One-Centimeter Stratigraphy in Foraminiferal Ooze: Theory and Practice.
SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA
Pagination or Media Count:
The bug-bear of high-resolution stratigraphy in the deep sea is sediment mixing by animals at the sea floor. Here we address several theoretical and practical problems in removing the effects of mixing. The objective of 1-cm stratigraphy is to recover a record of earth and ocean history more detailed than that known today. The research reported here concentrates on foraminiferal ooze, in which 1-cm of accumulation usually corresponds to an interval of less than 1000 yrs. In a later chapter, we try to construct a 1-cm stratigraphy of box cores of ooze from Ontong-Java Plateau. The theory we use to reconstruct events recorded at 1-cm intervals has, in part, already been developed. It is based on Goldberg and Koides model of a discrete sediment mixed layer. This report develops a number of useful formulas to account for the effects of dissolution, winnowing, fragmentation and horizontal sediment influx. The problem of finite mixing rates is also accommodated by a simplification of some results from Guinasso and Schink. Dating the reconstructed record with C14 is a matter of knowing contemporaneous mixed layer ages. In this light, this report describes a number of properties of mixed layer ages and the C14 record in general.
- Physical and Dynamic Oceanography
- Geology, Geochemistry and Mineralogy