Timing of slip across the South Tibetan detachment system and Yadong–Gulu graben, Eastern Himalaya

2020 ◽  
Vol 178 (1) ◽  
pp. jgs2019-197
Author(s):  
Hanwen Dong ◽  
Kyle P. Larson ◽  
Dawn A. Kellett ◽  
Zhiqin Xu ◽  
Guangwei Li ◽  
...  
Keyword(s):  
Late Miocene ◽  
Analytical Data ◽  
Eastern Himalaya ◽  
Model Parameters ◽  
The South ◽  
Southern Tibet ◽  
Content Type ◽  
The North ◽  
Extensional Strain ◽  
Supplementary Material

The Yadong–Gulu graben preserves the kinematic and temporal relationships between east–west-directed extension in southern Tibet and north–south extensional strain in the Himalaya. In the Yadong region, distinct outer and inner top-down-to-the-north segments of the South Tibetan detachment system (STDS) are recognized. Herein, we combine high- to medium-T (U–Pb, 40Ar/39Ar) and low-T (apatite fission-track, apatite (U–Th)/He and zircon (U–Th)/He) thermochronometry to investigate the timing of slip across the STDS and Yadong–Gulu structures. These data demonstrate that the cessation of the Yadong shear zone, the structurally outer ductile segment of the STDS, occurred c. 20 Ma and that motion along the inner brittle–ductile Zherger La detachment continued after c. 16.6 Ma, ending by 11 Ma. The cooling history in the immediate STDS footwall is characterized by two main episodes of relatively rapid cooling and exhumation. The first occurred in the middle Miocene (c. 15–11 Ma), and is common along-strike of the innermost STDS footwall, related to cooling of the STDS. The second occurred in the late Miocene–Pliocene (c. 7–3 Ma), and is local to the Yadong–Gulu graben footwall in NW Bhutan, indicating that late Miocene–Pliocene slip along the graben system contributed to exhumation of the STDS east of the graben rift.Supplementary material: Tables of analytical data, dating results, and input data and model parameters of HeFTy are available at https://doi.org/10.6084/m9.figshare.c.5132941

scholarly journals Suitability of surficial media for Ni-Cu-PGE exploration in an established mining camp: a case study from the South Range of the Sudbury Igneous Complex, Canada

2021 ◽  
pp. geochem2021-051
Author(s):  
Sarah Hashmi ◽  
Matthew I. Leybourne ◽  
Stewart Hamilton ◽  
Daniel Layton-Matthews ◽  
M. Beth McClenaghan
Keyword(s):  
Anthropogenic Contamination ◽  
The South ◽  
Aqua Regia ◽  
Content Type ◽  
Igneous Complex ◽  
Sudbury Igneous Complex ◽  
Geochemical Study ◽  
Pge Mineralization ◽  
Supplementary Material

A geochemical study over the southwestern part of the South Range of the Sudbury Igneous Complex (SIC) was completed to assess the suitability of surficial media (humus, B-horizon soil and C-horizon soil) for delineating geochemical anomalies associated with Ni-Cu-PGE mineralization. Another objective was to test whether Na pyrophosphate can eliminate the effects of anthropogenic contamination in humus. Results of this study suggest that the natural geochemical signature of humus is strongly overprinted by anthropogenic contamination. Despite no indication of underlying or nearby mineralization, metal concentrations in humus samples by aqua regia collected downwind from smelting operations are higher compared to background, including up to 13 times higher for Pt, 12 times higher for Cu and 9 times higher for Ni. The high anthropogenic background masks the geogenic signal such that it is only apparent in humus samples collected in the vicinity of known Ni-Cu-PGE deposits. Results of this study also demonstrate that anthropogenically-derived atmospheric fallout also influences the upper B-horizon soil; however, lower B-horizon soil (at > 20 cm depth) and C-horizon soil (both developed in till) are not affected. Glacial dispersal from Ni-Cu-PGE mineralization is apparent in C-horizon till samples analyzed in this study. Compared to the background concentrations, the unaffected C-horizon till samples collected immediately down-ice of the low-sulfide, high precious metal (LSHPM) Vermilion Cu-Ni-PGE deposit are enriched over 20 times in Pt (203 ppb), Au (81 ppm) and Cu (963 ppm), and over 30 times in Ni (1283 ppm).Supplementary material:https://doi.org/10.6084/m9.figshare.c.5691080

The onset of the early Toarcian flooding of the Pliensbachian carbonate platform of Central Tunisia (North-South Axis) as inferred from trace fossils and geochemistry

2021 ◽  
pp. SP514-2021-10
Author(s):  
Matías Reolid ◽  
Mohamed Soussi ◽  
Jesús Reolid ◽  
Wolfgang Ruebsam ◽  
Ilef Belhaj Taher ◽  
...  
Keyword(s):  
Carbonate Platform ◽  
High Energy ◽  
Trace Fossils ◽  
Energy Conditions ◽  
Local Conditions ◽  
Content Type ◽  
The North ◽  
Sea Bottom ◽  
Supplementary Material ◽  
South Axis

AbstractThe flooding of the Lower Jurassic shelf in the North Gondwana Palaeomargin during the early Toarcian occurred on a fragmented and irregular topography affected by differential subsidence—due to the activity of listric faults along the North-South Axis of Tunisia—that favoured lateral changes in facies and thickness at a kilometric scale. The onset of Toarcian sedimentation (Polymorphum ammonite Zone, NJT5c nannofossil Subzone) in two adjacent sections was characterised by the deposition of limestones under high-energy conditions. The Châabet El Attaris section was located in a depressed sub-basin, and recorded restricted environmental conditions owing to water stagnation and an oxygen-depleted sea-bottom. Therefore, dark mudstones developed, with increased TOC contents and enhanced accumulation of redox-sensitive elements. The sedimentation of limestones bearing gutter cast structures is related to gravity flows probably linked to storm activities. These processes favoured the remobilization of sediments at the sea floor, as well as oxygen input to bottom waters, as shown by the record of trace fossils including Zoophycos, Ophiomorpha, and secondarily, Chondrites and Diplocraterion. The thinly interbedded dark mudstones are locally rich in thin-shelled bivalves that re-colonised the sea bottom after the sedimentation of these high-energy deposits, and subsequently underwent mass mortality related to the return of oxygen-depleted conditions. The Kef El Hassine section is located in the upper part of a tilted, less subsident block, as indicated by its reduced thickness compared with the Châabet El Attaris section; the absence of dark mudstones implies oxic conditions. The Polymorphum Zone consists of limestones showing evidence of sedimentation under high-energy conditions, along with hardgrounds. The occurrence of Zoophycos (deep-tiers) in the upper part of some limestone beds of the Polymorphum Zone is linked to minor erosive processes. The top of the high-energy sequence—below the deposits of a marly interval corresponding to the Levisoni Zone—is interpreted as a hardground given the high content of belemnites and Arenicolites, some of them boring on the eroded Zoophycos and Thalassinoides. This study shows that the sedimentary expression of the Jenkyns Event is not uniform across Tunisia, supporting the importance of local conditions in determining the development of anoxic conditions.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5510162

Carboniferous records of the Zoophycos group of trace fossils from England, Wales, the Isle of Man and the North Sea

2020 ◽  
Vol 63 (2) ◽  
pp. 135-145
Author(s):  
Duncan McLean ◽  
Matthew Booth ◽  
David J. Bodman ◽  
Finlay D. McLean
Keyword(s):  
North Sea ◽  
Trace Fossils ◽  
Depositional Environments ◽  
Common Component ◽  
Content Type ◽  
Clastic Rocks ◽  
Isle Of Man ◽  
The North ◽  
The North Sea ◽  
Supplementary Material

The Zoophycos group of trace fossils is common in Carboniferous to recent marine strata and sediments, and is a common component of ichnofaunas in the Visean and Namurian stages of England and Wales. A review of new and published records indicates that it is often present in limestones and sandstones of Chadian to Arnsbergian age. Thereafter it is less common, and restricted to clastic rocks. There are no known records within Carboniferous strata above the lowest Westphalian. The form is most common and often abundant in limestones of the Yoredale facies in the upper Visean and lower Namurian stages of northern England, particularly so in northern Northumberland. Where detailed sedimentological data exist, they indicate that the organisms responsible for the Zoophycos group burrowed into unconsolidated carbonate substrate that was deposited under low accumulation rates, often affected by storm wave action and where seawater flow provided a nutrient supply. However, in mixed carbonate–clastic settings, the deep-tier nature of Zoophycos may indicate that the organism lived in overlying shallow-marine, clastic-dominated depositional environments and burrowed down into the carbonate substrate. The same may be true of siliciclastic depositional settings where the presence of Zoophycos in some sandstones may reflect the palaeoenvironment of the overlying, finer-grained transgressive marine (prodelta and distal mouth bar) deposits.Supplementary material: A spreadsheet with details of Carboniferous records of Zoophycos group fossils from England, Wales, the Isle of Man and the North Sea is available at https://doi.org/10.6084/m9.figshare.c.4994636

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.

Saleh’s death will intensify Yemen fighting

2017 ◽  
Keyword(s):  
The South ◽  
Content Type ◽  
The North

Significance The Huthi fighters behind Saleh’s killing on December 4, who control the north of the country, only allowed a few relatives to attend the burial. Saleh’s death followed an attempted coup against his former Huthi allies, which may have been inspired -- and was certainly welcomed -- by the Saudi-led military coalition supporting the internationally-recognised government of President Abd Rabbu Mansur Hadi, in the south. Impacts Whatever happens, the Huthis will keep their Sa’ada heartland, which will have to be taken into account in any future peace deal. Humanitarian and commercial food and fuel shipments are likely to remain largely blocked, especially if Hodeida comes under attack. The war could take on an increasingly sectarian character, potentially exacerbating Sunni-Shia tensions across the region.

Sri Lanka opposition will struggle in upcoming poll

2020 ◽  
Keyword(s):  
Sri Lanka ◽  
Prime Minister ◽  
Parliamentary Election ◽  
National Party ◽  
The South ◽  
Content Type ◽  
The North ◽  
Main Challenge ◽  
Provincial Councils ◽  
To Come

Subject Outook for Sri Lanka's opposition ahead of a parliamentary election. Significance President Gotabaya Rajapaksa on March 2 dissolved parliament and called a parliamentary election for April 25. Interim Prime Minister Mahinda Rajapaksa, Gotabaya’s brother, will be aiming to return to power. The main challenge to the pro-Rajapaksa alliance, the Sri Lanka Nidahas Podujana Sandanaya (SLNPS), is set to come from an alliance formed by members of the opposition United National Party (UNP), the Samagi Jana Balawegaya (SJB). Impacts Concerns over COVID-19 are unlikely to disrupt the election. The SJB will likely win more votes in the north and east, where ethnic Tamil voters are concentrated, than in the south and west. Elections for provincial councils will probably be held after the parliamentary poll.

Unmasking the factors behind income inequalities in Ghana

2017 ◽  
Vol 44 (7) ◽  
pp. 884-899 ◽  
Author(s):  
Michael Danquah ◽  
Williams Ohemeng
Keyword(s):  
Junior High School ◽  
Community Level ◽  
The South ◽  
Economic Activities ◽  
Public And Private ◽  
Content Type ◽  
The Sustainable Development ◽  
Community Factors ◽  
The North ◽  
Nationally Representative

Purpose The purpose of the paper is to examine the extent and trends of income inequality as well as the contribution of household and community-level factors in explaining inequality within north and south in Ghana. Design/methodology/approach The study employs both descriptive and regression methods. The study adopts the methodology by Fields (2002) to assess the importance of household and community attributes in explaining the level of inequality within the north and the south. Findings The findings of the study show that household characteristics such as urban location, no education, public and private formal economic activities, and not covered by National Health Insurance Scheme are major determinants of inequality within the north and the south. Specifically, within the north, the 20-34 year age group is the most prominent contributor to inequality. Within the south, the most important determinant of inequality is the completion of junior high school. The contribution of community-level features shows that, within the north, access to banks is the most vital factor to inequality, whereas within the south, access to electricity and public transport is the most important community factor. Practical implications The study provides an understanding of the underlying household and community factors driving the observed inequality patterns within the north and the south in Ghana. Policy options are identified for achieving the sustainable development goals. Originality/value The study uses the latest round of the Ghana Living Standards survey, GLSS 6, which covers new data on a nationally representative sample of 18,000 households in 1,200 enumeration areas.

scholarly journals New microfossil and strontium isotope chronology used to identify the controls of Miocene reefs and related facies in NW Cyprus

2020 ◽  
pp. jgs2020-081
Author(s):  
Torin Cannings ◽  
Elizabeth M. Balmer ◽  
Giovanni Coletti ◽  
Ryan B. Ickert ◽  
Dick Kroon ◽  
...  
Keyword(s):  
Late Miocene ◽  
Regional Scale ◽  
Early Miocene ◽  
Late Oligocene ◽  
Sr Isotope ◽  
Two Phase ◽  
Planktic Foraminifera ◽  
Content Type ◽  
Supplementary Material ◽  
Global Sea Level

The existing chronostratigraphic framework in NW Cyprus of two-phase, Early and Late Miocene reef and associated facies development is tested and improved using a combination of calcareous nannofossil, benthic and planktic foraminiferal, and also Sr isotope dating. Following localised Late Oligocene neritic carbonate deposition (e.g. benthic foraminiferal shoals), reefs and related facies (Terra Member) began to develop c. 24 Ma (Aquitanian) and terminated c. 16 Ma (end-Burdigalian). Early Miocene reef and marginal facies were then extensively redeposited as multiple debris-flow deposits until c. 13.7 Ma, influenced by a combination of global sea-level fall (related to growth of the East Antarctic Ice Sheet) and local- to regional-scale tectonics. Reef growth and related deposition resumed (Koronia Member) c. 9.1 Ma (Tortonian), then terminated by c. 6.1 Ma (mid-Messinian), followed by the Messinian salinity crisis. Neritic accumulation in NW Cyprus began earlier (Late Oligocene), than in southern Cyprus (Early Miocene). The Early Miocene reefs developed on a c. N-S-trending structural high in the west (Akamas Peninsula area) whereas the Late Miocene reefs developed on both flanks of the neotectonic Polis graben. The two-phase reef development is mirrored in SE Cyprus and in some other Mediterranean areas; e.g. S Turkey, Israel, Italy, S Spain.Supplementary material: GPS Locations of dated samples, the Sr isotope method and the samples examined for planktic foraminifera biostratigraphy are available at https://doi.org/10.6084/m9.figshare.c.5205315.

scholarly journals The impact of climate change on food and human security in Nigeria

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Kelechi Johnmary Ani ◽  
Vincent Okwudiba Anyika ◽  
Emmanuel Mutambara
Keyword(s):  
Climate Change ◽  
Focus Group ◽  
Qualitative Data ◽  
Human Security ◽  
Primary Data ◽  
The South ◽  
Focus Group Discussions ◽  
Group Discussions ◽  
Content Type ◽  
The North

Purpose The purpose of this study is to unravel the changing nature of climate change impact on the food and human security sector of the Nigerian State. Design/methodology/approach This study is an in-depth case study that involves the use of both quantitative and qualitative data. Statistical data on climate variability in Nigeria obtained from reliable databases were use in the making of analysis. Also, data derived from semi-structure interviews and special reports from International Non-governmental organizations on the subject matter were also used in the study. The findings of the study were based on an in-depth analysis of both primary and secondary sources of data. The secondary data were derived from existing published academic works. The primary data was developed using qualitative data that were collected from January to November, 2018 to 2019 in the different regions of Nigeria. For the South East, primary data was collected from Abakaliki, Ebonyi State. In the South-South, primary data was collected from Asaba, Delta State. In the South West, primary data was collected from Barutin, Kwara State. In the North East, primary data was collected from Maiduguri, while in North West, data was collected from Gusau, Zamfara State. In the North Central, data was collected from Markurdi, Benue State. During the data collection, 48 semi-structured Key Informant Interviews (KIIs) were carried out in the six selected research areas that represented their geo-political zones. Six Focus Group Discussions (FGDs) were carried out, one for each of these six selected cities. Each of the Focus Group Discussions comprised between five and seven respondents. The idea of KIIs and FGDs is to allow the respondents to freely express their ideas comprehensively. Again, in other to get varied forms of responses, the respondents are mainly farmers however, a number of NGOs, civil servants, fertilizer sellers, government officials, transporters and aged men and women/retirees. It should be noted that the respondents cut across male and female gender of all ages and ethnic configuration. The respondents were also randomly selected through social networking. To avoid having people of similar The KIIs were three academics; two community leaders; two small scale fish farmers; rice, cassava, fish, livestock and crop farmers. All KIIs ad TIs were transcribed and analysed using thematic content analysis. Findings The findings revealed that climate change has negatively affected food security in Nigeria. it has also led to continuous armed confrontations over natural resources thereby undermining human security in the country. Originality/value This study is 100% original and can be assessed through turn it in evaluation.

Post-orogenic exhumation in the western Pyrenees: evidence for extension driven by pre-orogenic inheritance

2020 ◽  
pp. jgs2020-079
Author(s):  
Charlotte Fillon ◽  
Frédéric Mouthereau ◽  
Sylvain Calassou ◽  
Raphaël Pik ◽  
Nicolas Bellahsen ◽  
...  
Keyword(s):  
Thermal Evolution ◽  
Foreland Basin ◽  
Normal Faulting ◽  
Axial Zone ◽  
Content Type ◽  
The North ◽  
Supplementary Material ◽  
Thermal Histories ◽  
Relationship Of ◽  
Western Pyrenees

We discuss the drivers of the Pyrenean post-orogenic exhumation, including drainage migration, flexural rebound and tectonic reactivation.We provide new low-temperature thermochronological data and inverse thermal modeling from both the hinterland and foreland of the western Pyrenees. Our new thermochronological ages range from 6.6 to 61.4 Ma and reveal a Late Miocene exhumation phase in several massifs. The contrasting thermal histories define a domain of focused exhumation in the western Pyrenees that coincides with the present-day extensional tectonics in a region to the north of the Axial Zone. Based on the inferred cooling rates and paleogradient estimates, we highlight an exhumation phase of c. 1 mm yr–1 between 11 and 9 Ma in the Axial Zone, well above rates expected for a post-orogenic evolution. The thermal evolution inferred from three boreholes of the Aquitaine foreland basin reveals that sediments eroded from the hinterland did not accumulate in the Piedmont region but were transported offshore in the Bay of Biscay. We infer that the significant c. 10 Ma post-orogenic exhumation event must be related to the modern normal faulting regime of the western Pyrenees, associated with contrasting crustal thickness and densities, inherited from the Mesozoic rift evolution of the northern Pyrenees.Supplementary material: Laboratory analytical procedures, radial plot visualization of AFT detrital data and Age/eU relationship of AHe and ZHe samples are available at https://doi.org/10.6084/m9.figshare.c.5212581

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