Le Miocene marin du revers septentrional du bassin du Hodna (partie orientale) (department de Constantine, Algerie)

1952 ◽  
Vol S6-II (4-6) ◽  
pp. 275-281
Author(s):  
Jacques Bertraneu ◽  
Magne Jean
Keyword(s):  
Shallow Water ◽  
Northern Flank ◽  
Lower Miocene ◽  
Water Origin

Abstract The Miocene microfaunas of the thick marine series on the northern flank of the eastern Hodna basin, Constantine, Algeria, show that it is of shallow-water origin and lower Miocene age. The existence of an important basin of subsidence in the region in Miocene time is thus established.

Stone rosettes as indicators of ancient shorelines: examples from the Precambrian Belcher Group, Northwest Territories

1979 ◽  
Vol 16 (9) ◽  
pp. 1887-1891 ◽  
Author(s):  
B. D. Rlcketts ◽  
J. A. Donaldson
Keyword(s):  
Shallow Water ◽  
Northwest Territories ◽  
Close Packing ◽  
Desiccation Cracks ◽  
Cross Bedding ◽  
Vertical Arrays ◽  
Water Origin ◽  
Shallow Subtidal ◽  
Shore Platforms

Flat-pebble conglomerates in the McLeary Formation of the Belcher Group display close packing of intraformational slabs in near-vertical arrays that appear distinctively polygonal in sections parallel to bedding. Such arrangements of flat pebbles, known by names such as stone rosettes and slone packings, are common on modem beaches, especially within the swash and backwash zone of shore platforms. Association of the McLeary stone rosettes with sedimentary features suggestive of shallow subtidal to supratidal origin (herringbone cross-bedding, reactivation surfaces, desiccation cracks, tepee structures, gypsum casts, oncolites, stromatolites, and probable beachrock) supports a hydrodynamic origin for these polygonal arrays of flat pebbles, an origin that has been demonstrated for modern occurrences. Where associated structures corroborate interpretation of a shallow-water origin, such stone rosettes provide evidence for ancient strandlines, and the designation "beach rosettes" is suggested as appropriate to distinguish them from stone rosettes formed by periglacial processes.

Sedimentology of the Partry Series in the Partry Mountains, Co. Mayo, Eire

1967 ◽  
Vol 104 (6) ◽  
pp. 585-607 ◽  
Author(s):  
John McManus
Keyword(s):  
Shallow Water ◽  
Marine Environment ◽  
Volcanic Rocks ◽  
Sedimentary Structures ◽  
Welded Tuff ◽  
Water Origin ◽  
Red Bed

AbstractThe Lettereeneen fault, a newly recognized structure, brings the Mweelrea and Maumtrasna Groups of the Partry Series (Caradocian-Llandeilian age) into contact. The stratigraphy of the Mweelrea Group, of red bed facies, is followed from the presence of welded tuff horizons; no such markers exist in the Maumtrasna Group which lies unconformably upon the former.Sedimentary structures of shallow water origin occur in each group. Three types of conglomerate recognized in the area are examined. The immature feldspathic sandstones increase in arkosity upwards.A proluvial or proluvio-marine environment of deposition is suggested, with debris derived from an eastward extension of the metamorphosed Dalradian rocks of the Connemara Cordillera and foothills of sedimentary and volcanic rocks.

Quelques aspects des conditions de depot du flysch

1962 ◽  
Vol S7-IV (1) ◽  
pp. 41-48 ◽  
Author(s):  
Marguerite Rech-Frollo
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Organic Material ◽  
Detrital Material ◽  
Water Origin ◽  
The Moment ◽  
Bird Tracks ◽  
Marine Basin

Abstract Analysis of the Niesen flysch between Le Sepey and Mosses lake does not confirm the deep-water bathymetry commonly attributed to flysch deposits. The juxtaposition of organic material over continental alluvium--a typical flysch characteristic--was observed only at shallow depths. The muddy sands, source of the flysch deposits, are actually formed at shallow depths. Bird tracks reported from certain flysch beds also suggest shallow-water origin for the deposits. Cross currents produced after periodic disruption of tectonic and climatic equilibria in parts of a marine basin corresponding to the continental platforms explain the mechanical sorting of the organisms and detrital material as well as the granoclastic structure of the flysch. After deposition of the flysch and before its compaction orogenic mobility at the bottom of the basin affected the petrography of the flysch causing corrosion of the quartz and feldspars at the moment of consolidation. Evidence presented by proponents of a deep-water origin for the flysch deposits--based on foraminifera and the petrographic and paleo-oceanographic characters of the deep-water sands--is reviewed.

Hyalotuff deltaic deposits in the Ballantrae ophiolite of SW Scotland: evidence for crustal position of the lava sequence

1982 ◽  
Vol 72 (4) ◽  
pp. 217-228 ◽  
Author(s):  
B. J. Bluck
Keyword(s):  
Shallow Water ◽  
Hot Spots ◽  
Oceanic Islands ◽  
Lava Flows ◽  
Marked Contrast ◽  
Marginal Basin ◽  
Ocean Ridges ◽  
Water Origin ◽  
Lava Sequence ◽  
Radiometric Ages

ABSTRACTHyalotuff deltaic deposits, a high proportion of volcanogenic sediment and a repeated occurrence of conglomerate with well-rounded clasts constitute evidence for the shallow-water origin of spilitic lavas and volcanogenic sediments in an Ordovician ophiolite at Ballantrae, SW Scotland. One section, >1.5 km thick, shows repeated evidence for a shallow-water origin. This implies accumulation in a subsiding area. In this sense the sequence at Ballantrae is in marked contrast to those found in oceanic islands (hot spots) which are known to grow from deep into shallow water. Neither does it compare well with those from ocean ridges which usually begin in deep water and move, with cessation of vulcanicity, into even deeper water.The lava sequence at Ballantrae compares well with oceanic island-arc and remnant arc deposits where uplift and subsidence is common. This, the occurrence of intermediate and acidic lavas and clasts, and the restricted palaeontological and radiometric ages support an arc-marginal basin origin for the lavas. Diversity in the chemical composition of the lavas may reflect diverse origins within the marginal basin.An upward coarsening sedimentary sequence was built by a hyalotuff delta which formed in front of advancing lava flows. As the lavas advanced over the sediments so a sequence was generated where these sediments have a source in lava flows which were eventually to overlie them.Clasts of tholeiite were derived from lavas which are now spilite. This, together with the presence of spilitic lava clasts and tuff immediately beneath the flow suggests that the spilitisation resulted from metasomatic activity associated with the convective circulation of trapped water, with the lava as a heat source.

scholarly journals Decapod Crustacea of the Central Paratethyan Ottnangian Stage (middle Burdigalian): implications for systematics and biogeography

2015 ◽  
Vol 66 (3) ◽  
pp. 217-233 ◽  
Author(s):  
Matúš Hyžný ◽  
Mathias Harzhauser ◽  
Wolfgang Danninger
Keyword(s):  
Shallow Water ◽  
Deep Water ◽  
Fossil Record ◽  
Outer Shelf ◽  
Decapod Crustaceans ◽  
Lower Miocene ◽  
Western Tethys ◽  
Decapod Crustacea ◽  
Portunid Crab ◽  
First Time

AbstractDecapod crustaceans from the Ottnangian (middle Burdigalian, Lower Miocene) of the Western and Central Paratethys remain poorly known. In this study, we review and re-describe mud shrimps (Jaxea kuemeli), ghost shrimps (Gourretiasp.,Calliax michelottii) and brachyuran crabs of the families Leucosiidae, Polybiidae and Portunidae. A dorsal carapace of the genusCalliaxis reported for the first time in the fossil record. Re-examination of the type material ofRandallia strouhali(Leucosiidae) andGeryon ottnangensis(Geryonidae) resulted in a transfer of these species intoPalaeomyra(Leucosiidae) andLiocarcinus(Polybiidae), respectively.Achelous vindobonensis, originally described as a chela of a portunid crab, probably belongs to a member of Polybiidae and is provisionally treated asLiocarcinussp. Only two species,J. kuemeliandC. michelottii, are also known from the Karpatian, the succeeding Paratethyan stage. In most cases, the decapod assemblages of the Ottnangian consist of rather shallow-water taxa whereas the assemblages of the Karpatian consist of deep-water taxa from the middle and outer shelf. The Central Paratethyan assemblages show similarities in genus composition to the Proto-Mediterranean and recent Indo-Pacific regions.Gourretiasp. represents the earliest occurrence of the respective genus in the fossil record. The Oligocene–Early Miocene appearance ofPalaeomyraandLiocarcinusin the circum-Mediterranean implies that sources of present-day diversity hotspots in the Indo-Pacific trace to the Western Tethys (as for other decapod genera), although coeval decapod assemblages in the Indo-Pacific remain poorly known.

Radiolarian biostratigraphic constraints for latest Jurassic-earliest Cretaceous submarine volcanic activity in the Tethyan oceanic realm of the Sevan ophiolite (Armenia)

2012 ◽  
Vol 183 (4) ◽  
pp. 319-330 ◽  
Author(s):  
Gayané Asatryan ◽  
Taniel Danelian ◽  
Lilit Sahakyan ◽  
Ghazar Galoyan ◽  
Monique Seyler ◽  
...  
Keyword(s):  
Shallow Water ◽  
Volcanic Activity ◽  
Sedimentary Cover ◽  
Volcanic Rocks ◽  
Greenschist Facies ◽  
Igneous Rocks ◽  
The South ◽  
Lake Sevan ◽  
Northern Flank ◽  
Radiolarian Assemblages

AbstractBiostratigraphic constraints for the sedimentary cover of the ophiolites preserved in Armenia are of key importance for the palaeogeographic and geodynamic reconstruction of the greater area between Eurasia and the South-Armenian block, which is a micro-continent of Gondwanian origin. We present here radiolarian data obtained from radiolarites that are intercalated in a sequence of mafic volcanic rocks on the northern flank of the Dali valley (east of Lake Sevan), which is considered to be part of the Sevan ophiolite. Mafic sills and dykes with well-preserved igneous textures are probably part of the same sequence. The pseudomorphosis of primary phases indicates that the igneous rocks are strongly affected by alteration in the greenschist facies condition. The plagiogranites that are present in this locality appear to be intrusive into the mafic sequence. The radiolarian assemblages extracted from radiolarian cherts intercalated in the mafic volcanic rocks are dated as latest Tithonian-Late Valanginian; they contain metric rounded blocks of oolitic limestones with crinoid fragments, suggesting that these shallow water limestones slid during the Jurassic/Cretaceous transition into a rugged oceanic floor in which radiolarian ooze accumulated.

Incised valleys and tidal seaways: the example of the Miocene Uzès-Castillon basin, SE France

2012 ◽  
Vol 183 (5) ◽  
pp. 471-486 ◽  
Author(s):  
Jean-Yves Reynaud ◽  
Emmanuelle Vennin ◽  
Olivier Parize ◽  
Jean-Loup Rubino ◽  
Chantal Bourdillon
Keyword(s):  
Shallow Water ◽  
Middle Miocene ◽  
Foreland Basin ◽  
Tidal Currents ◽  
Borehole Data ◽  
Depositional Sequences ◽  
Lower Miocene ◽  
Incised Valley ◽  
Valley Fills ◽  
Se France

Abstract The sedimentology and stratigraphy of the Miocene deposits of the Uzès-Castillon basin are revisited. This basin, located in SE France at the junction between the perialpine foreland basin and the W Mediterranean margin, sits in a syncline that formed during the latest Cretaceous Pyrenean tectonic phase. It records the succession of shallow-water mixed siliciclastic to dominantly bioclastic carbonates that alternate with shelf marls. The clastic carbonates were accumulated as a stack of subtidal dunes and bars that were formed by tidal currents channelized in a seaway following the syncline axis. The marls indicate deposition in more protected and locally deeper waters, as interfluves of the sea-way were drowned. Borehole data suggest that the marls are encased over tens of meters in the underlying bioclastic deposits, thus pointing to incised-valley fills. Contrarily to what is observed in the main Rhodanian basin, the molassic deposits are not restricted to transgressive systems tracts but may also correspond to forced regressive systems tracts. Four depositional sequences are identified, ranging from the Lower Burdigalian to the Langhian. They constitute a transgressive-regressive sequence set which might express the uplift of the area starting in the Late Burdigalian. This is consistent with the incision of the Middle Miocene deposits into the Lower Miocene ones as observed in other places of the main Rhodanian basin.

scholarly journals Faunistické společenstvo kroměřížského souvrství na lokalitě Litenčice (karpatská předhlubeň, střední Morava)

2020 ◽  
Vol 27 (1-2) ◽  
Author(s):  
Ruzena Gregorova ◽  
Pavla Tomanová Petrová ◽  
Helena Gilíková ◽  
Slavomír Nehyba ◽  
Rostislav Brzobohatý ◽  
...  
Keyword(s):  
Shallow Water ◽  
Marine Environment ◽  
Middle Part ◽  
Coarse Grained ◽  
Turbidity Currents ◽  
Central Paratethys ◽  
Lower Miocene ◽  
Submarine Slope ◽  
Carpathian Foredeep ◽  
High Dynamics

The fossil assemblages of the foraminifers, bryozoans, molluscs, corals, decapods, sharks and teleosteans were analysed from the Litenčice sand pit in the middle part of the Carpathian Foredeep. The section can be assigned to the Karpatian Stage of the Central Paratethys regional stratigraphy (uppermost Lower Miocene) on the basis of species Uvigerina graciliformis Papp et Turn., Lampanyctus carpaticus (Brz.) and Agapilia pachii (Hoern.). Rich and diversified assemblages indicate mainly shallow water marine environment. Foraminifers and molluscs indicate salinity perturbations. Bryozoans and also molluscs document environment with relatively high dynamics and depth of water about 100 m. Foraminifers, fishes and sharks represent deeper water taxa and indicate a possible reworking of shallow-water elements. The studied sands and gravels of the Holešov Member of the Kroměříž Formation are interpreted as sediments of gravitational currents, more precisely dense turbidity currents (high-density turbidity currents) in the sense of Lowe (1982). The deposition environment can probably be placed on the submarine slope of the coarse-grained delta of the Gilbert type (so-called foresets). This study provided evidence of a number of fossil groups that occur at the site.

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