Basic features and genesis of the early - middle cambrian epoch volcanics in the xiangmaoshan district of western part of northern qilian 中寒武世基性火山岩基本特征及其成因
Geochemical constraint on the origin and sources of early - middle cambrain acidic volcanic rocks from baiyin ore deposit 甘肃白银厂矿田早中寒武世酸性火山岩成因及源区特征的地球化学制约
It used to be considered that the loushanguan formation was composed of thick - bedded dolomite , which is very difficult for division 传统上认为湘黔交界处的中寒武统?下奥陶统娄山关组为均一性极强的厚层白云岩,可分性极差。
The middle cambrian early devonian ( 513 - 397ma ) tectonic stage was characterized by a series of tectonic events with different features , which are completely different from the caledonian event that occurred in the appalachian orogen and in scotland 摘要中国大陆早古生代(中寒武世早泥盆世)构造期以发生系列各具特征、分布局限、准同时的构造事件为特征。
Samples for strontium isotopic screened were selected by way of the test of cathodoluminescence , observation of thin sections , and analysis of sr and mn . the mn / sr value of all samples presented in this paper are less than 2 , and the cathodoluminescence is dull , however , the samples from the cambrian underwent diagenetic alteration to a certain degree , and the plotted points of the thickness and 87sr / 86sr value are somewhat discrete . the strontium isotope evolution curve drawn from the data with relatively low 87sr / 86sr value are consistent with other curves based on samples from different areas of the world , supporting the notion of global consistency of strontium isotope composition of marine carbonates 根据锯同位素地层学的基本原理,利用已有的锯同位素演化曲线,笔者确定重庆秀山寒武系剖面寒武系底界、下一中寒武统界线和中一上寒武统界线都应适当下移;另外尝试确定了重庆秀山寒武纪剖面一些关键点的年龄,累积厚度1380m处的年龄为503 ? 509ma ,累积厚度1900m处的年龄约为500ma ,这对秀山寒武系剖面下、中寒武统和中、上寒武统界线的确定具有参考价值。
中: hit; fit exactly肝中寒: cold attacking liver掌中寒: cold palms中寒泻: splenogastric cold diarrhea肺中寒证: cold pulmonary disease肝中寒症: cold invasion of liver夹阴中寒: cryopathy with renal impairment脾中寒证: cold splenic syndrome心中寒证: frigid heart disease中寒武纪: changhsia series中寒武世: middle cambrian山中寒冬短篇小说集: a winter in the hills中含有维护: egt中含有水蒸气的可信证据: a hint of water中含有二烯丙基化三硫: mats中旱生植物: mesoxerophytes中含有独特武靴叶酸: gymnema acid中焊垫内过孔: via on pad中含有保护: egt