scholarly journals Testing carbonate chemostratigraphy across differentiated ancient shallow-platform environments (Early Kimmeridgian, S Iberia)

2019 ◽  
Vol 10 (6) ◽  
pp. 2203-2218 ◽  
Author(s):  
Rute Coimbra ◽  
Beatriz Marques ◽  
Federico Olóriz
Keyword(s):  
Shallow Platform

Significance in the Integration of Facies Analysis, Stable Isotopes and Diagenetical Results for the High-Resolution Sequence Stratigraphy Characterization in the Shallow Platform of Shuaiba Formation, Lower Cretaceous, Abu Dhabi Onshore, UAE

2021 ◽  
Author(s):  
Kevin Michael Torres ◽  
Noura Al Madani ◽  
Rodrigo Rafael Gutierrez
Keyword(s):  
High Resolution ◽  
Direct Evidence ◽  
Facies Analysis ◽  
Carbonate Platform ◽  
Nutrient Supply ◽  
Abu Dhabi ◽  
Small Scale ◽  
Facies Association ◽  
Accommodation Space ◽  
Shallow Platform

Abstract The study presents the sequence stratigraphy of the carbonate platform focused in lower part of Shuaiba Formation, as well as the organization of the arrangement formed by the cyclical sedimentological evolution at high-resolution scale, through the facies analysis, diagenetical imprints and finally, significance of stable carbonate isotope results in the building up of carbonate platform in southeast Abu Dhabi. Interpreted stratigraphic surfaces from integration of depositional facies reviewed in all available cored data within studied area and stable carbon isotope results allowed that four small-scale regression-transgression depositional cycles can be discriminated which are stacked into a medium-scale sequence, that may record a 600 kyr Milankovitch signal. The small-scale sequences were correlated within the studied area using both conventional well logs and stable isotope records. Transgression hemicycles represent the increasing of accommodation space and can be identified in direct evidence, such as 25-40 ft. thickness of lithocodium/bacinella floatstones and skeletal peloidal packstones facies, association of facies interpreted within upper slope sub-environment. Likewise, in δ13C profiles, the rise/fall turnarounds of small-scale sequences are marked by negative δ13C peaks and associated with characteristics patterns: (1) proportion decrease of shallower sub-environments facies is interpreted as an rising relative sea-level and (2) decreasing δ13C trends interpreted to be related to decreasing nutrient supply. The medium/big pores of floatstones poorly connected in packstone matrix are expressed in the medium/high porosity with low permeabilities. In contrast, regressive hemicycles represent the reduction in accommodation space and can be characterized in direct evidence, such as the growing up of persistent 10-20 ft. thickness with thousands of meters of correlation of stromatoporoids and rudist facies, association of facies interpreted within shelf-margin complex sub-environment. In addition, the fall/rise turnarounds are marked by positive δ13C peaks, associated with the stromatoporoids/rudists mounds with characteristic patterns: (1) proportion increase of shallower sub-environments facies is interpreted as falling relative sea-level and increase in proximity and (2) increasing δ13C values interpreted to reflect increasing nutrient supply. Unusually very high permeability is attributed to the present of fractures and dissolution events that is enhanced where proportion of stromatoporoids facies are more pronounced. The described characterization resulted in the identification of genetic cycles that reproduce the sedimentological evolution, which are presented in small-scale sequences. In addition, the δ13C values enabled to understand the internal organization and the development of the carbonate building up in the Shuaiba shallow platform evolution. This study provides update and understanding on sedimentary facies, depositional pattern, and expands on previous published works, using new approach from semi-regional to local scales. Finally, results help to understand the laterally extensive water break-through thin intervals, which are directly related to the regressive hemicycles described previously.

Quelques observations petrographiques sur un recif du Sequanien d'Angoulins (Charente-Maritime)

1955 ◽  
Vol S6-V (4-6) ◽  
pp. 403-410
Author(s):  
Jean Lafuste
Keyword(s):  
Coral Reef ◽  
Terrigenous Material ◽  
Petrographic Study ◽  
Shallow Platform

Abstract A petrographic study of a Sequanian (Jurassic) coral reef deposit exposed in the cliff at Angoulins near La Rochelle, France. Formation of the reef probably took place on a shallow platform, and was accompanied by deposition of abundant terrigenous material under conditions of extremely variable currents.

scholarly journals Mapping of Conflicts of Use and Occupation of the Paranaguá Estuary Complex and Shallow Platform: Subsidies for Marine Spatial Planning

2020 ◽  
pp. 53-72
Author(s):  
Aika Miura ◽  
Mauricio A. Noernberg
Keyword(s):  
Human Activities ◽  
Spatial Planning ◽  
Marine Spatial Planning ◽  
Conservation Units ◽  
Conflict Zones ◽  
Gis And Remote Sensing ◽  
Commercial Housing ◽  
Rational Organization ◽  
Remote Sensing Techniques ◽  
Shallow Platform

The preference for housing in coastal environments has become a human strategy due to several factors; as biodiversity wealth, geographic strategy, or abundance of fishing resources. The coastal and estuarine environment is a place of multiple uses for industrial, commercial, housing, port, and ecologically essential purposes. An effective Marine Spatial Planning (MSP) is essential to establish a rational organization of the use of the marine space and the interactions between its uses, in order to balance the demands of development with the need to protect marine ecosystems, as well as to achieve social and economic objectives in a transparent and planned way (UNESCO-IOC, 2011). The present study identifies, maps, and separates the main human activities developed in the territorial space of the Paranaguá Estuarine Complex - Paraná, Brazil (CEP) and nearby shallow platform. Through Geographic Information Systems (GIS) and remote sensing techniques, it established the conflict zones and their impact on the marine environment and quantified areas of environmental protection affected by human activities. The results shows the regions between Pontal do Sul and Ponta do Poço, the southern portion of Baía das Laranjeiras and the Rasa Platform classified with High Conflict levels. Approximately 19% of the administrative limits of the Conservation Units (CU) in the region and 33% of the Damping Zones (DZ) are affected by anthropic activities and uses. In this way, the spatialization of existing conflicts in a place with broad uses for different purposes, would support to define economic strategies; direct actions for public policies, and decision making. Still, it can be a tool for the mitigation and compensation of environmental and social impacts, due to human activities in the study area. Keywords: Coastal management, geoprocessing, protected coastal areas, conservation units, coastal zone.

THE MARYBOROUGH BASIN

1966 ◽  
Vol 6 (1) ◽  
pp. 30 ◽  
Author(s):  
Peter L. Ellis
Keyword(s):  
Normal Fault ◽  
Lower Triassic ◽  
Deep Drilling ◽  
Offshore Area ◽  
Eastern Margin ◽  
The North ◽  
Reservoir Potential ◽  
Structural Entity ◽  
Shallow Platform ◽  
Time Point

The Maryborough Basin, occupying an area of 9,500 square miles, developed as a structural entity in the Mesozoic. Onshore regional mapping has shown that subsidence is controlled by ancient lineaments which have a north-westerly trend. These structural lines are characterised by normal fault movements with downthrow to the east. The eastern margin of the basin has been interpreted from geophysical data as a shallow platform. The sediments of the basin were severely folded in a post-Aptian orogeny.A maximum thickness of 31,000 feet is known in the post-Permian section. Marine conditions prevailed in the Lower Triassic, and again in the Aptian when 7,000 feet of shallow-water quartzose sediments were deposited. The remainder of the section comprises continental sediments. Currents flowing from the east in Aptian time point to an emergent high in this direction. Such a high may have been downfaulted during the post-Aptian orogeny. Four thousand feet of trachyandesitic pyroclastics and tuffaceous sediments which were deposited during the Neocomian may have been derived from an oceanic eruptive zone. This possibly corresponds to the eastern margin of the basin, and also to an interpreted vental belt in the Swain Reefs area immediately to the north-west.Mesozoic and Tertiary marine rocks are possible sources of hydrocarbon. Porous Jurassic orthoquartzite has reservoir potential, but this unit may only be tested by very deep drilling. Much of the onshore Cretaceous section is known to be tight. In the offshore area, the flattening of the northwesterly plunge of the fold structures in the Cretaceous rocks, with the possibility of the development of closures, together with the known thickening of porous, marine Tertiary sediments, enhance the prospect of hydrocarbon accumulation in this area.

scholarly journals Characteristics, distribution and diagenetic stages of chert in the La Silla Formation (Lower Ordovician), Argentine Precordillera

2009 ◽  
Vol 81 (4) ◽  
pp. 781-792 ◽  
Author(s):  
Mariana M. Raviolo ◽  
José A. Barbosa ◽  
Virgínio H. Neumann
Keyword(s):  
San Juan ◽  
Late Cambrian ◽  
Lower Ordovician ◽  
Argentine Precordillera ◽  
Diagenetic Evolution ◽  
Porous Sediments ◽  
Shallow Platform

The late Cambrian - late Tremadocian La Silla Formation is a carbonate unit of the eastern Precordillera in Argentina whose facies indicate a shallow platform environment. Until this moment, there were no studies that referred to the diagenetic evolution of these rocks. The present study involves the characteristics and distribution of the silicification that affects this unit and determines its different diagenetic stages through petrographic (with cathodoluminescence support) and stratigraphic analyses. An early diagenetic chert, in a stage previous to the compactation, was observed. This chert is related to silica-rich seawater in contact with permeable and porous sediments. A later pulse of chert, associated with fracturing, also occurs. The knowledge provided by the characteristics and distribution of chert in these carbonates is significant, especially when considering that the La Silla Formation in San Juan province is the most quarried unit for the elaboration of lime.

Middle Triassic carbonates of Eastern Iberia (Western Tethyan Realm): A shallow platform model

2021 ◽  
pp. 105904
Author(s):  
Alberto Pérez-López ◽  
Constantino Benedicto ◽  
Federico Ortí
Keyword(s):  
Middle Triassic ◽  
Shallow Platform

scholarly journals Mapeamento dos Recifes de Corais de Maracajaú/RN com o uso de Fotografias Aéreas de Pequeno Formato

2001 ◽  
Vol 28 (2) ◽  
pp. 417 ◽  
Author(s):  
WILLIAMS DA SILVA GUIMARÃES DE LIMA ◽  
RICARDO FARIAS DO AMARAL
Keyword(s):  
Coral Reef ◽  
Natural Resources ◽  
Rio Grande ◽  
Aerial Photographs ◽  
Climatic Parameters ◽  
Sand Waves ◽  
Environmental Damages ◽  
Tropical Weather ◽  
Favorable Conditions ◽  
Shallow Platform

The Rio Grande do Norte State has many attractive natural resources. One of them is its large coast, which still contains many native beaches. Due the tropical weather, beaches of the Rio Grande do Norte can be visited by local people and tourist nearly all seasons of the year. The Maracajaú Coral Barrier, located at the shallow platform of Maxaranguape – RN, consists of a region that has turned into a touristic attraction in the last decades. The principal reason for the increasing in the touristic exploration of the region is the favorable conditions of temperature of water, transparence and the shallow depth of the region that surround the Maracajú Coral Barrier. Despite of supporting a large part of the local finances, the disorganized exploration of the touristic activities, specially at the adjacencies of the coral barrier, has produced several damages to the environment. The first step to a prudent exploration of the touristc activities, and other ways of exploration of the coral barrier, is the identification of the protected areas by developing of an appropriate cartographic basis that can be used to aid planning for the exploration of the environment. The development of maps began with the interpretation of small format aerial photographs (scale near of 1:5000), which were used to delimitate the geometry and morphologic features of the coral reef. The acquisition of small format photographs depends of climatic parameters, such as influence of tides, winds and the limpidity of the sky. Respecting these parameters, it is possible to investigate many features. In this work was identified sand waves, submerged and emerged coral reef bodies and submerged channels. Thus, it is necessary to improve the knowledge of the coral barriers of Maracajaú in the way to support more specific researches on this ecosystem, which can establish the potentialities of the area, allowing the exploration with minimized environmental damages.

scholarly journals Paleocene Larger Foraminifera from the Pyrenean Basin with a recalibration of the Paleocene Shallow Benthic Zones

2020 ◽  
Vol 18 ◽  
pp. 1-69 ◽  
Author(s):  
J. Serra-Kiel ◽  
V. Vicedo ◽  
J.I. Baceta ◽  
G. Bernaola ◽  
A. Robador
Keyword(s):  
Taxonomic Study ◽  
Calcareous Nannofossil ◽  
Larger Foraminifera ◽  
Planktic Foraminifera ◽  
Depositional Settings ◽  
Stratigraphic Framework ◽  
Platform Margin ◽  
Two New Species ◽  
Reference Section ◽  
Shallow Platform

A taxonomic study of the larger foraminifera found in Paleocene rocks from the Pyrenean basin has led to the description of sixty taxa including two new species: Alveolina korresensis and Valvulineria bacetai. In this work, we present a chronostratigraphic recalibration of the Paleocene Shallow Benthic Zones (SBZ 1 to SBZ 4) based on correlation with calcareous nannofossil and planktic foraminifera biozones, all integrated within the stratigraphic framework of Paleocene platform to basin depositional sequences established for the whole Pyrenean domain. The samples were collected in autochtonous and parautochtonous deposits from ten key shallow platform stratigraphic sections, representative from coastal to platform margin depositional settings. The results from two base of slope sections with numerous intercalations of calcareous turbidites with penecontemporaneous platform-derived biota have been integrated in the study. The regional chronostratigraphic framework is derived from magneto-biochronological studies carried out in the Zumaia section, global reference section for the Danian-Selandian and Selandian-Thanertian GSSPs. The new calibration of the Paleocene SBZs is summarized as follows. The SBZ 1 is constrained to the first 1.09 m.y. of the Paleocene; this first Paleogene biozone lacks distinct larger foraminifera biomarkers and thus is defined by an association of non-exclusive taxa composed of Valvulineria patalaensis, Stomatorbina? binkhorsti, P.? antiqua and Bangiana hanseni. The SBZ 2 now appears as the biozone encompassing most of the Danian stage (from ca. 64.91 m.y. to 61.6 m.y.), and is characterized by the association of Haymanella elongata, Haymanella paleocenica, Kayseriella decastroi, Rotospirella conica, Pyrenerotalia depressa, Elazigina dienii and Paralockhartia eos. The SBZ 2-SBZ 3 boundary coincides with the base of the Selandian stage (ca. 61.6 m.y.). The SBZ 3 biozone is defined by Glomalveolina primaeva, Periloculina slovenica, Vania anatolica, Coskinon rajkae, Fallotella alavensis, Cribrobulimina carniolica, Miscellanea yvettae, Miscellanea juliettae, Miscellanites primitivus, Miscellanites minutus, Ranikothalia soldadensis, Nummulites heberti and Discocyclina seunesi. The SBZ 3-SBZ 4 boundary is now ascribed to ca. 57.2 m.y. The SBZ 4 biozone appears characterized by Glomalveolina levis, Alveolina korresensis, Hottingerina lukasi, Daviesina garumnensis, Assilina yvettae, Assilina azilensis and Nummulites catari. The SBZ 4-SBZ 5 boundary is placed at the Paleocene-Eocene boundary event (ca. 56.0 m.y.).

scholarly journals Geochemistry of volcanogenic clayey marine sediments from the Hazar-Maden Basin (Eastern Turkey)

2013 ◽  
Vol 64 (6) ◽  
pp. 467-482 ◽  
Author(s):  
Dicle Bal Akkoca ◽  
Sevcan Kürüm ◽  
Warren D. Huff
Keyword(s):  
Marine Sediments ◽  
Middle Eocene ◽  
Basic Type ◽  
Shallow Marine ◽  
X Ray ◽  
Eu Anomaly ◽  
Icp Ms ◽  
Southern Branch ◽  
Main Effects ◽  
Shallow Platform

Abstract The Hazar-Madeıı Basin sediments were deposited along the southern branch of the Neotethys Ocean margin during Late Maastrichtian-Middle Eocene times. X-ray powder diffraction (XRD), ICP-AES, ICP-MS and scanning electron microscopy (SEM) were performed on samples of the Upper Maastrichtian-Middle Eocene Hazar Group and the Middle Eocene Maden Complex from the Hazar-Maden Basin to investigate the main effects of depositional envi- ronmental parameters in three sections belonging to deeper marine (slope), proximal arc volcanic (Mastarhill and Yukaribag sections) and shallow platform marine (Sebken section) settings. Marine sediments contain clay minerals (smectite, smectite/chlorite, chlorite, illite, interstratified illite/smectite, illite/chlorite, palygorskite), clinoptilolite, quartz, feldspar, calcite, dolomite, opal-CT and hematite. The clays are dominated by iron-rich smectites. La, Zr and Th concentrations are high in the shallow marginal Sebken section where the terrestrial detrital contribution is significant, while Sc and Co are more dominant in the deeper marine (slope) Yukaribag section, which is represented by basic-type volcanism and a higher contribution of hydrothermal phases. In a chondrite-normalized REE diagram, the negative Eu anomaly in samples from Sebken, the section which was deposited in a shallow marine environment, is less significant than that of the other two sections indicating the presence of a high terrestrial contribution in that part of the basin. A decrease in LREE v/HREEiV and Lajv/Ybv, LaiV/Sin v ratios from Sebken to Mastarhill and the Yukaribag sections indi- cates deepening of the basin and an increasing contribution of volcanism in that direction.

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