Abstract A new reservoir quality model is proposed for the Late Cretaceous Springar Formation sandstones of the Vøring Basin. Instead of a depth-related compactional control on reservoir quality, distinct high- and low-permeability trends are observed. Fan sequences which sit on the high-permeability trend are characterized by coarse-grained facies with a low matrix clay content. These facies represent the highest energy sandy turbidite facies within the depositional system, and were deposited in channelized or proximal lobe settings. Fan sequences on the low-permeability trend are characterized by their finer grain size and the presence of detrital clay, which has been diagenetically altered to a highly microporous, illitic, pore-filling clay. These fan sequences are interpreted to have been deposited in proximal–distal lobe environments. Original depositional facies determines the sorting, grain size and detrital clay content, and is the fundamental control on reservoir quality, as the illitization of detrital clay is the main mechanism for reductions in permeability. Core-scale depositional facies were linked to seismic-scale fan elements in order to better predict porosity and permeability within each fan system, allowing calibrated risking and ranking of prospects within the Springar Formation play.

Utah offers spectacular geologic features and valuable analog environments and processes for Mars studies. Horizontal strata of the Colorado Plateau are analogous to Mars because the overprint of plate tectonics is minimal, yet the effects of strong ground motion from earthquakes or impacts are preserved in the sedimentary record. The close proximity of analog environments and lack of vegetative cover are advantages for field and remote-sensing studies. Dry, desert climate and modern wind processes of Utah are comparable to Mars and its current surface. Analogs in Utah include eolian, sabkha and saline bodies, glacial, lacustrine, spring, alluvial, fluvial, delta, and outflow channel depositional environments, as well as volcanic landforms and impact craters. Analogous secondary processes producing modification features include: diagenetic concretions, weathering and soils, sinkholes, sapping, knobs and pinnacles, crusts and varnish, and patterned grounds. Utah's physical and chemical environments are analogous to conditions on Mars where water existed and could support microorganisms. The development of Mars includes: ancient and modern depositional records, burial and diagenesis, uplift and tectonic alteration, and modern sculpting or weathering of the surface exposures. Recent satellite images are providing unprecedented details that rival the outcrop scale. Analogs in Utah are prime field localities that can be utilized in planning future robotic and human missions to Mars, and for teaching the next generation of planetary explorers.

This paper is a case history of coastal development at Camp Ellis, Saco, Maine. It begins in 1867 with dredging and jetty construction at the mouth of the Saco River to facilitate commercial navigation. Beach accretion, resulting from tidal delta collapse, was followed by residential development before the ephemeral nature of the shoreline was recognized. A misunderstanding of the riverine source of beach sand and the net, northward direction of longshore transport confounded U.S. Army Corps of Engineers (USACOE) efforts to maintain navigation and the adjacent beach. Beach erosion at Camp Ellis claimed dozens of properties before the role of the north jetty at the mouth of the Saco River became apparent to state and university scientists. Erosion also led to sand migration to the north and to the closure of the Little River inlet and growth of Pine Point spit. This spit was later developed and a jetty was placed at its tip to preclude continued accretion into the Scarborough River inlet. Despite numerous studies, the USACOE failed to recognize the connection between beach erosion at Camp Ellis and beach accretion at Pine Point. Under political pressure, the USACOE recently conducted detailed modeling studies and has proposed construction of breakwaters seaward of Camp Ellis to solve the problem. A discussion of the pros and cons of this proposal is presented in light of the long history of development at Camp Ellis.

Through federal funding under the Stafford Act, private beachfront property and public infrastructure on the west end of Dauphin Island, Alabama, have repeatedly been restored following tropical storm impacts. The island has two distinct geomorphological portions due to the protection of the offshore ebb-tidal delta. The lower western end has become a prime target for beachfront development and consequently the recipient of the bulk of the federal largesse. It is clear that failed public policy at every level, local, state and federal, has contributed to an irresponsible fiscal commitment to constant redevelopment. Serious review and revision of the Stafford Act is recommended as a consequence of these considerations.

Galveston Island and Bolivar Peninsula have experienced a well-documented history of shoreline and bay shoreline change ranging from +3.63 m/yr to −1.95 m/yr. By integrating core, Light detection and ranging (LIDAR), and coastal change data, we develop a sand budget that attempts to quantify long-term sand sources (e.g., fluvial sand cannibalization through transgression) and sinks (washover fans, offshore sand bodies, and flood-tidal deltas). These results are then considered in light of anthropogenic influences (e.g., beach-nourishment projects, coastal engineering structures, and dredging operations) in an attempt to relate natural versus human influence on coastal change. Our findings suggest that hurricane washover (Galveston Island = 0.4 m/100 yr; Bolivar Peninsula varies from 0.154 m/100 yr to 0.095 m/100 yr) and offshore sand deposits are minimal long-term sand sinks. Flood-tidal deltas, however, appear to be major locations for natural sand sequestration. We also conclude that damming of rivers has had minimal impact on the upper Texas coast, although hard structures, such as the Galveston seawall and its groins, have exacerbated erosion along a shoreline that is currently sand starved. The impact of hard structures has mainly been one of trapping sand in locations where that sand would not have naturally accreted. Sand supply is minimal, so understanding and developing a better sand budget for the Texas coast are vital to sustainability.

In eastern coastal Maine, many flat-topped landforms, often identified as glacial-marine deltas, are cultivated for blueberry production. These agriculturally valuable features are not exploited for aggregate resources, severely limiting stratigraphic exposure. Coring is often forbidden; where permissible, coarse-grained surficial sediments make coring and sediment retrieval difficult. Ground penetrating radar (GPR) has become an invaluable tool in an ongoing study of the otherwise inaccessible subsurface morphology in this region and provides a means of detailing the large-scale sedimentary structures comprising these features. GPR studies allow us to reassess previous depositional interpretations and to develop alternative developmental models. The work presented here focuses on Pineo Ridge, a large, flat-topped ice-marginal glacial-marine delta complex with a strong linear trend and two distinct landform zones, informally termed East Pineo and West Pineo. Previous workers have described each zone separately due to local morphological variation. Our GPR work further substantiates this geomorphic differentiation. East Pineo developed as a series of deltaic lobes prograding southward from an ice-contact margin during the local marine highstand. GPR data do not suggest postdepositional modification by ice-margin re-advance. We suggest that West Pineo has a more complex, two-stage depositional history. The southern section of the feature consists of southward-prograding deltaic lobes deposited during retreat of the Laurentide ice margin, with later erosional modification during marine regression. The northern section of West Pineo formed as a series of northward-prograding deltaic lobes as sediment-laden meltwater may have been diverted by the existing deposits of the southern section of West Pineo.

Relict deltas of well-sorted and well-drained sands are among numerous strand-line deposits that mark the former shoreline positions of glacial Lake Iroquois in northern New York. In this study, ground penetrating radar (GPR) was used to image the subsurface architecture of four Late Pleistocene lacustrine deltas to provide information about their depositional environment. The surveyed deltas indicate two distinct glacial Lake Iroquois water levels, the Frontenac and Trenton water phases. A pulseEKKO 100 GPR unit and a 400 Vtransmitter, combined with 50 and 100 MHz antennas are used to provide a better understanding of the internal structures, delta thickness, and distinct facies units. Delta thickness varies generally from 10 to >20 m. High-resolution GPR profiles exhibit variable reflection continuity. Depositional patterns of four distinct radarfacies are described as being characteristic of foreset bed, braided channel, channel cut and fill, and lacustrine clay, in addition to fine-grained till deposits. Facies units reflect an environment of a braided delta in which high sediment volumes and unstable directions of deposition dominated. Larger boulders of nonriverine origin that are located within deltaic sediments are interpreted as dropstones. Waterlevels of glacial Lake Iroquois appear to be stable during the relatively short periods of delta formation. Deltas of glacial Lake Iroquois exhibit lobate morphology typical of a constructive environment.

The Pearl River Delta with its network system and estuarine bays is unique and one of the most complicated large-scale estuarine systems in China. In this paper, a long-term morphodynamic model is developed to simulate the long-term morphological evolution of the Pearl River Delta. The concepts of long-term model calibration and verification are discussed. The paleo–estuary bay topography formed in the last interglacial period is reconstructed and serves as an initial and boundary condition of this model with time steps of 100 yr. Events of shorter duration are ignored. The driving forces and control factors considered in the long-term delta evolution include representative tides, sediment supply from the Pearl River system, sea-level variation, sediment condensation rates, and neotectonic movement. Deposition rates and total deposition volume are investigated and determined and then used to calibrate the model. Core data with 14 C dating at 30 locations are used to verify the model output with satisfactory results. Approximately 1700 collected cores are carefully analyzed to justify the model-simulated evolution processes. Morphodynamic analysis is conducted to justify and explain the output of the model on delta evolution and deposition modes. The study also provides more temporal and spatial details to the delta development originated from the effects of the morphodynamic structures, such as bidirectional jets and the “men” system. The model confirms that the complicated morphology, e.g., the rocky islands in the shallow estuarine bays, is one of the important factors affecting the long-term evolution of the Pearl River Delta.