نتایج جستجو برای: Middle Holocene

تعداد نتایج: 162732  

2004
Seth D. Newsome Donald L. Phillips Brendan J. Culleton Tom P. Guilderson Paul L. Koch

The inherent sampling and preservational biases of the archaeological record make it difficult to quantify prehistoric human diets, especially in coastal settings, where populations had access to a wide range of marine and terrestrial food sources. In certain cases, geochemical proxies such as stable isotope ratios may be utilized to provide robust estimates on the relative proportions of vario...

2016
Navnith K P Kumaran Damodaran Padmalal Ruta B Limaye Vishnu Mohan S Tim Jennerjahn Pradeep G Gamre

Holocene sequences in the humid tropical region of Kerala, South-western (SW) India have preserved abundance of organic-rich sediments in the form of peat and its rapid development in a narrow time frame towards Middle Holocene has been found to be significant. The sub-coastal areas and flood plains of the Greater Pamba Basin have provided palaeorecords of peat indicating that the deposits are ...

2001
Henry T. Mullins John D. Halfman

Approximately 70 km of new decimeter-resolution seismic reflection profile data from Owasco Lake, New York define a middle Holocene (∼4600 14C yr B.P.) erosion surface in the north end of the lake at water depths as great as 26 m. Beneath the lake, postglacial sediments are up to 9 m thick and represent about 10% of the total sediment fill. Early to middle Holocene sediments, ∼6 m thick, contai...

2015
Flávio Góis Laureano Raúl González Ruiz Gustavo Juan Scillato-Yané Esteban Soibelzon Brian Lee Beatty

Pampatheriidae are a group of cingulates native to South American that are known from the middle Miocene to the lower Holocene. Two genera have been recognized between the lower Pleistocene and the lower Holocene: Pampatherium Gervais and Ameghino (Ensenadan, Bonaerian and Lujanian, lower Pleistocene-lower Holocene) and Holmesina Simpson (Blancan, Irvingtonian, upper Pliocene-lower Holocene). T...

1996
MARK B. ABBOTT GEOFFREY O. SELTZER KERRY R. KELTS JOHN SOUTHON

southern basin of Lake Titicaca (Lago Wiñaymarka) conTwo century-scale time series in northern Bolivia constrain the tains an incomplete Holocene record because it was almost ages of abrupt changes in the physical, geochemical, and biological completely desiccated prior to about 3500 C yr B.P. (Wirrcharacteristics of sediments obtained from lakes that formed durmann et al., 1990; Wirrmann and M...

1997
Zicheng Yu John H. McAndrews Ueli Eicher

Paleoclimatic studies with multiple proxy data have increasingly improved our understanding of Holocene climate. A dry and warm climate in the early and middle Holocene has been documented by numerous studies in eastern North America (T. Webb et al., 1983, 1993; COHMAP Members, 1988; Baker et al., 1992; R. Webb et al., 1993). Recent studies show that the classic dry and warm prairie period in m...

Journal: :Anais da Academia Brasileira de Ciencias 2017
Astolfo G M Araujo Francisco A Pugliese Rafael O Dos Santos Mercedes Okumura

Lapa do Santo rockshelter, a Paleoindian site located in Eastern-Central Brazil, presented two main occupations; one during Early Holocene (12,460 to 8700 cal BP), and a latter in Middle Holocene (5100 to 4200 cal BP). In spite of this 3600 year gap, the stratigraphy and general characteristics of the material culture did not indicate any visible discontinuity. This led us to hypothesise a reoc...

2006
TIIT HANG SIIM VESKI ATKO HEINSALU Hang

This article reports the first discovery of middle Holocene cryptotephra from a peat sequence in Estonia, eastern Baltic. Two sequences, Mustjärve and Parika (located 110 km apart), were chosen for a pilot study aimed at finding traces of tephra fallout during the middle Holocene. Peat accumulation at both sites started in the early Holocene (c. 9500 9000 C yr BP; c. 11 000 10 000 cal. yr BP) a...

2014
Yanhong Zheng Joy S. Singarayer Peng Cheng Xuefeng Yu Zhao Liu Paul J. Valdes Richard D. Pancost

Atmospheric methane concentrations decreased during the early to middle Holocene; however, the governing mechanisms remain controversial. Although it has been suggested that the mid-Holocene minimum methane emissions are associated with hydrological change, direct evidence is lacking. Here we report a new independent approach, linking hydrological change in peat sediments from the Tibetan Plate...

Journal: :Science 2013
Shaun A Marcott Jeremy D Shakun Peter U Clark Alan C Mix

Surface temperature reconstructions of the past 1500 years suggest that recent warming is unprecedented in that time. Here we provide a broader perspective by reconstructing regional and global temperature anomalies for the past 11,300 years from 73 globally distributed records. Early Holocene (10,000 to 5000 years ago) warmth is followed by ~0.7°C cooling through the middle to late Holocene (<...

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