[Renfield]

I din't say that bays were "deposited in a marine environment". They formed subaerially on marine sediments after marine regression. I forwarded the paper on to you. Read it carefully, especially the last section wherein the authors propose a mechanism for bay formation. I think they've nailed it.

[ForGod'sSake]

I din't say that bays were "deposited in a marine environment". They formed subaerially on marine sediments after marine regression.

Is that anything like being formed by "hydrologic" processes???

I forwarded the paper on to you. Read it carefully, especially the last section wherein the authors propose a mechanism for bay formation.

Well, they offer up several possibilites(so I'm not sure which one you refer to), while excluding only one: a metorite/asteroid impact. Maybe they overlooked the possibility of a really big snowball. Some excerpts from the paper I found interesting as they relate to the discussion re bay formation:

Comparison between surface topography and expression of the Upland Unit surface using coring and elevation data reveal that the surface of the Upland Unit generally lies above the level of the basin interiors. The Upland Unit is typically flat-lying beneath the east and south portions of the bay rims and often rises to the west-northwest of the basins.

Well, ok; this isn't speculation, opinion or conjecture, but some hard data apparently. It's not altogether clear from this statement, but it seems to imply there's a "bulge" towards the NW and a "depression" towards the SE in the Upland Unit layer within the bays. But it doesn't appear to help in the how or when department.

The bays themselves may occupy pre-existing depressions in the Upland Unit surface, but also reflect at least some erosion of the Upland Unit surface. Moreover, the regional sand sheet thickens towards the southeast sides of the bays, but is largely absent from within bays. It is possible, therefore, that excavation of the sand sheet after emplacement of the Upland Unit created the present bay depressions and that subsequent deposition of the excavated sands formed the observed bay rims. This statement is supported by significant differences in the age and degree of pedogenic development between the Upland Unit and bay rim and interior deposits that have been cored/excavated and dated (Brooks et al., 1996).

The point of this statement was lost on me. In fact, it doesn't make any sense to me.

Processes including dissolution, meteorite impact, and eolian deflation have been proposed to account for initial formation of the depressions (e.g., Johnson, 1942; Prouty, 1952; Thorn, 1970; Kaczorowski, 1977; Colquhoun, 1982; Blair, 1986) sometime during the period ~ 10-100 ka (Schalles et al., 1989). Investigations have been impeded, however, by the subdued topographic expression of the bays, the dense vegetative cover (e.g., Knight et al., 1989; Richardson and Gibbons, 1993), typically extensive historic era modification (Van Doren, 1928; Brooks et al., 1996; Kirkman et al., 1996), and a paucity of preserved organic material for accurately dating the formation. As a result, it remains uncertain whether some or all bays share a common age or how the present expression reflects the processes responsible for initial formation of the depressions versus subsequent modification. The GPR and supporting data presented herein provide clues to the subsequent modification of the bays that resulted in a common topographic expression, but does not specifically address the initial formation of the depressions.

I see.

Although not specifically addressed in the current study, a number of processes could account for generation of the initial basin that eventually evolves into a Carolina Bay. These processes might include, among others, spring activity, solution, deflation, abandonment of channel segments, and/or excavation of original relief on the surface of the Upland Unit. No evidence was found to support basin formation by meteorite impact as suggested by Johnson(1942), and others.

Uh huh.

Stratigraphy from the surface down in the vicinity of all four bays is similar (to first-order) and begins with a thin, regional, medium-to-coarse-grained sand sheet (typically ~ 1-3 m thick) that exhibits minimal pedogenic alteration, but whose emplacement likely predates bay formation (Willoughby, 1997).

So, the sand was there before the bays formed??? How long? If the bays are of differing ages(thousands of years even?), it just seems odd to me there's still a certain consistency to it all.

I think they've nailed it.

Maybe for you ;^)

FGS