Microfacies Analysis, Diagenetic Aspects and Depositional Environments of The Oligocene-Miocene Rock Units Exposed at Al Bardia Coastal Area, North East Tobruk City, Libya

2021 ◽  
Vol 1 (1) ◽  
pp. 24-31
Keyword(s):  
Coastal Area ◽  
Depositional Environments ◽  
Microfacies Analysis ◽  
North East ◽  
Area North

scholarly journals DEPOSITIONAL MODEL OF NGRAYONG FORMATION IN MADURA AREA, NORTH EAST JAVA BASIN, INDONESIA

2015 ◽  
Vol 7 (2) ◽  
pp. 51 ◽  
Author(s):  
Paike Htwe ◽  
Sugeng Sapto Surjono ◽  
Donatus Hendra Amijaya ◽  
Kyuro Sasaki
Keyword(s):  
Large Scale ◽  
Sedimentary Facies ◽  
Depositional Environments ◽  
Depositional Model ◽  
Shallow Marine ◽  
Marine Area ◽  
Fine Grained ◽  
North East ◽  
Area North ◽  
Depositional Units

The early Middle Miocene Ngrayong Formation, an important reservoir of North East Java Basin, is well exposed in the central anticlinal part of Madura Island. The purpose of current study is to classify the depositional environments of the study area based on the characteristics and geometry of sedimentary facies. In the Madura island, the thicker clastics and deeper carbonates of Ngimbang Formation and Kujung Formation of Late Oligocene-Early Miocene deposited in the northeast-southwest asymmetrical half grabens. After the deposition of Kujung Formation, the basin morphology developed nearly eastwest trending shelf edge and the deposition of Tuban Formation began. The fine grained complex of Tuban Formation was followed by the Ngrayong Sandstones deposition. The depositional model of Ngrayong Formation is being producing of wide variety of depositional environments. Large scale cross-bedded sandstones and bioturbated massive sandstones with thin to medium bedded argillaceous limestone that outcrop in the northern part of the study area are deposited in costal environment. The heterolithic sandstone with planar and trough cross-lamination, fine grained sandstone with interlaminated structure and bioclastic carbonate exposed in the central part of the study area are deposited in upper shallow marine area. Dark grey siltstones and mudstones deposited in lower shallow marine area are well exposed in southern part of the study area. In conclusion, Ngrayong Formation in Madura area is developed in three depositional units which are coastal, upper shallow marine and lower shallow marine.

The Archaean Atâ intrusive complex (Atâ tonalite), north-east Disko Bugt, West Greenland

1999 ◽  
pp. 103-112
Author(s):  
Feiko Kalsbeek ◽  
Lilian Skjernaa
Keyword(s):  
Intrusive Complex ◽  
The South ◽  
Original Series ◽  
Early Proterozoic ◽  
West Greenland ◽  
North East ◽  
The North ◽  
Southern Border ◽  
Area North ◽  
Igneous Layering

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Kalsbeek, F., & Skjernaa, L. (1999). The Archaean Atâ intrusive complex (Atâ tonalite), north-east Disko Bugt, West Greenland. Geology of Greenland Survey Bulletin, 181, 103-112. https://doi.org/10.34194/ggub.v181.5118 _______________ The 2800 Ma Atâ intrusive complex (elsewhere referred to as ‘Atâ granite’ or ‘Atâ tonalite’), which occupies an area of c. 400 km2 in the area north-east of Disko Bugt, was emplaced into grey migmatitic gneisses and supracrustal rocks. At its southern border the Atâ complex is cut by younger granites. The complex is divided by a belt of supracrustal rocks into a western, mainly tonalitic part, and an eastern part consisting mainly of granodiorite and trondhjemite. The ‘eastern complex’ is a classical pluton. It is little deformed in its central part, displaying well-preserved igneous layering and local orbicular textures. Near its intrusive contact with the overlying supracrustal rocks the rocks become foliated, with foliation parallel to the contact. The Atâ intrusive complex has escaped much of the later Archaean and early Proterozoic deformation and metamorphism that characterises the gneisses to the north and to the south; it belongs to the best-preserved Archaean tonalite-trondhjemite-granodiorite intrusions in Greenland.

Stratigraphy, structure and geochemistry of Archaean supracrustal rocks from Oqaatsut and Naajaat Qaqqaat, north-east Disko Bugt, West Greenland

1999 ◽  
pp. 65-78
Author(s):  
Henrik Rasmussen ◽  
Lars Frimodt Pedersen
Keyword(s):  
Tectonic Setting ◽  
Trace Element Geochemistry ◽  
Element Geochemistry ◽  
West Greenland ◽  
North West ◽  
North East ◽  
Metavolcanic Rocks ◽  
Arc Setting ◽  
Area North ◽  
Back Arc

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Rasmussen, H., & Frimodt Pedersen, L. (1999). Stratigraphy, structure and geochemistry of Archaean supracrustal rocks from Oqaatsut and Naajaat Qaqqaat, north-east Disko Bugt, West Greenland. Geology of Greenland Survey Bulletin, 181, 65-78. https://doi.org/10.34194/ggub.v181.5114 _______________ Two Archaean supracrustal sequences in the area north-east of Disko Bugt, c. 1950 and c. 800 m in thickness, are dominated by pelitic and semipelitic mica schists, interlayered with basic metavolcanic rocks. A polymict conglomerate occurs locally at the base of one of the sequences. One of the supracrustal sequences has undergone four phases of deformation; the other three phases. In both sequences an early phase, now represented by isoclinal folds, was followed by north-west-directed thrusting. A penetrative deformation represented by upright to steeply inclined folds is only recognised in one of the sequences. Steep, brittle N–S and NW–SE striking faults transect all rock units including late stage dolerites and lamprophyres. Investigation of major- and trace-element geochemistry based on discrimination diagrams for tectonic setting suggests that both metasediments and metavolcanic rocks were deposited in an environment similar to a modern back-arc setting.

Assessment of seawater intrusion in Kızılırmak delta coastal area (North Turkey) using hydrochemical and isotopic data

2021 ◽  
Vol 80 (11) ◽  
Author(s):  
Arzu Firat Ersoy ◽  
Nazlı Ayyildiz Turan ◽  
Hakan Arslan ◽  
Ayşe Kuleyin
Keyword(s):  
Seawater Intrusion ◽  
Coastal Area ◽  
Isotopic Data ◽  
Area North

scholarly journals Stratigraphy and Depositional Environment of Mauddud Formation in Ratawi Oil wells of Southern Iraq

2021 ◽  
Vol 877 (1) ◽  
pp. 012030
Author(s):  
Maha Razaq Manhi ◽  
Hamid Ali Ahmed Alsultani
Keyword(s):  
Deep Sea ◽  
Lower Cretaceous ◽  
Depositional Environment ◽  
Carbonate Platform ◽  
Depositional Environments ◽  
Oil Wells ◽  
Oil Field ◽  
Microfacies Analysis ◽  
Thin Sections ◽  
Southern Iraq

Abstract The Mauddud Formation is Iraq’s most significant and widely distributed Lower Cretaceous formation. This Formation has been investigated at a well-23 and a well-6 within Ratawi oil field southern Iraq. In this work, 75 thin sections were produced and examined. The Mauddud Formation was deposited in a variety of environments within the carbonate platform. According to microfacies analysis studying of the Mauddud Formation contains of twelve microfacies, this microfacies Mudstone to wackestone microfacies, bioclastic mudstone to wackestone microfacies, Miliolids wackestone microfacies,Orbitolina wackestone microfacies, Bioclastic wackestone microfacies, Orbitolina packstone microfacies, Peloidal packstone microfacies, Bioclastic packstone microfacies, Peloidal to Bioclastic packstone microfacies, Bioclastic grainstone microfacies, Peloidal grainstone microfacies, Rudstone microfacies. Deep sea, Shallow open marine, Restricted, Rudist Biostrome, Mid – Ramp, and Shoals are the six depositional environments in the Mauddud Formation based on these microfacies.

scholarly journals Pre-Nagssugtoqidian crustal evolution in West Greenland: geology, geochemistry and deformation of supracrustal and granitic rocks north-east of Kangaatsiaq

2006 ◽  
Vol 11 ◽  
pp. 33-52
Author(s):  
Jean-François Moyen ◽  
Gordon R. Watt
Keyword(s):  
Sedimentary Basin ◽  
Granulite Facies ◽  
Great Circle ◽  
Granitic Rocks ◽  
Early Event ◽  
Porphyritic Granite ◽  
The Core ◽  
North East ◽  
Greenstone Belts ◽  
Area North

The area north-east of Kangaatsiaq features polyphase grey orthogneisses, supracrustal rocks and Kangaatsiaq granite exposed within a WSW–ENE-trending synform. The supracrustal rocks are comprised of garnet-bearing metapelites, layered amphibolites and layered, likewise grey biotite paragneisses. Their association and geochemical compositions are consistent with a metamorphosed volcano-sedimentary basin (containing both tholeiitic and calc-alkali lavas) and is similar to other Archaean greenstone belts. The Kangaatsiaq granite forms a 15 × 3 km flat, subconcordant body of deformed, pink, porphyritic granite occupying the core of the supracrustal synform, and is demonstrably intrusive into the amphibolites. The granite displays a pronounced linear fabric (L or L > S). The post-granite deformation developed under lower amphibolite facies conditions (400 ± 50°C), and is characterised by a regular, NE–SW-trending subhorizontal lineation and an associated irregular foliation, whose poles define a great circle; together they are indicative of highly constrictional strain. The existence of a pre-granite event is attested by early isoclinal folds and a foliation within the amphibolites that is not present in the granite, and by the fact that the granite cuts earlier structures in the supracrustal rocks. This early event, preserved only in quartz-free lithologies, resulted in high-temperature fabrics being developed under upper amphibolite to granulite facies conditions.

CLIMATE@COA project: Climate and human adaptation during the Last Glacial Period in the Côa Valley region (Portugal)

2021 ◽  
Author(s):  
Luca Dimuccio ◽  
Thierry Aubry ◽  
Lúcio Cunha ◽  
Nelson Rodrigues
Keyword(s):  
Late Pleistocene ◽  
Interdisciplinary Approach ◽  
Evolutionary Model ◽  
Depositional Environments ◽  
Glacial Period ◽  
Upper Palaeolithic ◽  
Last Glacial Period ◽  
Last Glacial ◽  
North East ◽  
The Last Glacial

<p>In Portugal, climate fluctuations of Late Pleistocene are well-known from marine record on the western Iberian continental margin, particularly of Marine Isotope Stages 4, 3 and 2, and they include various events of secular abrupt climate changes. During cooling phases the Heinrich Events (HE) occurred, corresponding to episodes of massive ice-discharges from Northern Hemisphere ice sheets. Furthermore, several climate phases with relatively warmer conditions, known as Dansgaard-Oeschger (D-O) cycles, characterized by an abrupt warming (D-O event) followed by a more gradual cooling, took place in-between HE. This pronounced climate instability that characterizes the Last Glacial Period between ca. 80-12 ka is recorded in a variety of marine and terrestrial archives worldwide. It had a recognized impact on the bioclimatic zones and, possibly, on the Neanderthal and Anatomically Modern Human (AMH) settlements of Iberia.</p><p>Based mainly on the study of geoarchaeological records preserved in caves and rock-shelters of Iberia, a correlation framework with climate shifts has been proposed to explain the observed discontinuities between sequences containing late Middle and early Upper Palaeolithic remains. Moreover, a climate driven model has been advanced to explain the chronological differences between northern and southern Pyrenean data by a later dispersion of AMH and the persistence of last Neanderthals in Southern Iberia, which were interpreted as a direct impact of HE4 (40-38 ka) in the distribution of large ungulate populations.</p><p>Despite all these data, the exact impact of HE on terrestrial systems, the evaluation of the latitudinal differentiation of their impact and time-gap, as well as the correlation between periods of relative stabilization/soil formation and the D-O events remain to be clearly established. In addition, the whole framework relating to the Middle-to-Upper Palaeolithic transition has been excessively dependent on karst archives and it should be investigated in other geomorphological settings - among these the fluvial and Iberian plateau (“Meseta”), both present in the Côa Valley region (Douro Basin, north-east of Portugal). Alluvial and colluvial deposits preserved in the Côa Valley (e.g. at the Cardina-Salto do Boi, Quinta da Barca Sul, Penascosa, Fariseu, Olga de Ervamoira sites) have demonstrated to be a valuable record of information about Late Pleistocene sedimentary processes, depositional environments, and hunter-gatherer’s behaviour at local and regional scales.</p><p>In this context, the CLIMATE@COA project (COA/CAC/0031/2019), funded by the Fundação para a Ciência e Tecnologia (FCT), proposes an integrated multi/interdisciplinary approach based on the stratigraphical, sedimentological, geochemical, geomorphological, geoarchaeological, and geochronological analyses of terrestrial record (natural and cultural) preserved in the Côa Valley and surrounding plateau areas, with the aim to develop an evolutionary model for the region and to deduce the environmental forcing factors for such evolution - namely climate and ecosystem changes. In addition, the project’s data will allow to define better the chronology of the transition between Neanderthal and AMH and to infer on land use and social organization in its environmental context.</p>

Sign in / Sign up

Export Citation Format

Share Document