Cretaceous planktonic foraminifera and calpionellids from the Gulf of Mexico@en

Drilling on Leg 77 resulted in eight single-bit holes at five sites extending across the Yucatan Channel in the southeastern Gulf of Mexico. Sites 535, 539 (aborted hole of 7.5 m depth), and 540 were grouped as basin sites, whereas location on up-faulted blocks at Sites 536, 537, and 538 led to their grouping as basement sites. […]本次第77钻探航次（Leg 77）的钻探作业在横跨墨西哥湾东南部尤卡坦海峡的五个站位中共完成8个单钻头钻孔。其中站位535、539（7.5米深中途报废钻孔）与540被划归为盆地站位；而站位536、537、538位于抬升断块之上，因此被归为基底站位。[…]