The scientists were able to identify layers in the ice cores that corresponded to the passing years.
(The scientists; were; able to identify layers in the ice cores) (The scientists; to identify; layers; L:in the ice cores) (the ice cores; corresponded; to the passing years)
The scientists The scientists the ice cores
were to identify corresponded
able to identify layers in the ice cores
layers L:in the ice cores
to the passing years