...Figure 7. Vertical gradients between Glaciofluvial and Marshall aquifer units in response to ice loading. Negative values denote areas where flow direction is into the Marshall aquifer unit. The unshaded portions of the study area indicate locations where flow direction is from the Marshall aquifer...

...STEPHEN S. ANTHONY; FRANK L. PETERSON; FRED T. MACKENZIE; SCOTT N. HAMLIN Abstract In small limestone islands, the depositional history and subsequent chemical interactions between ground water and the aquifer host rock play critical roles in the occurrence, movement, and chemical quality of ground...

... and the Marshall aquifer unit appear to subcrop the inner and outer portions, respectively, of Saginaw Bay ( Hoaglund et al., 2004 ). Except for the Mississippian Marshall aquifer unit, the other lithologies do not underlie the Lake Michigan study area (see Harrell et al., 1991 , their fig. 4; Westjohn...

...). The special relations among the bedrock units of interest are shown in Figure 2. The Mississippian Coldwater Shale serves as the lower confining unit, and the contact between this shale and the overlying Marshall aquifer delineates the boundary of the Michigan RASA study area. In general, the Marshall aquifer...

... characteristics. The NGS, which consists of a Lower Durban Formation and an Upper Mariannhill Formation, forms a secondary/fractured aquifer system that has variable to good productivity across its members. This aquifer is characterised by borehole yields ranging from 0.2 L/s to 25 L/s, with more than 50...

... ; Marshall and Lang, 2013 ). A combination of dip closure and fault seal provide the typical lateral trap configurations ( Longley et al., 2003 ; Black et al., 2017 ). Intraformational shales can also provide seals within the Mungaroo Formation, namely between the TR24 and TR27 zones and between the TR27...

... into the Sea of the Hebrides Basin from the then Hebridean landmass. Modal porefluid flow rates were low, resulting in an approximately spherical concretion geometry. The concretions are zoned due to episodic recharge of the aquifer (which is tentatively related to seismic pumping). The sandstone was open...

...D. EMERY; J. D. HUDSON; J. D. MARSHALL; J. A. D. DICKSON Abstract The carbon and oxygen isotopic compositions of the Lincolnshire Limestone (Bajocian) of the East Midlands are shown to be determined largely by two end-member components: marine precipitates and later sparry burial cements...

... sandstone aquifers following the Great Oxidation Event, which also liberated sulfur by oxidation of pyrite. Evaporative conditions, as suggested by the widespread occurrence of dolomite and magnesite, may have increased the chloride content of seawater and enhanced its capacity to transport metals...

... activated. The initial pressure decline likely resulted in gas exsolution. None of the three fields have water or gas injection. Pressures have remained fairly steady since 2003 due to strong regional aquifer support. Madison and Marshall are subsea developments tied back to a deep draft caisson vessel...

...L. D. Slater; D. R. Glaser Abstract Resistivity and induced polarization (IP) measurements (0.1–1000 Hz) were made on clay-free unconsolidated sediments from a sandy, alluvial aquifer in the Kansas River floodplain. The sensitivity of imaginary conductivity σ″, a fundamental IP measurement...

... residence times for the midshelf region ranged between 10 4 and 10 6 yr at depths of <500 m. Simulated groundwater ages from wells completed within Pleistocene confined aquifers are consistent with measured groundwater ages within confined aquifers of Martha’s Vineyard and Nantucket Island (2750−5900 yr...

...MARSHALL REITER Abstract Subsurface temperatures and heat-flow data provide valuable information on both regional and local ground-water flow patterns. In the San Juan Basin of northwestern New Mexico and southwestern Colorado, heat-flow data are used to estimate basin-scale horizontal flow...

...L. C. Goldenberg; S. Mandel; M. Magaritz Summary Evidence of formation of entrapped saline bodies of water in a porous medium where fresh water displaces flowing sea water was observed in laboratory experiments, carried out on aquifer sands containing clay minerals. When sea water was flushed from...

...D. A. Spears; M. J. Reeves Summary Borehole samples were obtained from the glacial, lacustrine and fluviatile sands and clays which overlie the Permo-Triassic sandstone aquifer in the Vale of York. Mineralogical and chemical analyses were undertaken for 26 samples from which pore water was also...

...-aged Diep River Gravel Bed, Milnerton Member of the Bredasdorp Formation. This is the aquifer which was exploited by the shipwrecked crew of the Haarlem. Above this, between about -9 and -14 m there is an olive-grey sandy clay layer, with minor occurrences of shells of Protomella capenis , known...