ABSTRACT A 3 ton (2.7 metric tonnes [t]), granitoid lonestone with Appalachian provenance was found in situ in offshore Devonian black shale in northeastern Kentucky, United States, and is denoted herein as the Robinson boulder, or lonestone, after its discoverer, Michael J. Robinson. This large boulder appears to have been displaced nearly 500 km from its source on the opposite margin of the Acadian/Neoacadian Appalachian foreland basin. While previous identifications of possible lonestones have been attributed to Pleistocene glacial events, scrutiny of this lonestone’s origin suggests that the boulder, which was embedded in the Upper Devonian Cleveland Shale Member of the Ohio Shale in northeastern Kentucky, is most likely a Devonian ice-rafted glacial dropstone. Notably, palynologic correlation with reported glacial diamictites elsewhere in the basin indicates such a source. Together, the dropstone and diamictites, separated by ~500 km, provide evidence for alpine glaciation in the ancient Acadian/Neoacadian orogen and for tidewater glaciers in the adjacent, eastern margin of the foreland basin. The latest Devonian marine transgression and Neoacadian foreland subsidence are interpreted to have been associated with tidewater glacial connections to the open sea. Importantly, the existence of this dropstone and its likely glacial precursor events require new considerations about contemporary black-shale sedimentation and the influence of tectonics on the delivery of glacial sediments to foreland basins.

Abstract The Virgelle Member of the Milk River Formation, Alberta, Canada represents a sandy progradational depositional systems tract that contains linkages between offshore, estuarine, and coastal plain environments. Distinct upward-shoaling depositional successions include regional erosion surfaces that punctuate transitions from storm- and fair-weather-dominated deposition to tidal sand bars and estuarine channel complexes that developed as the systems tract prograded basinward. The lower part of the Virgelle Member is characterized by hummocky and swaley cross-bedded sandstones depicting the transition from offshore to storm-dominated middle shoreface. A sharp, regionally flat erosion surface separates middle shoreface deposits below from two end-member upper shoreface/foreshore lithofacies associations above: (1) rare fair weather wave-reworked deposits or, (2) common tidally reworked deposits represented by outer estuarine tidal bars. The upper shoreface unconformity is thus dominantly a tide-cut source diastem (TSD), overlain by bathymetrically equivalent subtidal to intertidal sand bars typified by planar-bound, herringbone, cross-bedded sandstone. The erosive base of extensive, laterally accreted estuarine channels (ECh) cuts into middle shoreface deposits and truncates the flat disconformity and the above-mentioned shoreface and esmarine successions. Tidal influence within the channels is recorded by carbonaceous bundles and couplets, reactivation surfaces, and subordinate, flood-directed, three-dimensional dunes. In addition, a restricted ichnofauna documents the influence of an estuarine environment. The resulting depositional model depicts a west-northwest/east-southeast trending estuarine system, open to the east, that truncates the storm-dominated middle shoreface, and is itself cut by a belt of meandering estuarine channels merged into overlying supralidal coastal plain mudstones. The genera] distribution of palynomorphs is consistent with the progression of marine dinoflagellate-rich assemblages in outer estuarine tidal bars to mostly terrestrial assemblages in ebb-dominated estuarine channels. A qualitative analysis of depositional regime variables Q, M, D and R within the supply-dominated depositional systems tract of the Virgelle Member highlights the critical importance of the sediment dispersal function D, in this case controlled by tides and storms. The corresponding relationship may be expressed as Q M ≥ D R. The proposed model for a progradational estuary contrasts with sequence stratigraphic models of transgressive estuaries because it is not restricted to specific relative sea-level stages, and because it arises from the linkage of depositional processes along the entire systems tract, from offshore to coastal plain.

Abstract: The Lower Carboniferous Mount Head, Livingstone and Turner Valley Formations of southwest Canada accumulated on a westward- deepening carbonate ramp on the western margin of Pangea. The ramp developed near the equator in the Mount Head Embayment: a broad, basement-controlled, regional downwarp and oceanic bight. The ramp is divided into inner, middle and outer zones based on gross lithology and degree of winnowing. The inner ramp comprises muddy carbonates that accumulated predominantly in calm-water in shallow-subtidal sellings and subaerially on sabkhas. The middle ramp is characterized by grainy carbonates deposited in shoals and current-swept banks under turbulent-water and wave-agitated conditions. The outer ramp consists of muddy carbonates that accumulated predominantly as tempestites and periplatform ooze in open-marine and slope settings. Evolution of the ramp is constrained by multiple-group biostratigraphy and sequence stratigraphy and is shown on eight chronostratigraphic slice maps of approximately 1.5 Ma duration each. Jn addition, the ramp is characterized by three distinct biotic associations, chloroforam, bryoderm- extended and bryoderm. These are similar to Upper Carboniferous-Portnian biotic associations interpreted by others to be indicators of depositional temperature; namely, warm-water for the first association, cool-water for the second and cold-water for the third. Deposits of the warm-water chloroforam association in Mount Head Embayment are represented by ooid grainstone shoals, shallow-subtidal limestones and peritidal sabkha dolo- stones with anhydrite. In contrast, cool-waters are represented by shallow-subtidal dolo-mudstones that have a bryoderm-extended biotic association. Cold-waters are represented by reworked pelmatozoan-grainstone banks that have a bryoderm biotic association. Mixed warm- and cool-water indicators occur in deeper-water winnowed grainy carbonates, open-marine wackestones and slope mudstones of the mid and outer ramp. These rocks contain faunal elements of the cool-water bryoderm-extended association along with ooids and dasycladacean algae of the chloroforam association. Ooids and dasyclads are transported, occur with tempestites and represent redistribution of materials from higher on the ramp. The ooids and dasyclads do not reflect conditions at the site of accumulation. Additional evidence for cold-water sedimentation is provided by syndepositional pseudomorphs after ikaite. These are common in deep, outer-ramp rocks and rare in irwer-ramp, shallow-subtidal dolostones. Ikaite is a known carbonate paleothermometer that is thermodynamically constrained to temperatures less than 7°C. Biotic association/temperature maps indicate that during lowstand systems tracts, cool- and cold-water masses blanketed most of the ramp and occurred in well-defined belts. Warm-water masses were rare. In contrast, during transgressive systems tracts, the pattern is more complex, with a mosaic of warm, warm and cool, cool and cold waters occurring over the ramp. The presence of both cold- and warm-water masses is probably the result of upwelling cold waters and solar heating of shallow, nearshore and offshore water. Upwelling would be driven by trade winds or by offshore oceanic current systems. Differences between lowstand and transgressive systems tracts may be the result of more efficient redistribution of ramp waters during lowstands. At these times, trade winds forcing surficial waters offshore over a much-narrowed ramp would more effectively maintain upwelling. Alternatively, on a narrower ramp, offshore oceanic currents may accelerate during lowstands and therefore intensify upwelling conditions. Lastly, palinspastic restorations indicate that the middle-ramp grainy carbonate bell was extremely broad. The width of this belt may have been the result of swell- and storm-wave sweeping beginning in deep, offshore waters and extending progressively shoreward into shallow’ water, as occurs along the present day coast of south Australia.

Abstract Upper Mannville G, U and W pools in the Little Bow field are hosted by separate parallel elongate estuarine sandstone bodies within an incised valley fill Each sandstone body is 3-4 km long, 300-500 m wide, up to 22 m thick, with an average porosity of 22%. Values of horizontal and (vertical) permeability vary widely and average 1324 (125) md in G pool, 2005 (472) md in U pool, and 258 (73) md in W pool. G pool was discovered in 1972 and placed on primary production. Oil production declined gradually and was accompanied by modestly increasing GOR and WOR. U and W pools were discovered in 1982 and 1983 respectively, and produced by primary methods until initiation of waterflooding in 1985. Response to waterflooding these two pools has been a rise, then decline, in the GOR, followed by rapidly rising WOR, to values much greater than those predicted from reservoir modelling, currently up to 10:1 in wells adjacent to water injectors. Despite the wide variation in permeability values and the different production histories, similar proportions of oil have been produced: 9.2% OOIP in G Pool; 10.5% in U Pool; and 9.3% in W Pool. Production response indicates controls by mesoscale and microscale reservoir heterogeneities. Mesoscale heterogeneities include permeable sandstone beds several meters thick that are continuous between adjacent wells, and stochastic shale beds up to 80 cm thick. Rapid breakth of water has occurred in producing wells adjacent to injectors due to channeling in thick permeable sandstone beds between