Sediments from the anoxic center (ca. 590m water depth; 34¡14'N;120¡01'W) of the Santa 
Barbara Basin were collected in February, 1988 during a sampling cruise (SABA 88-1) aboard 
the Scripps Institution of Oceanography vessel the R.V. Sproul . Continuous sediment sequences 
from multiple stations within the basin were collected over several 
days. The sediments were retrieved using a Soutar-style box corer (Soutar & Crill, 1977). Upon 
retrieval, the sediment surface was examined for disturbance and only those cores which showed 
no apparent disruption of the surface layer were considered and examined. 
	Subsampling of the box core with limited disturbance of the laminae was achieved using 
an acrylic core liner (8.3 cm i.d.) beveled on one end for clean penetration. Application of a 
carefully controlled vacuum on the top of the core liner allows insertion while maintaining a 
comparable level for the sediment water interface both inside and outside of the core liner, and 
thereby avoids disruption of the laminae (Schimmelmann et al., 1990). Three cores were 
collected in this manner for this study. Two (10a,10b) were subsampled from within the same 
box core, a few centimeters apart, and the third (9) was taken from an immediately adjacent box 
core recovered at the same station site. Cores 9 and 10b were capped, labeled and transferred to 
refrigerated storage aboard ship, and were held in cold storage in the core repository at SIO until 
subsampling in March, 1990. Subsampling of core 10a was started while aboard ship and 
completed at SIO.
	The procedures utilized for fine-scale subsampling of cylindrical cores were developed at 
SIO and are fully described by Schimmelmann et al (1990). In their technique, the core liner is 
mounted onto a plunger with a diameter approximately equal to that of the core liner. The acrylic 
tube and plunger are firmly affixed to a countertop in an upright position via a wall bracket. The 
plunger is forced upward a known distance (3.19mm) by each rotation of a worm gear. The 
sediment in the core liner is forced upward until the core surface is even with the lip of the core 
liner, establishing a baseline or zero position. The color of the surface layer is described using a 
Munsell soil color chart (5Y), and other unusual features are noted such as the presence of wood 
or shell fragments, small gastropods or foraminifera (Appendix A.1). The uniformly colored 
layer is removed to a clean, weighed, plastic sample bag by careful scraping with a stainless steel 
spatula until underlying sediment of a differing color can be seen. The plunger is then driven 
upward an appropriate number of rotations to bring the new surface layer level with the lip of the 
core liner, back to the zero position. The number of rotations enables calculation of the 
subsurface depth of all individually described laminae. 
	Somewhat contrary to their general description as a sequence of alternating light and dark 
layers, the SBB cores are not bimodal in their color distribution. Individual layers range from 
black to various shades of gray, green-gray, olive green, and yellow (Appendix A.1). Such layers 
may range in thickness from 1-2 millimeters (generally very black or yellow sediments) to 
several millimeters (frequently gray to olive green layers). Where possible, the carefully 
removed subsamples constituted individual layers of a uniform color. However, due to the 
significant cohesive strength between the layers, many samples include small portions of 
underlying and/or overlying layers. Those layers of uniform color which extended over several 
millimeters were generally split for ease of subsequent analytical workup. The average sample 
thickness collected was approximately 3mm. 
	Immediately after subsampling, wet sediments were heat-sealed (1 to 2 seconds in a "seal 
a meal"-type sealing device) in the plastic sample bags and then frozen. Sample weights were 
taken as frozen wet weights (Appendix A.2). Cores 10a and 10b were transported frozen to 
Stanford and held in freezer storage until subsequent work-up. Samples from core 9 were freeze-
dried over a period of 3 days at SIO using a freeze drying system designed and built by Dr. Arndt 
Schimmelmann. Dry weights were then taken for calculation of pore fluid content (Appendix 
A.2), aiding correlation to SIO stratigraphic age assignments determined on previously collected 
cores.

Stratigraphic Correlation of Santa Barbara Basin Cores

	Of the three cores collected from the SBB, core 10a consisted of 178 samples, of which 
100 were extracted and analyzed. 100 subsamples were taken from cores 10b and 9, of which 35 
and 30 were analyzed, respectively. All unprocessed, nonfreeze-dried subsamples remain in 
freezer storage. Assignment of stratigraphic ages for all samples in these cores was ultimately to 
be based on comparison with published stratigraphic age assignments (Schimmelmann et al., 
1990; many stratigraphic assignments based on more detailed unpublished results provided by A. 
Schimmelmann), utilizing subsurface depths and the pore fluid content of individual samples in 
core 9. Inherent in the correlation is the assumption that the physical characteristics of 
equivalent, individual layers are spatially consistent over the distances separating the cores, at 
most a few meters for core 9 and a few centimeters for cores 10a and 10b. 
	The subsurface depth assignments recorded for core 10a are not viewed with high 
confidence here, because of inexperience with the sampling technique and also jostling of the 
core during transport from the ship to the SIO lab midway through the subsampling process. 
However, the sampling of cores 9 and 10b, conducted on successive days in March of 1990, are 
viewed with greater confidence. As the pore fluid content was only applicable to core 9, and 
accurate subsurface depths were unavailable for 10a, the equivalency between cores 9, 10a and 
10b needed to be established by alternate criteria.
	The extracts of surface samples from all cores were analyzed for their alkenone 
unsaturation profiles and the profiles compared. The subsurface depths (and therefore the timing) 
of positive excursions seen in the profiles coincided well for cores 10a and 10b, but similar 
excursions in core 9 lagged, appearing approximately 8mm deeper in the core. This lag most 
probably can be attributed to the absence of the uppermost surface in the box core from which 
subcores 10a and 10b were collected, despite the lack of discernible disturbance to the surface of 
the core. Such loss can occur during the initial coring process and may not necessarily be 
visually evident, as the fluff layer which characterizes the surface can be 1-2cm thick. 
Alternative explanations such as nondeposition or local variability in the stratigraphic sequence 
are precluded by the close physical spacing of all cores (within a few meters); a distance over 
which sedimentological and molecular variability is unlikely. Therefore the records for cores 10a 
and 10b were shifted downwards by 8mm to become in phase with that of core 9. To confirm 
that the excursions in core 9 and those in 10a and 10b were equivalent events, the absolute 
distance in sediment depth between several excursions in the upper 5cm was calculated for all 
three cores and their values compared. The coincidence of depth differences between individual 
excursions confirmed that the three cores were all recording the events simultaneously, and that 
the uppermost 8mm of cores 10a and 10b had not been recovered in the coring process. Final 
sediment depths for these cores were therefore adjusted appropriately. 
	The wet (frozen) weights of the individual samples were used to establish absolute 
correspondence between the cores for all depths. The equivalent mass of the 8mm of sediment 
missing from cores 10a and 10b was calculated from the wet weight of the upper 8mm of 
sediment in core 9. The wet weights (minus the weight of the empty sample bag) off all samples 
from each of the cores were successively summed, so that the total wet mass overlying any given 
depth in the sediment column could be found (Appendix A.3). The weight of the missing mass 
was then added to the summed values for cores 10a and 10b. Correspondence between the cores 
was then established on the basis that, because of the mutual proximity of the cores and the 
overall uniformity of sedimentary conditions in the central basin, equivalent layers from among 
the cores would be overlain by equivalent wet masses. Correspondence of accumulated masses, 
therefore, gave equivalence of layers. This technique allowed a depth profile to be established for 
core 10a from measured core 9 depth values. Pore fluid contents and subsurface depths for core 9 
were compared to those of Schimmelmann et al. (1990 and unpublished results), and ages 
adopted accordingly. The depths of individual layers with characteristically high or low pore 
fluid contents were independently compared with the depths of the presumably equivalent SIO 
layers, and were found to be in agreement to within a few millimeters. This confirmed the more 
accurate subsampling technique employed during the later sampling interval. Ages established in 
this manner for layers within core 9 were adopted for the mass-equivalent layers in core 10a.