Files in this Data Supplement:

• Supplemental file 1 - Description of statistical methods (UniFrac and correspondence analysis) and supplemental figure legends.
  Zipped MS Word document, 12K.
• Supplemental file 2 - Rarefaction curves for archaeal and bacterial clone libraries derived from discrete sediment horizons of the Santa Barbara basin (Fig. S1), methyl coenzyme M reductase subunit A (mcrA) neighbor-joining distance tree for representative Santa Barbara Basin sequences (Fig. S2), correspondence analysis plot of marine sedimentary bacterial communities (Fig. S3), UniFrac cladograms based on key phylogenetic groups (Fig. S4), abundance of major bacterial phylogenetic groups in marine sediments (Table S1), and results of correspondence analysis on the abundance of major bacterial phylogenetic groups (Table S2).
  Zipped PDF file, 218K.
• Supplemental file 3 - Table listing the abundance of each 16S rRNA phylotype at the respective depth in the Santa Barbara Basin sediment.
  Zipped MS Excel file, 9K.