Table T1 summarizes the stratigraphic and bulk rock characteristics of the 10 samples included in this investigation. Samples were chosen in an attempt to represent all different-age black shale units; unfortunately, no Santonian samples suitable for extraction were available. The samples vary in their CaCO3 contents, reflecting the typical layer-by-layer scale lithologic changes caused by the alternation of calcite-rich laminae and clay-dominated black shale intervals. The TOC contents range from 4.5 to 28 wt% and are >8 wt% for all but one sample. Thus, the selection of samples is skewed toward the TOC-rich black shale facies (cf., Tables T16 in the "Site 1257" chapter and T16 in the "Site 1258" chapter). This bias is also evident from the Rock-Eval parameters, where the hydrogen index (HI) values are all >480 mg HC/g coupled with low (<70 mg CO2/g) oxygen index (OI) values (Table T1) (cf. Tables T17 in the "Site 1257" chapter and T17 in the "Site 1258" chapter). The Rock-Eval results (see van Krevelen-type diagrams in Figs. F15 in the "Site 1257" chapter and F19 in the "Site 1258" chapter) indicate a Type II kerogen typical of algal and microbial primary production (Espitalié et al., 1977; Peters, 1986; Baskin, 1997). For most of the samples, the Tmax value is below or close to 400°C, indicating a low thermal maturity for the organic matter. The exception is Sample 207-1258C-31R-2, 26–27 cm, of Albian age, which has a slightly higher Tmax of 415°C but still falls within the immature range.
A positive correlation between the TOC and extract yields (r2 = 0.88) is evident, although errors in weighing under the shipboard conditions limit confidence in this specific correspondence. The extracts differ in color (Table T1). Bright red and orange colors may indicate the presence of porphyrins and other derivatives of biopigments. Three samples showed weak to strong fluorescence under ultraviolet light, and in extract of Sample 207-1258C-31R-2, 26–27 cm, fluorescence was visible even under normal laboratory lighting.