scholarly journals Groningen Radiocarbon Dates VIII

Radiocarbon ◽  
1969 ◽  
Vol 11 (2) ◽  
pp. 351-390 ◽  
Author(s):  
J. C. Vogel ◽  
J. C. Lerman
Keyword(s):  
Latin America ◽  
Radiocarbon Dates ◽  
The Past ◽  
Pollen Diagrams ◽  
Geologic Samples

This list contains dates for Latin America which have mainly been measured during the past few years. The results are grouped into three categories: geologic, archaeologic, and geophysical, and arranged according to the country of provenance, passing roughly from N to S. Most of the geologic samples are connected with palynologic studies. In cases where the influence of man is apparent in the pollen diagrams, this is explicitly mentioned. Descriptions and comments are based on information provided by the collectors or submitters and on the publications referred to under each sample or series. For the archaeologic section reference has also been made to the general works of Meggers and Evans (1963), Jennings and Norbeck (1964), and Willey (1966).

scholarly journals Bern Radiocarbon Dates VII

Radiocarbon ◽  
1970 ◽  
Vol 12 (2) ◽  
pp. 358-384 ◽  
Author(s):  
H. Oeschger ◽  
T. Riesen ◽  
J. C. Lerman
Keyword(s):  
Human Activity ◽  
General Reference ◽  
Radiocarbon Dates ◽  
The Past ◽  
Pollen Diagrams ◽  
Selection Of

This list contains a selection of dates from analyses carried out during the past few years. Samples are grouped in geologic-palynologic, and archaeologic sections according to main problem. When influence of human activity on pollen diagrams has been observed it has been explicitly indicated. The descriptions and comments have been written in collaboration with collectors and submitters. For the samples from Switzerland, general reference has also been made to Welten (1958a) and to sections on palynology, geology, and archaeology in work edited by the Schweizerische Gesellschaft für Ur- und Frühgeschichte (1968-1970).

A review of the mid-Holocene elm decline in the British Isles

2002 ◽  
Vol 26 (1) ◽  
pp. 1-45 ◽  
Author(s):  
A. G. Parker ◽  
A. S. Goudie ◽  
D. E. Anderson ◽  
M. A. Robinson ◽  
C. Bonsall
Keyword(s):  
Standard Deviation ◽  
Probability Distribution ◽  
Climatic Change ◽  
Human Activities ◽  
Statistical Analyses ◽  
British Isles ◽  
Radiocarbon Dates ◽  
The Past ◽  
Northwest Europe ◽  
Pollen Diagrams

Over the past 50 years the most enigmatic feature of pollen diagrams from northwest Europe has been the mid-Holocene ‘elm decline’, and there has been much speculation as to the origin(s) and cause(s) of this event. A total of 150 radiocarbon dates from 139 sites spanning the elm decline in Britain and Ireland have been collated and scrutinized. Statistical analyses on 138 dates show that the event has a mean date of 5036 14C yr BP with a standard deviation of ± 247. Calibration of the dates and combining the sum probabilities yielded a range spanning 6347-5281 cal yr BP (1s), covering 1066 years. The start of the elm decline event lies between 6343 and 6307 cal yr BP (1s), a period of 36 years, indicating that the onset was rapid. The end of the event lies between 5290 and 5420 cal yr BP (1s), a period of 130 years. The probability distribution indicates that the elm decline was a uniform phased event across the British Isles. It appears that the elm decline can be explained to a large extent by the outbreak of disease. However, recent research on palaeoclimatic change and the nature of the transition from the Mesolithic to Neolithic in the British Isles suggests that both climatic change and human activities were implicated. It was probably the interplay between these factors, rather than any in isolation, that catalyzed the widespread, catastrophic decline of elm populations during the mid-Holocene.

scholarly journals Calibration of Radiocarbon Dates for the Late Pleistocene Using U/Th Dates on Stalagmites

Radiocarbon ◽  
1997 ◽  
Vol 39 (1) ◽  
pp. 27-32 ◽  
Author(s):  
John C. Vogel ◽  
Joel Kronfeld
Keyword(s):  
South Africa ◽  
Magnetic Dipole ◽  
Satisfactory Agreement ◽  
Late Pleistocene ◽  
Calibration Curve ◽  
Dipole Field ◽  
Radiocarbon Dates ◽  
The Past ◽  
The Earth ◽  
Magnetic Dipole Field

Twenty paired 14C and U/Th dates covering most of the past 50,000 yr have been obtained on a stalagmite from the Cango Caves in South Africa as well as some additional age-pairs on two stalagmites from Tasmania that partially fill a gap between 7 ka and 17 ka ago. After allowance is made for the initial apparent 14C ages, the age-pairs between 7 ka and 20 ka show satisfactory agreement with the coral data of Bard et al. (1990, 1993). The results for the Cango stalagmite between 25 ka and 50 ka show the 14C dates to be substantially younger than the U/Th dates except at 49 ka and 29 ka, where near correspondence occurs. The discrepancies may be explained by variations in 14C production caused by changes in the magnetic dipole field of the Earth. A tentative calibration curve for this period is offered.

Latin America and the League of Nations

1926 ◽  
Vol 20 (1) ◽  
pp. 14-30
Author(s):  
Percy Alvin Martin
Keyword(s):  
Latin America ◽  
International Relations ◽  
Latin American ◽  
The United States ◽  
League Of Nations ◽  
World War ◽  
The Past ◽  
Treaty Of Versailles ◽  
Post War ◽  
International Status

To students of international relations it has become almost a commonplace that among the most significant and permanent results of the World War has been the changed international status of the republics of Latin America. As a result of the war and post-war developments in these states, the traditional New World isolation in South America, as well as in North America, is a thing of the past. To our leading sister republics is no longer applicable the half-contemptuous phrase, current in the far-off days before 1914, that Latin America stands on the margin of international life. The new place in the comity of nations won by a number of these states is evidenced—to take one of the most obvious examples—by the raising of the legations of certain non-American powers to the rank of embassies, either during or immediately after the war. In the case of Brazil, for instance, where prior to 1914 only the United States maintained an ambassador, at the present time Great Britain, France, Italy, Belgium, Portugal, and Japan maintain diplomatic representatives of this rank.Yet all things considered one of the most fruitful developments in the domain of international relations has been the share taken by our southern neighbors in the work of the League of Nations. All of the Latin American republics which severed relations with Germany or declared war against that country were entitled to participate in the Peace Conference. As a consequence, eleven of these states affixed their signatures to the Treaty of Versailles, an action subsequently ratified in all cases except Ecuador.

scholarly journals Hydroclimate variability in the low-elevation Atacama Desert over the last 2500 yr

2012 ◽  
Vol 8 (1) ◽  
pp. 287-306 ◽  
Author(s):  
E. M. Gayo ◽  
C. Latorre ◽  
C. M. Santoro ◽  
A. Maldonado ◽  
R. De Pol-Holz
Keyword(s):  
Hydrological Cycle ◽  
Atacama Desert ◽  
Plant Macrofossils ◽  
Central Andes ◽  
Tropical Pacific ◽  
Riparian Ecosystems ◽  
Independent Evidence ◽  
Radiocarbon Dates ◽  
Climate Fluctuations ◽  
The Past

Abstract. Paleoclimate reconstructions reveal that Earth system has experienced sub-millennial scale climate changes over the past two millennia in response to internal/external forcing. Although sub-millennial hydroclimate fluctuations have been detected in the central Andes during this interval, the timing, magnitude, extent and direction of change of these events remain poorly defined. Here, we present a reconstruction of hydroclimate variations on the Pacific slope of the central Andes based on exceptionally well-preserved plant macrofossils and associated archaeological remains from a hyperarid drainage (Quebrada Maní, ∼21° S, 1000 m a.s.l.) in the Atacama Desert. During the late Holocene, riparian ecosystems and farming social groups flourished in the hyperarid Atacama core as surface water availability increased throughout this presently sterile landscape. Twenty-six radiocarbon dates indicate that these events occurred between 1050–680, 1615–1350 and 2500–2040 cal yr BP. Regional comparisons with rodent middens and other records suggest that these events were synchronous with pluvial stages detected at higher-elevations in the central Andes over the last 2500 yr. These hydroclimate changes also coincide with periods of pronounced SST gradients in the Tropical Pacific (La Niña-like mode), conditions that are conducive to significantly increased rainfall in the central Andean highlands and flood events in the low-elevation watersheds at inter-annual timescales. Our findings indicate that the positive anomalies in the hyperarid Atacama over the past 2500 yr represent a regional response of the central Andean climate system to changes in the global hydrological cycle at centennial timescales. Furthermore, our results provide support for the role of tropical Pacific sea surface temperature gradient changes as the primary mechanism responsible for climate fluctuations in the central Andes. Finally, our results constitute independent evidence for comprehending the major trends in cultural evolution of prehistoric peoples that inhabited the region.

Pollen diagrams from interior Labrador

1970 ◽  
Vol 48 (11) ◽  
pp. 1957-1975 ◽  
Author(s):  
Alastair Morrison
Keyword(s):  
Primary Succession ◽  
Vegetation Changes ◽  
Bare Ground ◽  
Radiocarbon Dates ◽  
River Watershed ◽  
Pollen Diagrams ◽  
Glacier Ice ◽  
Lake Waters

Six pollen zones can be distinguished in interior Labrador. The earlier zones represent the primary succession of vegetation from bare ground to boreal woodland or forest, which occupied about 500 years between 5700 and 5200 B.P. There have been only minor fluctuations in the nature of the vegetation since 5200 B.P. Radiocarbon dates show that the zones are contemporaneous over that part of the Lake Plateau within the Churchill River watershed, but similar vegetation changes occurred 1000 years earlier in the Kaniapiskau basin, further north, in New Quebec. These two areas must have been freed of a cover of glacier ice or lake waters immediately before 5700 B.P. and 6700 B.P. respectively.

Past and recent biodiversity profiling in ancient Lake Chalco Mexico by a metagenomics analysis

2021 ◽  
Author(s):  
Bárbara Moguel ◽  
Liseth Pérez ◽  
Luis David Alcaraz ◽  
Socorro Lozano-García ◽  
Luis Herrera-Estrella ◽  
...  
Keyword(s):  
Volcanic Belt ◽  
Environmental Dna ◽  
Radiocarbon Dates ◽  
The Past ◽  
Mexican Volcanic Belt ◽  
History Of ◽  
High Throughput Dna Sequencing ◽  
High Altitude Lake ◽  
Taxonomic Groups ◽  
The Relationship

<p>For decades, paleoecological studies in lake sediments have focused on reconstructing the environments of the past and explaining phenomena linked to climatic variations. Recent advances in high-throughput DNA sequencing have allowed access to environmental DNA (eDNA) and ancient sedimentary DNA (sedaDNA) as a new and efficient proxy for past and present biodiversity. The basin of Mexico (BM) is located in the central part of the Trans-Mexican Volcanic Belt at 2,200 m a.s.l.; with the southern portion harboring the Chalco sub-basin. Lake Chalco is one of the last remaining natural aquatic ecosystems within the ever-expanding urban area surrounding Mexico City. The paleoenvironmental history of this lake has been previously characterized using sedimentological and geochemical proxies, as well as preserved microfossils (diatoms, pollen) with a temporal framework based on multiple radiocarbon dates. However, information for the remaining taxonomic groups and metabolic pathways remained unexplored. Here, we present the first metagenomics-based study for the Holocene in a high-altitude lake in Central Mexico –Lake Chalco. We explored the relationship between the lake’s paleoenvironmental condition and estimations of taxonomic and metabolic profiles across the sedimentary sequence (2.5 meters long). Multiple biological and abiotic variables revealed three main environmental phases: 1) a cool freshwater lake (FW1: 11,500-11,000 cal years BP), 2) a warm hyposaline lake (HS2: 11,000-6,000 cal years BP), and 3) a temperate, subsaline lake (SS3, <6,000 cal years BP). We describe the structure of the microbiota community and taxonomy richness turnover in the three Holocene paleoenvironmental phases. During the past 12 000 years BP the most abundant domains in Lake Chalco sediments were Bacteria, followed by Archaea, and Eukarya (36,722 genera). The analysis of functional proteins showed high biodiversity with a total of 27,636,243 proteins identified, but it was only possible to annotate 3,227,398 of them. Also, we identified several genes associated with some relevant pathways, such as methanogenesis. Altogether, this study allowed us to reconstruct the natural history of lake Chalco and its surroundings.</p>

Introduction

2018 ◽  
pp. 1-17
Author(s):  
Matthew D. O'Hara
Keyword(s):  
Latin America ◽  
Case Studies ◽  
Historical Development ◽  
Colonial Mexico ◽  
Historical Case ◽  
Colonial Era ◽  
Historical Method ◽  
The Past ◽  
The Relationship

This introductory chapter provides an overview of the analysis of time experience and futuremaking through historical case studies in colonial Mexico. Colonial Mexico developed a culture of innovation, human aspiration, and futuremaking that was subsequently forgotten in part because it did not fit with later definitions of modernity and innovation as secular phenomena and things untethered to the past or tradition. This choice of historical method and topics is driven by a desire to step outside some of the dominant paradigms in the study of Latin America and colonialism in general. Examining the relationship between past, present, and future offers a way to reconsider Mexico's colonial era, its subsequent historical development, and how people have understood that history.

scholarly journals The Integration of Radiocarbon Dating in Archaeology

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 639-644 ◽  
Author(s):  
H T Waterbolk
Keyword(s):  
Radiocarbon Dating ◽  
The Other ◽  
New Method ◽  
Time Range ◽  
Traditional Methods ◽  
Radiocarbon Dates ◽  
Fully Integrated ◽  
Expected Time ◽  
The Past

In the past 30 years many hundreds of archaeologic samples have been dated by radiocarbon laboratories. Yet, one cannot say that 14C dating is fully integrated into archaeology. For many archaeologists, a 14C date is an outside expertise, for which they are grateful, when it provides the answer to an otherwise insoluble chronologic problem and when it falls within the expected time range. But if a 14C date contradicts other chronologic evidence, they often find the ‘solution’ inexplicable. Some archaeologists are so impressed by the new method, that they neglect the other evidence; others simply reject problematic 14C dates as archaeologically unacceptable. Frequently, excavation reports are provided with an appendix listing the relevant 14C dates with little or no discussion of their implication. It is rare, indeed, to see in archaeologic reports a careful weighing of the various types of chronologic evidence. Yet, this is precisely what the archaeologist is accustomed to do with the evidence from his traditional methods for building up a chronology: typology and stratigraphy. Why should he not be able to include radiocarbon dates in the same way in his considerations?

scholarly journals Issues in Latin America. Sociocultural contrasts and their representations in contemporary literature

Diacronia ◽  
2020 ◽  
Author(s):  
Sorina-Crina Ghiață
Keyword(s):  
Latin America ◽  
Latin American ◽  
Western Europe ◽  
Social Issues ◽  
Contemporary Literature ◽  
Cultural Environment ◽  
Religious Perspective ◽  
The Past ◽  
Introductory Part ◽  
Overseas Territories

Starting with the independence process of all the territories once colonies and later, overseas territories of the different states of Western Europe, Latin America meant an association of unique paradoxes. Portugal and Spain have dominated in the past, especially from a linguistic and religious perspective,the current space that became avaried cultural environment. In this context, the aim of this study is to capture, in the introductory part, characteristics of the Latin American complex identity(reflected, for example, in the names associated with this space of civilization, in political circumstances and social issues, in particular). In addition, another purpose is to highlight the way in which these aspects are considered in the prose of modern Latin American writers, Rodrigo Rey Rosa and Héctor Abad Faciolince. At the same time,emphasizing the scourge of discrimination or inequality, but especially the perpetual violence, thestudyconcludes with a reference (also found in the literary discourse of the two texts chosen for analysis, Los sordos and El olvido que seremos) to the ethical spirit, but also to the feeling of empathy—subjects approached by both writers—in a world that seems more and more fragmented and depersonalized, as if it has been occupied by a continuous stigma of imbalance.

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