In the northwestern circum-Pacific, two main trends in Late Cretaceous temp
eratures can be recognized. (1) In general, a recurrent warming trend is th
ought to have begun in the Turonian-Campanian, reaching temperature maxima
in the early Late Santonian and early Late Campanian, and temperature minim
a in the earliest Santonian and perhaps early Campanian. (2) During the Maa
strichtian, temperatures dropped sharply, with only a slight warming in the
early Late Maastrichtian. The existence of a thermal maximum at the Coniac
ian-Santonian transition has previously been expected, but is not confirmed
by new isotopic results. (C) 1999 Academic Press.