Late quaternary periplatform sediments and paleoenvironmental analysis of Pedro Channel, northeastern Nicaragua rise, Caribbean Sea
Schwartz, James P.
Master of Arts
Using four periplatform sediment cores of intermediate water depth (900 to 1400 m) from the western Caribbean Sea, an investigation was conducted to ascertain the difference in cyclicity between the late-Brunhes Mode and the mid-Brunhes Mode. The past 185 ky define the late-Brunhes Mode, which records extreme changes between glacial and interglacial conditions, and consistent behavior within isotopic stages. Defined as 525 to 185 ky for the purposes of this study, the mid-Brunhes Mode represents a time of mild changes between and within glacial and interglacial stages, much like an extended late-Brunhes interglacial stage. Changes between the two modes were monitored using proxies for dissolution, AAIW influx (influence of the Southern Ocean on intermediate Caribbean waters), nutrients, migration of the North Atlantic Gyre, sea level and strength of the Caribbean Current.