This project is to conduct paleomagnetic/rock magnetic studies on 504 samples of carbonate deposited by microbes (stromatolites) in the interstices of the macro-coral framework in Postglacial/late-Pleistocene coral-reef sediments from Tahiti on IODP Expedition #310. The aim is to develop a chronostratigraphic/lithostratigraphic framework for the microbial component of the entire Tahiti Coral Reef. This framework will be used to determine the age and growth rate for the reef microbialites and assess the timing of millennial-scale environmental variability in the coral reef for the last ~19,000 years.