INTERHOLE CORRELATIONS AT SITE 893, SANTA BARBARA BASIN: CONSTRUCTION OF A 16,000-YEAR COMPOSITE RECORD USING MAGNETIC SUSCEPTIBILITY AND DIGITAL COLOR IMAGING DATA

Frank R. Rack and Russell B. Merrill

ABSTRACT

Two independent sets of nearly continuous core measurements, comprising magnetic susceptibility and digital color data, were used to develop correlations between Holes 893A and 893B, located in the central Santa Barbara Basin. These data sets provide spatial (temporal) resolutions on the order of ~5 cm (~35 yr) for magnetic susceptibility measurements, and ~1 to 2 cm (<7–14 yr) for digital color measurements averaged over 12 points.

These two data sets contain information about changing paleoenvironments and/or climatic signals at temporal scales approaching those provided by studies of ice cores, lake records, or coral growth for the past 16 ka (kilo-annum, or 1000 yr before present). This potential makes it especially important that the age-depth relationship for these proposed proxy records is thoroughly investigated; especially considering the large amount of gas expansion encountered in the cores recovered from Site 893 (see gas-related void table in Merrill and Beck, this volume).

This manuscript first explores the continuity of the magnetic susceptibility and digital color data from Holes 893A and 893B by matching individual features observed in the records from each hole. Following this, we use the magnetic susceptibility data from the upper portion of these two holes to develop a spliced record for equivalent time intervals in each hole, from the sediment surface (approximating the present day) to approximately 16 ka, just after the Last Glacial Maximum.

Date of initial receipt: 26 August 1994
Date of acceptance: 23 March 1995


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