Lidar collects high-resolution spatial data, making it a popular tool for outcrop investigations; however, few of these studies utilize lidar's spectral capability. Lidar scanners commonly collect intensity returns (power returned/power emitted) that are influenced primarily by distance and target reflectivity, with lesser influence from angle of incidence, roughness, and environmental conditions. Application of distance normalization results in values that approximate target reflectivity. At the near-infrared wavelength of lidar, quartz-rich sandstones are more reflective than clay-rich mudstones. Scans of unweathered core and weathered outcrop were collected to investigate the relationship between lithology and lidar intensity. In unweathered, laboratory samples, intensity shows an inverse relationship to wt. % clay and are positively correlated to wt. % combined quartz, plagioclase, and K-feldspar. A similar relationship was also observed in scans of lightly weathered outcrop, although weathering and moisture diminished intensity contrast between sand-rich and shale-rich intervals. Thus, lidar intensity is a possible remote sensor of lithology, particularly in remotely located and inaccessible outcrops.

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The Campanian Loyd Sandstone Member of the Mancos Shale (Loyd) along the Rangely Anticline, Piceance Basin, Colorado, contains a series of multi-meter-thick, heterolithic, coarsening-upward successions (CUSs) with internal clinoforms comprising low-angle-dipping (< 5°), parallel-laminated sandstone beds interbedded with bioturbated flaser-wavy-lenticular bedded sandstone and siltstone. Loyd clinoforms are delta foresets composed of prodelta and delta-front deposits, including mouthbars. Many CUSs exhibit scours filled with bioturbated sandstone, or interbedded bioturbated sandstone and siltstone or mudstone representing aggradational fill of subaqueous terminal distributary channels or the migration of mouthbars into channel scours. Mud drapes on sedimentary structures and mud rip-up clasts are extremely common. A high-abundance, high-diversity, trace-fossil assemblage includes vertical, 1–4-m-deep Ophiomorpha that may penetrate multiple bedsets of parallel-laminated sandstones and highly bioturbated finer-grained interbeds. Bioturbation increases sandstone content in finer-grained interbeds, and provides sandy conduits that increase connectivity between beds. Although parallel-laminated sandstones volumetrically dominate Loyd delta clinoforms, they likely represent relatively short-term freshwater and sediment input during river flooding that produced delta-front turbidity currents. Interbedded finer-grained beds, mud-draped sedimentary structures, and the high-abundance, high-diversity trace-fossil assemblages record longer amounts of time during reduced fluvial discharge, tidal reworking of sediments, and intense bioturbation under marine salinities. Controls on the internal characteristics of the Loyd delta deposits include: 1) a high sediment influx into a relatively shallow marine basin protected from wave action during normal regression; 2) relatively short-duration, episodic freshwater and sediment discharge from distributaries that reduced salinities, deposited sand as turbidity currents, and promoted delta-front channelization; and 3) longer-duration periods of reduced discharge with deposition of finer-grained sediment, tidal reworking, and bioturbation of sediments under higher salinities. These controls combined to produce the heterolithic, highly bioturbated, river-flood delivered, and tidally modified clinoforms of the Loyd that differ from deposits typically considered to be classic examples of fluvial-flood-dominated or extensively tidally modified deltas.

The effect of the vertical to horizontal permeability ratio ( k v  / k h ) on many displacement properties is significant, making it an important parameter to estimate for reservoir models. Simple ‘streamline’ models have been developed which relate k v  / k h at the reservoir scale to shale geometry, fraction and vertical frequency. A limitation of these models, especially for tidally-influenced reservoirs, is the lack of quantitisative geological inputs. To address this lack of data, detailed shale characteristics were measured, using Lidar point clouds, from four different tidally-influenced reservoir analogues: estuarine point bar (McMurray Formation, Alberta, Canada), tidal sand ridge (Tocito Sandstone, New Mexico), as well as both unconfined and confined tidal bars (Sego Sandstone, Utah). Estuarine point bars have long ( x̄   = 67.8 m) shales that are thick and frequent relative to the other units. Tidal sand ridges have short shales ( x̄   = 8.6 m dip orientation) that are thin and frequent. Confined tidal bars contain shales that are thin, infrequent and anisotropic (x–  = 16.3 m dip orientation). Unconfined tidal bars contain nearly equidimensional shales of intermediate length ( x̄  = 18.6 m dip orientation) with moderate thicknesses and vertical frequency. The unique shale character of each unit results in a different distribution of estimated k v  / k h values. Estuarine point bars have lower average k v / k h values ( x̄   = 8.2 ×10 −4 ) than any other setting because of the long shales they contain. Tidal sand ridges have short, but frequent shales, which results in moderate k v  / k h estimates ( x̄   = .011). Estimates of k v / k h are typically highest in confined tidal bars ( x̄   = .038), which contain anisotropic and infrequent shales. Unconfined tidal bars have moderate lengths and frequency resulting in k v / k h estimates averaging 0.004. The results of this study highlight the link between heterogeneity, reservoir architecture and flow parameters.