scholarly journals PALEOAMBIENTE DEPOSICIONAL E ORIGEM DA MATÉRIA ORGÂNICA DOS FOLHELHOS BETUMINOSOS DA FORMAÇÃO IPUBI, PORÇÕES LESTE E SUDESTE DA BACIA DO ARARIPE, NE DO BRASIL: EVIDÊNCIA DE N-ALCANOS E ISOPRENOIDES

2020 ◽  
Vol 30 (1) ◽  
pp. 31-44
Author(s):  
William Moura ◽  
João Carlos Araujo ◽  
Thales Lucio ◽  
João Adauto Souza Neto
Keyword(s):  
Marine Environment ◽  
Black Shales ◽  
Terrestrial Organism ◽  
Reducing Conditions ◽  
Transitional Environment

Paleoenvironmental conditions from cretaceous black shales of Ipubi Formation (Araripe Basin-NE Brasil) are continuously debated. The main point of controversy is if these rocks were deposited in a lacustrine or restricted marine environment. The present study was developed in these black shales, by saturated biomarkers analyses (n-alkanes and isoprenoids) to discuss about the paleoenvironment of deposition of those shales. The n-alkanes predominance between n-C13 and n-C19 reveal algalic contribution. However an influence of terrestrial organism is also observed by the presence of n-C27, n-C28, and n-C29. The Pr/Ph ratio and Pr/Ph vs. (Pr+n-C17)/(Fi+n-C18) diagram indicated both anoxic and hypersaline conditions during the deposition of those shales. The Pr/n-C17 vs. Ph/n-C18 diagram also suggests reducing conditions, and classify an algalic contribution as marine-transitional source. Thus, this study indicates that the investigated shales were deposited in reducing and hypersaline conditions in a restricted marine to transitional environment.

Mobility of Uranium, Thorium and Lanthanides Around the Bangombe Natural Reactor (Gabon)

1994 ◽  
Vol 353 ◽  
Author(s):  
R. Bros ◽  
F. Gauthier-Lafaye ◽  
P. Larque ◽  
J. Samuel ◽  
P. Stille
Keyword(s):  
Rare Earth ◽  
Rare Earth Elements ◽  
Clay Minerals ◽  
Nuclear Reactor ◽  
Black Shales ◽  
Weathering Profile ◽  
The Core ◽  
Reducing Conditions ◽  
Isotopic Studies ◽  
Textural Evidence

AbstractNew mineralogical and isotopic studies were carried out on samples from the Bangombé natural nuclear reactor. This reactor is located at shallow depth in the weathering profile and has been subjected to severe supergene alteration. Textural evidence indicates partial dissolution of uraninite in the Bangombé ore related to precipitation of Fe-Ti oxi-hydroxides and clay minerals (kaolinite and metahalloysite). As a consequence of the alteration of the uraninite, uranium and f issiogenic rare earth elements were released in the clayey border of the reactor, whereas radiogenic 232Th remained confined in the close vicinity of the core. A retention effect is also evidenced, under reducing conditions, in the black shales located above the reactor.

scholarly journals Paleoenvironment and Organic Matter Accumulation Mechanism of Marine–Continental Transitional Shales: Outcrop Characterizations of the Carboniferous–Permian Strata, Ordos Basin, North China

Energies ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 7445
Author(s):  
Leifu Zhang ◽  
Qun Zhao ◽  
Sizhong Peng ◽  
Zhen Qiu ◽  
Congjun Feng ◽  
...  
Keyword(s):  
Organic Matter ◽  
Ordos Basin ◽  
Black Shales ◽  
Lower Permian ◽  
High Deposition Rate ◽  
Organic Matter Accumulation ◽  
Accumulation Mechanism ◽  
Transitional Environment ◽  
Geochemical Analyses ◽  
Benxi Formation

In the Carboniferous–Permian period, several organic-rich black shales were deposited in a marine–continental transitional environment in the Linfen area on the eastern margin of the Ordos Basin. Integrated sedimentological and organic geochemical analyses are performed on an outcrop in order to clarify the relationship between paleoenvironment and organic matter accumulation. The results of this study show that the marine–continental transitional strata of the Upper Carboniferous Benxi Formation to Lower Permian Taiyuan and Shanxi Formation exposed in the Linfen area are composed of sandstone, shale, coal, and limestone. Total organic carbon (TOC) contents of the studied samples were mainly distributed in the range of 0.59%–35.4%, with an average of 7.32%. From Benxi Formation to Shanxi formation, the humidity gradually increased, and the climate gradually changed from hot and humid to warm and humid during Carboniferous to Permian. The deposition of the Shanxi Formation ended with the climate returning to hot and humid, having an oxic-suboxic conditions and a high paleoproductivity. Paleoredox conditions and paleoproductivity are the two vital factors controlling the formation of organic matter in black shales. The transitional environment characterized by oxic-suboxic, relatively high deposition rate, and various source of organic matter, although different from the marine environment, provides a good material basis for the deposition of organic-rich shales.

scholarly journals Identification of Clay Mineral Content Using Spectral Gamma Ray on Y1 Well in Karawang Area, West Java, Indonesia.

2020 ◽  
Vol 5 (3) ◽  
pp. 153-160
Author(s):  
Rahmat Catur Wibowo ◽  
Alia Puja Pertiwi ◽  
Suci Kurniati
Keyword(s):  
Source Rock ◽  
Mineral Content ◽  
Gamma Ray ◽  
Clay Content ◽  
Black Shales ◽  
Reducing Conditions ◽  
Natural Gamma ◽  
Redox Indicator ◽  
U Value ◽  
Low K

Northwest Java Basin (NWJB) is one of the proven hydrocarbon basins in Indonesia. The scope of this paper will focus onthe shales and sandstone interval within Y1 well in Karawang area, NWJB, Indonesia.A cored interval from Y1 well was chosen for an investigation of the clay minerology for the gamma-ray activity and with the purpose of determining how the Spectral Natural Gamma (SNG) log could be used as an indicator of source rock and reservoir quality. The Th/U as a redox indicator is used to assert that the shales are of anoxic conditions of shallow marine environments. Despite the relatively high insoluble Th values (60-74.15) ppm, the presence of U in substantial amounts, which only occurs in reducing conditions where it is preserved as a lower insoluble valence (U4+) explains for the low Th/U values ranging between (5.8-7.1) ppm/ppm. The overall Th/U value of the evaluated shales remain less than 25, where Th/U <25 is suggestive of marine sediments, whereas Th/U <4 is indicative of marine black shales of reducing conditions. Although no linear relationship was found between clay content and K, Th, or U, the K content characteristic three discrete reservoir characteristic (RC). The RC-I has predicted a matrix-supported texture with the highest K signal, illite and illitised kaolinite are roughly equal in importance as source of K. The RC-II has predicted a grain-supported texture with intermediate K content. K-feldspar, mica and illite as the main sources. The RC-III has predicted have a low K content with grain-supported texture and most of the K is hosted in feldspar. Overall, the laboratory measurements appear to be applicable to the log data, and, using SEM or XRD, the detail facies subdivision can be extended throughout the source rock and reservoir section based on the SNG log.

scholarly journals A rare disc-like holdfast of the Ediacaran macroalga from South China

2017 ◽  
Vol 91 (6) ◽  
pp. 1091-1101 ◽  
Author(s):  
Ye Wang ◽  
Yue Wang ◽  
Wei Du
Keyword(s):  
Water Column ◽  
Marine Environment ◽  
South China ◽  
Tissue Differentiation ◽  
Black Shales ◽  
Low Energy ◽  
Doushantuo Formation ◽  
Phylogenetic Affinity

AbstractThe fixing organ of the Precambrian macroalga was briefly described by most researchers as a holdfast or rhizoid, suggesting a fixation structure and/or tissue differentiation. An Ediacaran macroscopic alga, Discusphyton whenghuiensis n. gen. n. sp., with a complex disc-like holdfast and an unbranching thallus, has been collected, together with abundant and diverse macrofossils (i.e., the Wenghui biota) in black shales of the upper Doushantuo Formation (~560–551 Ma) in northeastern Guizhou, South China. The Wenghui biota lived in a relatively low-energy marine environment and was preserved in situ or nearby their growth position. Morphologically, the macroalgal thallus, including the compressed lamina and cylindrical stipe, might have been suspended in the water column for photosynthesis. Its holdfast, a rare fixing form, is complex in structure and construction, consisting of a globular rhizome and a discoidal rhizoid. The large-sized discoidal rhizoid is regarded as a flat-bottomed and dome-shaped organ to attach the macroalga on the water-rich muddy seafloor. The globular rhizome, expanded by a thallus on the substrate, was originally harder and spherical nature within the dome-shaped rhizoid. It may have been an important organ as a steering knuckle to connect between the stipe and the rhizoid. The macroscopic metaphyte D. whenghuiensis n. gen. n. sp. shows the appearance of complex holdfast in morphology and bio-functions. However, not enough is known, in the absence of more information, to decipher the phylogenetic affinity of D. whenghuiensis n. gen. n. sp. and the origin of a discoidal rhizoid.

scholarly journals Sedimentological Analysis of Core Samples to Decipher Depositional Environments: A Case Study of ‘Valz-01’ Well Niger-Delta Basin, Nigeria

2019 ◽  
pp. 1-16
Author(s):  
G. E. Maju-Oyovwikowhe ◽  
F. A. Lucas
Keyword(s):  
Marine Environment ◽  
Niger Delta ◽  
Depositional Environments ◽  
Textural Characterization ◽  
Beach Sediments ◽  
Transitional Environment ◽  
Niger Delta Basin ◽  
Lithologic Unit

Sedimentological studies of ninety-seven feet (97ft) of core, covering 1643 -1797.74 m from ‘Valz-01’ well Offshore Eastern Niger Delta was carried out using twenty-four (24) core slabbed samples with the aim of identifying the textural characterization of sediments from the various sectors of the lithologic unit and to determine the environment of deposition. Six lithofacies units were identified within the cored interval. They include: Muddy heterolith, laminated fine sandstone/siltstone, Fine sandstone/siltstone, Hummocky fine sandstone/siltstone, laminated shale sandy, and shale. Three depositional environments identified include marine environment, transitional and continental environment. The marine environment is characterized by the deposits of shale (1644.27 - 1709) m, while the continental environment is characterized by sandstone (1779 - 1781) m. The transitional environment is characterized by alternation of siltstone and shale (1643 – 1644.22 and 1781 – 1797.74) m. From the studies most of the analyzed samples are deposited in the delta influenced by fluvial and waves actions revealing beach sediments and turbidites.

Functional Characterization of PM6/13, a β3-specific (GPIIIa/CD61) Monoclonal Antibody that Shows Preferential Inhibition of Fibrinogen Binding over Fibronectin Binding to Activated Human Platelets

1998 ◽  
Vol 79 (01) ◽  
pp. 177-185 ◽  
Author(s):  
Ashia Siddiqua ◽  
Michael Wilkinson ◽  
Vijay Kakkar ◽  
Yatin Patel ◽  
Salman Rahman ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
Functional Characterization ◽  
Human Platelets ◽  
Western Blots ◽  
Activated Platelets ◽  
Reducing Conditions ◽  
Fibronectin Binding

SummaryWe report the characterization of a monoclonal antibody (MAb) PM6/13 which recognises glycoprotein IIIa (GPIIIa) on platelet membranes and in functional studies inhibits platelet aggregation induced by all agonists examined. In platelet-rich plasma, inhibition of aggregation induced by ADP or low concentrations of collagen was accompanied by inhibition of 5-hydroxytryptamine secretion. EC50 values were 10 and 9 [H9262]g/ml antibody against ADP and collagen induced responses respectively. In washed platelets treated with the cyclooxygenase inhibitor, indomethacin, PM6/13 inhibited platelet aggregation induced by thrombin (0.2 U/ml), collagen (10 [H9262]g/ml) and U46619 (3 [H9262]M) with EC50 = 4, 8 and 4 [H9262]g/ml respectively, without affecting [14C]5-hydroxytryptamine secretion or [3H]arachidonate release in appropriately labelled cells. Studies in Fura 2-labelled platelets revealed that elevation of intracellular calcium by ADP, thrombin or U46619 was unaffected by PM6/13 suggesting that the epitope recognised by the antibody did not influence Ca2+ regulation. In agreement with the results from the platelet aggregation studies, PM6/13 was found to potently inhibit binding of 125I-fibrinogen to ADP activated platelets. Binding of this ligand was also inhibited by two other MAbs tested, namely SZ-21 (also to GPIIIa) and PM6/248 (to the GPIIb-IIIa complex). However when tested against binding of 125I-fibronectin to thrombin stimulated platelets, PM6/13 was ineffective in contrast with SZ-21 and PM6/248, that were both potent inhibitors. This suggested that the epitopes recognised by PM6/13 and SZ-21 on GPIIIa were distinct. Studies employing proteolytic dissection of 125I-labelled GPIIIa by trypsin followed by immunoprecipitation with PM6/13 and analysis by SDS-PAGE, revealed the presence of four fragments at 70, 55, 30 and 28 kDa. PM6/13 did not recognize any protein bands on Western blots performed under reducing conditions. However Western blotting analysis with PM6/13 under non-reducing conditions revealed strong detection of the parent GP IIIa molecule, of trypsin treated samples revealed recognition of an 80 kDa fragment at 1 min, faint recognition of a 60 kDa fragment at 60 min and no recognition of any product at 18 h treatment. Under similar conditions, SZ-21 recognized fragments at 80, 75 and 55 kDa with the 55kDa species persisting even after 18 h trypsin treatment. These studies confirm the epitopes recognised by PM6/13 and SZ-21 to be distinct and that PM6/13 represents a useful tool to differentiate the characteristics of fibrinogen and fibronectin binding to the GPIIb-IIIa complex on activated platelets.

Spatial assemblage structure of shallow-water reef fish in Southwest Australia

2020 ◽  
Vol 649 ◽  
pp. 125-140
Author(s):  
DS Goldsworthy ◽  
BJ Saunders ◽  
JRC Parker ◽  
ES Harvey
Keyword(s):  
Shallow Water ◽  
Reef Fish ◽  
Marine Environment ◽  
Fish Assemblages ◽  
Canopy Cover ◽  
Reef Fishes ◽  
Reef Fish Assemblage ◽  
Reef Type ◽  
Present Distribution ◽  
Southwest Australia

Bioregional categorisation of the Australian marine environment is essential to conserve and manage entire ecosystems, including the biota and associated habitats. It is important that these regions are optimally positioned to effectively plan for the protection of distinct assemblages. Recent climatic variation and changes to the marine environment in Southwest Australia (SWA) have resulted in shifts in species ranges and changes to the composition of marine assemblages. The goal of this study was to determine if the current bioregionalisation of SWA accurately represents the present distribution of shallow-water reef fishes across 2000 km of its subtropical and temperate coastline. Data was collected in 2015 using diver-operated underwater stereo-video surveys from 7 regions between Port Gregory (north of Geraldton) to the east of Esperance. This study indicated that (1) the shallow-water reef fish of SWA formed 4 distinct assemblages along the coast: one Midwestern, one Central and 2 Southern Assemblages; (2) differences between these fish assemblages were primarily driven by sea surface temperature, Ecklonia radiata cover, non-E. radiata (canopy) cover, understorey algae cover, reef type and reef height; and (3) each of the 4 assemblages were characterised by a high number of short-range Australian and Western Australian endemic species. The findings from this study suggest that 4, rather than the existing 3 bioregions would more effectively capture the shallow-water reef fish assemblage patterns, with boundaries having shifted southwards likely associated with ocean warming.

PERAN DESIGNATED PERSON ASHORE (DPA) DALAM PENGOPERASIAN KAPAL YANG AMAN SESUAI KETENTUAN NASIONAL DAN INTERNASIONAL

2019 ◽  
Vol 20 (1) ◽  
Author(s):  
Suganjar Suganjar ◽  
Renny Hermawati
Keyword(s):  
Marine Environment ◽  
Emergency Preparedness ◽  
Safety Management ◽  
Shipping Industry ◽  
Safe Operation ◽  
International Regulation ◽  
Loss Of Life ◽  
Shipping Company ◽  
Environmental Protection Policy ◽  
Human Injury

<p><em>Safety management in the shipping industry is based on an international regulation. It is International Safety Management Code (ISM-Code) which is a translation of SOLAS ‘74 Chapter IX. It stated that t</em><em>he objectives of the Code are to ensure safety at sea, prevention of human injury or loss of life, and avoidance of damage to the environment, in particular, to the marine environment, and to property.it is also</em><em> requires commitment from top management to implementation on both company and on board. The implementation of the ISM-Code is expected to make the ship’s safety is more secure. The ISM-Code fulfillment refers to 16 elements, there are; General; Safety and Environmental Protection Policy; Company Responsibility and Authority; Designated Person(s); Master Responsibility and Authority; Resources and Personnel; Shipboard Operation; Emergency Preparedness; Report and Analysis of Non-conformities, Accidents and Hazardous Occurrences; Maintenance of the Ship and Equipment; Documentation; Company Verification, Review, and Evaluation;  Certification and Periodical Verification; Interim Certification; Verification; Forms of Certificate. The responsibility and authority of Designated Person Ashore / DPA in a shipping company is regulated in the ISM-Code. So, it is expected that DPA can carry out its role well, than can minimize the level of accidents in each vessels owned/operated by each shipping company.</em></p><p><em></em><strong><em>Keywords :</em></strong><em> ISM Code,</em><em> </em><em>Safety management, </em><em>Designated Person Ashore</em></p><p> </p><p> </p><p>Manajemen keselamatan di bidang pelayaran saat ini diimplementasikan dalam suatu peraturan internasional yaitu <em>International Safety Management Code</em> (<em>ISM-Code</em>) yang merupakan penjabaran dari <em>SOLAS 74 Chapter IX</em>-<em>Management for the safe operation of ships</em>. Tujuan dari <em>ISM-Code</em> <em>“The objectives of the Code are to ensure safety at sea, prevention of human injury or loss of life, and avoidance of damage to the environment, in particular, to the marine environment, and to property”</em> dan  <em>ISM-Code</em> menghendaki adanya komitmen dari manajemen tingkat puncak sampai pelaksanaan, baik di darat maupun di kapal.  Pemberlakuan <em>ISM-Code</em> tersebut diharapkan akan membuat keselamatan kapal menjadi lebih terjamin. Pemenuhan <em>ISM-Code</em> mengacu kepada 16 elemen yang terdiri dari ; umum; kebijakan keselamatan  dan perlindungan lingkungan; tanggung jawab dan wewenang perusahaan; petugas yang ditunjuk didarat; tanggung jawab dan wewenang nahkoda; sumber daya dan personil; pengopersian kapal; kesiapan menghadapi keadaan darurat; pelaporan dan analisis ketidaksesuaian, kecelakaan dan kejadian berbahaya; pemeliharaan kapal dan perlengkapan;  Dokumentasi; verifikasi, tinjauan ulang, dan evaluasi oleh perusahaan; sertifikasi dan verifikasi berkala; sertifikasi sementara; verifikasi; bentuk sertifikat. Tugas dan tanggungjawab <em>Designated Person Ashore/DPA </em>didalam suatu perusahaan pelayaran<em>, </em>telah diatur di dalam <em>ISM-Code.</em>  Sehingga diharapkan agar DPA dapat melaksanakan peranannya dengan baik, sehingga dapat menekan tingkat kecelakaan di setiap armada kapal yang dimiliki oleh setiap perusahaan pelayaran.</p><p class="Style1"><strong>Kata kunci</strong> : <em>ISM Code</em>, Manajemen keselamatan, <em>Designated Person Ashore</em></p>

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