159 JERVEY, M.T. 1988. "Quantitative Geological Modeling of Siliciclastic 

 Rock Sequences and Their Seismic Expression," Wilgus , C. K. , Hastings, B. S., 

 Kendall, C. G., Posamentier , H. W. , Ross, C. A., and Van Wagoner , J. C., eds . , 

 Sea-Level Changes: An Integrated Approach . Special Publication No. 42, 

 Society of Economic Paleontologists and Mineralogists, Tulsa, OK, pp 47-70. 



In order to clarify the principles that govern the development of 

 siliciclastic sequences and their bounding surfaces, a mathematical model of 

 progradational basin filling was created for Atlantic-type continental 

 margins. This paper discusses the model and its implications with respect to 

 depositional facies, sandstone geometry, and seismic stratigraphic 

 interpretation. Basin filling is modeled as the interaction of subsidence, 

 change in sea- level, and sediment influx. The simulations show that seismic- 

 sequence boundaries are located, in time, near inflection points of eustatic 

 sea- level fluctuation, where rates of fall or rise are maximized. Changes in 

 the rate of accommodation development, both in time and space, are believed to 

 play a dominant role in shaping the internal facies distribution, the 

 geometry, and the nature of the bounding surfaces of depositional sequences. 

 The pattern of coastal onlap and offshore condensed sections displayed by 

 global -cycle charts are shown to develop in the context of smoothly 

 fluctuating eustatic and relative sea-level. (Authors). 



160 JONES, J. R., and CAMERON, B. 1977. "Landward Migration of Barrier 

 Island Sands Under Stable Sea-Level Conditions, Plum Island, Massachusetts," 

 Journal of Sedimentary Petrology . Vol 47, No, 4, pp 1475-1483. 



The origin and development of barrier islands systems has received much 

 attention during the last decade as marine scientists have become more con- 

 cerned with coastal environments. Plum Island, part of a barrier island sys- 

 tem located off the northeastern coast of Massachusetts where sea-level is 

 believed to have remained stable for the last three thousand years, was 

 selected to test the hypothesis that dune migration and longshore sediment 

 transport patterns are causing its landward (west) development and migration, 

 rather than the commonly accepted "rising sea-level hypothesis." Ninety-four 

 surface sand samples taken from the top 2 to 3 inches (5-7 cm) and 

 94 subsurface sand samples from a 3- ft depth (1 m) were collected for 

 statistical size analysis along six east-west traverses at one mile intervals 

 perpendicular to the island. Trend surface analysis was then performed with 

 the graphic mean size values from the surface and subsurface samples to 

 determine any consistent stratigraphic and geographic textural shifts between 

 the surfaces. Comparison of the third-order surface indicates that the 

 graphic mean grand size generally coarsens from the subsurface to surface. 

 This shift appears to indicate that there is a general landward (west) shift 

 through time in the graphic mean size distributions from the older subsurface 

 to the younger surface. This shift is interpreted to be a direct response of 

 the dune field to the predominant northeasterly storm conditions modified by 

 longshore currents in an area of stable sea- level. It is therefore concluded 

 that a rising sea-level is not necessary for barrier island migration 

 landward. (Authors). 



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