Eight sites were drilled during Ocean Drilling Program (ODP) Leg 199 in the eastern equatorial Pacific Ocean from October to December, 2001. The sites were separated into two north–south transects with the northernmost being Site 1215 (26°1.77´N, 147°55.99´W) and the southernmost Site 1219 (7°48.01´N, 142°00.94´W). The goal for Leg 199 was to drill through the relatively thin overlying Neogene sequence to recover Paleogene sediments that were not buried deep enough to be lithified (see Shipboard Scientific Party, 2002).
The general location for the Leg 199 area of study is west and slightly north of a transect of seven sites (Sites 848–854) drilled in Neogene sequences during ODP Leg 138 in 1991. These sites were drilled north and south of the equator along the 110°W meridian and were studied by McCartney et al. (1995). They found silicoflagellates to be both abundant and diverse, including some unusual skeletal morphologies showing remarkable variability, in those sites located within 3° of the equator (Sites 848–851), but both abundance and diversity diminished considerably at Sites 852 (5°N) and 854 (11°N). In Hole 854B (11°13.433´N, 109°35.652´W), silicoflagellates were absent in nearly half of the slides examined.
Preliminary silicoflagellate analysis of Leg 199 sites showed a continued trend of rapidly decreasing productivity away from the equator, with most of the samples studied having few or no silicoflagellates. A hole from the southernmost of the eight sites, Hole 1219A (7°48.019´N, 142°00.940´W), was selected for detailed study (Engel and McCartney, this volume) with an interval of one sample per section and whole microscope slides counted for silicoflagellates. Diversity and abundance were generally low, with most slides being barren of silicoflagellates, although 31 species and subspecies were identified.
This data report presents the preliminary results of a study on silicoflagellates of samples recovered during Leg 199 (see Tables T1, T2, T3, T4), not including Site 1219. No silicoflagellate specimens were found at Sites 1215, 1216, 1217, and 1222. At Site 1221, silicoflagellates were found in only 1 of 24 samples examined. These slides were not entirely barren, as radiolarian fragments were frequently abundant and whole radiolarians and diatoms were sometimes present. Besides the one sample in Hole 1221A, silicoflagellates were only found at three sites (Sites 1218, 1219, and 1220). The best of these was Hole 1219A, which as mentioned above was chosen for detailed study. Silicoflagellates were found in 13 of 46 samples studied from Hole 1218A and in 8 of 34 samples from Holes 1220A and 1220B.
1McCartney, K., Engel, R., Reed, T., and Williamson, R., 2006. Data report: Silicoflagellates and ebridians recovered from Leg 199 Sites 1218, 1220, and 1221, eastern equatorial Pacific. In Wilson, P.A., Lyle, M., and Firth, J.V. (Eds.), Proc. ODP, Sci. Results,199: College Station, TX (Ocean Drilling Program), 1–9. doi:10.2973/odp.proc.sr.199.210.2006
2Micropaleontology Undergraduate Research Laboratory, University of Maine at Presque Isle, Presque Isle ME 04769, USA. Correspondence author: mccartnk@polaris.umpi.maine.edu
Initial receipt: 16 April 2004
Acceptance: 5 January 2006
Web publication: 7 June 2006
Ms 199SR-210