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1
Lee, Won-Je. "Choanoflagellates (Protist) from Marine Sediments of South-Eastern Australia". Korean Journal of Systematic Zoology 23, n. 1 (31 maggio 2007): 1–7. http://dx.doi.org/10.5635/kjsz.2007.23.1.001.
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Maher, W. A. "Trace metal concentrations in marine organisms from St. Vincent Gulf, South Australia". Water, Air, and Soil Pollution 29, n. 1 (maggio 1986): 77–84. http://dx.doi.org/10.1007/bf00149330.
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Jones, MR. "Surficial sediments of the western Gulf of Carpentaria, Australia". Marine and Freshwater Research 38, n. 1 (1987): 151. http://dx.doi.org/10.1071/mf9870151.
Testo completoAbstract (sommario):
Modern sedimentation in the Gulf of Carpentaria is confined principally to marginal areas in water depths of less than 50 m. Within this zone, the distribution of sediments is irregular, being controlled by proximity to sediment sources and degree of exposure to waves and tidal activity. This is particularly so in the western gulf, where fluvial sediments supplied to Limmen Bight have been transported by waves and tides northwards beyond that embayment to accumulate in the sheltered environment of Blue Mud Bay. Limmen Bight is exposed to the south-easterlies, which produce sufficient wave action in the nearshore zone to prevent the widespread deposition of fine-grained terrigenous sediments. As a result, relict sand deposits occupy much of the floor of Limmen Bight in areas shallower than about 25 m. In deeper areas, terrigenous muds are deposited at a low rate over relict fluvial and marine sediments. The relict deposits accumulated in continental and nearshore marine environments during low-sea-level periods of the late Pleistocene.
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Fernandes, Milena, Ali Shareef, Rai Kookana, Sam Gaylard, Sonja Hoare e Tim Kildea. "The distribution of triclosan and methyl-triclosan in marine sediments of Barker Inlet, South Australia". Journal of Environmental Monitoring 13, n. 4 (2011): 801. http://dx.doi.org/10.1039/c0em00612b.
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Schrale, G., R. Boardman e M. J. Blaskett. "Investigating Land Based Disposal of Bolivar Reclaimed Water, South Australia". Water Science and Technology 27, n. 1 (1 gennaio 1993): 87–96. http://dx.doi.org/10.2166/wst.1993.0022.
Testo completoAbstract (sommario):
The Bolivar Sewage Treatment Works (STW) processes the urban and industrial sewage from the northern and eastern suburbs of Adelaide. The treatment capacity is equivalent to the sewage production of 1.1 million people. The disposal of more than 40 000 ML of reclaimed water into the sea has caused a progressive degradation of about 950 ha of seagrass beds which threatens the sustainability of the fisheries and marine ecosystems of Gulf St. Vincent. The current practice will no longer be viable to achieve compliance with the SA Marine Environment Protection Act, 1990. A Inter-Departmental Working Party recommmended that the Bolivar reclaimed water be disposed by irrigation of suitable land on the coastal plains north of Adelaide. They proposed the construction of two pipelines: a 12 km long pipeline to extend the distribution of reclaimed water in the most intense portion of the 3 500 hectares of irrigated horticulture on the Northern Adelaide Plains, and a second, 18 km long pipeline to deliver the remainder to a more northerly site for irrigation of an estimated 4 000 hectares of hardwood plantations. The paper summarizes the findings as they relate to public health, environmental, technical and financial aspects of land based disposal. Land based disposal would completely eliminate the marine degradation and also arrest the over-use of the NAP underground water resources for horticulture. The total net costs over thirty years for land based disposal are about $ 21.8 million. The ‘horticultural' pipeline of the land based disposal scheme is expected to be commercially viable. A shortfall in revenue from the afforestation component is expected and may need to be considered as an environmental cost of ceasing marine disposal.
6
Murray‐Wallace, C. V., e R. W. L. Kimber. "Evaluation of the amino acid racemization reaction in studies of Quaternary marine sediments in South Australia". Australian Journal of Earth Sciences 34, n. 3 (settembre 1987): 279–92. http://dx.doi.org/10.1080/08120098708729411.
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Cann, John H., Antonio P. Belperio, Victor A. Gostin e Colin V. Murray-Wallace. "Sea-Level History, 45,000 to 30,000 yr B.P., Inferred from Benthic Foraminifera, Gulf St. Vincent, South Australia". Quaternary Research 29, n. 2 (marzo 1988): 153–75. http://dx.doi.org/10.1016/0033-5894(88)90058-0.
Testo completoAbstract (sommario):
Surficial sediments of Gulf St. Vincent, South Australia, are predominantly bioclastic, cool-temperate carbonates. Benthic foraminifera are abundant and distribution of species is closely related to water depth. For example, Massilina milletti is most common at depths ca. 40 m, while Discorbis dimidiatus is characteristics of shallow, subtidal environments. Elphidium crispum, a shallow-water species, and E. macelliforme, favoring deeper water, provide a useful numerical ratio. Their logarithmic relative abundance, in the sediment size fraction 0.50–0.25 mm, correlates strongly with water depth. Vibrocores SV 4 and SV 5 recovered undisturbed sections of Quaternary strata from the deepest part (ca. 40 m) of Gulf St. Vincent. Amino acid racemization and radiocarbon age determinations show that late Pleistocene sections of the cores were deposited over the time ca. 45,000 to 30,000 yr B.P. Species of fossil foraminifera, recovered from these sections, are mostly extant in modern Gulf St. Vincent, thus allowing paleoecological inferences of late Pleistocene sea levels. These inferred sea-level maxima can be correlated with those determined from study of Huon Peninsula coral reef terraces. Initial estimates of tectonically corrected sea levels for transgressions in Gulf St. Vincent at 40,000 and 31,000 yr B.P. are −22.5 m and −22 m, respectively. The intervening regression lowered sea level to −28 m.
8
Shen, Li, Liu, Li e Zhang. "Gas Permeability and Production Potential of Marine Hydrate Deposits in South China Sea". Energies 12, n. 21 (28 ottobre 2019): 4117. http://dx.doi.org/10.3390/en12214117.
Testo completoAbstract (sommario):
The permeability of marine sediments is critical to the gas production assessment of hydrate reservoirs. In this work, the sample of natural marine sediments was obtained from Shenhu Area of South China Sea at the depth of 1600 m, and the gas permeability of the sample was measured in the laboratory under various confining pressures. The porosity of the sample decreased from 41.82% to 29.54%, and the effective gas permeability of the sample decreased from 2.638 × 10−16 m2 to 0.872 × 10−16 m2 as the confining pressure increased from 0 to 23 MPa. The gas permeability of the natural sediments was determined to be 1.535 × 10−16 m2 with confining pressure of 15 MPa and porosity of 32%. The deformation of sample in longitudinal direction was sensitive to the confining pressure, and the compressibility in the radial direction was limited. On the basis of the experimental results, the particle size term in the classical Kozeny–Carman equation was revised by correction factor N, and the experimental results fitted well with the curves with N = 2.40. Moreover, the gas production potential at the site of W–17 in the Shenhu Area was numerically studied based on the measured gas permeability. The simulation results showed that the cumulative volume of produced gas was approximately 1.46 × 106 ST m3 after 30 years. A new enlarged permeable well wall method was proposed to improve the poor gas production caused by low permeability. The cumulative gas production increased by 2.7 times as the permeable well wall radius increased from 0 to 5 m. Regarding the gas and water production rates, water production increased with the increase of permeable well wall radius. Spatial distributions of hydrate and gas saturations, pressure, and temperature were investigated as well.
9
Moussavi-Harami, R., e D. I. Gravestock. "BURIAL HISTORY OF THE EASTERN OFFICER BASIN, SOUTH AUSTRALIA". APPEA Journal 35, n. 1 (1995): 307. http://dx.doi.org/10.1071/aj94019.
Testo completoAbstract (sommario):
The intracratonic Officer Basin of central Australia was formed during the Neoproterozoic, approximately 820 m.y. ago. The eastern third of the Officer Basin is in South Australia and contains nine unconformity-bounded sequence sets (super-sequences), from Neoproterozoic to Tertiary in age. Burial history is interpreted from a series of diagrams generated from well data in structurally diverse settings. These enable comparison between the stable shelf and co-existing deep troughs. During the Neoproterozoic, subsidence in the north (Munyarai Trough) was much higher than in either the south (Giles area) or northeast (Manya Trough). This subsidence was related to tectonic as well as sediment loading. During the Cambrian, subsidence was much higher in the northeast and was probably due to tectonic and sediment loading (carbonates over siliciclastics). During the Early Ordovician, subsidence in the north created more accommodation space for the last marine transgression from the northeast. The high subsidence rate of Late Devonian rocks in the Munyarai Trough was probably related to rapid deposition of fine-grained siliciclastic sediments prior to the Alice Springs Orogeny. Rates of subsidence were very low during the Early Permian and Late Jurassic to Early Cretaceous, probably due to sediment loading rather than tectonic sinking. Potential Neoproterozoic source rocks were buried enough to reach initial maturity at the time of the terminal Proterozoic Petermann Ranges Orogeny. Early Cambrian potential source rocks in the Manya Trough were initially mature prior to the Delamerian Orogeny (Middle Cambrian) and fully mature on the Murnaroo Platform at the culmination of the Alice Springs Orogeny (Devonian).
10
Cann, John H., Colin V. Murray-Wallace, Naomi J. Riggs e Antonio P. Belperio. "Successive foraminiferal faunas and inferred palaeoenvironments associated with the postglacial (Holocene) marine transgression, Gulf St Vincent, South Australia". Holocene 16, n. 2 (febbraio 2006): 224–34. http://dx.doi.org/10.1191/0959683606hl907rp.
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Murray-Wallace, C. V., A. P. Belperio, V. A. Gostin e J. H. Cann. "Amino acid racemization and radiocarbon dating of interstadial marine strata (oxygen isotope stage 3), Gulf St. Vincent, South Australia". Marine Geology 110, n. 1-2 (febbraio 1993): 83–92. http://dx.doi.org/10.1016/0025-3227(93)90107-7.
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Hwang, Charnsmorn, Chih-Hua Chang, Michael Burch, Milena Fernandes e Tim Kildea. "Effects of Epiphytes and Depth on Seagrass Spectral Profiles: Case Study of Gulf St. Vincent, South Australia". International Journal of Environmental Research and Public Health 16, n. 15 (29 luglio 2019): 2701. http://dx.doi.org/10.3390/ijerph16152701.
Testo completoAbstract (sommario):
Seagrasses are a crucial indicator species of coastal marine ecosystems that provide substratum, shelter, and food for epiphytic algae, invertebrates, and fishes. More accurate mapping of seagrasses is essential for their survival as a long-lasting natural resource. Before reflectance spectra could properly be used as remote sensing endmembers, factors that may obscure the detection of reflectance signals must be assessed. The objectives in this study are to determine the influence of (1) epiphytes, (2) water depth, and (3) seagrass genus on the detection of reflectance spectral signals. The results show that epiphytes significantly dampen bottom-type reflectance throughout most of the visible light spectrum, excluding 670–679 nm; the depth does influence reflectance, with the detection of deeper seagrasses being easier, and as the depth increases, only Heterozostera increase in the exact “red edge” wavelength at which there is a rapid change in the near-infrared (NIR) spectrum. These findings helped improve the detection of seagrass endmembers during remote sensing, thereby helping protect the natural resource of seagrasses.
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Vetrimurugan, E., V. C. Shruti, M. P. Jonathan, Priyadarsi D. Roy, B. K. Rawlins e D. M. Rivera-Rivera. "Metals and their ecological impact on beach sediments near the marine protected sites of Sodwana Bay and St. Lucia, South Africa". Marine Pollution Bulletin 127 (febbraio 2018): 568–75. http://dx.doi.org/10.1016/j.marpolbul.2017.12.044.
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Beale, D. J., J. Crosswell, A. V. Karpe, S. S. Metcalfe, P. D. Morrison, C. Staley, W. Ahmed, M. J. Sadowsky, E. A. Palombo e A. D. L. Steven. "Seasonal metabolic analysis of marine sediments collected from Moreton Bay in South East Queensland, Australia, using a multi-omics-based approach". Science of The Total Environment 631-632 (agosto 2018): 1328–41. http://dx.doi.org/10.1016/j.scitotenv.2018.03.106.
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Fraser, Matthew W., Gary A. Kendrick, Pauline F. Grierson, James W. Fourqurean, Mathew A. Vanderklift e Diana I. Walker. "Nutrient status of seagrasses cannot be inferred from system-scale distribution of phosphorus in Shark Bay, Western Australia". Marine and Freshwater Research 63, n. 11 (2012): 1015. http://dx.doi.org/10.1071/mf12026.
Testo completoAbstract (sommario):
Differences in phosphorus (P) availability can influence the ecology and physiology of seagrass communities; and are usually inferred from changes in the relative P content in seagrass leaves. Shark Bay is a subtropical marine embayment, with decreasing P concentrations in the water column and sediments from north to south across the entire embayment. We examined the P and nitrogen (N) content of seagrass leaves and P content of sediments across the Faure Sill and Wooramel delta region of Shark Bay, to determine whether the leaf content of seagrasses in Shark Bay also decreased from north to south over smaller spatial scales. Nutrient content of Amphibolis antarctica and Halodule uninervis were highly variable and were not strongly correlated with sediment P concentrations. Mean N : P ratios of seagrasses (<33.5) were not indicative of P limitation, as has been previously assumed for Shark Bay. We conclude that availability of P for uptake by seagrasses across Shark Bay may be highly localised and cannot be predicted from system-scale gradients (>100 km) of sedimentary P distributions. We suggest that P availability to seagrasses is more likely a complex function of differing nutrient inputs, rates of delivery to the plants and cycling rates.
16
Maher, William A., Simon D. Foster, Anne M. Taylor, Frank Krikowa, Elliot G. Duncan e Anthony A. Chariton. "Arsenic distribution and species in two Zostera capricorni seagrass ecosystems, New South Wales, Australia". Environmental Chemistry 8, n. 1 (2011): 9. http://dx.doi.org/10.1071/en10087.
Testo completoAbstract (sommario):
Environmental context Arsenic concentrations and species were determined in seagrass ecosystems where the food web was established using carbon and nitrogen isotopes. There was a clear increase in the proportion of arsenobetaine in tissues of higher trophic level organisms, which is attributed to an increasing arsenobetaine content of the diet and the more efficient assimilation and retention of arsenobetaine over other arsenic species. The results provide an explanation for the prominence of arsenobetaine in higher marine animals. Abstract Arsenic concentrations and species were compared in biota from two Zostera capricorni ecosystems. Mean arsenic concentrations were not significantly different for non‐vegetative sediment, rhizosphere sediment, Z. capricorni blades, roots, rhizomes, epiphytes, amphipods, polychaetes, molluscs, crustaceans and fish, but were significantly different in detritus. Sediments and plant tissues contained mostly inorganic arsenic and PO4–arsenoriboside. Detritus contained mostly PO4–arsenoriboside. Fish tissues contained predominately arsenobetaine. Other animals had lower proportions of arsenobetaine and variable quantities of minor arsenic species. Bioconcentration but not biomagnification of arsenic is occurring with no evidence of arsenic hyper accumulation. The proportion of arsenobetaine increases through the food web and is attributed to a shift from a mixed diet at lower trophic levels to animals containing mostly arsenobetaine at higher trophic levels and the more efficient retention of arsenobetaine, compared to other arsenic species.
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Maloney, D., C. Sargent, N. G. Direen, R. W. Hobbs e D. R. Gröcke. "Re-evaluation of the Mentelle Basin, a polyphase rifted margin basin, offshore south-west Australia: new insights from integrated regional seismic datasets". Solid Earth Discussions 3, n. 1 (3 febbraio 2011): 65–103. http://dx.doi.org/10.5194/sed-3-65-2011.
Testo completoAbstract (sommario):
Abstract. Vintage 2-D (two dimensional) seismic reflection surveys from the sparsely explored Mentelle Basin (western Australian margin) have been re-processed and integrated with recent high quality seismic survey, and stratigraphic borehole data. Interpretation of these data sets allows the internal geometry of the Mentelle Basin fill and depositional history to be reanalysed with a greater degree of confidence. Basin stratigraphy can be subdivided into several seismically defined megasequences, separated by major unconformities related to both the Valanginian breakup between India-Madagascar and Australia-Antarctica, and tectonically-driven switches in deposition through the Albian. Resting on the Valanginian unconformity are several kilometre-scale mounded structures that formed during late Jurassic to early Cretaceous extension. These have previously been interpreted as volcanic edifices, although direct evidence of volcanic feeder systems is lacking. An alternative interpretation is that these features may be carbonate build-ups. The latter interpretation carries significant climatic ramifications, since carbonate build-ups would have formed at high palaeolatitude, ~60° S. Soon after breakup, initial subsidence resulted in a shallow marine environment and Barremian-Aptian silty-sandy mudstones were deposited. As subsidence continued, thick Albian ferruginous black clays were deposited. Internally, black clay megasequences show previously unresolved unconformities, onlapping and downlapping packages, which reflect a complex depositional, rifting and subsidence history, at odds with their previous interpretation as open marine sediments. Southwestwards migration of the Kerguelen hotspot led to thermal contraction and subsidence to the present day water depth (~3000 m). This was accompanied by Turonian-Santonian deposition of massive chalk beds, which are unconformably overlain by pelagic Palaeocene-Holocene sediments. This substantial unconformity is related to the diachronous breakup and onset of slow spreading between Australia and Antarctica, which may have led to the reactivation and inversion of basement faults, followed by rapid seafloor spreading from the middle Eocene to the present.
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Yuan, Yilong, Tianfu Xu, Yingli Xia e Xin Xin. "Effects of Formation Dip on Gas Production from Unconfined Marine Hydrate-Bearing Sediments through Depressurization". Geofluids 2018 (26 giugno 2018): 1–11. http://dx.doi.org/10.1155/2018/5836293.
Testo completoAbstract (sommario):
The effects of geologic conditions and production methods on gas production from hydrate-bearing sediments (HBS) have been widely investigated. The reservoir was usually treated as horizontal distribution, whereas the sloping reservoir was not considered. In fact, most strata have gradients because of the effects of geological structure and diagenesis. In this study, based on currently available geological data from field measurements in Shenhu area of the South China Sea, the effects of formation dip on gas production were investigated through depressurization using a horizontal well. The modeling results indicate that the strategy of horizontal well is an effective production method from the unconfined Class 2 HBS. The predicted cumulative volume of methane produced at the 1000 m horizontal well was 4.51 × 107 ST m3 over 5-year period. The hydrate dissociation behavior of sloping formation is sensitive to changes in the reservoir pressure. As in unconfined marine hydrate reservoir, the sloping formation is not conducive to free methane gas recovery, which results in more dissolved methane produced at the horizontal well. The obvious issue for this challenging target is relatively low exploitation efficiency of methane because of the recovery of very large volumes of water. Consequently, the development of the favorable well completion method to prevent water production is significantly important for realizing large scale hydrate exploitation in the future.
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Cann, John H., Robert P. Bourman e Elizabeth J. Barnett. "Holocene Foraminifera as Indicators of Relative Estuarine-Lagoonal and Oceanic Influences in Estuarine Sediments of the River Murray, South Australia". Quaternary Research 53, n. 3 (maggio 2000): 378–91. http://dx.doi.org/10.1006/qres.2000.2129.
Testo completoAbstract (sommario):
AbstractIn southeastern South Australia, the River Murray debouches through a coastal barrier separating euryhaline estuarine-lagoonal waters from the Southern Ocean. Depending upon the relative freshwater outflow of the river and ingress of the ocean, water salinity varies greatly within the lower estuary. Ammonia beccarii and Elphidium articulatum are euryhaline species of foraminifera that characterize the estuary and back-barrier Coorong Lagoon. The inner-shelf marine environment hosts an assemblage in which Discorbis dimidiatus, E. crispum, E. macelliforme, and various cibicidid species predominate. In cored sediments recovered from the shallow lower estuary, the relative abundance of A. beccarii + E. articulatum was compared with that of D. dimidiatus + E. crispum + E. macelliforme + other species. These data, and AMS radiocarbon ages determined for foraminifera and ostracods, provide evidence of a change from maximum oceanic influence (5255 ± 60 yr B.P.) to maximum estuarine influence (3605 ± 70 yr B.P.). Over this same time interval, sea level fell relatively by about 2 m. However, the event was also contemporaneous with falling water levels in several Victorian lakes, and it is thus attributed to onset of climatic aridity. Reduced precipitation in the River Murray catchment and reduced freshwater outflow enhanced development of the flood-tide delta and constriction of the mouth.
20
Parent, Michel, e Serge Occhietti. "Late Wisconsinan Deglaciation and Champlain Sea Invasion in the St. Lawrence Valley, Québec". Géographie physique et Quaternaire 42, n. 3 (18 dicembre 2007): 215–46. http://dx.doi.org/10.7202/032734ar.
Testo completoAbstract (sommario):
ABSTRACT Champlain Sea history is directly linked to Late Wisconsinan deglacial episodes. Champlain Sea Phase I (Charlesbourg Phase) began in the Québec area at about 12.4 ka. It represented a western extension of the Goldthwait Sea between remnant Appalachian ice masses and the Laurentide Ice Sheet. Further south, at about the same time, in the Appalachian uplands and piedmont, high-level glacial lakes were impounded by the ice-front during glacial retreat toward NNW: lakes Vermont, Memphrémagog and Mégantic. Lowlands of the Upper St. Lawrence and Lake Champlain valleys were progressively deglaciated and inundated by Lake Iroquois and Lake Vermont. At about 12.1 ka, these two lakes coalesced and formed a single water-body, here referred to as Lake Candona. After the Ulverton-Tingwick Moraine was constructed, this lake extended northeastward onto the Appalachian piedmont where varved sediments containing Candona subtriangulata underlie marine clays. Current data and interpretations bring into question the former concept of the Highland Front Moraine System. The invasion of the main basin, or Champlain Sea Phase II, began around 12 ka. Replacement of Lake Candona by the sea resulted in a fall of about 60 m in water levels. Champlain Sea Phase III began at the end of the Saint-Narcisse episode, at about 10.8 ka. At this time marine waters were able to enter valleys of the Laurentian Highlands where brackish or fresh paramarine basins developed.
21
Ward, TJ, e PA Hutchings. "Effects of trace metals on infaunal species composition in polluted intertidal and subtidal marine sediments near a lead smelter, Spencer Gulf, South Australia". Marine Ecology Progress Series 135 (1996): 123–35. http://dx.doi.org/10.3354/meps135123.
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Bush, Richard T., Roger McGrath e Leigh A. Sullivan. "Occurrence of marcasite in an organic-rich Holocene estuarine mud". Soil Research 42, n. 6 (2004): 617. http://dx.doi.org/10.1071/sr03079.
Testo completoAbstract (sommario):
Substantial marcasite and pyrite were recently identified in the upper-most unoxidised Holocene clay–peat sediments at Bungawalbin Swamp, a coastal backswamp on the Richmond River floodplain, north-east New South Wales, Australia. Marcasite (FeS2), the mineral dimorph of pyrite, is considered a rare secondary mineral in estuarine sediments and its abundance at Bungawalbin Swamp is highly unusual. The morphology and distribution of marcasite in the sulfidic sedimentary profile was examined and compared with the palynological record. Marcasite, recognised by its distinctive platy morphology and disulfide composition, occurred exclusively within organic remnants in only the upper most 1 m of the sulfidic sediment layer. Pyrite occurred throughout the sulfidic profile. A dramatic change in the sedimentary conditions at Bungawalbin Swamp from a marine environment, characterised by the presence of avicenniaceae (i.e. mangrove), to a fresh–brackish environment correlates directly with the occurrence of marcasite. The occurrence of substantial marcasite may provide a valuable environmental proxy of fresh–brackish depositional swamp environments.
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Monbet, Phil, Ian D. McKelvie e Paul J. Worsfold. "Phosphorus speciation, burial and regeneration in coastal lagoon sediments of the Gippsland Lakes (Victoria, Australia)". Environmental Chemistry 4, n. 5 (2007): 334. http://dx.doi.org/10.1071/en07049.
Testo completoAbstract (sommario):
Environmental context. Eutrophication can lead to the production of harmful algal blooms and is one of the world’s most serious water quality issues. Phosphorus is potentially the limiting macro-nutrient in fresh, estuarine and some marine waters. Consequently, it plays a crucial role in determining the ecological status of many aquatic ecosystems. Considerable effort has been invested in monitoring dissolved reactive phosphorus and total phosphorus in the water column, but less is known about the speciation of phosphorus, particularly in the sediment. This compartment is an important and dynamic reservoir of phosphorus and a potential long-term source of phosphorus release to the water column by the sediment–water interface. This paper investigates the solid-phase speciation and reorganisation of phosphorus within the sediments of a shallow lake system in south-east Australia (the Gippsland Lakes) which suffers from recurring harmful algae blooms. Various strategies are proposed to determine the minimum realistic timescale required to deplete the sediment of labile and reactive phosphorus species. Abstract. Solid-phase phosphorus pools in the sediments of two shallow lakes (Wellington and Victoria) in the Gippsland Lakes coastal lagoon system of south-east Australia are discussed. Cores (20-cm depth) were taken in summer and winter in both lakes and a sequential extraction scheme (SEDEX) was used to profile the exchangeable P (Pex), iron oxide/hydroxide bound P (PFe), authigenic P (Pauth), detrital P (Pdet) and organic P (Porg). Pore-water (Ppw) dissolved reactive phosphorus concentration profiles were also measured. The dominant forms of P were PFe (up to 53%) and Porg (35–55%), with the PFe fraction playing a key role in the short-term retention of P in the sediment. Benthic phosphorus fluxes at the sediment–water interface (μmol m–2 d–1) were determined from the sequential extraction data. The results were compared with flux measurements from the complementary approaches of benthic chamber experiments and Fickian diffusion calculations, to allow an insight into the nature and seasonal variations of the fluxes. The burial flux of phosphorus was also estimated from excess 210Pb profiles in the sediment of the lakes. All of these data were used to produce a phosphorus budget for the Gippsland Lakes which suggested that the sediment represents a substantial source of phosphorus within the lakes and thus clearly highlights the importance of the sedimentary compartment in shallow eutrophic ecosystems. Minimum realistic timescales for complete labile phosphorus depletion from the sediment (assuming no resupply from the sediment–water interface) were calculated and ranged from 8 to 22 years.
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Tixier, Paul, Mary-Anne Lea, Mark A. Hindell, Christophe Guinet, Nicolas Gasco, Guy Duhamel e John P. Y. Arnould. "Killer whale (Orcinus orca) interactions with blue-eye trevalla (Hyperoglyphe antarctica) longline fisheries". PeerJ 6 (8 agosto 2018): e5306. http://dx.doi.org/10.7717/peerj.5306.
Testo completoAbstract (sommario):
Over the past five decades, marine mammal interactions with fisheries have become a major human-wildlife conflict globally. The emergence of longline fishing is concomitant with the development of depredation-type interactions i.e., marine mammals feeding on fish caught on hooks. The killer whale (Orcinus orca) is one of the species most involved in depredation on longline fisheries. The issue was first reported in high latitudes but, with increasing expansion of this fishing method, other fisheries have begun to experience interactions. The present study investigated killer whale interactions with two geographically isolated blue-eye trevalla (Hyperoglyphe antarctica) fisheries operating in temperate waters off Amsterdam/St. Paul Islands (Indian Ocean) and south-eastern Australia. These two fisheries differ in the fishing technique used (vertical vs. demersal longlines), effort, catch, fleet size and fishing area size. Using 7-year (2010–16) long fishing and observation datasets, this study estimated the levels of killer whale interactions and examined the influence of spatio-temporal and operational variables on the probability of vessels to experience interactions. Killer whales interactions occurred during 58.4% and 21.2% of all fishing days, and over 94% and 47.4% of the fishing area for both fisheries, respectively. In south-eastern Australia, the probability of occurrence of killer whale interactions during fishing days varied seasonally with a decrease in spring, increased with the daily fishing effort and decreased with the distance travelled by the vessel between fishing days. In Amsterdam/St. Paul, this probability was only influenced by latitude, with an increase in the southern part of the area. Together, these findings document two previously unreported cases of high killer whale depredation, and provide insights on ways to avoid the issue. The study also emphasizes the need to further examine the local characteristics of fisheries and the ecology of local depredating killer whale populations in as important drivers of depredation.
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KIMPE, C. R. DE, M. R. LAVERDIERE e R. W. BARIL. "CARACTÉRISTIQUES DES SOLS SULFATÉS ACIDES DE LA SÉRIE DE L'ANSE EN MILIEU ESTUARIEN (QUÉBEC)". Canadian Journal of Soil Science 68, n. 3 (1 agosto 1988): 577–92. http://dx.doi.org/10.4141/cjss88-056.
Testo completoAbstract (sommario):
Acid sulfate soils were sampled according to the transect method in four bays along the south shore of the St. Lawrence river to determine their properties in their area of distribution. In each bay, six profiles of cultivated soils were sampled along a transect perpendicular to the river. One non-cultivated profile was also sampled at l'Isle-Verte. The lower limit of the B horizons, between 79 and 89 cm, suggested a homogeneous development of these soils across the area. Most profiles contained jarosite in the lower Bg and, sometimes, in the C horizons; this mineral was absent in the upper part of the profiles of soils that had been limed prior to cultivation. Total S content increased with depth, but only a few horizons had a content > 0.75% presumably because of sulfate leaching once the soils were drained. Organic C content in the de l'Anse soils decreased less rapidly with depth than in other gleysolic soils, because vegetation grew while sediments were being deposited. Key words: Acid sulfate soils, total S, recent marine sediments, jarosite
26
Kookana, Rai S., Ali Shareef, Milena B. Fernandes, Sonja Hoare, Sam Gaylard e Anu Kumar. "Bioconcentration of triclosan and methyl-triclosan in marine mussels (Mytilus galloprovincialis) under laboratory conditions and in metropolitan waters of Gulf St Vincent, South Australia". Marine Pollution Bulletin 74, n. 1 (settembre 2013): 66–72. http://dx.doi.org/10.1016/j.marpolbul.2013.07.030.
Testo completo
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tone, P. Feathers, T. Aigner, L. Brown, M. King e W. Leu. "STRATIGRAPHIC MODELLING OF THE GIPPSLAND BASIN". APPEA Journal 31, n. 1 (1991): 105. http://dx.doi.org/10.1071/aj90009.
Testo completoAbstract (sommario):
The Gippsland Basin is an asymmetric graben which initially formed during the break-up of Australia and Antarctica in the Early Cretaceous. During continental rifting the basin was filled by volcano-clastics of the Strzelecki Group. The overlying alluvial sediments of the Golden Beach Group represent a second phase of rift fill associated with the Tasman Sea rift. Following continental break-up in the Campanian, the Latrobe Group was deposited as a transgressive sequence of marine and coastal plain sediments. Thermal subsidence from the Oligocene to Recent was accompanied by the deposition of marine marls and limestones of the Lakes Entrance Formation and Gippsland Limestone.A north-south cross-section through the basin, based on regional seismic data and nine exploration wells, has been used to study the tectonic, thermal and basin-fill history. A detailed basin subsidence history based on a crustal rifting model was constructed, constrained by stratigraphic data and palaeo-water depth estimates at well locations. The history of sedimentation was then modelled by a Shell proprietary package, using the subsidence history and published eustatic sea level variations. This numerical model is based on a forward time-stepping scheme using semi-empirical algorithms to define the facies deposited. The gross basin architecture of the Gippsland Basin is successfully reproduced by the model. In addition the model details the timing and extent of marine incursions in the Golden Beach Group and the eustatic control on facies patterns in the Latrobe Group.The method has potential for predicting the sedimentary facies in undrilled parts of the Gippsland Basin and in frontier areas in general.
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Laing, S., C. N. Dee e P. W. Best. "THE OTWAY BASIN". APPEA Journal 29, n. 1 (1989): 417. http://dx.doi.org/10.1071/aj88034.
Testo completoAbstract (sommario):
The Otway Basin covers an area of some 150 000 km2 both onshore and offshore southwestern Victoria and southeastern South Australia. Exploration within the basin is at a moderately mature stage by Australian standards (though immature by world standards), with a well density of one per 1500 km2, including offshore areas.Formation of the Otway Basin commenced in the late Jurassic with the initiation of rifting between Australia and Antarctica. As rifting continued, a number of depositional cycles occurred. Initial deposition comprised fluvio- lacustrine sediments, followed by marine transgressions and associated regressive deltaic cycles. As subsidence continued into the Late Tertiary, a series of marine carbonates and marls were deposited. The Otway Basin is structurally complex as a result of the superposition of a number of tectonic events which occurredboth during and after the development of the basin.The Otway Basin is a proven gas province, with commercial production at Caroline 1 (carbon dioxide) and North Paaratte Field (methane). Although no commercial oil production has yet been established in the basin, oil has been recovered at Port Campbell 4, Lindon 1 and Windermere 1. The presence of excellent reservoir units within the basin, mature source rocks and adequate seals, together with a number of untested play types and favourable economics, augurs well for the prospectivity of the Otway Basin.
29
Marshall, Jennifer E., Daniel J. Bucher e Stephen D. A. Smith. "Patterns of infaunal macromollusc assemblages in a subtropical marine park: implications for management". Marine and Freshwater Research 69, n. 4 (2018): 502. http://dx.doi.org/10.1071/mf17122.
Testo completoAbstract (sommario):
Characterisation of habitats and communities is necessary to allow managers knowledge of the ecological resources they are charged with conserving. However, the high cost of gathering such data often precludes their incorporation into conservation planning, and habitat surrogates are often relied upon to represent underlying biotic patterns. In New South Wales (NSW), Australia, extensive surveys informed the development of a state-wide habitat classification scheme (HCS) for biodiversity management based on the distribution of habitat types by water depth. To test the suitability of the current HCS for soft sediments, we compared infaunal mollusc assemblages at two different depths, and at scales of kilometres to tens of kilometres, within five coastal regions of the Cape Byron Marine Park (CBMP). Mollusc assemblages differed significantly between depths and among the range of spatial scales examined, and patterns were significantly correlated with mean grain size and sorting. Species richness also differed between depths and among sampling locations, whereas abundance differed between depths and among sites nested within locations. Although the present study provides preliminary support for the relevance of the NSW HCS depth categories in the CBMP, it also suggests that future refinement should consider the inclusion of categories based on sediment characteristics.
30
McVay, I. R., W. A. Maher, F. Krikowa e R. Ubrhien. "Metal concentrations in waters, sediments and biota of the far south-east coast of New South Wales, Australia, with an emphasis on Sn, Cu and Zn used as marine antifoulant agents". Environmental Geochemistry and Health 41, n. 3 (21 novembre 2018): 1351–67. http://dx.doi.org/10.1007/s10653-018-0215-8.
Testo completo
31
Ward, TJ, RL Correll e RB Anderson. "Distribution of cadmium, lead and zinc amongst the marine sediments, seagrasses and fauna, and the selection of sentinel accumulators, near a lead smelter in South Australia". Marine and Freshwater Research 37, n. 5 (1986): 567. http://dx.doi.org/10.1071/mf9860567.
Testo completoAbstract (sommario):
The concentrations of Cd, Pb and Zn in 23 species of marine animal and three species of seagrass were determined from samples collected near a large lead smelter. The spatial patterns of metal distribution in sediments, seagrasses, crustaceans and fish could be described in terms of distance from the smelter, although the fit of the mathematical model was often improved by the inclusion of other environmental variables, such as clay content of the sediment or time of sample collection. In the fish and seagrasses, Zn was the most widely dispersed metal, followed by Cd, then Pb, which was least dispersed. In general, organisms at higher trophic levels (fish) had lower metal concentrations than primary producers (seagrass). There was evidence for bioaccumulation of metals in many species, especially in the molluscs, but no biomagnification of any metal could be detected. The strong relationship between distance and metal content of several species of seagrass, fish and crustacean indicates that they are potential sentinel accumulators for monitoring the distribution of Cd, Pb and Zn. Although bivalve molluscs contained high concentrations of Cd, Pb and Zn, their contents did not consistently relate to distance from the smelter, suggesting that, except for Pinna bicolor, they are of little value as sentinel accumulators for these metals. The implications of the results for the design of monitoring programs using sentinel accumulators are discussed.
32
Taylor, Matthew D., Alistair Becker, Jane Quinn, Michael B. Lowry, Stewart Fielder e Wayne Knibb. "Stock structure of dusky flathead (Platycephalus fuscus) to inform stocking management". Marine and Freshwater Research 71, n. 10 (2020): 1378. http://dx.doi.org/10.1071/mf19364.
Testo completoAbstract (sommario):
Delineating stocks and quantifying population structure are critical for the management of exploited populations, but the stock structure of many species remains unclear. In New South Wales (NSW), Australia, a marine stock enhancement program for dusky flathead (Platycephalus fuscus) is developing, and knowledge of stock structure is required to inform enhancement strategies, as well as to support broader fisheries management. A combination of mitochondrial and microsatellite markers was used in this study to evaluate structuring among fish from eight estuaries, spanning the majority of the NSW coast. Pairwise comparisons of mitochondrial haplotypes revealed that seven of the eight estuaries were genetically homogeneous (St Georges Basin was distinct). Moreover, analysis of molecular variance showed that 97% of sequence diversity occurred within estuaries. The results from microsatellite markers were almost identical to those for mitochondrial DNA, with St George’s Basin having the only distinct genotype, and within estuary variation accounting for 99% of the genotype variation. Isolation by distance analysis showed that <5% of genetic variation was due to distance. These results indicate that dusky flathead forms a single stock across NSW, where mixing most likely occurs during early life phases and through limited adult migration. The outlying estuary, St Georges Basin, likely suffers from limited connectivity due to a constricted entrance, and it is possible that stocking may improve local genetic diversity.
33
Kemper, C. M., I. Tomo, J. Bingham, S. S. Bastianello, J. Wang, S. E. Gibbs, L. Woolford, C. Dickason e D. Kelly. "Morbillivirus-associated unusual mortality event in South Australian bottlenose dolphins is largest reported for the Southern Hemisphere". Royal Society Open Science 3, n. 12 (dicembre 2016): 160838. http://dx.doi.org/10.1098/rsos.160838.
Testo completoAbstract (sommario):
Cases of morbillivirus have been recorded in the Southern Hemisphere but have not been linked to significant marine mammal mortality. Post-mortems were conducted on 58 carcasses (44 Indo-Pacific bottlenose dolphins, two common bottlenose dolphins, 12 short-beaked common dolphins) from South Australia during 2005–2013, including an unusual mortality event (UME) in St Vincent Gulf Bioregion (SVG) during 2013. Diagnostic pathology, circumstance of death, body condition, age and stomach contents were documented for Indo-Pacific bottlenose dolphins. At least 50 dolphins died during the UME, 41 were Indo-Pacific bottlenose dolphins and most were young. The UME lasted about seven months and had two peaks, the first being the largest. Effect on the population is unknown. Diagnostic testing for morbillivirus was conducted on 57 carcasses, with evidence for infection in all species during 2011–2013. All tested UME bottlenose dolphins were positive for cetacean morbillivirus (CeMV), and the pathology included interstitial pneumonia, lymphoid depletion and syncytia. Concurrent pathologies, including lung parasite and fungal infections, and severe cutaneous bruising were observed in many dolphins. The event coincided with elevated water temperatures, a diatom bloom and significant fish die-offs. We conclude that the cause for the UME was multifactorial and that CeMV was a major contributor.
34
Borissova, Irina, e Gabriel Nelson. "Petroleum potential of the offshore southern Carnarvon Basin—insights from new Geoscience Australia data". APPEA Journal 51, n. 2 (2011): 746. http://dx.doi.org/10.1071/aj10126.
Testo completoAbstract (sommario):
In 2008–9, under the Offshore Energy Security Program, Geoscience Australia (GA) acquired 650 km of seismic data, more than 3,000 km of gravity and magnetic data, and, dredge samples in the southern Carnarvon Basin. This area comprises the Paleozoic Bernier Platform and southern part of the Mesozoic Exmouth Sub-basin. The new seismic and potential field data provide a new insight into the structure and sediment thickness of the deepwater southernmost part of the Exmouth Sub-basin. Mesozoic depocentres correspond to a linear gravity low, in water depths between 1,000–2,000 m and contain between 2–3 sec (TWT) of sediments. They form a string of en-echelon northeast-southwest oriented depressions bounded by shallow-dipping faults. Seismic data indicates that these depocentres extend south to at least 24°S, where they become more shallow and overprinted by volcanics. Potential plays in this part of the Exmouth Sub-basin may include fluvio-deltaic Triassic sandstone and Lower–Middle Jurassic claystone source rocks sealed by the regional Early Cretaceous Muderong shale. On the adjoining Bernier Platform, minor oil shows in the Silurian and Devonian intervals at Pendock–1a indicate the presence of a Paleozoic petroleum system. Ordovician fluvio-deltaic sandstones sealed by the Silurian age marine shales, Devonian reef complexes and Miocene inversion anticlines are identified as potential plays. Long-distance migration may contribute to the formation of additional plays close to the boundary between the two provinces. With a range of both Mesozoic and Paleozoic plays, this under-explored region may have a significant hydrocarbon potential.
35
Maher, William, Joel Waring, Frank Krikowa, Elliott Duncan e Simon Foster. "Ecological factors affecting the accumulation and speciation of arsenic in twelve Australian coastal bivalve molluscs". Environmental Chemistry 15, n. 2 (2018): 46. http://dx.doi.org/10.1071/en17106.
Testo completoAbstract (sommario):
Environmental contextKnowledge of the pathways by which arsenic is accumulated and transferred in marine ecosystems is scarce. Molluscs are important keystone organisms providing a link between primary producers (micro and macroalgae) and higher trophic levels such as fish. The present study examines the accumulation and species of arsenic in common bivalve molluscs from south-east Australia to understand the cycling of arsenic in marine food webs. AbstractThe present paper reports the whole-tissue total arsenic concentrations and water-soluble arsenic species in 12 common coastal Australian bivalve mollusc species. Mean arsenic concentrations ranged from 18 to 57 µg g−1 dry mass. Planktivores had significantly less arsenic (20–40 µg g−1; 22 ± 3 µg g−1) than did suspension and deposit feeders (36–57 µg g−1; 43 ± 7 µg g−1), with those associated with fine clay–silt sediments (49 ± 7 µg g−1) having significantly more arsenic than those associated with sand substrates (31 ± 11 µg g−1 ). Most planktivores and suspension feeders had similar arsenic species, with high proportions of arsenobetaine (AB) (64–92 %) and relatively low proportions of other arsenic species (0.55–15.8 %). Lower proportions of AB (13–57 %) and larger proportions of inorganic arsenic (6–7 %) were found in deposit feeders, reflecting increased exposure to inorganic arsenic in sediments. The study indicated that at lower trophic levels, organisms feed on algae and suspended matter containing a range of arsenic species including arsenosugars and AB. The implications for arsenic cycling are that as all bivalve molluscs accumulate AB and are a source of AB in benthic food webs. Because all bivalve molluscs also contained appreciable concentrations of arsenoriboses, precursors are present for the de novo synthesis of AB. As well, deposit feeders have higher proportions of inorganic arsenic that can be metabolised to different end products when ingested by higher trophic organisms
36
González-Bonorino, Gustavo. "Early development and flysch sedimentation in Ordovician Taconic foreland basin, west-central Newfoundland". Canadian Journal of Earth Sciences 27, n. 9 (1 settembre 1990): 1247–57. http://dx.doi.org/10.1139/e90-133.
Testo completoAbstract (sommario):
During the Early to Late Ordovician the Taconic foredeep in west-central Newfoundland evolved from an underfilled to an overfilled state in response to cratonward advance, thickening, and erosion of the Taconic Orogen. Early orogen-derived sediment in the foreland basin consisted of middle(?) to lake Arenigian deep-water mudstones that accumulated on an inner (craton-facing) slope prism (uppermost parts of Shallow Bay and Green Point formations and correlative units). These deposits are interbedded with and overlie passive-margin slope sediments. In the middle Arenigian to early Llanvirnian, sand from the orogen formed several small, sand-rich submarine fans (Lower Head Formation and correlative units) on the lower reaches of the inner slope and basin plain. The fans may have been fed by closely spaced rivers draining the orogen, as presently occurs in western South America. Only proximal portions of these fans are now exposed. The flysch basin was narrow, constricted by the inner slope and the passive-margin slope, and located a short distance seaward from the buried hingeline of the proto-North American craton. As the orogen thickened sufficiently to override the crustal ramp, the carbonate shelf on the craton drowned, clastic depocentres migrated onto the foundered craton, and a thicker flysch (Mainland Sandstone) accumulated in Llanvirnian-Llandeilian time. In the Caradocian the foreland basin was overfilled with shallow-marine terrigenous sediments (Long Point Formation). Regional flysch dispersal was from a St. Lawrence promontory to a Quebec reentrant.
37
Haque, Md Masidul, e Mrinal Kanti Roy. "Geology and sedimentary environment of the Surma Group of rocks, Bandarban anticline, Bandarban, Bangladesh". Journal of Nepal Geological Society 62 (14 settembre 2021): 88–106. http://dx.doi.org/10.3126/jngs.v62i0.38697.
Testo completoAbstract (sommario):
The study illustrates the effect of tectonics, climate, and relative sea-level change on the depositional process of the Miocene Bhuban and Boka Bil Formation of Bengal Basin. Outcrop sediments of five transverse sections exposed along the axial zone of Bandarban anticline were studied. Twelve lithofacies such as Gm, Gms, Sm, ST, Sp, Sr, Sl, Sf, Sll, Fw, Fl and Fm have been identified within the successions and grouped into (i) turbidite generated, (ii) outer fan distal lobe basin plain and (iii) tide-influenced facies association. The analyses reveal that the Bhuban Formation was turbidite- generated that deposited below the continental shelf-slope environment. The Lower Bhuban Member consists of gray to brownish-gray calcareous sandstone with shale deposited under the channelized lobe of submarine fan. The Middle Bhuban Member dominated by black shale-siltstone deposited in distal turbidite lobe due to change the flow regime. The Upper Bhuban Member consists of yellow to yellowish gray, coarse to medium-grained sandstone-siltstone with black shale that deposited under channelized to nonchannelized lobes of submarine fan. The increasing sedimentation during the formation of the Upper Bhuban Member can be caused by increased the intensity of the Asian Monsoon that carried huge sediment from the Himalaya. The Boka Bil Formation was deposited under estuary to tidal flat environment. The area was uplifted during and/or after subduction of the Indian Plate beneath the Burmese Plate. The monsoonal intensity enhances sedimentation that moved prograding delta towards the south. These processes shifted depositional environment from continental shelf-slope to marginal shallow marine during deposition of the Boka Bil Formation. The continental slope aligned east-west direction and sediments likely derived from the Himalaya and Trans-Himalaya in the present geographical setup during deposition of the sediments.
38
Fowler, A. J., C. Huveneers e M. T. Lloyd. "Insights into movement behaviour of snapper (Chrysophrys auratus, Sparidae) from a large acoustic array". Marine and Freshwater Research 68, n. 8 (2017): 1438. http://dx.doi.org/10.1071/mf16121.
Testo completoAbstract (sommario):
Snapper is a significant fishery species in Australasia whose movement behaviour remains poorly understood. This was addressed in the present study at the within-region scale using acoustic telemetry in the Gulf St Vincent, South Australia. Over 3 years from May 2011, 54 snapper were monitored throughout ~160km2 using 41 acoustic receivers. The dispersion of >500000 detections varied in space and time, reflecting three types of space use, dependent on different types of movement behaviour. One station, near a large shipwreck, accounted for 67.8% of all detections, particularly during winter, when fish were sedentary and site attached. In spring, the fish dispersed throughout the study area to different habitats and, through summer, occupied different larger restricted areas than used in winter. Snapper were highly mobile and demonstrated systematic behaviour at several temporal scales. They moved linear distances of up to ~100km and could achieve tens of kilometres in a day in episodic movements. Through the year, their activity was distributed across areas of hundreds of square kilometres. The regional spatial management regimen was assessed against this enhanced understanding of movement behaviour. A new marine park sanctuary zone that encompassed the shipwreck was appropriately located, but possible benefits of a nearby spatial spawning closure area appear limited.
39
St-Pierre, Luc, Q. H. J. Gwyn e J. M. M. Dubois. "Lithostratigraphie et dynamique glaciaires au Wisconsinien, île d'Anticosti, golfe du Saint-Laurent". Canadian Journal of Earth Sciences 24, n. 9 (1 settembre 1987): 1847–58. http://dx.doi.org/10.1139/e87-175.
Testo completoAbstract (sommario):
The Laurentide Ice Sheet deposited three tills on Anticosti Island. The oldest, the Rivière à la Patate Till, was formed by southeastward-flowing ice as determined from till fabrics. The till has an estimated age of 85 000 years BP based on the aminoacid racemization of shell fragments in overlying marine sediments. Thus it is probably Early Wisconsinan in age. The Middle Wisconsinan Rivière Jupiter Till and the Late Wisconsinan Île d'Anticosti Till are the result of the southwest-flowing Laurentide ice. The ice flowed without restriction though without accomplishing deep erosion of the bedrock, as indicated by glaciotectonic structures and till fabrics. However, striated blocks and pebbles in the tills reveal that basal shearing occurred. The ice limit in the Gulf of St. Lawrence from about 36 000 years BP onwards was located along the south coast of the island. This was the result of active calving at the margin of the relatively slow moving ice sheet. During retreat of the ice sheet, an ice cap became isolated on the island. It appears to have remained active in the western part of the island, where it formed the Sainte-Marie Moraine on the south, west, and north coasts, but was less active in the eastern part of the island, where a loose, sandy, but rare till (the Sainte-Marie Till) is the only proof of its activity. Deeper water in the eastern end of the Jacques-Cartier Strait, north of the island, accelerated ice calving and thus probably reduced the ice dynamic in the eastern part of the island. The names of tills used here are proposed as formal nomenclature.
40
Birch, Gavin F., e Marco A. Olmos. "Sediment-bound heavy metals as indicators of human influence and biological risk in coastal water bodies". ICES Journal of Marine Science 65, n. 8 (15 settembre 2008): 1407–13. http://dx.doi.org/10.1093/icesjms/fsn139.
Testo completoAbstract (sommario):
AbstractBirch, G. F., and Olmos, M. A. 2008. Sediment-bound heavy metals as indicators of human influence and biological risk in coastal water bodies. – ICES Journal of Marine Science, 65: 1407–1413. Currently, many institutions are conducting or planning large, regional-scale ecosystem assessments of estuarine health. A full, integrated assessment of these environments requires a large suite of biological, physical, and chemical indicators, including sedimentary chemistry, ecotoxicology, benthic community structure, and bioaccumulation. This commitment is beyond the capacity of most organizations, and a simpler approach is required to accommodate limited financial resources. A case is made for the use of sedimentary heavy metals as an easy and inexpensive indicator. The advantages are that sediments identify the “pristine” condition and give baseline information against which future management strategies may be benchmarked, and that they differentiate solely human-induced change from natural variation. Sediment indicators in depositional environments are also less dynamic than those associated with water and biota. Our objective is to demonstrate that sediment-bound heavy metals data provide the spatial extent and magnitude of chemical change, as well as the risk of biological stress attributable to contamination in estuarine ecosystems. An assessment of this scheme involving seven New South Wales (Australia) estuaries suggests that sedimentary heavy-metal indicators used in a weight-of-evidence approach, with data collected during the recent Australian National Land and Water Resources Audit, enhances estuarine condition assessment.
41
Peybernès, Bernard, Marie-José Fondecave-Wallez e Pierre-Jean Combes. "Evidences of Palaeocene marine breccias unconformably overlying the Cretaceous orogenic axis of the Pyrenees, between Garonne and Gave de Pau". Bulletin de la Société Géologique de France 173, n. 6 (1 novembre 2002): 523–32. http://dx.doi.org/10.2113/173.6.523.
Testo completoAbstract (sommario):
Abstract Recently, have been evidenced in central/eastern French Pyrenees sub-marine polygenic breccias (Comus/Baixas Breccias), assigned to Upper Danian-Lower Selandian (P1c-P3) by means of planktonic foraminifera found either within their matrix, or within associated microrhythmic hemipelagites. These ante-Upper Eocene breccias, which are posterior to the HT-LP « Pyrenean » metamorphism (Mid.-Cretaceous in age and characterized by dipyre-bearing marbles and hornfelses) and to the Upper to Uppermost Cretaceous foldings, are only restricted to the Cretaceous orogenic axis of the range [Internal Metamorphic Zone (IMZ) and North-Pyrenean Zone (NPZ)]. They are dated in about 20 layers known from Mediterranean coast to Garonne valley. The breccias define in this part of Pyrenees a wide and long (more than 200 km) W-E trough (subdivided into several meridian palaeocanyons) inherited from former karstic topographies and separated by mountains with a steep topography, flanked to the South and the North of continental areas (covered by « Vitrollian » fluvio-lacustrine deposits). It was important to evidence if this marine breccia-filled « trough », Palaeocene in age, could extend westwards, West of Garonne, in Comminges/Barousse and Bigorre, where, laterally, the « Vitrollian » continental areas are replaced by outer-shelf marine sediments (clinoform carbonates), both covering the Sub-Pyrenean Zone (SPZ) and the High Primary Range (HPR) (Gavarnie-Mont-Perdu thrust sheet). In fact, the presence of those breccias has been already suggested (but without micropalaeontologic arguments) by Mattauer [in Choukroune, 1969 and 1976] in the Lourdes area (Bigorre). The topic of this paper is to characterize and to assign to the lower part of Palaeocene (63-59 Ma interval) several significant outcrops (St-Béat, Bramevaque/Troubat/Gembrié, Lortet, Medous/Bagnères-de-Bigorre and Lourdes/Pibeste) of these marine breccias (some of them previously used as black/yellow marbles called « Brèche romaine de St-Béat », « Portor des Pyrénées » or « Marbres de Medous ») recently identified from Garonne to Gave-de-Pau (fig. 1). Although quite poor in argillaceous hemipelagites, most of the breccias (which contain Mesozoic clasts) are now well dated by sections of « globigerinids » (= superfamily of Globerinacea) observed within their matrix. Other marine Palaeocene breccias also exist, more to the South (col de Gembre) along segments of the North-Pyrenean Fault, but they only rework Palaeozoic clasts. The « globigerinid » assemblage checked within all the Palaeocene breccias of Comminges/Bigorre includes, as more to the east, the following taxa: Globanomalina compressa, Gl. ehrenbergi, Gl. imitata, Parasubbotina varianta, P. variospira, Igorina pusilla, Morozovella angulata, M. praeangulata, Praemurica spiralis, Pr. inconstans and Woodringina hornestownensis. This assemblage is also laterally present within the marine carbonate sequences of the SPZ – HCR cover (« Lasseube Limestones » from the Nay/Pont Labau area, « Globigerinid-bearing Limestones » from the Gavarnie-Mont-Perdu thrust sheet), regions which are peripheric to the Pyrenean Lower/Mid. Cretaceous orogen (IMZ, NPZ) because exempt of major angular unconformity between Maastrichtian and Danian marine deposits (only a short gap of Lower/Lowermost Danian underlines the K/T boundary). On the contrary, the herein studied regions, belonging to this orogen, are characterized by a clear unconformity (both angular and cartographic) along a well-marked ravining surface inherited from erosional processes and karstification. The substratum of these breccias is strongly folded, cleaved and sometimes metamorphic and its younger formation seems to be Mid.– Cretaceous in age at least. Thus, it is very probable that the ante-Palaeocene unconformity seals compressional/transpressional structures (followed by emersions) assigned to the Uppermost Cretaceous phase (palinspastic transect, fig. 5). Danian/Selandian marine breccias and their already folded Mesozoic substratum are later tectonically reactived together by the « Pyrenean » compressions, Upper Eocene in age. If the elements of these breccias sometimes correspond to marbles induced by the Mid.-Cretaceous thermometamorphism (as around the famous « Etang de Lherz », more to the East, where lherzolites are also reworked in similar Danian/Selandian breccias), their matrix locally contain neogenic phyllites (never dipyre !) which could be related to a light (hydrothermal ?) post-breccia metamorphism. The clasts are generally angular, showing a very short transport from emerged steep topographies separating the different elementary canyons of the trough. The last problem is to determine the eventual westwards extension in the Bearn and Basque Pyrenees (fig. 6), particularly in the « Chaînons Béarnais » Zone which belonged to the North-Iberian palaeomargin (Iberian Plate) of the future range during Lower/Mid.-Cretaceous times. At this first level of micropalaeontologic investigations, it seems that several breccias (Lauriolle, Etchebar, Bosmendiette etc …), previously interpreted by several authors (synthesis in James and Canerot [1999]) as Aptian and « diapiric » (collapse) breccias, should be assigned to marine Palaeocene deposits because containing (in their matrix and associated hemipelagites) Danian-Selandian planktonic foraminifera similar to the Comminges/Bigorre ones.
42
Guilbault, Jean-Pierre. "Foraminiferal Distribution in the Central and Western Parts of the Late Pleistocene Champlain Sea Basin, Eastern Canada". Géographie physique et Quaternaire 43, n. 1 (18 dicembre 2007): 3–26. http://dx.doi.org/10.7202/032750ar.
Testo completoAbstract (sommario):
ABSTRACT Marine sediments from the late-glacial Champlain Sea have been sampled at 20 localities representing the deeper part of the basin, between Ottawa and the Rivière St-François, Québec. Foraminiferal assemblages have been extracted and a sequence of three deep water and two shallow water ecozones recognized. The lowermost zone (A) is characterized by Cassidulina reniforme, Islandiella helenae and I. norcrossi and represents a paleosalinity of 25 to 30%o. The overlying zone B is dominated by Elphidium excavatum. It represents salinities decreasing from 25 to as low as 10%o. The uppermost zone (C) contains only a sparse assemblage of a morphotype of E. excavatum. If suggests a paleosalinity of no more than 10%o. A mostly unfossiliferous silt and clay layer of variable thickness (post-C) occurs above zone C. It is probably lacustrine. Below zone A and above the Late Wisconsinan till there is a pre-A interval whose variable assemblages represent hyposaline environments east of Montréal, predominantly lacustrine conditions west of Montréal and alternating hyposaline/ lacustrine environments near and south of Montréal. Bottom water temperatures were probably "Arctic" (within a few degrees of 0°) from the pre-A interval up to zone B inclusively. The data from zone C are too poor to estimate temperatures. The shallow water zones indicate environments with high (zone EH) or low (zone EA) salinities but of shallower depths than the deep water zones. The existence of two sequences is interpreted as the result of (probably seasonal) water stratification. The data does not allow to determine the depth of the limit between the shallow and deep waters.
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De Falco, Giovanni, Emanuela Molinaroli, Alessandro Conforti, Simone Simeone e Renato Tonielli. "Biogenic sediments from coastal ecosystems to beach–dune systems: implications for the adaptation of mixed and carbonate beaches to future sea level rise". Biogeosciences 14, n. 13 (5 luglio 2017): 3191–205. http://dx.doi.org/10.5194/bg-14-3191-2017.
Testo completoAbstract (sommario):
Abstract. Coastal ecosystems produce and store carbonate particles, which play a significant role in the carbonate dynamics of coastal areas and may contribute to the sediment budget of adjacent beaches. In the nearshore seabed of temperate zones (e.g. Mediterranean Sea and South Australia), marine biogenic carbonates are mainly produced inside seagrass meadows. This study quantifies the contribution of biogenic sediments, mainly produced in Posidonia oceanica seagrass meadows and secondarily in photophilic algal communities, to the sediment budget of a Mediterranean beach–dune system (San Giovanni beach, western Sardinia, western Mediterranean Sea). A set of geophysical, petrographic and sedimentological data was used to estimate the sediment volume and composition of the beach–dune system as a whole. The San Giovanni beach–dune system contains 3 797 000 ± 404 000 t of sediment, 83 % (3 137 000 ± 404 000 t) of which is located in the coastal wedge, 16 % (619 000 ± 88 000 t) in the dune fields and 1 % (41 000 ± 15 000 t) in the subaerial beach. The sediments are composed of mixed modern bioclastic and relict bioclastic and non-bioclastic grains from various sources. The system receives a large input of modern bioclastic grains, mainly composed of rhodophytes, molluscs and bryozoans, which derive from sediment production of present-day carbonate factories, particularly P. oceanica seagrass meadows. Radiocarbon dating of modern bioclastic grains indicated that they were produced during the last 4.37 kyr. This value was used to estimate the long-term deposition rates of modern bioclastic sediments in the various beach compartments. The total deposition rate of modern bioclastic grains is 46 000 ± 5000 t century−1, mainly deposited in the coastal wedge (39 000 ± 4 000 t century−1) and dunes (7000 ± 1000 t century−1), and 46 000 t represents ∼ 1.2 % of the total beach–dune sediment mass. Carbonate production from coastal ecosystems was estimated to be 132 000∕307 000 t century−1, 28 % (15 % ∕ 34 %) of which is transported to the beach–dune system, thus significantly contributing to the beach sediment budget. The contribution to the beach sediment budget represents a further ecosystem service, which our data can help quantify, provided by P. oceanica. The value of this sediment-supply service is in addition to the other important ecological services provided by seagrass meadows. The dependence of the beach sediment budget on carbonate production associated with coastal ecosystems has several implications for the adaptation of mixed and carbonate beaches to the loss of seagrass meadows due to local impacts and the changes expected to occur over the next few decades in coastal ecosystems following sea level rise.
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Alder, J. D., S. Hawley, T. Maung, J. Scott, R. D. Shaw, A. Sinelnikov e G. Kouzmina. "PROSPECTIVITY OF THE OFFSHORE SYDNEY BASIN: A NEW PERSPECTIVE". APPEA Journal 38, n. 1 (1998): 68. http://dx.doi.org/10.1071/aj97004.
Testo completoAbstract (sommario):
Approximately 40 per cent of the 52,000 km2 Sydney Basin lies in shallow waters (less than 200 m) off the central New South Wales coast. Containing more than 5,000 m of Permo-Triassic marine and non-marine sediments, and having been the subject of several previous exploration campaigns, no wells have been drilled in the offshore despite widespread numerous occurrences of oil and gas onshore.The Sydney Basin, together with the Bowen and Gunnedah basins, form a major longitudinal Permo-Triassic basinal complex stretching 2,500 km down the eastern margin of Australia. Whereas the onset of this basinal development may have been extensional, reinterpretation of seismic and other geophysical data highlight the potential role played in the early development of the Sydney Basin by easterly directed compression. A compressional style is to be contrasted with the dominantly extensional style interpreted by others for the adjacent onshore areas. The most conspicuous structural element in the offshore, the Offshore Uplift, is interpreted to represent the western overthrust edge of the Currarong Orogen. Accepting the Panthalassan margin geometry of Veevers and Powell (1994) it follows that the Offshore Uplift and restored Dampier Ridge would have constituted a 'greater Currarong Orogen'. A series of progressive westerly directed thrust fronts may have been established across the Panthalassan margin, including the uplifted western margin of the Currarong Orogen, which over-rode and created a thrust load onto the eastern margin of the Lachlan Fold Belt. Much of the Early Permian development of the Sydney Basin therefore could have resulted as a consequence of foreland loading. This is consistent with depositional trends including the overall westerly directed marine transgression which dominated the sedimentary record of the Early Permian. Alternatively, this marine transgression may represent the sag phase induced along a segment of the Bowen-Sydney rift system that had been offset by the Hunter River Transverse Zone from the Gunnedah Basin to a site coincident with the Offshore Syncline.Previous interpretations identified structural development of the Currarong Orogen as either a Cretaceous (Tasman Sea rift related) or Middle to Late Permian phenomena. Early Permian structural growth of the offshore Uplift has important implications for petroleum exploration. The major impediment to exploration appears to be the perception that the Sydney Basin lacks suitable reservoir targets and is gas-prone. Potential source and seal sequences occur extensively within both Early Permian marine shales and siltstones and Early and Late Permian coal measure sequences. The emerging uplift provided a major sediment provenance area and represented a barrier behind which restricted anoxic conditions flourished, conditions favouring the preservation of organic matter. Late Permian and Triassic sequences are absent across the crestal portions of the uplift. However, the emerging, sea-ward facing flank of the uplift would have been subject to marginal and shallow marine, wave-base, barrier and strand bar deposition during the Lower Permian, conditions known in the onshore to favour better reservoir development.Gas demand to the greater Sydney region is anticipated to exceed supply by the year 2000, and new gas markets are being eagerly sought in time for the expiration, in 2006, of the current contract under which gas is supplied to Sydney via the Moomba pipeline.Cretaceous, Tasman Sea rift related, structuring is subordinate to that of the earlier compressional and wrench related structuring. Several new structural targets have been added to the existing inventory of prospects and leads, including some now considered optiminally located with respect to source rock and reservoir development.
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Thanh, Nguyen Trung, Paul Jing Liu, Mai Duc Dong, Dang Hoai Nhon, Do Huy Cuong, Bui Viet Dung, Phung Van Phach, Tran Duc Thanh, Duong Quoc Hung e Ngo Thanh Nga. "Late Pleistocene-Holocene sequence stratigraphy of the subaqueous Red River delta and the adjacent shelf". VIETNAM JOURNAL OF EARTH SCIENCES 40, n. 3 (4 giugno 2018): 271–87. http://dx.doi.org/10.15625/0866-7187/40/3/12618.
Testo completoAbstract (sommario):
The model of Late Pleistocene-Holocene sequence stratigraphy of the subaqueous Red River delta and the adjacent shelf is proposed by interpretation of high-resolution seismic documents and comparison with previous research results on Holocene sedimentary evolution on the delta plain. Four units (U1, U2, U3, and U4) and four sequence stratigraphic surfaces (SB1, TS, TRS and MFS) were determined. The formation of these units and surfaces is related to the global sea-level change in Late Pleistocene-Holocene. SB1, defined as the sequence boundary, was generated by subaerial processes during the Late Pleistocene regression and could be remolded partially or significantly by transgressive ravinement processes subsequently. The basal unit U1 (fluvial formations) within incised valleys is arranged into the lowstand systems tract (LST) formed in the early slow sea-level rise ~19-14.5 cal.kyr BP, the U2 unit is arranged into the early transgressive systems tract (E-TST) deposited mainly within incised-valleys under the tide-influenced river to estuarine conditions in the rapid sea-level rise ~14.5-9 cal.kyr BP, the U3 unit is arranged into the late transgressive systems tract (L-TST) deposited widely on the continental shelf in the fully marine condition during the late sea-level rise ~9-7 cal.kyr BP, and the U4 unit represents for the highstand systems tract (HST) with clinoform structure surrounding the modern delta coast, extending to the water depth of 25-30 m, developed by sediments from the Red River system in ~3-0 cal.kyr BP.ReferencesBadley M.E., 1985. Practical Seismic Interpretation. International Human Resources Development Corporation, Boston, 266p.Bergh G.D. V.D., Van Weering T.C.E., Boels J.F., Duc D.M, Nhuan M.T, 2007. Acoustical facies analysis at the Ba Lat delta front (Red River delta, North Vietnam. Journal of Asian Earth Science, 29, 532-544.Boyd R., Dalrymple R., Zaitlin B.A., 1992. Classification of Elastic Coastal Depositional Environments. Sedimentary Geology, 80, 139-150.Catuneanu O., 2002. Sequence stratigraphy of clastic systems: concepts, merits, and pitfalls. Journal of African Earth Sciences, 35, 1-43.Catuneanu O., 2006. Principles of Sequence Stratigraphy. Elsevier, Amsterdam, 375p.Catuneanu O., Abreu V., Bhattacharya J.P., Blum M.D., Dalrymple R.W., Eriksson P.G., Fielding C.R., Fisher W.L., Galloway W.E., Gibling M.R., Giles K.A., Holbrook J.M., Jordan R., Kendall C.G. St. C., Macurda B., Martinsen O.J., Miall A.D., Neal J.E., Nummedal D., Pomar L., Posamentier H.W., Pratt B.R., Sarg J.F., Shanley K.W., Steel R. J., Strasser A., Tucker M.E., Winker C., 2009. Towards the standardization of sequence stratigraphy. Earth-Science Reviews, 92, 1-33.Catuneanu O., Galloway W.E., Kendall C.G. St C., Miall A.D., Posamentier H.W., Strasser A. and Tucker M.. E., 2011. Sequence Stratigraphy: Methodology and Nomenclature. Newsletters on Stratigraphy, 44(3), 173-245.Coleman J.M and Wright L.D., 1975. Modern river deltas: variability of processes and sand bodies. In: Broussard M.L (Ed), Deltas: Models for exploration. Houston Geological Society, Houston, 99-149.Doan Dinh Lam, 2003. History of Holocene sedimentary evolution of the Red River delta. PhD thesis in Vietnam, 129p (in Vietnamese).Duc D.M., Nhuan M.T, Ngoi C.V., Nghi T., Tien D.M., Weering J.C.E., Bergh G.D., 2007. Sediment distribution and transport at the nearshore zone of the Red River delta, Northern Vietnam. Journal of Asian Earth Sciences, 29, 558-565.Dung B.V., Stattegger K., Unverricht D., Phach P.V., Nguyen T.T., 2013. Late Pleistocene-Holocene seismic stratigraphy of the Southeast Vietnam Shelf. Global and Planetary Change, 110, 156-169.Embry A.F and Johannessen E.P., 1992. T-R sequence stratigraphy, facies analysis and reservoir distribution in the uppermost Triassic-Lower Jurassic succession, western Sverdrup Basin, Arctic Canada. In: Vorren T.O., Bergsager E., Dahl-Stamnes O.A., Holter E., Johansen B., Lie E., Lund T.B. (Eds.), Arctic Geology and Petroleum Potential. Special Publication. Norwegian Petroleum Society (NPF), 2, 121-146.Funabiki A., Haruyama S., Quy N.V., Hai P.V., Thai D.H., 2007. Holocene delta plain development in the Song Hong (Red River) delta, Vietnam. Journal of Asian Earth Sciences, 30, 518-529.General Department of Land Administration., 1996. Vietnam National Atlas. General Department of Land Administration, Hanoi, 163p.Hanebuth T.J.J. and Stattegger K., 2004. Depositional sequences on a late Pleistocene-Holocene tropical siliciclastic shelf (Sunda shelf, Southeast Asia). Journal of Asian Earth Sciences, 23, 113-126.Hanebuth T.J.J., Voris H.K.., Yokoyama Y., Saito Y., Okuno J., 2011. Formation and fate of sedimentary depocenteres on Southeast Asia’s Sunda Shelf over the past sea-level cycle and biogeographic implications. Eath-Science Reviews, 104, 92-110.Hanebuth T., Stattegger K and Grootes P. M., 2000. Rapid flooding of the Sunda Shelf: a late-glacial sea-level record. Science, 288, 1033-1035.Helland-Hansen W and Gjelberg, J.G., 1994. Conceptual basis and variability in sequence stratigraphy: a different perspective. Sedimentary Geology, 92, 31-52.Hori K., Tanabe S., Saito Y., Haruyama S., Nguyen V., Kitamura., 2004. Delta initiation and Holocene sea-level change: example from the Song Hong (Red River) delta, Vietnam. Sedimentary Geology, 164, 237-249.Hunt D. and Tucker M.E., 1992. Stranded parasequences and the forced regressive wedge systems tract: deposition during base-level fall. Sedimentology Geology, 81, 1-9.Hunt D. and Tucker M.E., 1995. Stranded parasequences and the forced regressive wedge systems tract: deposition during base-level fall-reply. Sedimentary Geology, 95, 147-160.Lam D.D. and Boyd W.E., 2000. Holocene coastal stratigraphy and model for the sedimentary development of the Hai Phong area in the Red River delta, north Vietnam. Journal of Geology (Series B), 15-16, 18-28.Lieu N.T.H., 2006. Holocene evolution of the Central Red River Delta, Northern Vietnam. PhD thesis of lithological and mineralogical in Germany, 130p.Luu T.N.M., Garnier J., Billen G., Orange D., Némery J., Le T.P.Q., Tran H.T., Le L.A., 2010. Hydrological regime and water budget of the Red River Delta (Northern Vietnam). Journal of Asian Earth Sciences, 37, 219-228.Mather S.J., Davies J., Mc Donal A., Zalasiewicz J.A., and Marsh S., 1996. The Red River Delta of Vietnam. British Geological Survey Technical Report WC/96/02, 41p.Mathers S.J. and Zalasiewicz J.A.,1999. Holocene sedimentary architecture of the Red River delta, Vietnam. Journal of Coastal Research, 15, 314-325.Milliman J.D. and Mead R.H., 1983. Worldwide delivery of river sediment to the oceans. Journal of Geology, 91, 1-21.Milliman J.D and Syvitski J.P.M., 1992. Geomorphic/tectonic control of sediment discharge to the Ocean: the importance of small mountainous rivers. Journal of Geology, 100, 525-544.Mitchum Jr. R.M., Vail P.R., 1977. Seismic stratigraphy and global changes of sea-level. Part 7: stratigraphic interpretation of seismic reflection patterns in depositional sequences. In: Payton C.E. (Ed.), Seismic Stratigraphy-Applications to Hydrocarbon Exploration, A.A.P.G. Memoir, 26, 135-144.Nguyen T.T., 2017. Late Pleistocene-Holocene sedimentary evolution of the South East Vietnam Shelf, PhD thesis (in Vietnamese), Hanoi University of Science, Vietnam, 169p.Nummedal D., Riley G.W., Templet P.T., 1993. High-resolution sequence architecture: a chronostratigraphic model based on equilibrium profile studies. In: Posamentier H.W., Summerhayes C.P., Haq B.U., Allen G.P. (Eds.), Sequence stratigraphy and Facies Associations. International Association of Sedimentologists Special Publication, 18, 55-58.Posamentier H.W. and Allen G.P., 1999. Siliciclastic sequence stratigraphy: concepts and applications. SEPM Concepts in Sedimentology and Paleontology, 7, 210p.Posamentier H.W., Jervey M.T. and Vail P.R., 1988. Eustatic controls on clastic deposition I-Conceptual framework. Sea-level changes-An Integrated Approach, The Society of Economic Paleontologists and Mineralogist. SEPM Special Publication, 42, 109-124.Reineck H.E., Singh I.B., 1980. Depositional sedimentary environments with reference to terrigenous clastics. Springer-Verlag Berlin Heidelberg New York, 551p. Ross K., 2011. Fate of Red River Sediment in the Gulf of Tonkin, Vietnam. Master Thesis. North Carolina State University, 91p.Saito Y., Katayama H., Ikehara K., Kato Y., Matsumoto E., Oguri K., Oda M., Yumoto M. 1998. Transgressive and highstand systems tracts and post-glacial transgression, the East China Sea. Sedimentary Geology, 122, 217-232.Stattegger K., Tjallingii R., Saito Y., Michelli M., Nguyen T.T., Wetzel A., 2013. Mid to late Holocene sea-level reconstruction of Southeast Vietnam using beachrock and beach-ridge deposits. Global and Planetary Change, 110, 214-222.Tanabe S., Hori K., Saito Y., Haruyama S., Doanh L.Q., Sato Y., Hiraide S., 2003a. Sedimentary facies and radiocarbon dates of the Nam Dinh-1 core from the Song Hong (Red River) delta, Vietnam. Journal of Asian Earth Sciences, 21, 503-513.Tanabe S., Hori K., Saito Y., Haruyama S., Phai V.V., Kitamura A., 2003b. Song Hong (Red River) delta evolution related to millennium-scale Holocene sea-level changes. Quaternary Science Reviews, 22(21-22), 2345-2361.Tanabe S., Saito Y., Lan V.Q., Hanebuth T.J.J., Lan N.Q., Kitamura A., 2006. Holocene evolution of the Song Hong (Red River) delta system, northern Vietnam. Sedimentary Geology, 187, 29-61.Thanh T.D. and Huy D.V., 2000. Coastal development of the modern Red River Delta. Bulletin of the Geological Survey of Japan, 5, 276.Tjallingii R., Stattegger K., Wetzel A., Phung VP., 2010. Infilling and flooding of the Mekong River incised valley during deglacial sea-level rise. Quaternary Science Reviews, 29, 1432-1444.Vail P.R., 1987. Seismic stratigraphy interpretation procedure. In: Bally, A.W. (Ed), Atlats of Seismic Stratigraphy. American Association of Petroleum Geologist Studies in Geology, 27, 1-10.Van Wagoner J.C., Posamentier H.W., Mitchum R.M., Vail P.R., Sarg P.R., Louit J.F., Hardenbol J., 1988. An overview of the fundamental of sequence stratigraphy and key definitions. An Integrated Approach, SEPM Special Publication, 42, 39-45.Veeken P.C.H., 2006. Seismic stratigraphy Basin Analysis and Reservoir Characterization. Handbook of geophysical exploration, Elsevier, Oxford, 37509p.Yoo D.G., Kim S.P., Chang T.S., Kong G.S., Kang N.K., Kwon Y.K., Nam S.L., Park S.C., 2014. Late Quaternary inner shelf deposits in response to late Pleistocene-Holocene sea-level changes: Nakdong River, SE Korea. Quaternary International, 344, 156-169.
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"Trace metal concentrations in marine organisms from St. Vincent Gulf, South Australia". Deep Sea Research Part B. Oceanographic Literature Review 33, n. 12 (gennaio 1986): 1034. http://dx.doi.org/10.1016/0198-0254(86)94585-1.
Testo completo
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Heinson, Graham, Jingming Duan, Alison Kirkby, Kate Robertson, Stephan Thiel, Sasha Aivazpourporgou e Wolfgang Soyer. "Lower crustal resistivity signature of an orogenic gold system". Scientific Reports 11, n. 1 (4 agosto 2021). http://dx.doi.org/10.1038/s41598-021-94531-8.
Testo completoAbstract (sommario):
AbstractOrogenic gold deposits provide a significant source of the world’s gold and form along faults over a wide range of crustal depths spanning sub-greenschist to granulite grade faces, but the source depths of the gold remains poorly understood. In this paper we compiled thirty years of long-period magnetotelluric (MT) and geomagnetic depth sounding (GDS) data across western Victoria and south-eastern South Australia that have sensitivity to the electrical resistivity of the crust and mantle, which in turn depend on past thermal and fluid processes. This region contains one of the world’s foremost and largest Phanerozoic (440 Ma) orogenic gold provinces that has produced 2% of historic worldwide gold production. Three-dimensional inversion of the long-period MT and GDS data shows a remarkable correlation between orogenic gold deposits with > 1 t production and a < 20 Ω m low-resistivity region at crustal depths > 20 km. This low-resistivity region is consistent with seismically-imaged tectonically thickened marine sediments in the Lachlan Orogen that contain organic carbon (C), sulphides such as pyrite (FeS2) and colloidal gold (Au). Additional heat sources at 440 Ma due to slab break-off after subduction have been suggested to rapidly increase the temperature of the marine sediments at mid to lower crustal depth, releasing HS− ligands for Au, and CO2. We argue that the low electrical resistivity signature of the lower crust we see today is from a combination of flake graphite produced in situ from the amphibolite grade metamorphism of organic-carbon in the marine sediments, and precipitated graphite through retrograde hydration reactions of CO2 released during the rapid heating of the sediments. Thus, these geophysical data image a fossil source and pathway zone for one of the world’s richest orogenic gold provinces.
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Fan, Haifeng, Xuewu Fu, Jack F. Ward, Runsheng Yin, Hanjie Wen e Xinbin Feng. "Mercury isotopes track the cause of carbon perturbations in the Ediacaran ocean". Geology, 12 ottobre 2020. http://dx.doi.org/10.1130/g48266.1.
Testo completoAbstract (sommario):
The unusual carbon biogeochemical cycling that occurred in the Ediacaran (ca. 635–541 Ma) ocean may have been critical for ocean oxygenation and Ediacaran life evolution. However, the triggers of the peculiar Ediacaran carbonate carbon isotope (δ13Ccarb) excursions are not well understood. Because mercury (Hg) has a strong affinity for organic carbon, we measured Hg isotope compositions (δ202Hg and Δ199Hg) from Ediacaran marine sediments of South China and South Australia to better understand the causes of the Ediacaran δ13Ccarb excursions. During two local positive δ13Ccarb excursions in the Doushantuo Formation, gradually decreasing Δ199Hg and increasing δ202Hg trends are primarily ascribed to enhanced terrestrial input. Decreasing δ202Hg in both the Doushantuo and Wonoka Formations during the latter part of the Shuram negative δ13Ccarb excursion demonstrates the significant, and potentially widespread, contribution of upwelling Hg associated with dissolved organic carbon (Hg-DOC) from the open deep ocean. New Hg isotope data also suggest that a large Hg-DOC reservoir may have been present in the open ocean continuously from the early to mid–late Ediacaran Period (ca. 635–551 Ma), buffering ocean oxygenation at that time.
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Germain, Alexandra, Nathan Lee Young, Jean-Michel Lemieux, A. Locat, Hugo Delottier, Philippe Fortier, Serge Leroueil et al. "Hydrogeology of a complex Champlain Sea deposit (Quebec, Canada): Implications for slope stability". Canadian Geotechnical Journal, 25 novembre 2020. http://dx.doi.org/10.1139/cgj-2020-0500.
Testo completoAbstract (sommario):
The thick sequences of marine clayey deposits which blanket the St. Lawrence Lowlands in south-eastern Canada are highly susceptible to landslides. With 89% of the population of the Province of Quebec living in this region, improving our understanding of the mechanisms causing landslides in these sediments is a matter of public security. To accomplish this goal, instruments were deployed at a field site in Sainte-Anne-de-la-Pérade, Quebec, Canada to monitor atmospheric, soil, and groundwater conditions. Field and laboratory measurements of soil geotechnical and hydraulic properties were also performed. Results indicate that the groundwater and pore pressure dynamics at the site cannot be explained using simplified site conceptual models. Further analysis indicates that groundwater dynamics and pore pressures in the massive clay deposits on-site are determined by (i) the highly-heterogeneous nature of the local geological materials (ii) the contrasting hydraulic and geotechnical properties of these materials, (iii) the presence of two unconfined aquifers at the site, one surficial and one at depth, and (iv), the presence of the Sainte-Anne River. These results were used to create a new conceptual model which illustrates the complex groundwater flow system present on site, and shows the importance of including hydrogeologic context in slope stability analysis.
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Schwarzhans, Werner W., e Sven N. Nielsen. "Fish otoliths from the early Miocene of Chile: a window into the evolution of marine bony fishes in the Southeast Pacific". Swiss Journal of Palaeontology 140, n. 1 (27 luglio 2021). http://dx.doi.org/10.1186/s13358-021-00228-w.
Testo completoAbstract (sommario):
AbstractFew fossil fish otolith associations have been described from the Pacific side of the Americas and, except for a single species (Steindachneria svennielseni), none have been described from Pacific South America south of the Central American tropical region. Here, we describe a rich otolith assemblage obtained from fifteen early Miocene outcrop locations along the Chilean coast from about 33°S to about 45°S. More than 2,000 specimens were studied resulting in the recognition of 67 species, with 27 being new to science. This assemblage represents an important new data point distant from any previously known otolith-based fish fauna, with the nearest coeval associations being from the Caribbean Province in Venezuela, which lies about 5000 km to the north, and New Zealand, which is about 9000 km to the west. The fauna represents a mixture of offshore and shallow water fishes and is rich in myctophids, paralichthyids (Citharichthys), ophidiids (Lepophidium), steindachneriids, and macrourids. Typical tropical American fishes are nearly completely absent, with the exception of Steindachneria and certain anguilliforms. The mesopelagic faunal component, chiefly Myctophidae, shows a striking resemblance to the well-known coeval fish fauna from New Zealand, and both are interpreted as representing an early South Pacific mesopelagic bioprovince. The strong correlation with the mesopelagic otolith-based fish fauna from New Zealand constricts the time interval of the sampled sediments to the middle Burdigalian (approximately 17.5 to 18.5 Ma). All otoliths obtained from the early Miocene of Chile relate to extant fish groups of the area and few exotic components not currently present in the East Pacific. The sole exception is a morpho-type described as Navidadichthys which has an unresolved relationship, possibly with the Prototroctidae, a family that is today endemic to the freshwater and nearshore marine environments of Australia and New Zealand. The new taxa are in the sequence of taxonomic description: Pterothrissus transpacificus n. sp., Pythonichthys panulus n. sp., Chiloconger chilensis n. sp., Gnathophis quinzoi n.sp., Rhynchoconger chiloensis n. sp., Navidadichthys mirus n. gen. et n. sp., Maurolicus brevirostris n. sp., Polyipnus bandeli n. sp., Lampanyctus ipunensis n. sp., Physiculus pichi n. sp., Coelorinchus fidelis n. sp., Coelorinchus rapelanus n. sp., Nezumia epuge n. sp., Paracarapus chilensis n. gen. et n. sp., Lepophidium chonorum n. sp., Lepophidium mapucheorum n. sp., Sirembola supersa n. sp., Spectrunculus sparsus n. sp., Pseudonus humilis n. sp., Capromimus undulatus n. sp., Agonopsis cume n. sp., Cottunculus primaevus n. sp., Kuhlia orientalis n. sp., Citharichthys parvisulcus n. sp., Citharichthys vergens n. sp., Achirus australis n. sp., Achirus chungkuz n. sp.