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江西早:一个水稻品种的足迹 被引量:1
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作者 曾雄生 《农业考古》 北大核心 2021年第6期7-33,共27页
江西早,是明清以来外省对原产于江西的一个早稻品种的名称。江西早稻种植由来已久,品种江西早则是稻作农业发展和环境因素相互作用的产物。这个品种秉承了占城稻的主要特征,具有生育期短、成熟早,耐旱,适应性广等多种特征,使其在近千年... 江西早,是明清以来外省对原产于江西的一个早稻品种的名称。江西早稻种植由来已久,品种江西早则是稻作农业发展和环境因素相互作用的产物。这个品种秉承了占城稻的主要特征,具有生育期短、成熟早,耐旱,适应性广等多种特征,使其在近千年的中国水稻种植中大放异彩,它不仅对江西粮食增产发挥了关键性的作用,而且通过移民、引种及推广等多种方式和途径对周边甚至更远省份的水稻生产产生了积极的影响,成为中国稻作史上值得书写的一笔。江西早的引种的范围主要包括安徽、浙江、江苏、湖南、湖北、四川、河南、福建、广东、广西、云南、贵州等省区。江西早所到之处,不仅仅品种本身的输入,同时也包括技术,甚至是农业生产和生活方式的引进。本文关注江西早的出现、特征、分布、传播途径及在各地的影响,并藉由此提出一个"技术综合体"的概念,为考察不同区域间农业交流提供一个视角。 展开更多
关键词 江西早 起源 传播 影响 技术综合体
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Geochemistry, geochronology, and petro-genesis of the early Paleozoic granitic plutons in the central-southern Jiangxi Province,China 被引量:23
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作者 ZHANG Yuan SHU LiangShu CHEN XiangYun 《Science China Earth Sciences》 SCIE EI CAS 2011年第10期1492-1510,共19页
This paper reports the systematic study on petrology, geochemistry, LA ICPMS zircons U-Pb dating, and in situ Hf isotope geology of the four plutons in the central-southern Jiangxi Province, an important part of the S... This paper reports the systematic study on petrology, geochemistry, LA ICPMS zircons U-Pb dating, and in situ Hf isotope geology of the four plutons in the central-southern Jiangxi Province, an important part of the South China Block. In the outcrops, rocks are gradually changed from wall rock (slate or schist) to pluton (gneissic granite); some residual blocks of sandy rock occur in the margin of pluton, and the foliations of residual blocks are parallel to those of both wail rock and gneissic granite. The thin-section observations show that the four plutons contain peraluminous minerals such as muscovite and sillimanite. The flattened and elongated feldspar and quartz grains are often visible in the gneissic granite, parallel to direction of lineation, suggesting that the granitic rock were subjected to a strong ductile sheafing. Geochemically, the A/CNK values from 13 granitic samples are between 1.03 and 1.37 with an average of 1.16, indicating that the granites are of strongly peraluminous plutons. The REE compositions of the 13 samples are similar, showing higher EREE contents, with enrichment in LREEs, depletion in Eu and REE patterns with relative LREE-enrichment and negligible Eu anomalies. They show enrichment in Rb, Th, U and depletion in Ba, Sr, Nb, Ti, belonging to a low Ba-Sr type of granite. Thus, the four bodies should be derived from the same magmatic source. Zircons used as U-Pb dating mostly exhibit euhedral shape and high Th/U values from 0.52 to 1.54 with an average of 1.08, suggesting that most zircons are of magmatic genesis. The zircons from four plutons yielded rather similar 206pb/238U vs. 207Tpb/235U concordia ages: 436.1±5.7 Ma for the Tangwan granite, 440.6±4 Ma for the Jiekou gneissic granite, 435.9±6.2 Ma for the Dongbao gneissic granite, and 441.9±3.1 Ma for the Jinxi K-granite, respectively, corresponding to Silurian Llandovery. Several xenocrysts yielded U-Pb ages around 700 Ma, implying that a breakup event took place during Neoproterozoic in the South China Block. In situ Lu-Hf isotopic analysis shows that all εHf(t) values of zircons are negative and have two-stage Hf model ages (TDM2) from 1.4 to 3.6 Ga, indicating that the Silurian granitic magma came from the re- cycle of Meso-Paleoproterozoic basement and even partly Archean rocks, and had not been effected by mantle magma. Re- searches on regional geology suggest that an intracontinental tectono-magmatic event took place during the early Paleozoic in the study areas, which is characterized by folding and thrusting, leading to crustal shortening and thickening, up to 20 km thickness. The high geothermal temperature from thickening crust and accumulation of producing high-heat radioactive elements gradually softened crustal rocks and caused a partial melting, forming peraluminous granitic magma. Under the post-orogenic extensional and de-pressure condition, these granitic magma rose and was emplaced in the upper crust, leading to development of S-type plutons 展开更多
关键词 granite GEOCHEMISTRY LA ICPMS zircon U-Pb dating Hf isotope early Paleozoic central-southern Jiangxi Province
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