scholarly journals Anomalous Radiocarbon Dates from Easter Island

Radiocarbon ◽  
2004 ◽  
Vol 46 (1) ◽  
pp. 395-405 ◽  
Author(s):  
Kevin Butler ◽  
Christine A Prior ◽  
John R Flenley
Keyword(s):  
Sample Selection ◽  
South Pacific ◽  
Easter Island ◽  
The South ◽  
Depositional History ◽  
Radiocarbon Dates ◽  
Organic Components ◽  
Scirpus Californicus ◽  
History Of ◽  
Age Determinations

The largest volcanic crater on Easter Island in the South Pacific contains a lake 1 km in diameter with large floating mats of vegetation, mainly Scirpus californicus. A core taken through a mat near the center produced anomalous dates, with older dates above younger ones. The possibility that the mat had become inverted was considered, but palynological evidence refutes this idea because it shows a progressive upward decline of forest pollen, which is well known from other swamp cores on the island. A new series of radiocarbon dates made directly on pollen concentrates was obtained. These dates also produced inconsistencies, particularly when pollen concentrate ages were compared with 14C ages on plant fragments from the same depth. This series of 14C ages seems to indicate that both old and young organic components in the sediment are deposited contiguously and that the depositional history of these cores is more complex than previously known. Previous age determinations on bulk sediments from Easter Island, which also show anomalous dates, may be too simplistic. This paper provides a warning to other researchers dating sediments from Easter Island. We suggest that sample selection and dating procedures be carefully considered for these sediments.

scholarly journals Modern and Pleistocene Reservoir Ages Inferred from South Pacific Corals

Radiocarbon ◽  
2009 ◽  
Vol 51 (1) ◽  
pp. 319-335 ◽  
Author(s):  
G S Burr ◽  
J W Beck ◽  
Thierry Corrège ◽  
G Cabioch ◽  
F W Taylor ◽  
...  
Keyword(s):  
Papua New Guinea ◽  
South Pacific ◽  
New Guinea ◽  
Easter Island ◽  
The South ◽  
Marquesas Islands ◽  
Surface Ocean ◽  
Reservoir Age ◽  
Age Determinations

This paper presents radiocarbon results from modern South Pacific corals from the Marquesas Islands, Vanuatu, Papua New Guinea (PNG), and Easter Island. All of the measurements are from pre-bomb Porites corals that lived during the 1940s and 1950s. The data reflect subannual to multiannual surface ocean 14C variability and allow for precise, unambiguous reservoir age determinations. The results are compared with published values from other coral records throughout the South Pacific, with striking consistency. By comparisons with other published values, we identify 3 South Pacific regions with uniform pre-bomb reservoir ages (1945 to 1955). These are 1) the Central Equatorial South Pacific (361.6 − 8.2 14C yr, 2 σ); 2) the Western Equatorial South Pacific (322.1 − 8.6 14C yr, 2 σ); and 3) the subtropical Pacific (266.8 − 13.8 14C yr, 2 σ).

Daily accumulation rates of marine litter on the shores of Rapa Nui (Easter Island) in the South Pacific Ocean

2021 ◽  
Vol 169 ◽  
pp. 112535
Author(s):  
Martin Thiel ◽  
Bárbara Barrera Lorca ◽  
Luis Bravo ◽  
Iván A. Hinojosa ◽  
Hugo Zeballos Meneses
Keyword(s):  
Pacific Ocean ◽  
South Pacific ◽  
Easter Island ◽  
Accumulation Rates ◽  
The South ◽  
Rapa Nui ◽  
Marine Litter ◽  
South Pacific Ocean

Sailing into the Anthropocene

2016 ◽  
Author(s):  
Peter Dauvergne
Keyword(s):  
South Pacific ◽  
The Political ◽  
Pacific Island ◽  
The South ◽  
Large Numbers ◽  
The Pacific ◽  
History Of ◽  
The Pacific Ocean ◽  
Starting Date ◽  
History Of The South

Chapters 2–6 survey the political and socioeconomic forces underlying the global sustainability crisis. Understanding the scale and depth of contemporary forces of capitalism and consumerism requires a close look at the consequences of imperialism and colonialism on patterns of violence and exploitation. This chapter begins this process of understanding by sketching the history of ecological imperialism after 1600, seeing this as a reasonable starting date for the beginning of what many scholars are now calling the Anthropocene Epoch (or the age of humans, replacing the geologic epoch of the Holocene beginning 12,000 years ago). It opens with Captain Pedro Fernandes de Queirós’s voyage across the Pacific Ocean in 1605–06 to “discover” modern-day Vanuatu, before turning to look more globally at the devastation of imperialism – and later colonialism – for the South Pacific, the Americas, Africa, and Asia. Over this time conquerors enslaved and murdered large numbers of indigenous people; cataclysmic change came as well, however, from the introduction of European diseases, plants, and animals. This chapter’s survey of imperialism, colonialism, and globalization sets the stage for Chapter 3, which explores the devastating history of the South Pacific island of Nauru after 1798.

New conodont records of the Los Sombreros Formation (Cambrian–Ordovician) from the Western Precordillera, Argentina: biostratigraphic and palaeoenvironmental implications

2019 ◽  
Vol 157 (4) ◽  
pp. 539-550
Author(s):  
Gabriela Torre ◽  
Guillermo L. Albanesi
Keyword(s):  
Continental Margin ◽  
Carbonate Platform ◽  
South American ◽  
The South ◽  
Depositional History ◽  
The Matrix ◽  
Minimum Age ◽  
History Of ◽  
Lower Palaeozoic ◽  
Early Palaeozoic

AbstractThe presence of a carbonate platform that interfingers towards the west with slope facies allows for the identification of an ancient lower Palaeozoic continental margin in the Western Precordillera of Argentina. The Los Sombreros Formation is essential for the interpretation of the continental slope of the Precordillera, which accreted to Gondwana as part of the Cuyania Terrane in the early Palaeozoic. The age of these slope deposits is controversial; therefore, a precise biostratigraphic scheme is critical to reveal the evolution of the South American continental margin of Gondwana. The study of lithic deposits of two sections of the Los Sombreros Formation, the El Salto and Los Túneles sections, provides important information for further understanding the depositional history of the slope. At El Salto section, the conodonts recovered from an allochthonous block refer to the Cordylodus proavus Zone (upper Furongian). The conodonts recovered from the matrix of a calclithite bed of the Los Sombreros Formation in the Los Túneles section are assigned to the Lenodus variabilis Zone (early Darriwilian), providing a minimum age for this stratigraphic unit. In addition, clasts from this sample yielded conodonts from the Paltodus deltifer − Macerodus dianae zones (upper Tremadocian). The contrasting conodont colour alterations and preservation states from the elements of two latter records, coming from the same sample, argue the reworked clasts originated in the carbonate platform and later transported to the slope during the accretion process of the Precordilleran Terrane to the South American Gondwanan margin during the Middle–Late Ordovician.

scholarly journals Norfolk Island and Australia: a history of uneasy relationship

2020 ◽  
pp. 224-231
Author(s):  
S. E. Pale ◽  
Keyword(s):  
New South ◽  
New South Wales ◽  
South Pacific ◽  
Past Century ◽  
The South ◽  
The Past ◽  
South Wales ◽  
Norfolk Island ◽  
History Of

This article is about the complicated relations between Norfolk Island located in the South Pacific and Australia that possesses the island as its ‘external territory’. Over the past century Australia and its tiny but strategically important possession have overcome many difficult moments, the most dramatic of which took place in 2015, when the Australian Parliament ended self-government on the island and put Norfolk under the laws of New South Wales thus making it part of Australia.

scholarly journals Depositional History of Paleocene Sediments in the Offshore Canterbury Basin, New Zealand

2021 ◽  
Author(s):  
◽  
Sanjay Paul Samuel
Keyword(s):  
Seismic Data ◽  
The South ◽  
Depositional History ◽  
Reservoir Rocks ◽  
The North ◽  
Late Paleocene ◽  
Shelf Slope ◽  
History Of ◽  
Well Correlation ◽  
First Time

<p>The Paleocene interval within the Canterbury Basin has been relatively understudied with respect to the Neogene and Cretaceous intervals. Within the Paleocene interval is the Tartan Formation and the Charteris Bay Sandstone, which are potential source and reservoir rocks respectively. These two formations have not been previously mapped in the offshore Canterbury Basin and their limits have not been defined. This study utilises a database of nearly 12,000km of 2D seismic data together with data from four open–file wells and sidewall core samples from three wells and newly availiable biostratigraphic information to better constrain the chronostratigraphical interpretation of seismic data. Seismic mapping together with corroboration from well correlation and core lithofacies analysis revealed new insights into the development of the offshore Canterbury Basin through the Paleocene. These include the delineation of the lateral extents and thicknesses of the Tartan Formation and Charteris Bay Sandstone and location of the palaeo shelf–slope break and also the development of a new well correlation panel that incorporates the Tartan Formation for the first time.  This study presents four new paleogeographic maps for the offshore Canterbury Basin that significantly improves our understanding of the development of the basin during the Paleocene. These maps show that during the Earliest Paleocene, the mudstones of the Katiki Formation were being deposited in the south of the study area, with the siltier sediments of the Conway Formation being deposited in the north. The coarser grained Charteris Bay Sandstone was deposited from Early to possibly Middle Paleocene in the northeast. The mudstones of the Moeraki Formation were being deposited in the south at this time. From Middle to Late Paleocene, the mudstones of the Moeraki Formation were deposited in the south and these mudstones onlapped against the Charteris Bay Sandstone which remained as a high in the north. The Tartan Formation was deposited during the Late Paleocene in the central and southern areas of the offshore Canterbury Basin, during a relative fall in sea–level. Deposition had ceased in the north of the study area or erosion possibly removed Late Paleocene sediments from there. During the Latest Paleocene, the mudstones of the Moeraki Formation were deposited over the Tartan Formation in the central and southern parts of the offshore Canterbury Basin with the northern area undergoing erosion, sediment bypass or both.</p>

Travelling light: Fouling biota on macroplastics arriving on beaches of remote Rapa Nui (Easter Island) in the South Pacific Subtropical Gyre

2018 ◽  
Vol 137 ◽  
pp. 119-128 ◽  
Author(s):  
Sabine Rech ◽  
Martin Thiel ◽  
Yaisel J. Borrell Pichs ◽  
Eva García-Vazquez
Keyword(s):  
South Pacific ◽  
Easter Island ◽  
Subtropical Gyre ◽  
The South ◽  
Rapa Nui
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