scholarly journals SEDIMENTOLOGY AND SEQUENCE STRATIGRAPHY OF SHALLOW MARINE SEDIMENTS IN A SYN-RIFT SETTING: HUGIN FORMATION, SOUTH VIKING GRABEN

2018 ◽  
Author(s):  
Rachel Kieft ◽  
Christopher Aiden-Lee Jackson ◽  
Gary J. Hampson
Keyword(s):  
Sequence Stratigraphy ◽  
Structural Features ◽  
Sediment Supply ◽  
Structural Development ◽  
The South ◽  
Candidate Sequence ◽  
Shallow Marine ◽  
The North ◽  
Facies Associations ◽  
The Impact

Fault growth and linkage within rift basins generates localised uplift and subsidence, which may exert significant control over syn-rift sedimentation. The shallow-marine Hugin Formation within the South Viking Graben, a salt-influenced rift basin, is studied as an example of such sedimentation. The principal aims of this thesis are to: (1) characterise the sedimentology and sequence stratigraphy of the succession, (2) investigate structural development within the graben by analysis of the hangingwall dipslope, and (3) establish the impact of syn-depositional structural development on shallow marine sedimentation. Sedimentological analysis of the Hugin Formation has recognised fifteen facies that are grouped into six facies associations: bay-fill, shoreface, fluvio-tidal channel fill, mouth bar, coastal plain and offshore open marine. Combining the results of this analysis with biostratigraphy, the studied succession is subdivided into a series of units delineated by regionally correlatable maximum flooding surfaces. Within the stratigraphic framework delineated by these surfaces each of the main facies associations are developed coevally in distinct and different geographical locations. Higher order flooding surfaces, transgressive surfaces and candidate sequence boundaries can also be interpreted within this framework which are geographically localised. Structural analysis of the hangingwall dipslope identified a series of distinct structural features that were evolving contemporaneous with Hugin Formation deposition. To the north, the gravity-driven Gudrun-Brynhild fault array initiated as a series of distinct segments which subsequently propagated and linked. Further south, the salt-cored highs at Dagny and Alpha Central were also developing. Palaeogeographical localisation of facies associations is interpreted to reflect deposition within these different structural locations along with proximity to the axial fluvial feeder system to the south of the basin. Sediment supply via wave-driven longshore drift from the north of the basin and local re-working of structurally controlled palaeohighs was also important.

scholarly journals THE BRANCHING CHANNEL NETWORK IN THE YANGTZE ESTUARY

2012 ◽  
Vol 1 (33) ◽  
pp. 69
Author(s):  
Zheng Bing Wang ◽  
Pingxing Ding
Keyword(s):  
Yangtze Estuary ◽  
River Delta ◽  
Sediment Supply ◽  
Channel Structure ◽  
The South ◽  
Channel Network ◽  
The Yangtze Estuary ◽  
The North ◽  
Navigation Channel ◽  
The Impact

The channels in the Yangtze Estuary have an ordered-branching structure: The estuary is first divided by the Chongming Island into the North Branch and the South Branch. Then the South Branch is divided into the North Channel and South Channel by the Islands Changxing and Hengsha. The South Channel is again divided into the North and South Passage by the Jiuduansha Shoal. This three-level bifurcation and four-outlet configuration appears to be a natural character of the estuary, also in the past (Chen et al., 1982), although the whole system has been extending into the East China Sea in the southeast direction due to the abundant sediment supply from the Yangtze River. Recently, the natural development of the system seems to be substantially disturbed by human interferences, especially the Deep Navigation Channel Project. For the understanding of the behaviour of the bifurcating channel system in the estuary we present analysis on two aspects: (1) the equilibrium configuration of river delta distributary networks, and (2) influence of tidal flow on the morphological equilibrium of rivers. Based on the analyses we conclude that the branching channel structure of the Yangtze Estuary can be classified as tide-influenced river delta distributary networks. Its basic structure is the same as in case of river dominated delta. The empirical relations describing the basic features of the river-dominated distributary delta networks can be explained by theoretical analysis, although they are not fully satisfied by the Yangtze Estuary because of the influence of the tide. Two major influences of the tide are identified, viz. increasing the resistance to the river flow into the sea and increasing the sediment transport capacity. As consequence of these two influences the cross-sectional area of the river/estuary increases in the seawards direction and the bed slope decreases. The insights from the analyses are helpful for the understanding of the impact of the Deep Navigation Channel Project on the large scale morphological development of the estuary.

Mechanism of Carboniferous-Permian transgression/regression in the east Ordos basin and associated paleoecological variability: Insight from detrital geochronology and palaeontology data

2020 ◽  
Author(s):  
Chao Fu ◽  
Xinghe Yu ◽  
Marc Jolivet ◽  
Shunli Li ◽  
Zixiao Peng ◽  
...  
Keyword(s):  
North China ◽  
Ordos Basin ◽  
Second Order ◽  
Sediment Supply ◽  
Late Carboniferous ◽  
Coarse Grained ◽  
Early Permian ◽  
The South ◽  
The North ◽  
Facies Associations

<p>Developed on the North China Craton, the intra-cratonic Ordos basin contains a complete Paleozoic to Cenozoic sediment record allowing long-term paleo-environmental and climate change investigation. During the Carboniferous-the early Permian period, convergence between the North China block and the paleo-Yangtze plate to the south lead to a general marine regression characterised by a series of second-order transgression/regression cycles diachronous along the eastern margin of the Ordos. However, the detailed mechanisms that induced these cycles, as well as the associated paleoecological changes, are still unknown. In this study, we integrated the description of numerous core samples with electric-log data and 2-D seismic data to reconstruct the sediment facies associations across the first-order regression from the Carboniferous tidal flat depositional system to the early Permian prograding fluvial delta system. δ<sup>18</sup>O, δ<sup>13</sup>C and clay content (w(Illite + Kaolinite)/w(smectite) ratio) stratigraphic variations were then used to reconstruct the paleo-sea level from the late Carboniferous to the early Permian. We conclude that the direction of second-order transgression/regression mainly stroke to the east during the late Carboniferous and switched clockwise towards the north during the early Permian. We suggest that the variability of the second-order cycles, diachronous in space and time was mainly linked to local variations in sediment supply and regional uplift.  Using detrital zircon U-Pb data, major and trace elements content and heavy minerals assemblages (HMA), we estimated the sediment provenance area. The sediment volumes deposited in the basin through time were obtained using 3Dseismic data. During the Carboniferous, the coarse-grained sediments deposited in the eastern Ordos were derived from the uplifting Helan Mountain. By the early Permian, the detrital material became multi-sourced issuing from both the Yinshan range to the north and the Qinling range to the south. During the first stage, regression was controlled by regional uplift, while the sediment supply controlled the second stage. Indeed, based on sediment dispersal volume calculation, we can infer that the sediment supply during the early Permian was more extensive than during the Late Carboniferous – early Permian. We correlate this observation to a more humid climate during the early Permian: multi- paleoecological indexes, including the sporopollenin content and microsomal type assemblage, suggest that glaciation prevailed during the Late Carboniferous – early Permian shallow-marine stage. In contrast, the early Permian alluvial and deltaic series were deposited under a warmer, interglacial climate (Sakmarian). Finally, the typical interglacial coal accumulation pattern occurs earlier than the Pennsylvanian–Permian transition it characterises around the world (Artinskian).</p>

Nachhaltigkeit im Wald – vor und hinter der Welle der Globalisierung | Sustainable Forest Management – In Front and Behind the Wave of Globalization

2000 ◽  
Vol 151 (12) ◽  
pp. 502-507
Author(s):  
Christian Küchli
Keyword(s):  
Forest Management ◽  
Cultural Landscape ◽  
Sustainable Forest Management ◽  
Essential Element ◽  
Specific Situation ◽  
The South ◽  
The North ◽  
Time Space ◽  
Starting Point ◽  
The Impact

Are there any common patterns in the transition processes from traditional and more or less sustainable forest management to exploitative use, which can regularly be observed both in central Europe and in the countries of the South (e.g. India or Indonesia)? Attempts were made with a time-space-model to typify those force fields, in which traditional sustainable forest management is undermined and is then transformed into a modern type of sustainable forest management. Although it is unlikely that the history of the North will become the future of the South, the glimpse into the northern past offers a useful starting point for the understanding of the current situation in the South, which in turn could stimulate the debate on development. For instance, the patterns which stand behind the conflicts on forest use in the Himalayas are very similar to the conflicts in the Alps. In the same way, the impact of socio-economic changes on the environment – key word ‹globalisation› – is often much the same. To recognize comparable patterns can be very valuable because it can act as a stimulant for the search of political, legal and technical solutions adapted to a specific situation. For the global community the realization of the way political-economic alliances work at the head of the ‹globalisationwave›can only signify to carry on trying to find a common language and understanding at the negotiation tables. On the lee side of the destructive breaker it is necessary to conserve and care for what survived. As it was the case in Switzerland these forest islands could once become the germination points for the genesis of a cultural landscape, where close-to-nature managed forests will constitute an essential element.

scholarly journals Assessing the Sensitivity of Main Crop Yields to Climate Change Impacts in China

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 172
Author(s):  
Yuan Xu ◽  
Jieming Chou ◽  
Fan Yang ◽  
Mingyang Sun ◽  
Weixing Zhao ◽  
...  
Keyword(s):  
Climate Change ◽  
Crop Yield ◽  
Food Production ◽  
Crop Yields ◽  
Climatic Factors ◽  
Climatic Data ◽  
The South ◽  
The North ◽  
Output Elasticity ◽  
The Impact

Quantitatively assessing the spatial divergence of the sensitivity of crop yield to climate change is of great significance for reducing the climate change risk to food production. We use socio-economic and climatic data from 1981 to 2015 to examine how climate variability led to variation in yield, as simulated by an economy–climate model (C-D-C). The sensitivity of crop yield to the impact of climate change refers to the change in yield caused by changing climatic factors under the condition of constant non-climatic factors. An ‘output elasticity of comprehensive climate factor (CCF)’ approach determines the sensitivity, using the yields per hectare for grain, rice, wheat and maize in China’s main grain-producing areas as a case study. The results show that the CCF has a negative trend at a rate of −0.84/(10a) in the North region, while a positive trend of 0.79/(10a) is observed for the South region. Climate change promotes the ensemble increase in yields, and the contribution of agricultural labor force and total mechanical power to yields are greater, indicating that the yield in major grain-producing areas mainly depends on labor resources and the level of mechanization. However, the sensitivities to climate change of different crop yields to climate change present obvious regional differences: the sensitivity to climate change of the yield per hectare for maize in the North region was stronger than that in the South region. Therefore, the increase in the yield per hectare for maize in the North region due to the positive impacts of climate change was greater than that in the South region. In contrast, the sensitivity to climate change of the yield per hectare for rice in the South region was stronger than that in the North region. Furthermore, the sensitivity to climate change of maize per hectare yield was stronger than that of rice and wheat in the North region, and that of rice was the highest of the three crop yields in the South region. Finally, the economy–climate sensitivity zones of different crops were determined by the output elasticity of the CCF to help adapt to climate change and prevent food production risks.

scholarly journals A tale of two parts of Switzerland: regional differences in the impact of the COVID-19 pandemic on parents

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Michelle Seiler ◽  
Georg Staubli ◽  
Julia Hoeffe ◽  
Gianluca Gualco ◽  
Sergio Manzano ◽  
...  
Keyword(s):  
Public Health ◽  
Regional Differences ◽  
Online Survey ◽  
Pediatric Emergency ◽  
The South ◽  
Public Health Agencies ◽  
The North ◽  
Regional Strategies ◽  
Health Agencies ◽  
The Impact

Abstract Background We aimed to document the impact of the coronavirus disease 2019 (COVID-19) pandemic on regions within a European country. Methods Parents arriving at two pediatric emergency departments (EDs) in North of Switzerland and two in South of Switzerland completed an online survey during the first peak of the pandemic (April–June 2020). They were asked to rate their concern about their children or themselves having COVID-19. Results A total of 662 respondents completed the survey. Parents in the South were significantly more exposed to someone tested positive for COVID-19 than in the North (13.9 and 4.7%, respectively; P <  0.001). Parents in the South were much more concerned than in the North that they (mean 4.61 and 3.32, respectively; P <  0.001) or their child (mean 4.79 and 3.17, respectively; P <  0.001) had COVID-19. Parents reported their children wore facemasks significantly more often in the South than in the North (71.5 and 23.5%, respectively; P <  0.001). Conclusion The COVID-19 pandemic resulted in significant regional differences among families arriving at EDs in Switzerland. Public health agencies should consider regional strategies, rather than country-wide guidelines, in future pandemics and for vaccination against COVID-19 for children.

Understanding Societies in War

2018 ◽  
Author(s):  
Paul D. Escott
Keyword(s):  
Ethnic Groups ◽  
Irregular Warfare ◽  
The South ◽  
Factors Affecting ◽  
The North ◽  
Role Of Women ◽  
Democratic Parties ◽  
The Impact

This chapter emphasizes the analysis of the wartime forces in both sections that affected unity or division. It raises questions about the roots of the large amount of internal violence or irregular warfare in the South. For the North, it probes the nature of nationalism and asks about that section’s social, political, and religious divisions. Factors affecting both the Republican and the Democratic Parties of the North deserve new attention, as do the role of women in both sections, ethnic groups in the North especially, and the impact of emancipation and racism.

The Wenlock sediments of north-west Galway, Ireland.

1970 ◽  
Vol 107 (4) ◽  
pp. 297-317 ◽  
Author(s):  
M. G. Laird ◽  
W. S. McKerrow
Keyword(s):  
Sediment Supply ◽  
Shallow Marine ◽  
North West ◽  
Sedimentary Sequences ◽  
The North ◽  
Upper Silurian

SummaryThis work describes the Wenlock sedimentary sequences south of Killary Harbour where the fullest successions in north-west Galway are exposed; much of the Upper Silurian in the east (Joyces Country) has been removed by erosion.The Wenlock beds (the Upper Owenduff and Killary Harbour Groups) rest on shallow marine and continental sediments (the Lower Owenduff Group) of Upper Llandovery (C5–6) age. Conglomerates near the base of the Wenlock are followed by 1,500 m of sandstones, which are mostly turbidites and which contain Middle Wenlock graptolites. These basin deposits are succeeded by a transitional sequence of rise, slope and shelf clastics, also of Middle Wenlock age. The youngest Silurian beds exposed are 800 m of red lagoonal deposits withLingula.During Wenlock times, the sediment supply to north-west Galway was mainly from the north and north-west. This observation fits well with the regional picture which places Galway near the north-west margin of a Silurian basin which extended eastwards across Ireland.

Relative prosperity will prolong Libya's civil war

2016 ◽  
Keyword(s):  
Civil War ◽  
The Other ◽  
Armed Groups ◽  
The South ◽  
Content Type ◽  
The North ◽  
The Impact ◽  
Local Dominance

Significance His comments are optimistic. The other two rival administrations that are based in Libya have resisted efforts to form a unified government, while armed groups (some associated with the administrations, others independent) compete for local dominance. As a result, intermittent escalations in fighting and sporadic attacks by fringe militias continue to occur in parts of the country. Concern has grown about the impact on civilians. Impacts Bombings and outbreaks of intense fighting will remain a risk in key contested locations in the north. Clashes between militias will recur sporadically in the south. The number of migrants working in Libya and seeking to travel to Europe may increase again.

Ecogeography and the Great American Interchange

Paleobiology ◽  
1991 ◽  
Vol 17 (3) ◽  
pp. 266-280 ◽  
Author(s):  
S. David Webb
Keyword(s):  
North America ◽  
South America ◽  
North American ◽  
Mammalian Fauna ◽  
The South ◽  
Land Bridge ◽  
Southern Mexico ◽  
The North ◽  
Land Mammal ◽  
The Impact

When the isthmian land bridge triggered the Great American Interchange, a large majority of land-mammal families crossed reciprocally between North and South America at about 2.5 Ma (i.e., Late Pliocene). Initially land-mammal dynamics proceeded as predicted by equilibrium theory, with roughly equal reciprocal mingling on both continents. Also as predicted, the impact of the interchange faded in North America after about 1 m.y. In South America, contrary to such predictions, the interchange became decidedly unbalanced: during the Pleistocene, groups of North American origin continued to diversify at exponential rates. Whereas only about 10% of North American genera are derived from southern immigrants, more than half of the modern mammalian fauna of South America, measured at the generic level, stems from northern immigrants. In addition, extinctions more severely decimated interchange taxa in North America, where six families were lost, than in South America, where only two immigrant families became extinct.This paper presents a two-phase ecogeographic model to explain the asymmetrical results of the land-mammal interchange. During the humid interglacial phase, the tropics were dominated by rain forests, and the principal biotic movement was from Amazonia to Central America and southern Mexico. During the more arid glacial phase, savanna habitats extended broadly right through tropical latitudes. Because the source area in the temperate north was six times as large as that in the south, immigrants from the north outnumbered those from the south. One prediction of this hypothesis is that immigrants from the north generally should reach higher latitudes in South America than the opposing contingent of land-mammal taxa in North America. Another prediction is that successful interchange families from the north should experience much of their phylogenetic diversification in low latitudes of North America before the interchange. Insofar as these predictions can be tested, they appear to be upheld.

Notes on Southern Etruria and the Ager Veientanus

1955 ◽  
Vol 23 ◽  
pp. 44-72 ◽  
Author(s):  
J. B. Ward Perkins
Keyword(s):  
Field Survey ◽  
Classical Antiquity ◽  
Mechanical Equipment ◽  
The South ◽  
The North ◽  
British School ◽  
First Results ◽  
Comprehensive Survey ◽  
The Impact ◽  
Great Reforms

The notes that follow are the first results of a programme of field-survey undertaken by the writer and by various members of the British School during the autumn of 1954 in the area that lies immediately to the north of Rome, between the Tiber and the sea. This area is one that has been strangely neglected by modern students of Italian topography. Ashby's published work is concerned mainly with those parts of the Campagna that lie to the south and east of Rome; and Tomassetti's work, invaluable as a repertory of manuscript and published sources, lays no claim to be a comprehensive survey of the material remains surviving on the ground.Such a survey is badly needed today. The romantic desolation of Southern Etruria is being transformed from one day to the next under the impact of a scheme of landreform comparable in scale to the great reforms of classical antiquity, and vast estates which for centuries have been used for stock-breeding and seasonal pasture are being broken up and brought into cultivation with all the devastating thoroughness that modern mechanical equipment entails. Whole regions are accessible today as they have never been before, and within them the bulldozer and the mechanical plough are busy destroying whatever lies in their path.

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