Chemical stratigraphy of the Paran� lavas (South America): classification of magma types and their spatial distribution

1992 ◽  
Vol 55 (1-2) ◽  
pp. 119-139 ◽  
Author(s):  
David W Peate ◽  
Chris J Hawkesworth ◽  
Marta S M Mantovani
Keyword(s):  
Spatial Distribution ◽  
South America

scholarly journals Patterns of Style, Diversity, and Similarity in Middle Orinoco Rock Art Assemblages

Arts ◽  
2019 ◽  
Vol 8 (2) ◽  
pp. 48 ◽  
Author(s):  
Philip Riris ◽  
José Oliver
Keyword(s):  
Spatial Distribution ◽  
Literature Review ◽  
South America ◽  
River Basin ◽  
Field Survey ◽  
Rock Art ◽  
Orinoco River

The area encompassed by the Orinoco river basin is home to some of the largest and most diverse rock art sites in lowland South America. In this paper, we aim to formally describe the spatial distribution and stylistic attributes of rock engravings and paintings on both banks of the Orinoco, centred on the Átures Rapids. Drawing on an exhaustive literature review and four years of field survey, we identify salient aspects of this corpus by investigating patterns of diversity and similarity. Based on a stylistic classification of Middle Orinoco rock art, this permits us to discuss potential links, as well as notable discontinuities, within the assemblage and possibly further afield. We consider the theoretical implications of our work for the study of pre-Columbian art and conclude with some suggestions for advances in methods for achieving the goal of deriving broader syntheses.

scholarly journals Mapping the spatial distribution of global 137Cs fallout in soils of South America as a baseline for Earth Science studies

2021 ◽  
Vol 214 ◽  
pp. 103542
Author(s):  
Pierre-Alexis Chaboche ◽  
Nicolas P.A. Saby ◽  
J. Patrick Laceby ◽  
Jean P.G. Minella ◽  
Tales Tiecher ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
South America ◽  
Science Studies ◽  
Earth Science ◽  
137Cs Fallout

scholarly journals Dry and Wet Climate Periods over Eastern South America: Identification and Characterization through the SPEI Index

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 155
Author(s):  
Anita Drumond ◽  
Milica Stojanovic ◽  
Raquel Nieto ◽  
Luis Gimeno ◽  
Margarida L. R. Liberato ◽  
...  
Keyword(s):  
South America ◽  
Potential Evapotranspiration ◽  
Monthly Precipitation ◽  
Economic Activities ◽  
Central Brazil ◽  
Moisture Analysis ◽  
Dry Conditions ◽  
Wet Climate ◽  
Climate Events

A large part of the population and the economic activities of South America are located in eastern regions of the continent, where extreme climate events are a recurrent phenomenon. This study identifies and characterizes the dry and wet climate periods at domain-scale occurring over the eastern South America (ESA) during 1980–2018 through the multi-scalar Standardized Precipitation–Evapotranspiration Index (SPEI). For this study, the spatial extent of ESA was defined according to a Lagrangian approach for moisture analysis. It consists of the major continental sink of the moisture transported from the South Atlantic Ocean throughout the year, comprising the Amazonia, central Brazil, and the southeastern continental areas. The SPEI for 1, 3, 6, and 12 months of accumulation was calculated using monthly precipitation and potential evapotranspiration time series averaged on ESA. The analysis of the climate periods followed two different approaches: classification of the monthly SPEI values as mild, moderate, severe, and extreme; the computation of the events and their respective parameters (duration, severity, intensity, and peak). The results indicate that wet periods prevailed in the 1990s and 2000s, while dry conditions predominated in the 2010s, when the longest and more severe dry events have been identified at the four scales.

scholarly journals On the fossil Remains of Panochthus Burmeister, 1866 (Xenarthra, Cingulata, Glyptodontidae) from the Pleistocene of southern Brazil

2015 ◽  
Vol 87 (1) ◽  
pp. 15-27 ◽  
Author(s):  
José D. Ferreira ◽  
Martín Zamorano ◽  
Ana Maria Ribeiro
Keyword(s):  
South America ◽  
Rio Grande ◽  
Species Level ◽  
External Morphology ◽  
Latitudinal Distribution ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Diagnostic Features ◽  
New Material

The genus Panochthus represents the last lineage of "Panochthini" recorded in the Pleistocene. This genus has a wide latitudinal distribution in South America, and in Brazil it occurs in the southern and northeastern regions. In this paper we describe new material (isolated osteoderms and caudal tube fragments) assigned to Panochthus from the state of Rio Grande do Sul (southern Brazil) and discuss some taxonomic issues related to Panochthus tuberculatus and Panochthus greslebini based on this material . The occurrence of P. greslebini is the first for outside the Brazilian Intertropical Region. In addition, we describe new diagnostic features to differentiate the osteoderms of P. greslebini and P. tuberculatus. Unfortunately, it was not possible to identify some osteoderms at the species level. Interestingly, they showed four distinct morphotypes characterized by their external morphology, and thus were attributed to Panochthus sp. Lastly, we conclude that in addition to P.tuberculatus registered to southern Brazil, there is another species of the genus, assignable to P. cf. P. greslebini. Our analysis reinforce the reliability of caudal tube characters for the classification of species of Panochthus.

scholarly journals Multiple incursion pathways for Helicoverpa armigera in Brazil show its genetic diversity spreading in a connected world

2019 ◽  
Author(s):  
Jonas A. Arnemann ◽  
Stephen H. Roxburgh ◽  
Tom Walsh ◽  
Jerson V.C. Guedes ◽  
Karl H.J. Gordon ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Gene Flow ◽  
South America ◽  
New World ◽  
Flow Patterns ◽  
South American ◽  
Southern Brazil ◽  
American Continent ◽  
Central Brazil ◽  
South American Continent

AbstractThe Old World cotton bollworm Helicoverpa armigera was first detected in Brazil with subsequent reports from Paraguay, Argentina, Bolivia, and Uruguay. This pattern suggests that the H. armigera spread across the South American continent following incursions into northern/central Brazil, however, this hypothesis has not been tested. Here we compare northern and central Brazilian H. armigera mtDNA COI haplotypes with those from southern Brazil, Uruguay, Argentina, and Paraguay. We infer spatial genetic and gene flow patterns of this dispersive pest in the agricultural landscape of South America. We show that the spatial distribution of H. armigera mtDNA haplotypes and its inferred gene flow patterns in the southwestern region of South America exhibited signatures inconsistent with a single incursion hypothesis. Simulations on spatial distribution patterns show that the detection of rare and/or the absence of dominant mtDNA haplotypes in southern H. armigera populations are inconsistent with genetic signatures observed in northern and central Brazil. Incursions of H. armigera into the New World are therefore likely to have involved independent events in northern/central Brazil, and southern Brazil/Uruguay-Argentina-Paraguay. This study demonstrates the significant biosecurity challenges facing the South American continent, and highlights alternate pathways for introductions of alien species into the New World.

scholarly journals A weather regime characterisation of winter biomass aerosol transport from southern Africa

2021 ◽  
Author(s):  
Marco Gaetani ◽  
Benjamin Pohl ◽  
Maria del Carmen Alvarez Castro ◽  
Cyrille Flamant ◽  
Paola Formenti
Keyword(s):  
Spatial Distribution ◽  
Southern Africa ◽  
Forest Fires ◽  
South Atlantic ◽  
Austral Winter ◽  
The South ◽  
Predictive Tool ◽  
Weather Regime ◽  
Synoptic Variability

Abstract. During austral winter, a compact low cloud deck over South Atlantic contrasts with clear sky over southern Africa, where forest fires triggered by dry conditions emit large amount of biomass burning aerosols (BBA) in the free troposphere. Most of the BBA burden crosses South Atlantic embedded in the tropical easterly flow. However, midlatitude synoptic disturbances can deflect part of the aerosol from the main transport path towards southern extratropics. In this study, a characterisation of the synoptic variability controlling the spatial distribution of BBA in southern Africa and South Atlantic during austral winter (August to October) is presented. By analysing atmospheric circulation data from reanalysis products, a 6-class weather regime (WR) classification of the region is constructed. The classification reveals that the synoptic variability is composed by four WRs representing disturbances travelling at midlatitudes, and two WRs accounting for pressure anomalies in the South Atlantic. The WR classification is then successfully used to characterise the aerosol spatial distribution in the region in the period 2003–2017, in both reanalysis products and station data. Results show that the BBA transport towards southern extratropics is controlled by weather regimes associated with midlatitude synoptic disturbances. In particular, depending on the relative position of the pressure anomalies along the midlatitude westerly flow, the BBA transport is deflected from the main tropical route towards southern Africa or the South Atlantic. This paper presents the first objective classification of the winter synoptic circulation over South Atlantic and southern Africa. The classification shows skills in characterising the BBA transport, indicating the potential for using it as a diagnostic/predictive tool for aerosol dynamics, which is a key component for the full understanding and modelling of the complex radiation-aerosol-cloud interactions controlling the atmospheric radiative budget in the region.

scholarly journals Multiple incursion pathways for Helicoverpa armigera in Brazil show its genetic diversity spreading in a connected world

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Jonas Andre Arnemann ◽  
Stephen Roxburgh ◽  
Tom Walsh ◽  
Jerson Guedes ◽  
Karl Gordon ◽  
...  
Keyword(s):  
Spatial Distribution ◽  
Gene Flow ◽  
South America ◽  
New World ◽  
Flow Patterns ◽  
South American ◽  
Southern Brazil ◽  
American Continent ◽  
Central Brazil ◽  
South American Continent

AbstractThe Old World cotton bollworm Helicoverpa armigera was first detected in Brazil with subsequent reports from Paraguay, Argentina, Bolivia, and Uruguay. This pattern suggests that the H. armigera spread across the South American continent following incursions into northern/central Brazil, however, this hypothesis has not been tested. Here we compare northern and central Brazilian H. armigera mtDNA COI haplotypes with those from southern Brazil, Uruguay, Argentina, and Paraguay. We infer spatial genetic and gene flow patterns of this dispersive pest in the agricultural landscape of South America. We show that the spatial distribution of H. armigera mtDNA haplotypes and its inferred gene flow patterns in the southwestern region of South America exhibited signatures inconsistent with a single incursion hypothesis. Simulations on spatial distribution patterns show that the detection of rare and/or the absence of dominant mtDNA haplotypes in southern H. armigera populations are inconsistent with genetic signatures observed in northern and central Brazil. Incursions of H. armigera into the New World are therefore likely to have involved independent events in northern/central Brazil, and southern Brazil/Uruguay-Argentina-Paraguay. This study demonstrates the significant biosecurity challenges facing the South American continent, and highlights alternate pathways for introductions of alien species into the New World.

scholarly journals Measuring urban form: Overcoming terminological inconsistencies for a quantitative and comprehensive morphologic analysis of cities

2020 ◽  
pp. 239980832091044 ◽  
Author(s):  
Martin Fleischmann ◽  
Ombretta Romice ◽  
Sergio Porta
Keyword(s):  
Spatial Distribution ◽  
Quantitative Analysis ◽  
Urban Form ◽  
Large Scale ◽  
Global Scale ◽  
Urban Morphology ◽  
Systematic Classification ◽  
Social Patterns ◽  
The Impact

Unprecedented urbanisation processes characterise the Great Acceleration, urging urban researchers to make sense of data analysis in support of evidence-based and large-scale decision-making. Urban morphologists are no exception since the impact of urban form on fundamental natural and social patterns (equity, prosperity and resource consumption’s efficiency) is now fully acknowledged. However, urban morphology is still far from offering a comprehensive and reliable framework for quantitative analysis. Despite remarkable progress since its emergence in the late 1950s, the discipline still exhibits significant terminological inconsistencies with regards to the definition of the fundamental components of urban form, which prevents the establishment of objective models for measuring it. In this article, we present a study of existing methods for measuring urban form, with a focus on terminological inconsistencies, and propose a systematic and comprehensive framework to classify urban form characters, where ‘urban form character’ stands for a characteristic (or feature) of one kind of urban form that distinguishes it from another kind. In particular, we introduce the Index of Elements that allows for a univocal and non-interpretive description of urban form characters. Based on such Index of Elements, we develop a systematic classification of urban form according to six categories (dimension, shape, spatial distribution, intensity, connectivity and diversity) and three conceptual scales (small, medium, large) based on two definitions of scale (extent and grain). This framework is then applied to identify and organise the urban form characters adopted in available literature to date. The resulting classification of urban form characters reveals clear gaps in existing research, in particular, in relation to the spatial distribution and diversity characters. The proposed framework reduces the current inconsistencies of urban morphology research, paving the way to enhanced methods of urban form systematic and quantitative analysis at a global scale.

Lucerne investigation I. Identification and classification of lucerne ‘varieties’ and ‘strains’

1954 ◽  
Vol 44 (2) ◽  
pp. 199-220 ◽  
Author(s):  
A. Zaleski
Keyword(s):  
South America ◽  
Soil Fertility ◽  
Environmental Conditions ◽  
Management System ◽  
Morphological Characters ◽  
Distinguishing Features

Detailed investigations on identification and classification of lucerne varieties and strains were conducted at Cambridge for four years, 1949–52, on lucerne sown in row plots and on twelve typical varieties planted out in replicated trials as single spaced plants, using 200 plants of each variety. A number of physiological and morphological characters were examined and the resulting data was analysed statistically.The characteristics used for classification are those which showed considerable variation between varieties, but at the same time these differences were maintained consistently from year to year. They proved to be unaffected by a different way of growing the plants or by small differences in soil fertility or season. The results are shown in Tables 1–17, and three basic classifications with distinguishing features of types and varieties are given. The correlations established between various characters on twelve varieties are given under the heading ‘Correlations’ at the end of the results.(a) The first classification into early, mid-season, late and extra-late types, based on the time of flowering, spring and autumn growth, gives a fair indication to the growers regarding earliness and productivity of various varieties.(b) The behaviour of certain varieties from South America, and in particular Saladina, an Argentine variety, which is vigorous and productive under native country conditions but has lost this ability under Cambridge conditions, indicates plainly that classification based on these three characters can be applied only to the country under whose conditions it was established. Therefore any variety especially obtained from a country of extremely different environmental conditions and management system should be checked in these respects even if a description is given.

scholarly journals CLASSIFICATION OF THE HORNTAILS AND SAWFLIES, OR THE SUB-ORDER PHYTOPHAGA

1898 ◽  
Vol 30 (7) ◽  
pp. 177-183 ◽  
Author(s):  
William H. Ashmead
Keyword(s):  
South America ◽  
North Central ◽  
Malay Archipelago ◽  
Parasitic Hymenoptera ◽  
Single Genus

This group was recognized as a sub-family by Newman as early as 1834, and as a distinct family by Haliday in 1839. It is represented at present by a single genus, Oryssus, Latr., which is apparenrly the stem from whence some of the parasitic Hymenoptera originated; i. e., the Megalyridae, Stephanidae, etc.I have now, however, the pleasure of indicating below another genus, indigenous to Africa.Although comparatively few species are described in the group, it yet appears to be widely distributed, species having been found in North, Central and South America, Europe, Africa, Asia and Aru, in the Malay Archipelago.

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