A Triassic homoclinal ramp from the Western Tethyan realm, Western Balkanides, Bulgaria: Integrated insight with special emphasis on the Anisian outer to inner ramp facies transition

2013 ◽  
Vol 386 ◽  
pp. 34-58 ◽  
Author(s):  
Athanas Chatalov
Keyword(s):  
Homoclinal Ramp ◽  
Facies Transition

scholarly journals A CARBONATE RAMP EVOLUTION IN THE TRANSITION FROM THE APULIA PLATFORM TO THE IONIAN BASIN DURING EARLY TO LATE CRETACEOUS (NW GREECE)

2018 ◽  
Vol 40 (1) ◽  
pp. 53
Author(s):  
K. Getsos ◽  
F. Pomoni-Papaioannou ◽  
A. Zelilidis
Keyword(s):  
Sea Level ◽  
Late Cretaceous ◽  
Facies Analysis ◽  
Carbonate Ramp ◽  
Time Interval ◽  
Storm Wave ◽  
Lowermost Part ◽  
Storm Deposits ◽  
Homoclinal Ramp ◽  
Apulia Platform

Facies analysis of Cretaceous carbonate sequences from the external and central Ionian zone revealed a homoclinal ramp model of evolution. During Berriasian to Valanginian, the carbonate ramp was differentiated to an inner-mid and outer ramp environment, which corresponded to the external and central Ionian zone, respectively, while the main inner ramp environment is assumed that was located in the Pre-Apulian zone. The external Ionian zone (inner-mid ramp) is characterized by muds tones-wackes tones with fragmented echinoderms, bivalves, radiolarians and rare aptychus considered to be deposited below the fairweather wave base (FWWB). Locally, thin graded storm deposits intervene, indicating deposition above the storm weather wave base (SWB). Minor occurrences of packs tonesgrainstones, with fragmented echinoderms, calcareous algae, tubiphytes, lagenid foraminifera and rare ooids occur, as well, considered to be deposited at the lowermost part of the inner ramp, near the constantly agitated fairweather wave base (FWWB). The central Ionian zone (outer ramp) is mainly characterized by mudstones-wackestones with abundant radiolarians and rare calpionellids and calcispheres, considered to be deposited below the storm wave base (SWB). No talus or breccias deposits were observed, during the mentioned time interval, in any part of the studied area. From Hauterivian to Turonian, continual sea-level rise, led to establishment of outer ramp environment in the external Ionian zone, over the previous inner-mid ramp, and outer ramp-basin environment, over the previous outer ramp, in the central Ionian zone. The transition from shallower to deeper conditions is characterized by an overall deposition of mudstones-wackestones with abundant radiolarians rooted in pure micrite. 

Occurrence of Zoophycos in the Ruteh Formation, Middle Permian (Guadalupian), Central Alborz, Iran: palaeoenvironmental and sequence stratigraphy implications

2020 ◽  
Vol 298 (3) ◽  
pp. 285-309
Author(s):  
Forough Abasaghi ◽  
Asadollah Mahboubi ◽  
Mohammad Hosein Mahmoudi Gharaie ◽  
Mohammad Khanehbad
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Middle Permian ◽  
Hydrodynamic Condition ◽  
Anal Ysis ◽  
Sea Level Fluctuations ◽  
Marine Strata ◽  
System Tracts ◽  
Environmental Sequences ◽  
Homoclinal Ramp

Zoophycos is widely distributed in the marine strata of the Middle Permian Ruteh For- mation in the Alborz Mountain, Iran. The investigation of the Zoophycos, along with environmental variables is a useful tool for interpretation of the palaeoenvironmental and sequence stratigraphy anal- ysis. The petrographic observations led to the identification of ten facies in four facies belts including tidal flat, lagoon, shoal, and open marine, deposited on a homoclinal ramp. Moreover, two third- order depositional sequences were recognized in response to the sea- level fluctuations within the Ruteh For - mation. Detailed studies of the sequence stratigraphy revealed a relationship between the occurrences of Zoophycos and changes in the hydrodynamic condition in the basin. It appears that Zoophycos has been influenced by the ecological and palaeoenvironmental parameters, such as sedimentation rate, nutrient supply, oxygen, wave base, and substrate in the shallow to deep environments. Based on the sedimentological and ichnological analysis, Zoophycos has been formed with various dimensions, morphology, fillings, and densities together with rising and falling in the sea-level. The trace- maker has followed an opportunistic strategy in the unstable conditions of shallow environments, whereas it has chosen a k-selected strategy in more stable deep environments. Additionally, variability in Zoophycos illustrates, how the trace- maker adopted itself with environmental sequences. This reason, owing to optimal conditions, has caused that the abundance of Zoophycos was high in the Transgres- sive System Tracts (TST). Evidence shows that the response of Zoophycos to the ecological properties of the environment usually has deposit- feeder and chemosymbiosis behaviours.

Marine to nonmarine facies transition in Permian evaporites of the Palo Duro Basin, Texas: Geochemical response

1993 ◽  
Vol 105 (8) ◽  
pp. 1119-1134 ◽  
Author(s):  
SUSAN D. HOVORKA ◽  
L. PAUL KNAUTH ◽  
R. STEPHEN FISHER ◽  
GUOQIU GAO
Keyword(s):  
Facies Transition

Stratigraphie sequentielle du Dinantien type (Belgique) et correlation avec le Nord de la France (Boulonnais, Avesnois)

2001 ◽  
Vol 172 (4) ◽  
pp. 411-426 ◽  
Author(s):  
Luc Hance ◽  
Eddy Poty ◽  
Francois-Xavier Devuyst
Keyword(s):  
Early Phase ◽  
Outer Shelf ◽  
Large Area ◽  
Third Order ◽  
Inner Shelf ◽  
Southern England ◽  
The North ◽  
Western Germany ◽  
Local Tectonics ◽  
Homoclinal Ramp

Abstract The relative influences of local tectonics and global eustasy in the architecture of the sedimentary units of the Namur-Dinant Basin (southern Belgium) are determined. Nine third-order sequences are recognised. During the Lower Tournaisian (Hastarian and lower Ivorian) a homoclinal ramp extended from southern Belgium through southern England (Mendips) and into southern Ireland. From the upper Ivorian to the lower Visean rapid facies changes occurred due to progradation and increasing prominence of Waulsortian mudmounds. Progradation gradually produced a situation in which inner shelf facies covered the Namur (NSA), Condroz (CSA) and southern Avesnes (ASA) sedimentation areas, whereas outer shelf facies were restricted to the Dinant sedimentation area (DSA). During the middle and late Visean a broad shelf was established from western Germany to southern Ireland. Because the shelf built up mainly by aggradation, parasequences can be followed over a large area. An early phase of Variscan shortening is perceptible during the Livian. The stratigraphic gap between the first Namurian sediments (E2 Goniatite Zone) and the underlying Visean varies from place to place, but is more important in the north.

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