Taxonomy and paleoecology of Albian Madiela Formation gastropods, Gabonese coastal basin: N’Toum quarry section

2015 ◽  
Vol 186 (1) ◽  
pp. 35-42 ◽  
Author(s):  
Benjamin Musavu Moussavou ◽  
Rolf Mabicka Obame
Keyword(s):  
Depositional Environment ◽  
Photic Zone ◽  
Organic Debris ◽  
Geological Section ◽  
First Time ◽  
Coastal Basin

Abstract The taxonomy and paleoecology of the Albian gastropods from the N’Toum quarry geological section (N’Toum locality) are here discussed. Three genera including four species are identified: Ampullina sp., Tylostoma pallaryi (Peron & Fourtau), Lithomphalus sp. A and Lithomphalus sp. B. Three morphotypes are identified as Aporrhaidae gen. et sp. indet., Gast. gen. et sp. indet. 1 and Gast. gen. et sp. indet. 2. The genus Lithomphalus as the rest of gastropods assemblage are reported for the first time in the Gabonese coastal basin. The gastropod fauna from the N’Toum quarry section is marine. Its composition suggests soft to firm substrate. The depositional environment is considered as within the shallow photic zone with probably high amounts of organic debris in the substrate.

scholarly journals Albian bivalves from Madiela Formation in north Gabonese coastal basin

2019 ◽  
Vol 190 ◽  
pp. 5
Author(s):  
Benjamin Musavu Moussavou
Keyword(s):  
Geographical Distribution ◽  
Geological Section ◽  
Age Range ◽  
First Time ◽  
Coastal Basin

A study of Albian bivalves from Madiela Formation in north of Gabonese coastal basin has been carried out from N’Toum quarry geological section. Four genera including six species are identified: Liopistha (Psilomya) sp. 1, ? Liopistha (Psilomya) sp. 2, Megaporomya sp., Neithea (Neithea) dutrugei (Coquand, 1862), Pleuromya sp. 1 and Pleuromya sp. 2. One morphotype is identified as Bivalvia gen. et sp. indet. The genus Megaporomya Ayoub-Hannaa et al., 2013 and all identified species, except Neithea (Neithea) dutrugei (Coquand, 1862), are found for the first time in Gabonese coastal basin. Now, a total of twelve species of bivalves have been reported from the Madiela Formation. In Gabon, the presence for the first time of genera Liopistha and Pleuromya in N’Toum quarry geological section which is assigned to the Albian permits us to expand their geographical distribution until N’Toum region, and their age range to Albian.

scholarly journals Palynological profile and depositional environment of the Ishim formation (upper Miocene) in Tobol-Ishim interfluve, Western Siberia

2019 ◽  
Vol 27 (6) ◽  
pp. 103-123
Author(s):  
O. B. Kuzmina ◽  
I. V. Khazina ◽  
P. V. Smirnov ◽  
A. O. Konstantinov ◽  
A. R. Agatova
Keyword(s):  
Late Pleistocene ◽  
Organic Substance ◽  
Late Miocene ◽  
Depositional Environment ◽  
Western Siberia ◽  
Ice Age ◽  
Quaternary Sediments ◽  
Upper Miocene ◽  
Neogene Sediments ◽  
First Time

For the first time some outcrops of the Upper Miocene Ishim Formation on the south of Tyumen Area near Pyatkovo, Masali and Bigila villages are studied by palynological method in detail. A series of mineralogical analyzes of these sediments and radiocarbon analysis of the Quaternary sediments overlying the Ishim Formation are done. Four palynocomplexes (PC) are established in the Ishim Formation: PC1 with Botryococcus; PC2 with Botryococcus, Sigmopollis; PC3 with Alnus, Polypodiaceae, Botryococcus, Sigmopollis; PC4 with Betula, Alnus, Corylus. The layers with PC1, PC2 и PC3 are traced in two outcrops near Masali and Bigila Villages. PC4 is revealed from the sands and aleuropelits of the outcrop near Pyatkovo Village, it is characterized by a significant content of diverse pollen of temperate termophylic broad-leafed taxa and by the presence of rare typical Miocene elements (Таxodiaceae, Nyssa, Tsuga). The PC3 and PC4 are compared with the complexes well known from the Neogene sediments of Western Siberia. PC5 with Betula, Herbae, Fungi is revealed from the bedded silts overlying the Ishim Formation in Masali outcrop. Previously, these sediments were attributed to the Late Miocene Pavlodar Formation. The composition and the structure of PC5 allowed making an assumption about Quaternary age of the enclosing sediments. Radiocarbon analysis of the organic substance from the silts showed, that these sediments were accumulated in the Late Pleistocene (Sartan Ice Age). For the first time the information about microphytoplankton (Botryococcus, Pediastrum, Zygnemataceae, Sigmopollis) and other nonpollen palynomorphs, contained in Ishim Formation (Upper Miocene) and in Pleistocene sediments, is given. On palynological data, some stages of development of the Late Miocene Ishim Basin and the type of vegetation surrounding this basin are considered. The depositional environment of Pleistocene sediments (Masali outcrop) is reconstructed.

Molecular organic geochemistry of a proposed stratotype for the Oxfordian/Kimmeridgian boundary (Isle of Skye, Scotland)

2012 ◽  
Vol 149 (5) ◽  
pp. 857-874 ◽  
Author(s):  
APOLLINE LEFORT ◽  
YANN HAUTEVELLE ◽  
BERNARD LATHUILIÈRE ◽  
VINCENT HUAULT
Keyword(s):  
Organic Matter ◽  
Depositional Environment ◽  
Organic Geochemistry ◽  
Soluble Organic Matter ◽  
Precise Location ◽  
Exceptional Preservation ◽  
The North ◽  
Nodular Limestone ◽  
First Time ◽  
Isle Of Skye

AbstractThe composition of the soluble organic matter of the Oxfordian–Kimmeridgian Flodigarry Shale Member (Isle of Skye, Scotland) is presented for the first time. A continuous succession of silty clays and nodular limestone beds is exposed on a rocky shore to the north of Staffin Bay. This succession is proposed as a potential stratotype of the boundary between the Oxfordian and Kimmeridgian stages. This paper points out the exceptional preservation and very low thermal degradation of the organic matter. Indeed, the molecular composition is characterized by the abundance of unsaturated biomarkers (hopenes and diasterenes) as well as undamaged bioterpenoids (ferruginol and sugiol). The abundance of long-chainn-alkanes characterized by an odd-over-even predominance reveals a dominant continental contribution. This is also attested to by the relatively high amounts of plant biomarkers (e.g. ferruginol, sugiol, cadalene and retene), which suggest a palaeovegetation largely composed of pinophytes, especially Cupressaceae, Taxodiaceae and Cheirolepidiaceae, on the nearest emerged lands. The water column of the depositional environment was oxic in its upper part and rather dysoxic in its lower part. The composition of the organic matter does not significantly change along the Flodigarry Shale Member. In other words, no evolutionary events or drastic change in palaeoenvironments can be deduced from the molecular content of these sedimentary rocks, and it does not allow us to support a precise location for the Oxfordian/Kimmeridgian boundary in the succession.

scholarly journals Deep-water ostracods from the Middle Anisian (Reifling Formation) of the Northern Calcareous Alps (Austria)

2015 ◽  
Vol 34 (1) ◽  
pp. 71-91 ◽  
Author(s):  
Wolfgang Mette ◽  
Avi Honigstein ◽  
Sylvie Crasquin
Keyword(s):  
New Species ◽  
Deep Water ◽  
Depositional Environment ◽  
Middle Triassic ◽  
Taxonomic Composition ◽  
Northern Calcareous Alps ◽  
Northern Calcareous ◽  
First Time ◽  
Neritic Species

Abstract. A diverse silicified ostracod aassemblage from Middle Anisian, Middle Triassic, intra-shelf basin deposits (Reifling Formation) is described. It comprises 32 species, of which 5 are new species (Bairdia biforis n. sp., B. schneebergiana n. sp., Mirabairdia praepsychrosphaerica n. sp., M. plurispinosa n. sp., Bairdiacypris aequisymmetrica n. sp.). The assemblage consists of both neritic species and deep-water taxa which have been considered as representatives of the ‘Thuringian Ecotype’ or the ‘Palaeopsychrospheric Fauna’. Lithofacies, palaeogeographical setting and taxonomic composition are suggestive of a deep neritic to upper bathyal depositional environment. ‘Archaic’ faunal elements are relatively rare and include the genera Spinomicrocheilinella and Processobairdia, which were formerly known only from the Palaeozoic and are now recorded for the first time from the Mesozoic.

Seismic Facies Analysis of Lower Productive Series of Gurgan-Deniz Field in South Caspian Basin with the Aid of Seismic Attributes

2021 ◽  
Author(s):  
Ulvi Zamanbayov
Keyword(s):  
Sea Level ◽  
Mass Flow ◽  
Depositional Environment ◽  
Facies Analysis ◽  
Seismic Facies ◽  
Seismic Survey ◽  
Caspian Basin ◽  
South Caspian Basin ◽  
Migration Pathways ◽  
First Time

Abstract Drilled for the first time in 1946 and one of the oldest fields in the South Caspian Basin located in the western part of Apsheron sill, Gurgan-Deniz has been subject to redevelopment. A 3D seismic survey, conducted over the area for the first time, has been interpreted, analysing the lower Productive Series with regard to seismic facies and prospectivity. The facies analysis allows for better understanding of eustatic levels in the region and depositional environments of lower Productive Series in the area. A composite seismic attribute Sweetness and an RGB blend of Spectral Decomposition have been applied to the 3D volume, as well as to the interpreted stratigraphic surfaces. With the aid of the attributes and petrophysical well description, direct and indirect facies interpretation have been carried out. First, considering reflection parameters such as parallelism, continuity and hummockiness, as well as sedimentary features. Subsequently, reaching conclusions on depositional processes, environments, and geological evolution. Finally, analysing field prospectivity and migration pathways. Eight seismic facies have been identified by analysing stratigraphic horizons representing the tops of Kalin Suite (KaS), Pre-Kirmaky Sand Suite (PK) and Kirmaky Suite (KS). Facies have been interpreted as mass-flow deposits, amalgamated channel systems, channel and bar systems, sheetflow and floodplain deposits in a varying lacustrine-fluvial environment. KaS has been deposited following a sea- level drop and increased sediment inflow from Palaeo-Volga. The origin of the mass-flow facies is thought to be related to the increase of sedimentation speed, as well as tectonics decreasing the terrace stability. PK shows evidence of further sea-level drop and shows mainly fluvial depositional environment. Starting from KS, sea level has started to rise, once again showing mixed depositional environment. Attribute anomalies have been explored in the lower wing of the anticline structure in PK and KaS. A 3-way trap and possible migration pathways generate considerable risks.

The age and palaeoecology of the St Erth Beds, southern England, based on planktonic foraminifera

1982 ◽  
Vol 119 (2) ◽  
pp. 201-205 ◽  
Author(s):  
D. Graham Jenkins
Keyword(s):  
Planktonic Foraminifera ◽  
Photic Zone ◽  
Late Pliocene ◽  
Southern England ◽  
Neogloboquadrina Pachyderma ◽  
First Time

SummaryPlanktonic foraminifera are recorded for the first time from the St Erth Beds but they are small and very rare. A late Pliocene G. inflaia Zone age is postulated on the presence of Globorotalia inflata and dextrally coiled Neogloboquadrina pachyderma. It is suggested that the depth of water at the time of deposition was much less than 100 m, possibly in the photic zone, and the palaeotemperature was in the range of 10–18 °C.

Lower Cretaceous of the southern North Sea Basins: reservoir distribution within a sequence stratigraphic framework

2010 ◽  
Vol 89 (3-4) ◽  
pp. 203-237 ◽  
Author(s):  
J.M. Jeremiah ◽  
S. Duxbury ◽  
P. Rawson
Keyword(s):  
High Resolution ◽  
Sea Level ◽  
North Sea ◽  
Depositional Environment ◽  
Rhenish Massif ◽  
Short Term ◽  
Sequence Stratigraphic ◽  
Tectonic Events ◽  
Stratigraphic Framework ◽  
First Time

AbstractFacies belts exhibit a back-stepping trend towards the London Brabant/ Rhenish Massif through the Early Cretaceous. The overall eustatic sea-level rise was punctuated by short-term tectonic events identified either as localised or North Sea wide in extent. The biostratigraphically constrained sequences have, for the first time, allowed a detailed calibration of tectonic and eustatic events on a North Sea scale. The most extensive database available to any North Sea Cretaceous study was available to the authors together with a comprehensive suite of new high-resolution biostratigraphy and sedimentology. This has allowed unique insights into provenance, depositional environment, extent of sequence stratigraphical events and the degree to which unconformities have been tectonically accentuated.

scholarly journals Coincidence of photic zone euxinia and impoverishment of arthropods in the aftermath of the Frasnian-Famennian biotic crisis

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Krzysztof Broda ◽  
Leszek Marynowski ◽  
Michał Rakociński ◽  
Michał Zatoń
Keyword(s):  
Bottom Water ◽  
Geochemical Data ◽  
Photic Zone ◽  
Diversity Patterns ◽  
Bottom Waters ◽  
Phosphorous Content ◽  
Abundance And Diversity ◽  
Fossil Preservation ◽  
First Time ◽  
Palaeoenvironmental Changes

AbstractThe lowermost Famennian deposits of the Kowala quarry (Holy Cross Mountains, Poland) are becoming famous for their rich fossil content such as their abundant phosphatized arthropod remains (mostly thylacocephalans). Here, for the first time, palaeontological and geochemical data were integrated to document abundance and diversity patterns in the context of palaeoenvironmental changes. During deposition, the generally oxic to suboxic conditions were interrupted at least twice by the onset of photic zone euxinia (PZE). Previously, PZE was considered as essential in preserving phosphatised fossils from, e.g., the famous Gogo Formation, Australia. Here, we show, however, that during PZE, the abundance of arthropods drastically dropped. The phosphorous content during PZE was also very low in comparison to that from oxic-suboxic intervals where arthropods are the most abundant. As phosphorous is essential for phosphatisation but also tends to flux off the sediment during bottom water anoxia, we propose that the PZE in such a case does not promote the fossilisation of the arthropods but instead leads to their impoverishment and non-preservation. Thus, the PZE conditions with anoxic bottom waters cannot be presumed as universal for exceptional fossil preservation by phosphatisation, and caution must be paid when interpreting the fossil abundance on the background of redox conditions.

The genus Brycon Müller & Troschel (Ostariophysi: Characiformes: Bryconidae) of Espírito Santo State, Brazil: new records and comments on conservation

Zootaxa ◽  
2021 ◽  
Vol 5072 (2) ◽  
pp. 145-156
Author(s):  
LEYDIANE NUNES RODRIGUES ◽  
JULIANA PAULO DA SILVA ◽  
FLÁVIO CÉSAR THADEO LIMA ◽  
LEONARDO FERREIRA DA SILVA INGENITO ◽  
LUIZ FERNANDO DUBOC ◽  
...  
Keyword(s):  
Rio De Janeiro ◽  
New Records ◽  
River Basins ◽  
Minas Gerais ◽  
Espírito Santo ◽  
Minas Gerais State ◽  
Espirito Santo ◽  
First Time ◽  
Coastal Basin

The occurrence of the species of the genus Brycon (Characiformes: Bryconidae) in Espírito Santo State is herein reviewed. Brycon opalinus, a species formerly known only from the upper rio Paraíba do Sul and upper rio Doce basins, is recorded for the first time in the rio Itapemirim, an independent coastal basin in southern Espírito Santo State, Brazil. With the records of B. opalinus, four Brycon species are now known from Espírito Santo State: B. insignis in the rio Itabapoana basin, on the boundary between Rio de Janeiro and Espírito Santo, B. opalinus in the rio Itapemirim basin, B. dulcis in the rio Doce basin, and B. ferox in the rio Barra Seca, rio Itaúnas and the rio São Mateus basins. Additionally worth highlighting is that several fisherman and local inhabitants report the occurrence Brycon vermelha in the rio Cotaxé, a tributary of the rio São Mateus in Espírito Santo and Minas Gerais states, although there are no preserved specimens of B. vermelha from river basins other than the rio Mucuri, in Minas Gerais state.  

A new near-shore marine fauna and flora from the Early Neogene of northwestern Venezuela

2000 ◽  
Vol 74 (5) ◽  
pp. 957-968 ◽  
Author(s):  
M. R. Sánchez-Villagra ◽  
R. J. Burnham ◽  
D. C. Campbell ◽  
R. M. Feldmann ◽  
E. S. Gaffney ◽  
...  
Keyword(s):  
Depositional Environment ◽  
Three Dimensional ◽  
Early Miocene ◽  
Marine Fauna ◽  
Palm Fruit ◽  
Early Neogene ◽  
Near Shore ◽  
The Caribbean ◽  
First Time ◽  
Molluscan Species

A diverse near-shore marine fauna existed during the early Miocene in what is today an arid inland region about 90 km south of the Caribbean coast of northern Venezuela, a poorly known area geologically and paleontologically. The fossil locality consists of more than 100 m of section exposed in an area of about 1 km2. We report the discovery of 20 molluscan species, one crab (Portunus oblongus), at least three sharks (Hemipristis serra and Carcharhinus spp.), one turtle (“Podocnemis” venezuelensis), one crocodile (Crocodylidae), two whales (Odontoceti) and a three dimensional cast of the mesocarp or endocarp of a palm fruit. Several taxa are reported for the first time in Venezuela or in northern South America. The fauna indicates, or at least is consistent with, an early Miocene age for the locality, and a near-shore and shallow water marine depositional environment. We suggest that the earliest mammal previously reported from Venezuela, the pyrothere Proticia venezuelensis, was collected in Miocene rocks of the Castillo Formation instead of Eocene rocks of the Trujillo Formation.

Sign in / Sign up

Export Citation Format

Share Document