Concentrations of organic carbon and selected major and trace elements are presented stratigraphically for a 100-m cored section of Cenomanian through Santonian calcareous black shales from the Maracaibo Basin, western Venezuela. Significant geochemical variation within these laminated, organic-rich marls suggests a five-part stratigraphic subdivision for the La Luna Formation in the Alpuf-6 (ALP-6) core recovered by Maraven, South America. Geochemical variation is interpreted to reflect the combined influences of relative sea level change, episodic volcanism, variations in the intensity of upwelling, and subtle geochemical alteration. High concentrations of organic carbon and trace metals in La Luna strata are inferred to result from (1) moderately high accumulation rates of organic matter resulting from pulsed high primary productivity, (2) recurrent episodes of widespread oxygen depletion that enhanced accumulation of both organic carbon and trace metals in localized areas, and (3) reduced terrigenous dilution of marine organic carbon and trace metals caused by high sea level and low rates of bulk sedimentation in pelagic settings.A refined biostratigraphic framework for the ALP-6 core allows calculation of accumulation rates for early-middle Turonian, late Turonian, Coniacian, and Santonian time intervals. Calculated accumulation rates of organic carbon and trace metals are highest during the late Turonian, when bulk sedimentation is highest. Concentrations of organic carbon are highest during the Coniacian, when bulk sedimentation rates are lowest. Calculated organic carbon accumulation rates for the La Luna in ALP-6 range from approximately 100 to 400 mg/cm 3 /k.y., similar to rates estimated for mid-Cretaceous strata from a number of other sites but approximately an order of magnitude lower than rates measured beneath modern upwelling zones. Relative to organic carbon and bulk sediment accumulation rates, the calculated accumulation rates of selected metals in La Luna strata are unusually high when compared with rates of metal accumulation in many modern Davis, C., Pratt, L.