scholarly journals Lower Kimmeridgian facies and sedimentary succession of a shallow-water coated-grain-dominated carbonate ramp of the northern peri-Tethyan shelf: an example from the Radomsko Folds (central Poland)

2020 ◽  
Vol 64 (4) ◽  
Author(s):  
Piotr OLCHOWY ◽  
Marcin KRAJEWSKI
Keyword(s):  
Shallow Water ◽  
Carbonate Ramp ◽  
Central Poland ◽  
Sedimentary Succession ◽  
Lower Kimmeridgian

scholarly journals Lithostratigraphy and biostratigraphy of the Lower Carboniferous (Mississippian) carbonates of the southern Askrigg Block, North Yorkshire, UK

2016 ◽  
Vol 154 (2) ◽  
pp. 305-333 ◽  
Author(s):  
C. N. WATERS ◽  
P. CÓZAR ◽  
I. D. SOMERVILLE ◽  
R. B. HASLAM ◽  
D. MILLWARD ◽  
...  
Keyword(s):  
Shallow Water ◽  
Sea Level ◽  
Carbonate Ramp ◽  
Fault System ◽  
Lower Carboniferous ◽  
Shallow Marine ◽  
Sea Level Fluctuations ◽  
Algal Assemblages ◽  
Lower Palaeozoic ◽  
Southern Flank

AbstractA rationalized lithostratigraphy for the Great Scar Limestone Group of the southeast Askrigg Block is established. The basal Chapel House Limestone Formation, assessed from boreholes, comprises shallow-marine to supratidal carbonates that thin rapidly northwards across the Craven Fault System, onlapping a palaeotopographical high of Lower Palaeozoic strata. The formation is of late Arundian age in the Silverdale Borehole, its northernmost development. The overlying Kilnsey Formation represents a southward-thickening and upward-shoaling carbonate development on a S-facing carbonate ramp. Foraminiferal/algal assemblages suggest a late Holkerian and early Asbian age, respectively, for the uppermost parts of the lower Scaleber Force Limestone and upper Scaleber Quarry Limestone members, significantly younger than previously interpreted. The succeeding Malham Formation comprises the lower Cove Limestone and upper Gordale Limestone members. Foraminiferal/algal assemblages indicate a late Asbian age for the formation, contrasting with the Holkerian age previously attributed to the Cove Limestone. The members reflect a change from a partially shallow-water lagoon (Cove Limestone) to more open-marine shelf (Gordale Limestone), coincident with the onset of marked sea-level fluctuations and formation of palaeokarstic surfaces with palaeosoils in the latter. Facies variations along the southern flank of the Askrigg Block, including an absence of fenestral lime-mudstone in the upper part of the Cove Limestone and presence of dark grey cherty grainstone/packstone in the upper part the Gordale Limestone are related to enhanced subsidence during late Asbian movement on the Craven Fault System. This accounts for the marked thickening of both members towards the Greenhow Inlier.

Middle Oxfordian–Lower Kimmeridgian chert nodules in the Holy Cross Mountains, south-central Poland

2006 ◽  
Vol 187 (1-2) ◽  
pp. 11-28 ◽  
Author(s):  
Zdzisław M. Migaszewski ◽  
Agnieszka Gałuszka ◽  
Tomasz Durakiewicz ◽  
Ewa Starnawska
Keyword(s):  
Holy Cross Mountains ◽  
Central Poland ◽  
South Central ◽  
Lower Kimmeridgian

scholarly journals Evolution, paleoecology and sequence architecture of an Eocene carbonate ramp, southeast Zagros Basin, Iran

GeoArabia ◽  
2013 ◽  
Vol 18 (4) ◽  
pp. 49-80
Author(s):  
Afshin Zohdi ◽  
Reza Mousavi-Harami ◽  
Seyed Ali Moallemi ◽  
Asadollah Mahboubi ◽  
Adrian Immenhauser
Keyword(s):  
Shallow Water ◽  
Sea Level ◽  
Facies Analysis ◽  
Carbonate Platform ◽  
Middle Eocene ◽  
Depositional Environments ◽  
Carbonate Ramp ◽  
Salt Diapir ◽  
Zagros Basin ◽  
Facies Associations

ABSTRACT We document and discuss the results of detailed fieldwork, facies analysis and the subsequent integration of paleoecological evidence from the Middle Eocene carbonate ramp succession in the southeast Zagros Basin (Jahrum Formation). A combination of a sea-level fall and tectonic and diapiric basement uplift favored the initiation of the Jahrum carbonate platform. The lower portions are affected by pervasive, probably early diagenetic dolomitization, whilst the upper Jahrum consists mainly of limestone. Here, the focus is on the limestone portions of the Jahrum Formation. Based on the abundance, diversity and rapid evolutionary turnover of the alveolinids and nummulitids, the limestone intervals of the Jahrum Formation are interpreted for the upper Middle Eocene (Bartonian). The Jahrum Formation is capped by a major unconformity and overlain by the Lower Oligocene mixed clastic/carbonate Razak Formation. Based on data from field sections, eight facies associations and a series of sub-types have been established, which correspond to inner-, middle-and outer-ramp depositional environments. In their overall context, these data show a southward-dipping inner-ramp-to-basin transect. Towards the Coastal Fars (e.g. Hulur-01 Well) the Jahrum grades laterally into deep-marine Pabdeh foredeep shale units. Based on facies analysis and paleoecological evidence from larger benthic foraminifera, a major transgressive-regressive pattern is recognized in all outcrop sections of the Jahrum. The lowermost stratigraphic units of the formation are here interpreted as a distally steepened ramp. Evidence comes from abundant allochthonous shallow-water facies in the distal, deeper-ramp setting. Shallow-water carbonate clasts were exported towards the basin, a feature that is probably linked to relative sea-level fall control. Furthermore, local to regional basement instabilities by salt diapir-related basement reorganization was arguably of significance. Upsection, evidence is found that the ramp system evolved from a distally steepened to a homoclinal geometry with an overall very gentle slope geometry during the Late Bartonian. The data shown here are significant for those concerned with the Paleogene evolution of the southeast Zagros Basin and provide a well-exposed case example of a Middle Eocene carbonate ramp factory.

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