They would leave subtle clues in the isotopic composition of the limestone by shifting the ratios of light to heavy carbon and oxygen atoms in its calcium carbonate.
因为如果是那样的话，阳光将会被转换成大量的碳、氧原子保存到石灰岩中的碳酸钙里，而事实却是，岩层的同位素组成（Isotopic composition）中没有留下任何蛛丝马迹。
The trick they used to do this was to look at the isotopic composition of the oxygen in the wood of local trees.
他们所使用的办法是观测当地树木的木材中的氧同位素组成（isotopic composition）。
Now, by examining the isotopic composition of that water, researchers have found that it matches that of meteorites, the likes of which also delivered Earth its first drink.
现在，通过检查水的同位素构成，研究人员发现这与第一次给地球带来水的陨石相吻合。
应用推荐