reef core in a sentence

1. It is estimated through radiocarbon dating of reef cores that the reefs have been living on the continental shelf of Western Canada for 8500 9000 years.
2. On the basis of core sample analysis and seismic studies the following depositional settings have been identified : limestone, talus, normal marine, shallow marine, inner reef lagoon, reef core, relatively deep water, slope, and anhydrite.
3. It's difficult to find reef core in a sentence.