By contrast, because sedimentation is much less continuous in continental regions, estimating the age of a continental bed from the known ages of beds above and below is more risky.

相比之下，由于沉积作用在大陆地区的连续性要小得多，因此根据已知的上下岩层的年龄来估计一个大陆岩层的年龄风险更大。