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The timing and effect of the earliest human arrivals in North America 期刊论文
NATURE, 2020
作者:  Lorena Becerra-Valdivia;  Thomas Higham
收藏  |  浏览/下载:27/0  |  提交时间:2020/08/09

The peopling of the Americas marks a major expansion of humans across the planet. However, questions regarding the timing and mechanisms of this dispersal remain, and the previously accepted model (termed '  Clovis-first'  )-suggesting that the first inhabitants of the Americas were linked with the Clovis tradition, a complex marked by distinctive fluted lithic points(1)-has been effectively refuted. Here we analyse chronometric data from 42 North American and Beringian archaeological sites using a Bayesian age modelling approach, and use the resulting chronological framework to elucidate spatiotemporal patterns of human dispersal. We then integrate these patterns with the available genetic and climatic evidence. The data obtained show that humans were probably present before, during and immediately after the Last Glacial Maximum (about 26.5-19 thousand years ago)(2,3)but that more widespread occupation began during a period of abrupt warming, Greenland Interstadial 1 (about 14.7-12.9 thousand years beforead 2000)(4). We also identify the near-synchronous commencement of Beringian, Clovis and Western Stemmed cultural traditions, and an overlap of each with the last dates for the appearance of 18 now-extinct faunal genera. Our analysis suggests that the widespread expansion of humans through North America was a key factor in the extinction of large terrestrial mammals.


A Bayesian age model suggests that human dispersal to the Americas probably began before the Last Glacial Maximum, overlapping with the last dates of appearance for several faunal genera.


  
Last glacial atmospheric CO(2)decline due to widespread Pacific deep-water expansion 期刊论文
NATURE GEOSCIENCE, 2020
作者:  Yu, J.;  Menviel, L.;  Jin, Z. D.;  Anderson, R. F.;  Jian, Z.;  Piotrowski, A. M.;  Ma, X.;  Rohling, E. J.;  Zhang, F.;  Marino, G.;  McManus, J. F.
收藏  |  浏览/下载:12/0  |  提交时间:2020/08/09
Earth's soil harbours ancient carbon 期刊论文
NATURE GEOSCIENCE, 2020
作者:  Billings, Sharon A.;  de Souza, Ligia F. T.
收藏  |  浏览/下载:4/0  |  提交时间:2020/07/21
Holocene earthquake history and slip rate of the southern Teton fault, Wyoming, USA 期刊论文
GEOLOGICAL SOCIETY OF AMERICA BULLETIN, 2020, 132 (7-8) : 1566-1586
作者:  DuRoss, Christopher B.;  Gold, Ryan D.;  Briggs, Richard W.;  Delano, Jaime E.;  Ostenaa, Dean A.;  Zellman, Mark S.;  Cholewinski, Nicole;  Wittke, Seth J.;  Mahan, Shannon A.
收藏  |  浏览/下载:7/0  |  提交时间:2020/08/18
The age distribution of global soil carbon inferred from radiocarbon measurements 期刊论文
NATURE GEOSCIENCE, 2020
作者:  Shi, Zheng;  Allison, Steven D.;  He, Yujie;  Levine, Paul A.;  Hoyt, Alison M.;  Beem-Miller, Jeffrey;  Zhu, Qing;  Wieder, William R.;  Trumbore, Susan;  Randerson, James T.
收藏  |  浏览/下载:18/0  |  提交时间:2020/07/06
Estimating US fossil fuel CO2 emissions from measurements of C-14 in atmospheric CO2 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (24) : 13300-13307
作者:  Basu, Sourish;  Lehman, Scott J.;  Miller, John B.;  Andrews, Arlyn E.;  Sweeney, Colm;  Gurney, Kevin R.;  Xu, Xiaomei;  Southon, John;  Tans, Pieter P.
收藏  |  浏览/下载:14/0  |  提交时间:2020/06/09
fossil fuel CO2  radiocarbon  atmospheric inverse modeling  
Millennial-scale hydroclimate control of tropical soil carbon storage 期刊论文
NATURE, 2020, 581 (7806) : 63-+
作者:  Lam, Tommy Tsan-Yuk;  Jia, Na;  Zhang, Ya-Wei;  Shum, Marcus Ho-Hin;  Jiang, Jia-Fu;  Zhu, Hua-Chen;  Tong, Yi-Gang;  Shi, Yong-Xia;  Ni, Xue-Bing;  Liao, Yun-Shi;  Li, Wen-Juan;  Jiang, Bao-Gui;  Wei, Wei;  Yuan, Ting-Ting;  Zheng, Kui;  Cui, Xiao-Ming;  Li, Jie;  Pei, Guang-Qian
收藏  |  浏览/下载:25/0  |  提交时间:2020/05/13

Over the past 18,000 years, the residence time and amount of soil carbon stored in the Ganges-Brahmaputra basin have been controlled by the intensity of Indian Summer Monsoon rainfall, with greater carbon destabilization during wetter, warmer conditions.


The storage of organic carbon in the terrestrial biosphere directly affects atmospheric concentrations of carbon dioxide over a wide range of timescales. Within the terrestrial biosphere, the magnitude of carbon storage can vary in response to environmental perturbations such as changing temperature or hydroclimate(1), potentially generating feedback on the atmospheric inventory of carbon dioxide. Although temperature controls the storage of soil organic carbon at mid and high latitudes(2,3), hydroclimate may be the dominant driver of soil carbon persistence in the tropics(4,5)  however, the sensitivity of tropical soil carbon turnover to large-scale hydroclimate variability remains poorly understood. Here we show that changes in Indian Summer Monsoon rainfall have controlled the residence time of soil carbon in the Ganges-Brahmaputra basin over the past 18,000 years. Comparison of radiocarbon ages of bulk organic carbon and terrestrial higher-plant biomarkers with co-located palaeohydrological records(6) reveals a negative relationship between monsoon rainfall and soil organic carbon stocks on a millennial timescale. Across the deglaciation period, a depletion of basin-wide soil carbon stocks was triggered by increasing rainfall and associated enhanced soil respiration rates. Our results suggest that future hydroclimate changes in tropical regions are likely to accelerate soil carbon destabilization, further increasing atmospheric carbon dioxide concentrations.


  
Monumental architecture at Aguada Fenix and the rise of Maya civilization 期刊论文
NATURE, 2020
作者:  Bedding, Timothy R.;  Murphy, Simon J.;  Hey, Daniel R.;  Huber, Daniel;  Li, Tanda;  Smalley, Barry;  Stello, Dennis;  White, Timothy R.;  Ball, Warrick H.;  Chaplin, William J.;  Colman, Isabel L.;  Fuller, Jim;  Gaidos, Eric;  Harbeck, Daniel R.;  Hermes, J. J.;  Holdsworth, Daniel L.;  Li, Gang;  Li, Yaguang;  Mann, Andrew W.;  Reese, Daniel R.;  Sekaran, Sanjay;  Yu, Jie;  Antoci, Victoria;  Bergmann, Christoph;  Brown, Timothy M.;  Howard, Andrew W.;  Ireland, Michael J.;  Isaacson, Howard;  Jenkins, Jon M.;  Kjeldsen, Hans;  McCully, Curtis;  Rabus, Markus;  Rains, Adam D.;  Ricker, George R.;  Tinney, Christopher G.;  Vanderspek, Roland K.
收藏  |  浏览/下载:30/0  |  提交时间:2020/07/03

Archaeologists have traditionally thought that the development of Maya civilization was gradual, assuming that small villages began to emerge during the Middle Preclassic period (1000-350 bc  dates are calibrated throughout) along with the use of ceramics and the adoption of sedentism(1). Recent finds of early ceremonial complexes are beginning to challenge this model. Here we describe an airborne lidar survey and excavations of the previously unknown site of Aguada Fenix (Tabasco, Mexico) with an artificial plateau, which measures 1,400 m in length and 10 to 15 m in height and has 9 causeways radiating out from it. We dated this construction to between 1000 and 800 bc using a Bayesian analysis of radiocarbon dates. To our knowledge, this is the oldest monumental construction ever found in the Maya area and the largest in the entire pre-Hispanic history of the region. Although the site exhibits some similarities to the earlier Olmec centre of San Lorenzo, the community of Aguada Fenix probably did not have marked social inequality comparable to that of San Lorenzo. Aguada Fenix and other ceremonial complexes of the same period suggest the importance of communal work in the initial development of Maya civilization.


Lidar survey of the Maya lowlands uncovers the monumental site of Aguada Fenix, which dates to around 1000-800 bc and points to the role of communal construction in the development of Maya civilization.


  
The spatiotemporal spread of human migrations during the European Holocene 期刊论文
PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA, 2020, 117 (16) : 8989-9000
作者:  Racimo, Fernando;  Woodbridge, Jessie;  Fyfe, Ralph M.;  Sikora, Martin;  Sjogren, Karl-Goran;  Kristiansen, Kristian;  Vander Linden, Marc
收藏  |  浏览/下载:11/0  |  提交时间:2020/05/13
migrations  ancient DNA  Neolithic  Bronze Age  land cover  
Seasonal source variability of carbonaceous aerosols at the Rwanda Climate Observatory 期刊论文
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2020, 20 (8) : 4561-4573
作者:  Andersson, August;  Kirillova, Elena N.;  Decesari, Stefano;  DeWitt, H. Langley;  Gasore, Jimmy;  Potter, Katherine;  Prinn, Ronald G.;  Rupakheti, Maheswar;  Ndikubwimana, Jean de Dieu;  Nkusi, Julius;  Safari, Bonfils
收藏  |  浏览/下载:10/0  |  提交时间:2020/05/13