Figure F17. Examples of first derivatives of reflectance spectra in (A) green sediments from a region of strong reductive diagenesis (Section 202-1235-A-20H-5, 100 cm) and (B) brownish sediments overlaying the green sediments (Section 202-1235-A-18H-2, 70 cm). The presence of hematite and goethite is inferred from characteristic first-derivative peaks (Deaton and Balsam, 1991).

Figure F17. Examples of first derivatives of reflectance spectra in (A) green sediments from a region of strong reductive diagenesis (Section 202-1235-A-20H-5, 100 cm) and (B) brownish sediments overlaying the green sediments (Section 202-1235-A-18H-2, 70 cm). The presence of hematite and goethite is inferred from characteristic first-derivative peaks (Deaton and Balsam, 1991).