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1.
During 2007–2008 excavations at the Lingjing site near Xuchang, Henan Province, dated back to around 100–80 ka ago, a large quantity of mammalian fossil remains were recovered along with a remarkable cluster of Early Modern Human (EMH) skull fragments in situ. Observably some of those animal bones were probably modified into tools. A use-wear analysis was carried out to examine the functions of modified bone tools. The results suggest that Lingjing bone tools were used for drilling, penetrating, and scraping animal substances, and that some might have been hafted during the use. This study confirms that early existence of intentionally-modified bone tools at human occupations of the early Late Pleistocene in northern China. This discovery suggests making and use of bone tools were inevitably a part of early human behaviors and cultural development, as such of stone tools. 相似文献
2.
小兴安岭泥炭沼泽甸杜种群分株的年龄结构与生长分析 总被引:3,自引:0,他引:3
甸杜(Chamaedaphne calyculata)是常绿小灌木,为无性系植物,主要分布于贫营养泥炭沼泽中.通过对大量样本的观察,应用计数芽鳞痕的方法划分了甸杜分株的年龄结构.在小兴安岭泥炭沼泽生长季中期,沼泽中心与沼泽边缘的甸杜种群分株均由8个龄级组成,呈现稳定型年龄结构.分株平均高度和生物量沼泽中心低于沼泽边缘.不同养分条件是两种生境甸杜种群分株间的年龄结构、生物量和高度生长特征及其生态可塑性等出现差异的主要因素.生境的环境异质性决定了甸杜种群分株的生物量和高度的生态可塑性. 相似文献
3.
Paleoproterozoic reworking of ancient crust in the Cathaysia Block, South China: Evidence from zircon trace elements, U-Pb and Lu-Hf isotopes 总被引:4,自引:0,他引:4
LIU Rui ZHOU HanWen ZHANG Li ZHONG ZengQiu ZENG Wen XIANG Hua JIN Song LU XinQian & LI ChunZhong State Key Laboratory of Geological Processes Mineral Resources Faculty of Earth Sciences China University of Geosciences Wuhan China State Key Laboratory of Continental Dynamics Northwest University Xi’an The th Geological Team of Zhejiang Province Lishui 《科学通报(英文版)》2009,54(9):1543-1554
A combined study of zircon LA-ICP-MS U-Pb dating, trace elements and Hf isotope was carried out for gneissic granite from
the Sanzhishu area in Jingning, SW Zhejiang Province. Nearly all the zircons separated from the granite exhibited oscillatory
zoning and high Th/U ratios (>0.1). The REE profile showed a pronounced positive Ce anomaly, negative Eu anomaly and an enrichment
of HREE, which are typical characteristics of magmatic zircon. Thirteen concordant or nearly concordant analytical data yielded
a weighted mean 207Pb/206Pb age of 1860±13 Ma (MSWD=0.084), representing the formation age of the granite. The magmatic zircons had negative εHf(t)
values of −15.6 to −10.0 and two-stage Hf model ages of 3.1 to 3.4 Ga, indicating that the granites were formed by reworking
of ancient crust. The major- and trace-element data indicate that the gneissic granites are metaluminous high-K calc-alkaline
rocks and exhibit the same geochemical characteristics as aluminous A-type granites, implying the emplacement of the granite
in a post-orogenic extensional tectonic setting. We conclude that the Paleoproterozoic crustal reworking event in the Cathaysia
Block of South China marked the transition from assembly to break-up of the Columbia supercontinent.
Supported by National Natural Science Foundation of China (Grant No. 40873004), Special Funds for National Scientific Research
of Commonweal Industries, the Ministry of Land and Resources of China (Grant No. 2008110015), Opening Foundation of State
Key Laboratory of Continental Dynamics, Northwest University (Grant No. 06LCD12) and the Project of Land and Resources Bureau
of Zhejiang Province (Grant No. 2004005) 相似文献