the continental arrangement along the Gondwana border than to latitudes. This distribution shows some similarities with recent investigations in Silurian acritarch palaeogeography [Le Hérissé and Gourvennec, 1995] that provides evidence that the global distribution of Silurian acritarchs is under the interdependence of continental arrangement, latitudinal position, environmental conditions and oceanic currents, and that it is not simply latitudinally controlled as previous interpretations have suggested. The Yangtze Plaform of southern China presents elements of both early to middle Ordovician “provinces”, i.e., from both the “warm-water” and the “peri-Gondwanan” geographic assemblages. The South China Plate is therefore one of the areas that shows typically mixed assemblages. Although it remains difficult to define clearly a “Baltic” province, it is important to note that between the latest Tremadoc and the early Llanvirn a clear distinction of the acritarch assemblages between peri-Gondwana and Baltica is possible.

scholarly journals Salinity effects on cultured Neogloboquadrina pachyderma (sinistral) from high latitudes: new paleoenvironmental insights

2021 ◽  
Vol 41 (1) ◽  
Author(s):  
Jacqueline Bertlich ◽  
Nikolaus Gussone ◽  
Jasper Berndt ◽  
Heinrich F. Arlinghaus ◽  
Gerhard S. Dieckmann
Keyword(s):  
Sea Ice ◽  
Cold Water ◽  
Weddell Sea ◽  
Wall Thickening ◽  
High Latitudes ◽  
Neogloboquadrina Pachyderma ◽  
Antarctic Sea Ice ◽  
The Antarctic ◽  
Water Species ◽  
Cold Water Species

AbstractThis study presents culture experiments of the cold water species Neogloboquadrina pachyderma (sinistral) and provides new insights into the incorporation of elements in foraminiferal calcite of common and newly established proxies for paleoenvironmental applications (shell Mg/Ca, Sr/Ca and Na/Ca). Specimens were collected from sea ice during the austral winter in the Antarctic Weddell Sea and subsequently cultured at different salinities and a constant temperature. Incorporation of the fluorescent dye calcein showed new chamber formation in the culture at salinities of 30, 31, and 69. Cultured foraminifers at salinities of 46 to 83 only revealed chamber wall thickening, indicated by the fluorescence of the whole shell. Signs of reproduction and the associated gametogenic calcite were not observed in any of the culture experiments. Trace element analyses were performed using an electron microprobe, which revealed increased shell Mg/Ca, Sr/Ca, and Na/Ca values at higher salinities, with Mg/Ca showing the lowest sensitivity to salinity changes. This study enhances the knowledge about unusually high element concentrations in foraminifera shells from high latitudes. Neogloboquadrina pachyderma appears to be able to calcify in the Antarctic sea ice within brine channels, which have low temperatures and exceptionally high salinities due to ongoing sea ice formation.

scholarly journals Nannofossil record across the Cenomanian-Coniacian interval in the Bohemian Cretaceous Basin and Tethyan foreland basins (Outer Western Carpathians), Czech Republic

2012 ◽  
Vol 63 (3) ◽  
pp. 201-217 ◽  
Author(s):  
Lilian Švábenická
Keyword(s):  
Czech Republic ◽  
Black Shales ◽  
Western Carpathians ◽  
High Latitudes ◽  
Foreland Basins ◽  
Mutual Correlation ◽  
The Czech Republic ◽  
Outer Western Carpathians ◽  
First Occurrence ◽  
Bohemian Cretaceous Basin

Nannofossil record across the Cenomanian-Coniacian interval in the Bohemian Cretaceous Basin and Tethyan foreland basins (Outer Western Carpathians), Czech Republic Nannofossil biostratigraphy and mutual correlation was worked out for the Cenomanian-Coniacian deposits of the Bohemian Cretaceous Basin (BCB) and Outer Western Carpathians (OWC) in the territory of the Czech Republic. Similar assemblages of the BCB and from sediments deposited on the SE slopes of West European Platform, Waschbergždánice-Subsilesian Unit, OWC support the hypothesis that the two areas were connected by a sea way (nowadays the Blansko trough). The nannoflora of the Silesian Unit, OWC show more afinity to high latitudes as is documented by the presence of Marthasterites furcatus in the Lower Turonian, UC6b and UC7 Zones. Turonian and Coniacian deep-water flysch sediments of the Silesian Unit and Magura Group of Nappes provide nannofossils on rare occassions. Strongly atched nannofossils dominated by W. barnesiae from Cenomanian black shales of the BCB are comparable to those of the Silesian Unit and reflect a similar shallow nearshore sea. In the BCB, uppermost Cenomanian is marked by the last occurrence (LO) of Axopodorhabdus albianus and first occurrence (FO) of Quadrum intermedium (6 and 7 elements) and lowermost Turonian by a sudden quantitative rise in nannoflora and by the FO Eprolithus octopetalus. First Eiffellithus eximius and thus the base of the UC8 Zone was recorded in the upper part of ammonite Zone Collignoniceras woollgari in the lower Middle Turonian. Lithastrinus grillii is the stratigraphically youngest nannofossil species in this region and indicates the uppermost Coniacian. In the OWC, the Albian-Cenomanian boundary was recorded in the Silesian Unit and is marked by the LO Crucicribrum anglicum and FO Prediscosphaera cretacea and Corollithion kennedyi in the uppermost Albian. The Turonian-Coniacian boundary found both in the BCB and Waschberg-Ždánice-Subsilesian Unit, OWC is indicated by the FO Broinsonia parca expansa and by the base of the interval with common Marthasterites furcatus. In both areas, events were found closely below the FO inoceramid species Cremnoceramus waltersdorfensis. The Coniacian-Santonian boundary interval (Waschberg-Ždánice-Subsilesian and Foremagura Units, OWC) is indicated by Lithastrinus grillii occasionally accompanied by Lucianorhabdus ex gr. cayeuxii, Hexalithus sp. and Arkhangelskiella specillata.

scholarly journals Foreign and domestic contributions to springtime ozone over China

2018 ◽  
Vol 18 (15) ◽  
pp. 11447-11469 ◽  
Author(s):  
Ruijing Ni ◽  
Jintai Lin ◽  
Yingying Yan ◽  
Weili Lin
Keyword(s):  
Southern China ◽  
Surface Ozone ◽  
Coupled Model ◽  
Lower Troposphere ◽  
Emission Source ◽  
Anthropogenic Emissions ◽  
Source Attribution ◽  
Global Emission ◽  
Source Regions ◽  
Northern Border

Abstract. China is facing a severe ozone problem, but the origin of its ozone remains unclear. Here we use a GEOS-Chem based global–regional two-way coupled model system to quantify the individual contributions of eight emission source regions worldwide to springtime ozone in 2008 over China. The model reproduces the observed ozone from 31 ground sites and various aircraft and ozonesonde measurements in China and nearby countries, with a mean bias of 10 %–15 % both near the surface and in the troposphere. We then combine zero-out simulations, tagged ozone simulations, and a linear weighting approach to account for the effect of nonlinear chemistry on ozone source attribution. We find considerable contributions of total foreign anthropogenic emissions to surface ozone over China (2–11 ppb). For ozone of anthropogenic origin averaged over China, foreign regions together contribute 40 %–60 % below the height of 2 km and 85 % in the upper troposphere. For total ozone contributed by foreign anthropogenic emissions over China at various heights, the portion of transboundary ozone produced within foreign emission source regions is less than 50 %, with the rest produced by precursors transported out of those source regions. Japan and Korea contribute 0.6–2.1 ppb of surface ozone over the east coastal regions. Southeast Asia contributes 1–5 ppb over much of southern China and South Asia contributes up to 5–10 ppb of surface ozone over the border of southwestern China; and their contributions increase with height due to strong upwelling over the source regions. The European contribution reaches 2.1–3.0 ppb for surface ozone over the northern border of China and 1.5 ppb in the lower troposphere averaged over China. North America contributes 0.9–2.7 ppb of surface ozone over most of China (1.5–2.1 ppb over the North China Plain), with a China average at 1.5–2.5 ppb at different heights below 8 km, due to its large anthropogenic emissions and the transport-favorable midlatitude westerly wind. In addition to domestic emission control, global emission reduction is critical for China's ozone mitigation.

scholarly journals Pátek, Levousy a Chlumčany – významné fosiliferní středopleistocénní lokality na pravém břehu Ohře mezi Louny a Libochovicemi [Pátek, Levousy and Chlumčany – important mid-pleistocene localities on the right bank of the Ohře River between Louny and Libochovice]

2005 ◽  
Vol 3 ◽  
pp. 149-172
Author(s):  
Jiří Kovanda ◽  
Ivan Horáček ◽  
Radka Symonová
Keyword(s):  
Interglacial Period ◽  
Northern Germany ◽  
The Czech Republic ◽  
Fine Grained ◽  
The North ◽  
The Alps ◽  
Loess Deposits ◽  
Floodplain Deposits ◽  
The Right ◽  
First Time

Due to a complete predominance of non-calcareous fluvial sediments in the Czech Republic, any find of fossil malacofauna is always considered as rare. The present work describes three localities in the Ohře river area, which contain, especially in the case of the Pátek locality, very abundant mid-Pleistocene malacofaunas. They were mainly collected in the floodplain fine-grained loam and back swamp deposits but also in sandy gravels. The molluscan thanatocenoses from localities near the Pátek village indicate the interglacial maximum (with up to 25 forest species s.l.), which developed directly on a 30 m thick river terrace dating back to the period, during which the Ohře river established its present-day easterly course. The fossil molluscs from the Levousy locality come from floodplain loam deposits as well as from the underlying sandy terrace gravels. The species distribution, nevertheless, indicates only a transitional glacial-interglacial period. The somewhat higher morphologic position of the locality, as well as that of another section at Chlumčany, and complete predominance of local late Cretaceous material indicates that the Ohře river did not flow to the east yet during the accumulation of the floodplain deposits with molluscs, but still to the north, towards Bílina. The terrestrial malacofauna from the Chlumčany section came from floodplain marls, particularly from sandy tufa deposits in the alluvium, which contains no forest-biotope elements, but the presence of the species Columella columella – distinct representative of our „coldest“ loess deposits – is an absolute surprise, since the peak of production of the sandy tufa deposits has always been associated with climate optima of the interglacials and of the Holocene.Therefore, the described malacofaunas come from a boundary period, during which the Ohře river did not use its present-day valley (Levousy and Clumčany) yet. Then, from the oldest time span, it took up for the first time its eastward course. Stratigraphy of the localities cannot be determined with a reasonable certainty in regard to the current controversial situation in Pleistocene chronology both in the northern foothills of the Alps and in the area of the „classic“ localities belonging to the continental ice-sheet region in northern Germany (Kovanda 2005a). Altogether 12 mid-Pleistocene species of small mammals were found in thanaotocoenoses at localities Pátek and Levousy. Ostracod assemblages analysis was also undertaken (11 species in 8 samples were determined)

Recognition of the Trans-European Suture Zone (TESZ) by the palaeobiogeographical distribution pattern of early to middle Ordovician acritarchs

1997 ◽  
Vol 134 (5) ◽  
pp. 617-625 ◽  
Author(s):  
THOMAS SERVAIS ◽  
OLDA FATKA
Keyword(s):  
Distribution Pattern ◽  
Cold Water ◽  
Northern China ◽  
The United States ◽  
Suture Zone ◽  
Warm Water ◽  
Time Interval ◽  
Low Latitude ◽  
Middle Ordovician ◽  
Northern Border

The Tremadoc to early Llanvirn is the time interval in the Ordovician for which a global acritarch distribution pattern can be proposed. It is possible to differentiate a high latitude, cold- to temperate-water realm and a low latitude, warm-water realm. The cold-water assemblages, recorded from numerous localities at the northern border of Gondwana in the southern hemisphere, include some diagnostic morphotypes, such as Arbusculidium filamentosum, Arkonia, Aureotesta, Coryphidium-Vavrdovella, Dicrodiacrodium, Frankea and Striatotheca. Assemblages related to warm-water areas are described from Canada, the United States, northern China, Australia, and Baltica. Although a distinction of separate provinces within the cold-water and warm-water realms is difficult, the differentiation between these two units appears evident and a distinction of the assemblages from peri-Gondwana and the microfloras from Baltica is possible. This enables a recognition of the Trans-European Suture Zone in the early to middle Ordovician.

Assertions of Cultural Well-being in Fourteenth-Century Vietnam: Part II

1980 ◽  
Vol 11 (1) ◽  
pp. 74-90 ◽  
Author(s):  
O. W. Wolters
Keyword(s):  
Fourteenth Century ◽  
Southern China ◽  
Well Being ◽  
Northern Border

Phạm Sū Mạnh's name first appears in the annals during the 1340s, and by 1358 he is described as a hanh-khǐên. Several of his surviving poems were written when he was travelling on duty in northwestern Vietnam, perhaps in the 1360s. In 1364 and 1365, military precautions were taken on the northern border to safeguard Vietnam from consequences of the civil warin southern China on the eve of the Ming dynasty's accession in 1368.

scholarly journals Foreign and domestic contributions to springtime ozone over China

2018 ◽  
Author(s):  
Ruijing Ni ◽  
Jintai Lin ◽  
Yingying Yan ◽  
Weili Lin
Keyword(s):  
Southern China ◽  
Surface Ozone ◽  
Coupled Model ◽  
Lower Troposphere ◽  
Emission Source ◽  
Anthropogenic Emissions ◽  
Source Attribution ◽  
Global Emission ◽  
Source Regions ◽  
Northern Border

Abstract. China is facing a severe ozone problem, but the origin of its ozone remains unclear. Here we use a GEOS-Chem based global-regional two-way coupled model system to quantify the individual contributions of eight emission source regions worldwide to springtime ozone in 2008 over China. The model reproduces the observed ozone from 31 ground sites and various aircraft and ozonesonde measurements in China and nearby countries, with a mean bias at 10–15 % both near the surface and in the troposphere. We then combine zero-out simulations, tagged ozone simulations, and a linear weighting approach to accounting for the effect of nonlinear chemistry on ozone source attribution. We find considerable contributions of total foreign anthropogenic emissions to surface ozone over China (2–11 ppb). For ozone averaged over China of anthropogenic origin, foreign regions together contribute 40–50 % below the height of 2 km and 85 % in the upper troposphere. For total foreign anthropogenic emissions contributed ozone over China at various heights, the portion of transboundary ozone produced within foreign emission source regions is less than 50 %, with the rest produced by precursors transported out of those source regions. Japan and Korea contribute 0.6–2.1 ppb of surface ozone over the east coastal regions. South-East Asia contributes 1–5 ppb over much of southern China and South Asia contributes up to 5–10 ppb of surface ozone over border of southwestern China; and their contributions increase with height due to strong upwelling over the source regions. European contribution reaches 2.1–3.0 ppb for surface ozone over the northern border of China and 1.5 ppb in the lower troposphere averaged over China. North America contributes 0.9–2.7 ppb of surface ozone over most of China (1.5–2.1 ppb over the North China Plain), with a China average at 1.5–2.5 ppb at different heights below 8 km, due to its large anthropogenic emissions and the transport-favorable mid-latitude westerly. Global emission reduction is critical for China's ozone mitigation.

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