| 1. | The youngest rocks found on the moon are 3 billion years old .
在月球上发现的地质年代最晚的岩石已有30亿年历史了。 |
| 2. | This part of geologic calendar has not been satisfactorily subdivided .
这部分地质年代表还没有令人满意地再细分出来。 |
| 3. | Cambrian the earliest period of the paleozoic era , about 590 - 510 million years ago
寒武纪:地质年代古生代的第一个纪，在五亿九千万到五亿一千万前。 |
| 4. | Cretaceous the most recent period of the mesozoic era , 145 - 66 million years ago
白垩纪：地质年代中生代的最后一个纪，距今一亿四千五百万年至六千六百万年前。 |
| 5. | Geological dates are usually obtained by using the rates of decay of various radioactive elements found in minerals
人们通常用矿物中所发现的各种放射性元素的衰变率来计算地质年代。 |
| 6. | As geological time is reckoned , man has so far existed only for a very short period one million years at the most
按照地质年代来计算，人类到目前为止只存在了一个极短的时期? ?最多100万年。 |
| 7. | It was very long time the for loess forming , and it faced many changing , so , its behaviors are unstable
黄土是在漫长的地质年代里形成，经历着各种变化中的过程，因此，其性质具有很大的变异性。 |
| 8. | A large number of studies of geochronology and geochemistry indicate that mesozoic intermediate - felsic rocks from the dabie orogen have originated from recycling of the subducted yangtze continental crust itself
摘要大量的同位素地质年代学和地球化学研究表明，大别山中生代中酸性岩为俯冲扬子陆壳再循环的产物。 |
| 9. | 3 . re - os isotope chronology study suggesting the forming of jinchuan nickel - copper deposit which is magmatic dominanted and multi - mineralization attributed may lasting a long period of time
Re ? os同位素地质年代学研究表明，以岩浆成矿作用为主但有多种成矿作用贡献的金川镍矿床的形成可能经历了长时期的演化过程。 |
| 10. | 2 . it is discovered by research on the ore deposit , ore bodies and ores that the zhulazaga deposit is formed in two stages with quite different geological structure environment and large geological time gap
2 、通过对矿床、矿体、矿石的研究，发现朱拉扎嘎金矿是在地质构造环境差别较大，地质年代相距甚远的两个阶段形成的。 |
