查询词典 ma

Based on plentiful isotopic dating data and geological studies, the authors, in this paper, discuss the geological meanings of the two isotopic ages given by Lapierre et al., and conclude:① Mesozoic volcanic activities in Zhejiang are most frequent in 130～83 Ma, that is, from the early to late Cretaceous but not the late Jurassic;② The Jiande and Moshishan groups are nearly in the same period and not in an upper—lower stratigraphic relationship with each other;③ The period of 110～100 Ma is a transitional stage from the early high-K calc-alkaline dacite—rhyolite associated with diorite—granodiorite） to the late basalt—rhyolite（associated with K-feldspar granite—alkali granite）.

本文就Lapierre等文中124 Ma和97 Ma两个年龄的地质意义、幕次划分以及浙西与浙东火山岩时代对比作出评论，并厘定浙江中生代火山岩时代归属，提出：①浙江中生代火山活动时代为132～83 Ma；②浙西建德群与浙东磨石山群火山岩并不存在上下关系，地质接触关系、古生物组合和大量同位素定年数据都不支持Lapierre等的浙西与浙东火山活动幕次的对比方案；③ 110～100 Ma为早期高钾钙碱性英安岩—流纹岩（伴生闪长岩—花岗闪长岩）向晚期玄武岩—流纹岩（伴生钾长花岗岩—碱性花岗岩）过渡的转折期。

The average Re-Os model ages determined by ICP-MS and NTIMS are (138.3±4.0) Ma and (141.0±3.6) Ma (2σ, n=9), the isochrone ages calculated with the ISOPLOT using the Model 1 are (138.6±2.9) Ma (2σ, n=9) and (141.6±1.9) Ma (2σ, n=9) respectively.

结果表明，该组样品的平均Re-Os模式年龄分别为(138.3±4.0)Ma和(141.0±3.6)Ma(2σ，n=9)和(141.6±1.9)Ma(2σ，n=9)，两者在目前水平下的误差范围内基本一致。

Tiaojishan Formation in Western Hills of Beijing was dated at Late Jurassic based on the Ar-Ar ages for tachyandesites (all plateau ages and isochrone ages of plagioclase are respectively 148.91±2.98 Ma and 146.60±2.93 Ma).

对北京西山髫髻山组粗安岩斜长石Ar-Ar年龄测定获得全坪年龄和等时线年龄分别为148.91 Ma±2.98 Ma和146.60 Ma±2.93 Ma(相关系数r=0.9997)，本文将其时代划为晚侏罗世。

Base on above studies, some conclusions were obtained as follows:(1) ore-forming background of the studied ferromanganese crusts are mainly controlled by intensity of Antarctic Bottom Waters and variations of material source;(2) it is confirmed that the ferromanganese crusts are mainly hydrogenetic and their composition are affected by volcanic and continental material simultaneously; there are no obvious phosphatization reconstruction and element reaction occurred in them, so they have important paleoceanological significance;(3) from researches on element occurrence modes in the new-type ferromanganese crusts and the lying sediments, it is proposed that there is no great biological affection on the crusts formation and their composition mainly came from the adsorptive action of the ferromanganese oxides in them;(4) two major types of ore-controlling factors are identified through compilation of ore-controlling factors, which are geological and oceanic factors;(5) considering the long-term variation trends of the crusts composition, combing the U-series and 10Be isotope dating results, it is proposed that the ore-forming processes of ferromanganese crusts in the studied areas can be divided into three major stages (5.6~2.8 Ma, 2.8~2.7 Ma and since 2.7 Ma), and then the activities of AABW since the Late Miocene, changes of input flux coming from volcanic and continental material are confirmed.

通过研究，得出如下结论：(1)研究区铁锰结壳的成矿背景主要受控于南极底流强弱及物源供给的变化；(2)证实铁锰结壳主要为水成成因，同时其物质组成也受一定程度的火山和陆源物质的影响；结壳自形成以来没有遭受到明显的磷酸盐化等成岩后期改造和元素再迁移，具有重要的古海洋学意义；(3)通过新型铁锰结壳及下伏沉积物元素赋存状态的研究，认为生物作用对研究区结壳的形成并没有很大的直接影响，其物质成分主要来自于结壳中铁锰氧化物的吸附作用；(4)在控矿要素的研究中，归纳出了地质与海洋两大类结壳控矿要素；(5)根据结壳成分长周期变化趋势，结合铀系和10Be测年结果，将研究区结壳的形成过程划分为三个主要阶段(5.6~2.8 Ma，2.8~2.7 Ma和2.7 Ma以来)，并确定了晚中新世以来研究区南极底流的活动情况、火山和大陆来源物质输入量的变化。

40Ar/39Ar dating of detrital white mica from Cenozoic sediments from the Qaidam Basin in western China yielded several age groups, including: 1 350～450 Ma, 2 220～280 Ma, 3 122～140 Ma, and 4 ~500 Ma.

摘 要：对柴达木盆地新生代沉积物的碎屑白云母40Ar/39Ar年龄测试获得4组年龄峰值：1） 350～450 Ma； 2 220～280 Ma； 3 122～140 Ma； 4 ~500 Ma。

SHRIMP and LA-ICP-MS zircon U-Pb dating yielded some age data: the Longchahe porphyritic granite is (81.2±1.4)~(83.2±1.4) Ma, the porphyritic granite in Malage-Songshujia area is (82.8±1.7) Ma, the porphyritic granite in Laochang area is (83.3±1.6) Ma and the Baishachong equigranular granite is (77.4±2.5) Ma.

文章首次采用LA-ICP-MS和SHRIMP U-Pb方法对研究区内的花岗岩进行了精确定年，数据表明，不同类型的花岗岩同时或近于同时形成。龙岔河似斑状花岗岩主要形成于(82.0±0.3)~(83.2±1.4)Ma，马拉格－松树脚似斑状花岗岩形成于(82.8±1.7)Ma，老厂似斑状花岗岩形成于(83.3±1.6)Ma，白沙冲等粒花岗岩形成于(77.4±2.5)Ma，均集中形成于晚白垩世。

The original Seluohe Group contains at least four parts: Late Archean metamorphic rocks (zircon SHRIMP protolith ages 2517~2534 Ma), Late Paleozoic metamorphosed volcanic-sedimentary strata (zircon SHRIMP 252 Ma), Permian gneissic granitic complex (zircon SHRIMP 260 Ma), and Jurassic mylonitized granites (zircon SHRIMP 168 Ma).

原划分的色洛河群至少由4部分组成：新太古代变质火山－沉积地层（锆石SHRIMP年龄为2517~2534 Ma）、晚古生代变质火山－沉积地层（英安岩锆石SHRIMP年龄为252 Ma）、二叠纪片麻状杂岩体（锆石SHRIMP年龄为260 Ma）和侏罗纪糜棱岩化花岗岩（锆石SHRIMP年龄为168 Ma）。

The results showed that the blending system could form surface gel and internal spumescent char layer to achieve flame retardant properties.The flame retardant properties of flame resistant PA6 contenting TPMP/MA complex system were studied by LOI,UL-94 and cone calorimeter tests.The results showed that the LOI value of PA6/17%MA system was 27.2,and the LOI value of PA6/4%TPMP/13%MA system was 28.6.The UL-94 test was V-0 level.The flame retardant mechanism analysis indicated that the TPMP/MA complex system could form thick intumescent char layer to execute the flame retardant functions both in the condensation phase and the gas phase.

将阻燃剂TPMP、MA复配后添加到PA6中，通过采用LOI、垂直燃烧及锥型量热仪研究了体系的阻燃性能，PA6/17%MA体系的LOI值为27.2，PA6/4%TPMP/13%MA体系的LOI值达到了28.6；上述体系的垂直燃烧性均为V-0级，对阻燃机理的分析表明，TPMP与MA复配应用时，可形成膨胀的较厚炭层，在气相和凝固相共同发挥阻燃作用。

From about 206 Ma there occurred arc-continent collision accompanied by compressional contraction and shearing deformation of the arc crust and development of syn-collision granites. In the late Yanshanian epoch (138-73 Ma) post-orogenic extension came into action and resulted in the generation of A-type granites. During the Himalayan (65-15 Ma) intra-continental orogenic movement a large-scale strike-slip thrusting induced the intrusion of granites and development of pull-apart basins.

据此，再造了造山带的形成过程与演化历史：印支期的大规模俯冲造山作用(238～210 Ma)，形成义敦火山岩浆弧；大约自206 Ma始，发生弧-陆碰撞，伴随岛弧地壳挤压收缩和剪切变形，发育同碰撞花岗岩；进入燕山晚期(138～73 Ma)，岛弧碰撞造山带发生造山后伸展作用，形成A型花岗岩带；喜马拉雅期发生陆内造山作用(65～15 Ma)，岛弧碰撞造山带出现逆冲-推覆和大规模走滑平移，伴随喜马拉雅期花岗岩的侵位和拉分盆地的形成。

The ore-forming ages of the epithermal gold deposits in northern Xinjiang are in the range of 340~244 Ma, corresponding to the large-scale volcanic-subvolcanic activities at (350±10) Ma,(300±10) Ma and (250±10) Ma.

金矿成矿时代在340~244 Ma之间，金矿在时间和空间上与新疆古生代在(350±10) Ma、(300±10) Ma和(250±10) Ma 3个阶段的大规模火山－潜火山活动有密切关系。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。