Iona-1 Core_Continuous thin section high resolution images

Ma et al. (2022) presented an exceptionally well-preserved, millimeter-scale laminated marlstone from a succession of precession-driven limestone-marlstone couplets deposited in the Western Interior Seaway (North America) immediately preceding and during the Cretaceous mid-Cenomanian event (ca. 96.5 Ma). Astronomic analyses of a grayscale scan through a marlstone-limestone couplet reveal variations with 80–100 yr, 200–230 yr, 350–500 yr, ∼1650 yr, and 4843 yr periodicities. The grayscale data were measured at 230 μm resolution (Δt = ∼23 yr) from a continuous thin section comprising twelve segments. This dataset comprises the high resolution digital scans (jpeg2000 format) of these thin sections from which the grayscale and microfossil count data were derived. Included is the sedimentological interpretation and schematic ordering of the thin sections to form the composite (continuous) thin section (see Iona-1_continuous thin section description.pdf).