The [d.sub.104] value of the dolomite coexisting with calcite in limestone (2.8964-2.9872 [Angstrom]) is equal to that of the dolomite in lagoonal
dolostone near the contact with the limestone (Table 3, Fig.
The lower boundary of the Rootsikula Stage is quite clear in the main part of Saaremaa and coincides with the upper boundary of lagoonal
bioturbated dolomites of the Tagavere Beds.
The evolving carbonate platform was predominantly characterized by 'muddy' carbonates (miliolid wackestones, bio-floatstones, rudistid bafflestones) which were deposited in a lagoonal
setting of an attached (coastal) platform.
glaucum is a result of the progressive adaptation by a cardiid lineage from shelf to tidal to lagoonal
Nestor & Einasto (1977), these rocks were formed, respectively, in the shoal and lagoonal
facies zones of the Baltic Palaeobasin.
The existence of dolomite towards continent and the premature dolomitization derivation from shallow subsurface suggesting that the MF-3 microfacies was deposited in the middle shelf lagoonal
(1) The epifaunal clams from Argyle Creek may be experiencing greater stress (e.g., occasional subaerial exposure and the inability to burrow) than their lagoonal
counterparts thus reducing their growth rates.
Different sources of Mg have been suggested for Silurian secondary dolomites: (1) Devonian sediments (Jurgenson 1970), (2) hypersaline lagoonal
waters (Vishnyakov 1956) or mixed fresh ground water and marine water of the northeastern part of the Devonian East European Basin (Kiipli 1983), and (3) the normal and modified (dilute) marine water of the northern part of the Silurian Baltic Basin (Teedumae et al.
The presence of limestone in the coal horizon indicates low energy lagoonal
facies which is developed within the deltaic sequence during the delta progradation or a subsequent phase of delta destruction.
However, the diatom assemblage does not imply that deep-water conditions were generated, on the contrary, shallow-water lagoonal
conditions existed in the basin.
However, the gravel bar death assemblage is more similar in taxonomic composition to the life assemblages than to the other two death assemblages, suggesting that the gravel bar approximates the present day composition of the local mollusc fauna ecosystem more closely than either the bay or lagoonal
There were three microfacies recognized; 1) Miliolid Lockhartia Mud-Wackstone Microfacies, inferred the deposition in a low energy, restricted circulation with slightly high salinity in a lagoonal
environment of the inner shelf, 2) Nummulitic Wack-Packstone Microfacies, inferred to be deposited in a subtidal conditions of the carbonate shelf and 3) Benthic Foraminiferal Wack-Packstone Microfacies, representing deposition in the distal middle shelf area relatively further offshore.
Due to wide occurrence of lagoonal
and shoal rocks in the very shallow-water sections of the upper Wenlock Rootsikula Formation in Estonia (Nestor 1997), chitinozoans are very rare in that part of the stratigraphic sequence (Nestor 1994).
Study sites were in the extensive lagoonal
marshes that exist along the backside of Waites Island.
The microfacies is formed in shallow brackish lagoonal
or inner ramp settings with restricted circulation.