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80 S. Todaro et al. / Sedimentary Geology 333 (2016) 70–83

Fig. 10. A segment of the studied section showing a thick lower cycle of bioturbated mud/wackestone overlain by thinner cycles with subtidal units made of algalgrainstone and/orcoral
boundstone (the cycle stacking is highlighted by black dotted lines and blue triangles). In the lower cycle the spongy dissolution is clearly visible. The red line is a tentative positioning of
the mixing lens base-level during the lowstand stage. (For interpretation of the references to color in this figure legend, the reader is referred to the web version of this article.)

horizons suggests that a meteoric vadose environment was not the reduction of the marine phreatic circulation by the ongoing early
established. Owing to the subsidence responsible for the cycle stacking, diagenetic processes and by the formation of the new subtidal muddy
most likely fully marine phreatic conditions remained after the first rel- unit on the paleosol.
ative sea level rise. Consequently, the upper part of the dissolution cavities remained
Contemporaneous to the precipitation of the RFC, a decantation of empty and was filled by subsequent generations of RFC cements and
internal sediments occurred on the cavity floors during the flooding of by later blocky calcite cements.
the platform as indicated by the lateral relationships between the sedi-
ment laminae and the RFC cements. This sediment is most likely derived 7.5. Role of Precursor Texture on Dissolution
from the newly-formed paleosol as suggested by the presence of abun-
dant hematite and black-stained pellets. As shown in Fig. 6 the infiltra- The analysis of the cyclical stacking pattern shows that the distribu-
tion of the laminated internal sediment does not fill completely the tion of the spongy-like porosity is almost irregular throughout the stud-
dissolution cavities. This indicates that the infiltration of the sediment ied section, as some cycles show preferential moldic dissolution and
stops at a certain point. A possible explanation of this phenomenon is some others vugs (Fig. 5). This is related, in our opinion, to the different

Fig. 11. Morphological comparison between present day spongy-like dissolution pattern from A) Great Bahama Bank (by Beach, 1995) and B) Yucatan platform (Back et al., 1986).