The new sea - level record was then used in combination with existing deep - sea oxygen isotope records from the open ocean, to work out deep - sea temperature changes. (sciencedaily.com)
Using long drill cores and uplifted sections of sea - floor sediments, previous work had analysed such microfossil - based oxygen isotope records from carefully dated sequences. (sciencedaily.com)
Evidence for approximately contemporaneous global cooling in sediments that do contain YTT glass shards has been found in marine core oxygen isotope records from the South China Sea (3), as have terrestrial carbon isotope and pollen records from Northern India and Bengal (23). (pnas.org)