Heavy Metals Concentration in Sediments of South Brittany Waters, France: An Ecological Risk Assessment Approach

Distribution patterns of selected heavy metals content in sediments from the Bay of Quiberon and Gulf of Morbihan were studied to understand the current heavy metals contamination due to urbanization and mariculture activities in the coastal area. Therefore, a survey was conducted and 196 sediments collected were characterized for heavy metals content using Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) after mix acid digestion process. The distribution maps of the concentrations of the heavy metals studied were produced as an isopleth map based on data interpolation by the ArcGIS software application. The association with the adverse effects on aquatic organisms was determined by the classification of the sediment according to the sediment quality guidelines. Therefore, two approaches were employed namely: direct comparison with Sediment Quality Guidelines (SQGs) by USEPA (United States Environmental Protection Agency) and comparison with other numerical SQGs, threshold effect level/probable effect level, and effect range low/effect range medium. In order to estimate the effect of multiple contaminations of heavy metals, the mean-ERM-quotient was calculated at each sampling point.

High resolution facies architecture and digital outcrop modeling of the Sandakan formation sandstone reservoir, Borneo:Implications for reservoir characterization and flow simulation

Advances in photogrammetry have eased the acquisition of high-resolution digital information from outcrops, enabling faster, non-destructive data capturing and improved reservoir modeling. Geocellular models for flow dynamics with in the virtual outcrop in siliciclastic deposits at different sets of sandstone facies architecture remain, however, a challenge. Digital maps of bedding, lithological contrast, spatial-temporal variations of bedding and permeability characteristics make it more easy to understand flow tortuosity in a particular architecture. An ability to precisely model these properties can improve reservoir characterization and flow modeling at different scales. Here we demonstrate the construction of realistic 2 D sandstone facies based models for a pragmatic simulation of flow dynamics using a combination of digital point clouds dataset acquired from LiDAR and field investigation of the Sandakan Formation, Sabah, Borneo.Additionally, we present methods for enhancing the accuracy of outcrop digital datasets for producing high resolution flow simulation. A well-exposed outcrop from the Sandakan Formation, Sabah, northwest Borneo having a lateral extent of 750 m was chosen in order to implement our research approach. Sandstone facies and its connectivity are well constrained by outcrop observations, data from air-permeability measurements, bilinear interpolation of permeability, grid construction and water vector analysis for flow dynamics.These proportions were then enumerated in terms of static digital outcrop model(DOM) and facies model based on sandstone facies bedding characteristics. Flow simulation of water vector analysis through each of the four sandstone facies types show persistent spatial correlation of permeability that align with either cross-bedded orientation or straight with more dispersion high quality sandstone(porosity 21.25%-41.2%and permeability 1265.20-5986.25 mD) and moderate quality sandstone(porosity 10.44%-28.75% and permeability 21.44-1023.33 mD). Whereas, in more heterolithic sandstone(wavy-to flaser-bedded and bioturbated sandstone), lateral variations in permeability show spatially non-correlated patterns over centimeters to tens of meters with mostly of low quality sandstone(porosity 3.4%-12.31% and permeability < 1 mD to 3.21 mD). These variations reflect the lateral juxtaposition in flow dynamics. It has also been resulted that the vertical connectivity and heterogeneities in terms of flow are mostly pragmatic due to the interconnected sandstone rather than the quality of sandstone.

Early Cenozoic rapid flight enigma of the Indian subcontinent resolved:Roles of topographic top loading and subcrustal erosion

Intrinsic magmatic processes are considered as critical operators of plate movements. Here we demonstrate the role of extrinsic processes consequent to intrinsic processes as a catalyst for anomalous rapid plate movement. The rapid and accelerated flight of the Indian subcontinent since Deccan volca- nism until its collision with Eurasia remains as one of the geological conundrums. Data on seismic to- mography, peninsular geomorphology and inferences on continuum of subcrustal structures are utilized to address this enigma. We propose geomorphic isostasy as the mechanism that has driven this fastest drift ever recorded in geological history. It was initiated by sudden instability after the Deccan volcanism and resultant extensive accumulation of lava pile over continental lithosphere of northern India, northern-eastern tilt due to crustal thickness heterogeneity and subcrustal thermal stratification. The drift was sustained by Carlsberg and Central Indian ridge-push until collision and sediment top loading at northeast thenceforth. These inferences and geomorphic isostasy as a catalytic mechanism necessitate variability of drift rates as integral inputs for any continental scale modeling.

Evolution of a Holocene banner bank controlled by morphodynamics and structural setting of a macrotidal coast: Saint-Brieuc Bay (NW-Europe)

The morphology and internal structure of the Horaine Bank(Bay of Saint-Brieuc,NW France)are described based on multibeam echosounder and high-resolution seismic datasets coupled with vibro-core data.The Horaine Bank shows large-scale bedforms in the lee of a submerged rocky shoal,which allowed defining it as a Banner Bank.The internal structure of the sandbank reveals four seismic units(U1-U4)on a Cambrian basement(U0).The basal unit U1 is interpreted as reworked lowstand fluvial sediments those infilled micro incised valleys during a rise in sea level.This unit is overlain by paleo-coastal barrier sand-spit(U2)whose development was controlled by swell in the context of a rapid rise in sea level.The successive prograding unit(U3)is interpreted as flooding deposits in continuity with unit U2.The unit U4 is characterized by oblique reflectors oriented in two opposite directions.This last unit,dated post 3500 yr BP,corresponds to migrating dunes superimposed on the bank and observable in the high-resolution bathymetric data.The strong correlation between tidal currents and the apparent clockwise migration of dune crests suggests the presence of a tidal gyre controlling the present-day dynamics of most of the Horaine bank dunes.This study proposes a new model for the construction of banner banks characterized by the gradual transition of a sand spit to a banner bank during marine transgression and ensuing hydrodynamic variability.

Hydrocarbon reserves of the South China Sea:Implications for regional energy security

The countries such as China,Vietnam,Philippines,Malaysia,Indonesia and Brunei that border South China Sea region have immense stakes in exploring and exploiting the natural resources of the region including hydrocarbon.More than the hydrocarbon reserves,the South China Sea is home to World’s high-networth trade route that brings the interests of non-geographic entities to this region.Further,the purported reserves of hydrocarbon in the region are in the orders of Persian Gulf but are not yet properly explored and the reserves recovered owing to territorial and non-claimant stakeholder’s influences/interventions.This paper is a synopsis of information on the hydrocarbon reserves of the South China Sea region,and evaluates the territorial and extra-territorial interests in the light of energy security and equitable development and utilization of natural resources from a geological perspective.We also suggest several measures for future consideration and implementation.

Removal notice to“Hydrocarbon reserves of the south China sea:Implications for regional energy security”[Energy Geosci.1/1-2(2020)1-7]

Available online<Date>This article has been removed:please see Elsevier Policy on Article Withdrawal(https://www.elsevier.com/about/our-business/policies/article-withdrawal).This article has been removed at the request of all the Authors,the Editor-in-Chief and the owner of the journal.

Structural Restoration of Carbonate Platform in the Southern Part of Central Luconia, Malaysia

Carbonates of Central Luconia, Malaysia, had been serving as hydrocarbon reservoirs for more than 25 years. However, the relationship and impacts of extensive tectonic events to the growth of Miocene carbonates in Central Luconia have not been revealed sufficiently. In this work, two carbonates platforms in the southern part of Central Luconia were used for detailed interpretation and seismic based structural restoration. This work had provided new insight for the interpreta- tion of carbonate growth in Central Luconia and its association with the surrounding tectonic. This work suggested three possible tectonic evolutions from Late Oligocene to Pliocene are responsible for the growth of carbonates in Central Luconia. These stages are equivalent with pre-carbonate stage （Late Oligocene-Early Miocene）, syn-carbonate stage （Middle-Late Miocene） and post-carbonate stage （Pliocene）. Rifting of the South China Sea and subduction of proto-South China Sea are believed to be responsible for the development of faulting during pre-carbonate stage, while movement of the ancient Baram Line is thought to control the parallel striking direction of normal faults during syn- carbonate stage. Finally, subsidence and compaction due to the overburden clastic materials from the prograding deltas is considered as the main reason for the impacts of gravitational tectonics in this area, which corresponding to the post-carbonate stage.