“Mohawk Guy” and his Band of Neogene Planktic Foraminifer Friends

Ocean Circulation We have one big ocean, separated into a number of basins One thing can affect another, even if it is in another region

Changes in Ocean Circulation Changes to ocean circulation patterns in the past have changed the temperature of ocean water Surface water, deep ocean circulation and the location of the thermocline may be affected Availability of nutrients may also be affected ……This will result in a change to foram structure and distribution throughout time

JOIDES Resolution ODP Leg 130, Hole 806 B ’ N, ’ E February 18, 1990 – February 22, samples examined (110 planktonic foraminifer species identified)

Events that Changed Circulation

Geologic Time Scale

Distribution of forams in a typical tropical ocean

Important Concepts – Biological/Environmental Changes in a population can be triggered by environmental causes – seasonal changes, dissolved oxygen, pH, temperature, water clarity, salinity or depth As one species becomes extinct, other species may move into that niche and replace it. – EX: hunting wolves to extinction can lead to an explosion in deer populations. climactic changes can cause populations to move into different regions