Delmarva Peninsula

Reay, W. G., Gallagher, D. L., and Simmons, G. M., Jr. (1995). Sediment-water column oxygen and nutrient fluxes in nearshore environments of the lower Delmarva Peninsula, USA. Mar. Ecol. Prog. Ser. 118, 215-227. 

The Atlantic Coastal Plain of the Delmarva Peninsula in the East Coast of the US is composed of Jurassic to Holocene sediments deposited during a series of transgressions and regressions (Figure 17). It is covered by a highly permeable surficial Pleistocene aquifer that is directly recharged by local precipitation. Thirty-three wells, some of which tap this formation, were used to sample H/ He (52 samples), CFCs (282 samples), and Kr (four samples) (Dunkle et al., 1993 Ekwurzel et al., 1994 Plummer et al., 1993 Reilly et al., 1994). 

Figure 17 Map of the Delmarva Peninsula, on the east coast of the US. Wells having the same series number (e.g., KE Be) are listed as the series number followed by a dash and well numbers listed in order of increasing depth within the boxes (Ekwurzel et aL, 1994) (reproduced by permission of American Geophysical Union from Water...

Figure 20 Comparison of H/ He and CFC-12 ages from the Delmarva Peninsula, including effects of dispersion. Average linear velocity of Imyr is plotted with different dispersion coefficients and with a 1 1 reference line (Ekwurzel et al., 1994) (reproduced by permission of American Geophysical Union from Water Resour. Res. 1994, 30, 1693-1708).

Chlorofluorocarbons (CCI3F and CCI2F2) as dating tools and hydrologic tracers in shallow groundwater of the Delmarva Peninsula, Atlantic Coastal Plain, United States. Water Resour. Res. 29, 3837-3861. 

Churchill J., Wirick C., Flagg C., and Pietrafesa L. (1994) Sediments resuspension over the continental shelf east of the Delmarva Peninsula. Deep-Sea Res. II41, 341-363. 

CFCs, and Kr were studied in a sandy, unconfined aquifer on the Delmarva Peninsula in the eastern USA by Ekwurzel et al. (1994). H and H+ He depth-profiles show peak-shaped curves that correspond to the time series of H concentration precipitation, smoothed by dispersion (Fig. 18a). The peak occuring at a depth of about 8m below the water table therefore most likely reflects the H peak in precipitation that occurred in 1963 (Fig. 6). The H- He ages show a linear increase with depth, reaching a maximum of about 32 years. The H- He ages are also supported by CFC-11, CFC-12, and Kr tracer data (Fig. 18b). The latter tracers are used here as dyes and their concentrations are converted into residence times by using the known history of the atmospheric concentrations and their solubility in water. From the vertical H- He age profile at well nest 4 at the Delmarva site, the vertical flow velocity can be... 

Figure 18. Results from a multi-tracer study, Delmarva Peninsula, USA. (a) and + He i versus depth for well nest 4. (b) Comparison of H- He, CFC-11, CFC-12, and Kr ages (after Ekwurzel et al. 1994).

Delmarva Peninsula, Virginia 210pb 0.1-0.2 Kastler and Wiberg (1996)... 

The Maryland Department of Natural Resources recently completed an assessment of the availability, cost, and reliability of wood fuels on the Delmarva Peninsula (14). The study concluded that cull trees and timber harvest residue could provide over 1.9 million tons of wood fuel annually at a cost to users of 12.50 per green ton. Other studies in Minnesota, New York. Oregon, and Washington are involved in similar utilization and biomass assessments to determine the availability of wood fuels for energy. 

---