REGIONAL EFFECT ON OLIGOCENE-MIOCENE SHALLOW MARINE CARBONATE ALONG THE SE CIRCUM - CARIBBEAN

In the southwest part of São Francisco Craton occur neoproterozoic metasedimentary rocks of the Bambuí Group. Among these rocks the Samburá Conglomerate outcrops nearby the external (eastern) region of the southernmost part of Brasilia Thrust Belt. Sedimentological studies carried on these rocks at Serra da Pimenta region reveals that they belong to a fan delta system developed at the toes of thrust fault escarpments of Brasilia Thrust Belt. Petrographic analysis of clasts of Samburá Conglomerate pointed to Canastra Group and Pium-í greenstone belt rocks of Serra da Pimenta mountains as source rocks. The fan delta deposits are rested above shallow marine carbonate rocks of the base of Bambuí Group.

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STUDYING IN THE PAXOS ZONE THE CARBONATE DEPOSITIONAL ENVIRONMENT CHANGES DURING UPPER CRETACEOUS, IN SAMI AREA OF KEFALLINIA ISLAND, GREECE

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.11245 ◽

2017 ◽

Vol 43 (2) ◽

pp. 793

Author(s):

E. Zoumpoulis ◽

F. Pomoni-Papaioannou ◽

A. Zelilidis

Keyword(s):

Depositional Environment ◽

Upper Cretaceous ◽

Carbonate Platform ◽

Upward Trend ◽

Shallow Marine ◽

Sedimentary Environments ◽

Stratigraphic Analysis ◽

Marine Carbonate ◽

Carbonate Sequence ◽

Shallow Subtidal

The shallow-marine carbonate sequence of Sami (Kefallinia isl. Fig. 1) is a part of the Upper Cretaceous carbonate platform of the Paxi zone. Detailed lithostratigraphic and microfacies analysis of that sequence revealed clear periodicities and cyclicity. The high-resolution stratigraphic analysis has shown a number of lithofacies organized in groups (lithofacies associations), suggesting, on the whole, sedimentary environments ranging from lagoonal to peritidal context. The vertical arrangement of these lithofacies allowed the identification of a cyclic recurrence of the depositional and early diagenetic features, including a meteoric overprint on top of the elementary cycles. The cycles exhibit a shallowing upward trend from shallow subtidal to inter-supratidal and hypersaline facies, in a warm shallow marine environment.

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SEDIMENTOLOGY AND BIOSTRATIGRAPHY OF AN UPPER TRIASSIC CARBONATE SUCCESSION OF TRIPOLITZA PLATFORM IN MARI AREA, PARNON MOUNTAIN, SE PELOPONNESUS, GREECE

Bulletin of the Geological Society of Greece ◽

10.12681/bgsg.16490 ◽

2018 ◽

Vol 40 (1) ◽

pp. 101

Author(s):

M. Kati ◽

A. Zambetakis-Lekkas ◽

E. Skourtsos

Keyword(s):

Carbonate Platform ◽

Upper Triassic ◽

Shallow Marine ◽

Carbonate Sedimentation ◽

Subaerial Exposure ◽

Arid Conditions ◽

Southern Margin ◽

Time Period ◽

Marine Carbonate ◽

Semi Arid

The Upper Triassic succession in the base of Tripolitza carbonate platform, in the Mari area of the Parnon Mt. in SE Peloponnesus, mostly consists of dolomites and to a lesser extent ofcalcitic dolomites. A detailed fades analysis and biostratigraphical study revealed that during Norian — Rhaetian times inter-supratidal and subtidal (shallow lagoonal) fades presenting cyclic development were deposited in the inner platform, similar to those that were formed in most of the Alpine platforms of the southern margin of the Tethys during the same time period. Diagenetic considerations further indicate that this shallow marine carbonate sedimentation was interrupted by subaerial exposure intervals and subsequent early lithification of the recently deposited sediments. The extensive and, mainly, early dolomitization and recrystallization, the presence of meteoric-vadose cements and specifically the repeated appearance of dolocrete horizons in the upper parts of many peritidal cycles, clearly show periodic subaerial exposure of the sediments, as well as the prevalence of semi-arid conditions in the area.

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