Located at different positions with respect to the Congo Canyon and Congo Fan, Sites 1075, 1076, and 1077 are distributed at varying distances from the shelf break. The shipboard biostratigraphic analyses (Fig. 1) suggest an overall decreasing sedimentation rate (i.e., reduced contribution of terrigenous input) with distance from shore. Average sedimentation rates range from 10 cm/k.y. for the deeper Site 1075 (water depth: 2995 m) to 15 cm/k.y. for the shallower Site 1076 (water depth: 1404 m). Sediments sampled at the intermediate Site 1077 accumulated at an average rate of 12 cm/k.y. Consequently, Site 1075 penetrated the upper Pliocene sediments, whereas Sites 1077 and 1076 did not reach sediments older than 1.7 and 1.3 Ma, respectively. The bottom age of Site 1077 is estimated from magnetostratigraphic data. Based on evidence for coring-induced magnetization below 148 mbsf (see "Paleomagnetism" section, "Site 1077" chapter, this volume), this bottom age is tentative and should be reviewed after detailed shore-based paleomagnetic measurements.
Common to the three LCB sites is the low abundance and poor preservation of calcareous microfossils in sediments older than ~0.7 Ma. The shallow Site 1076 shows evidence of common reworked shelf material. This, together with the overall poor preservation of calcareous nannofossils, might explain the disagreement between the magnetic- and microfossil-derived stratigraphy between 0.7 and 1 Ma (see "Biostratigraphy and Sedimentation Rates" section, "Site 1076" chapter, this volume).