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.

scholarly journals Sequence stratigraphy, basin morphology and sea-level history for the Permian Kapp Starostin Formation of Svalbard, Norway

2017 ◽  
Vol 155 (5) ◽  
pp. 1023-1039 ◽  
Author(s):  
DAVID P. G. BOND ◽  
DIERK P. G. BLOMEIER ◽  
ANNA M. DUSTIRA ◽  
PAUL B. WIGNALL ◽  
DANIEL COLLINS ◽  
...  
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Depositional History ◽  
Marine Strata ◽  
The North ◽  
Sverdrup Basin ◽  
Permian Extinction ◽  
Basin Morphology ◽  
Homoclinal Ramp

AbstractBased on seven measured sections from Svalbard, the marine strata of the Permian Kapp Starostin Formation are arranged into seven transgressive–regressive sequences (TR1–TR7) ofc. 4–5 Ma average duration, each bound by a maximum regressive surface. Facies, including heterozoan-dominated limestones, spiculitic cherts, sandstones, siltstones and shales, record deposition within inner, middle and outer shelf areas. The lowermost sequence, TR1, comprises most of the basal Vøringen Member, which records a transgression across the Gipshuken Formation following a hiatus of unknown duration. Temperate to cold, storm-dominated facies established in inner to middle shelf areas between the latest Artinskian and Kungurian. Prolonged deepening during sequences TR2 and TR3 was succeeded by a long-term shallowing-upward trend that lasted until the latest Permian (TR4–TR7). A major depocentre existed in central and western Spitsbergen while to the north, Dickson Land remained a shallow platform, leading to a shallow homoclinal ramp in NE Spitsbergen and Nordaustlandet. The Middle Permian extinction (late Capitanian) is recorded near the base of TR6 in deeper parts of the basin only; elsewhere this sequence is not recorded. Likewise the youngest sequence, TR7, extending to the upper formational contact of latest Permian age, is found only in the basin depocentre. Comparison with age-equivalent strata in the Sverdrup Basin of Canada reveals a remarkably similar depositional history, with, for example, two (third-order) sea-level cycles recorded in the Late Permian of both regions, in keeping with the global record. Sequence stratigraphy may therefore be a powerful correlative tool for onshore and offshore Permian deposits across NW Pangaea.

Sea-level fluctuations in the late Middle Permian estimated from palaeosols of the Sichuan Basin, SW China

2020 ◽  
Vol 157 (8) ◽  
pp. 1333-1348
Author(s):  
Jun Li ◽  
Zhong Han ◽  
Xingyue Wen ◽  
Gregory J. Retallack ◽  
Chengmin Huang
Keyword(s):  
Sea Level ◽  
Sichuan Basin ◽  
Chemical Properties ◽  
Middle Permian ◽  
Sea Level Changes ◽  
Yangtze Craton ◽  
Relative Sea Level ◽  
Carbonate Microfacies ◽  
Additional Tool ◽  
Sea Level Fluctuations

AbstractTwo upper Middle Permian palaeosols, consisting of coal and pyrite intercalated with a 20 cm thick limestone, were found near Mount Emei in the SW Sichuan Basin, China. The macro- and micromorphology and physico-chemical properties, in conjunction with the mineralogical composition of the palaeosol horizons were investigated. This type of palaeosol is common within the Permian intertidal facies of the Upper Yangtze Craton. The section reflects fluctuations within the range of 0–25 m in relative sea-level, with the depositional environment changing from shallow-marine to littoral, followed by tidal-flat to littoral, and finally to continental volcanic rocks, based on a combination of palaeopedological and carbonate microfacies analyses. Such short-term relative sea-level fluctuations in late Middle Permian times in the SW Sichuan Basin of South China are consistent with the long-term falling trend on a global scale in late Middle Permian times, and may be related to regionally variable subsidence and global cooling. The combination of coastal palaeosol and carbonate microfacies analyses is proposed as an additional tool for estimating the amplitude of sea-level changes.

scholarly journals Rift Basin Sequence Stratigraphy: Some Examples from the Gulf Of Suez

GeoArabia ◽  
1996 ◽  
Vol 1 (2) ◽  
pp. 343-358
Author(s):  
William A. Wescott ◽  
William N. Krebs ◽  
John C. Dolson ◽  
Salah A. Karamat ◽  
Dag Nummedal
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Structural Evolution ◽  
Gulf Of Suez ◽  
Depositional Sequence ◽  
Sea Level Fluctuations ◽  
Tectonic Events ◽  
Complex Structural ◽  
Sequence Boundaries ◽  
Bounded Sequences

ABSTRACT Unconformity-bounded sequences within the Miocene strata of the Suez Rift reflect a complex interplay between tectonism and sea level fluctuations. Analyses of Miocene outcrops along the Sinai margin of the Gulf of Suez provide new insights into the sequence stratigraphy of this basin. The Miocene strata can be subdivided into seven major sequences separated by biostratigraphically defined time breaks. These lacunae represent depositional sequence boundaries, transgressive surfaces and condensed sections. These basinwide time breaks were related to major tectonic events from rift initiation through rift climax, and post-rift stages. These events include regional sag and fault initiation, fault linkage, footwall uplift, shallowing of detachment depths and increased fault block rotations, regional isostatic uplift, and thermal subsidence. Superimposed on this complex structural evolution were Miocene sea level fluctuations of a magnitude of several tens of meters to a hundred meters. The Sinai outcrops expose the four oldest Miocene biostratigraphic sequences which correspond to two depositional sequences. The lower sequence consists of the Nukhul Formation which was deposited during a transgression (with the higher frequency events recorded as local erosional surfaces, flooding surfaces, and ravinements) and the Mheiherrat Formation which was deposited during a relative high stand. The upper sequence includes the Asl Formation which was deposited during a low stand and the Ras Budran Member of the Ayun Musa Formation which was deposited during the ensuing high stand.

Cenomanian sequence stratigraphy and sea-level fluctuations in the Tarfaya Basin (SW Morocco)

2009 ◽  
Vol 121 (11-12) ◽  
pp. 1695-1710 ◽  
Author(s):  
Wolfgang Kuhnt ◽  
Ann Holbourn ◽  
Andy Gale ◽  
El Hassane Chellai ◽  
William J. Kennedy
Keyword(s):  
Sea Level ◽  
Sequence Stratigraphy ◽  
Sea Level Fluctuations ◽  
And Sea Level
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