SUBMARINE GRAVITY SURVEYS IN ST. VINCENT GULF AND INVESTIGATOR STRAIT, SOUTH AUSTRALIA, IN RELATION TO OIL SEARCH

1965 ◽  
Vol 5 (1) ◽  
pp. 168
Author(s):  
C. Sprigg ◽  
W. F. Stackler

A total of 476 submarine and 307 coastal (beach) stations has been observed in and about St. Vincent Gulf and Investigator Strait. These were observed from the oceanographic vessel 'Saori' by manned sea-floor diving chamber, and/or scuba-operated encapsuled meter. Location control was by theodolite fix as from the shore and/or by sextant fix.The survey has provided Bouguer gravity station data contourable on 1 milligal intervals with an estimated maximum error of ± 0.3 milligals in the more remote seaward situations (principally due to surveying), down to ± 0.1 in closer inshore situations.The survey hasdefined the principal structural elements in and about St. Vincent Gulf and Investigator Strait;defined the western margin of the Upper Proterozoic to Cambrian Adelaide Geosyncline;provided a more detailed understanding of coastal block-faulting about the western escarpment of the Mt. Lofty Ranges;defined a longitudinal series of gravitational maxima beneath the Orontes Platform which are predicted to relate primarily to Cambrian fold structures, and which are probably erosionally breached in the north;outlined the probable margin of the submarine portion of the Troubridge (Permian) infra-basin;located a gravitational cross-feature displaying a strong north-south gradient opposite Port Vincent that relates in part to the northern margin of the Troubridge Permian infra-basin, but which appears also to be a locus of transcurrent faulting displaying south-block-west movement;subdivided the St. Vincent Basin into two provinces via a north-west-south-east structure extending south-east from about Macintosh Bank. Possible faulting in this zone indicates downthrow to the north defining potential southern limits of deeper Tertiary basin development.

Author(s):  
Futa Nakasugi ◽  
Motohiro Shimanaga ◽  
Hidetaka Nomaki ◽  
Hiromi Kayama Watanabe ◽  
Tomo Kitahashi ◽  
...  

Abstract Dirivultid copepods (Siphonostomatoida), one of the most successful meiobenthic organisms found at deep-sea hydrothermal vents, have been the focus of most previous ecological studies among meiofauna in these habitats. The ecology of Harpacticoida, a major benthic copepod group in typical deep-sea floor, however, is not well understood in terms of variations in community structure and controlling factors at venting sites. The spatial heterogeneities in benthic harpacticoid composition and their association with environmental parameters were investigated at hydrothermal vent chimney structures in the calderas of three neighbouring sea knolls (Bayonnaise Knoll, Myojin Knoll and Myojin-sho Caldera) in the western North Pacific. While a previous study had reported the distribution of dirivultids was strongly associated with spatial differences in stable carbon isotopic signatures (δ13C) of organic matter in the detritus on active chimneys in the field, multivariate analyses detected no significant corelation between the parameter and harpacticoid composition in this study. Instead, high associations of the harpacticoid composition with differences in water depth and total organic carbon (TOC) concentration were detected. Ectinosomatidae dominated at vent sites with lower TOC values in the shallowest Bayonnaise Knoll, while they were less prevalent at deeper vent fields in the other knolls, where Miraciidae was the most abundant family. This study indicated the availability of vent chemoautotrophic carbon is not a primary factor controlling the composition of harpacticoids even in the habitats on the hydrothermal vents, but instead by the food amount, regardless of its resources (including marine snow from the sea surface), in the study area.


2001 ◽  
Vol 41 (2) ◽  
pp. 80
Author(s):  
S.J. Smith

Last year the petroleum industry witnessed the enactment of new legislation both at Commonwealth and State levels. The principal legislative change to environmental management was the introduction of the Commonwealth Government’s Environmental Protection and Biodiversity Act, 2000 (EPBC Act). South Australia and Victoria also implemented new Petroleum Acts and/ or Regulations.Construction of the Eastern Gas Pipeline was also completed last year, whilst preliminary approvals and environmental assessment continues for the Papua New Guinea, Timor Sea and Tasmania Natural Gas pipelines. Offshore exploration continued, particularly in the North West Shelf, Otway Basin, Timor Sea and Bass Strait.Other critical areas of environmental management included greenhouse gases, national pollution inventory reporting and the increasing requirements for environmental approval and management under various state environmental legislation.This paper provides an overview of environmental developments in the petroleum industry during the year 2000, in particular, the implication of new legislation, new technology, e-commerce and a greater focus on environmental reporting.


2009 ◽  
Vol 49 (1) ◽  
pp. 465
Author(s):  
Thomas Bernecker

The Australian Government formally releases new offshore exploration areas at the annual APPEA conference. This year, 31 areas plus two special areas in five offshore basins are being released for work program bidding. Closing dates for bid submissions are either six or twelve months after the release date (i.e. 3 December 2009 and 29 April 2010), depending on the exploration status in these areas is and on data availability. The 2009 release areas are located in Commonwealth waters offshore Northern Territory, Western Australia, South Australia and Victoria, comprising intensively explored areas close to existing production as well as new frontiers. As usual, the North West Shelf features very prominently and is complimented by new areas along the southern margin, including frontier exploration areas in the Ceduna Sub-basin (Bight Basin) and the Otway Basin. The Bonaparte Basin is represented by one release area in the Malita Graben, while five areas are available in the Southern Browse Basin in an under-explored area of the basin. A total of 14 areas are being released in the Carnarvon Basin, with eight areas located in the Dampier Sub-basin, three small blocks in the Rankin Platform and three large blocks on the Northern Exmouth Plateau (these are considered a deep water frontier). In the south, six large areas are on offer in the Ceduna Sub-basin and five areas of varying sizes are being released in the Otway Basin, including a deep water frontier offshore Victoria. The special release areas are located in the Petrel Sub-basin, Bonaparte Basin offshore Northern Territory, and encompass the Turtle/Barnett oil discoveries. The 2009 offshore acreage release offers a wide variety of block sizes in shallow as well as deep water environments. Area selection has been undertaken in consultation with industry, the states and Territory. This year’s acreage release caters for the whole gamut of exploration companies given that many areas are close to existing infrastructure while others are located in frontier offshore regions. As part of Geoscience Australia’s Offshore Energy Security Program, new data has been acquired in offshore frontier regions and have yielded encouraging insights into the hydrocarbon prospectivity of the Ceduna-Sub-basin.


Author(s):  
Г.П. Яроцкий

Обосновано выделение орогенного Северо-Западно-Корякского вулканического пояса. В методологии авторской глыбово-клавишной структуры литосферы определён на границе регионального прогиба и северной активной окраины Корякского микроконтинента механизм образования вулканогенов пояса. На пересечении поперечными межглыбовыми глубинными разломами литосферы границы регионального прогиба и северной окраины микроконтинента образовались локальные впадины вулканогенов. В них в эпоху олигоценовой тектоно-магматической активизации внедрились породы гранитно-метаморфического слоя коры, в которых образовались рудные столбы с золотом, ртутью, ураганным серебром, сопутствующими месторождениями  олова в породах фундамента. Обосновано выделение олово-золото-серебряных рудных районов вулканогенов пояса. Простирание пояса в пределы и Чукотки дает основание определить Северо-Западно-Корякскую металлогеническую зону. We managed to reveal the North-Western-Koryak orogenic volcanic belt. Using the authors'methodology of block and key structure of lithosphere at the boundary of the regional downfold and the northern active margin of the continent we defined the mechanism of the belt volcanogenes formation. The local regional downfolds were formed at the intersection of the transverse intra-block deep faults of regional downfold lithospheric boundary and the Koryak microcontinent's northern margin. During Oligocene tectonic-magmatic activity rocks from the crustal granitic-metamorphic layer with ore columns of gold, mercury, hurricane silver, associated with Sn deposits in basement rocks were introduced in them. The allocation of the tin-gold-silver ore regions in volcanogenic belts is proved. The trend of the belt within the margins and Chukotka gives the basis to determine the North-West Koryak metallogenic zone.


1963 ◽  
Vol 3 (1) ◽  
pp. 69
Author(s):  
R. C. SPRIGG ◽  
J. B. WOOLLEY

The Geltwood Beach (buried) anticline is located near the ocean coast in south-east South Australia, directly west of the agricultural and industrial town of Millicent. The structure is developed in Mesozoic to Tertiary sediments forming the inner part of the continental sedimentary terrace which in this situation coincides also with the Nelson "half-graben".The Geltwood Beach anticline is more than five miles long by two or more miles wide. It is part of a still larger regional development which pitches south-east into the deeper known portions of the Gambier-Otway Cretaceous to Tertiary Basin. There is no surface expression to the structure.Structural "closure" on the base of the Tertiary may not exceed 100 feet, but an extensive area of structural flattening along the crest of the anticline (defined by structural drilling and geophysical techniques) overlies a zone of extensive sedimentary wedge-out within the predicted and prospective cretaceous sediments in depth. The wedging is predicted to be in the nature of progressive overlap onto structural "nosing" or alternatively, buried-ridge development in presumed Otway Group sediments in depth.A thickness of 5,000 to 8,000 feet of unconsolidated Upper Cretaceous to Tertiary sediments, wedging to the north-west along the crest of the anticline in the deeper developments is expected to include the prospective Belfast Mudstone equivalents and related beds of the Port Campbell (Victoria) Association.The Geltwood Beach structure lies approximately half way between the Mt. Salt No. 1 and Beachport No. 1 wells. In the distance of 45 miles between the latter wells, the dominantly Cretaceous (post-Otway) sedimentary section wedges spectacularly from 7,000 feet (possibly considerably more) to no more than 100 feet. The available geophysical evidence suggests that most of this wedging occurs within the zone of the Geltwood Beach anticline. For this reason, the anticline is believed to be well located for the development of structural and stratigraphic traps in a marginal continental shelf environment of proven thick sedimentation.In the Mt. Salt No. 1 well, clays and shales encountered at at least five stratigraphic levels within the Lower Tertiary to Middle Cretaceous section provided adequate capping to underlying highly porous and permeable reservoir sands, the lowermost of which were brine-bearing.Geltwood Beach is a locale of preferred coastal bitumen stranding. The weight of published evidence now points to nearby submarine seepage within the reach of erosive storm waves: recorded earthquakes in this vicinity are known to have greatly affected the activity of these seepages.The conclusion is reached that the Geltwood Beach anticline is favourably situated up-dip on the inner continental shelf margin to accumulate hydrocarbons in potentially commercial quantities. The structure lies south of the Beachport-Kalangadoo "hinge-line" of the Nelson half-graben in a zone of submarine oil seepage. A proposed deep test well to be located near the culmination of shallower structure is expected to provide a satisfactory test in respect to both structural and (to a lesser extent) deeper stratigraphic entrapment of petroleum.


Author(s):  
Michael Larsen ◽  
Morten Bjerager ◽  
Tor Nedkvitne ◽  
Snorre Olaussen ◽  
Thomas Preuss

NOTE: This article was published in a former series of GEUS Bulletin. Please use the original series name when citing this article, for example: Larsen, M., Bjerager, M., Nedkvitne, T., Olaussen, S., & Preuss, T. (2001). Pre-basaltic sediments (Aptian–Paleocene) of the Kangerlussuaq Basin, southern East Greenland. Geology of Greenland Survey Bulletin, 189, 99-106. https://doi.org/10.34194/ggub.v189.5163 _______________ The recent licensing round in the deep-water areas south-east of the Faeroe Islands has emphasised the continued interest of the oil industry in the frontier areas of the North Atlantic volcanic margins. The search for hydrocarbons is at present focused on the Cretaceous– Paleocene succession with the Paleocene deepwater play as the most promising (Lamers & Carmichael 1999). The exploration and evaluation of possible plays are almost solely based on seismic interpretation and limited log and core data from wells in the area west of the Shetlands. The Kangerlussuaq Basin in southern East Greenland (Fig. 1) provides, however, important information on basin evolution prior to and during continental break-up that finally led to active sea-floor spreading in the northern North Atlantic. In addition, palaeogeographic reconstructions locate the southern East Greenland margin only 50–100 km north-west of the present-day Faeroe Islands (Skogseid et al. 2000), suggesting the possibility of sediment supply to the offshore basins before the onset of rifting and sea-floor spreading. In this region the Lower Cretaceous – Palaeogene sedimentary succession reaches almost 1 km in thickness and comprises sediments of the Kangerdlugssuaq Group and the siliciclastic lower part of the otherwise basaltic Blosseville Group (Fig. 2). Note that the Kangerdlugssuaq Group was defined when the fjord Kangerlussuaq was known as ‘Kangerdlugssuaq’. Based on field work by the Geological Survey of Denmark and Greenland (GEUS) during summer 1995 (Larsen et al. 1996), the sedimentology, sequence stratigraphy and basin evolution of the Kangerlussuaq Basin were interpreted and compared with the deep-water offshore areas of the North Atlantic (Larsen et al. 1999a, b).


1968 ◽  
Vol 16 (3) ◽  
pp. 565 ◽  
Author(s):  
OB Williams

The changes in basal area and density of Danthonia caespitosa were measured over the 9-year period 1949-1957 by charting permanent quadrats in plots which were ungrazed, and lightly, moderately, and heavily grazed. Compared with the control, the grazing treatments had no effect on basal area, and a significant but not substantial effect on the contribution made by the various age groups of the dominant grass. There were no real differences between the age groups of D. caespitosa on continuously and intermittently grazed treatments, and it is suggested that the design of grazing experiments might be simplified, cognizance being given to the stage of degeneration reached by the pasture, and to the possibility that seasonal deferment procedures might cause substantial changes in botanical composition.. In the autumn or winter of 1951 the mature population of D. caespitosa was almost wiped out and the build-up of basal area and density over the 1951-1957 period was very slow. Dry summers and the late arrival of the opening rains in autumn appeared to be responsible for substantial losses in D. caespitosa. Abnormally high rainfall during the preceding growth season appeared to accentuate these losses. In the gilgai microrelief death rates were greater on the depression than on the shelf. It is suggested that the D. caespitosa grassland was degraded, and reached a "steady state" condition under the influence of cattle, sheep, rabbits, and drought. If grazing treatments are to induce changes in such a plant population, such treatments must be a wide departure from the previous procedures which have given rise to the existing plant community. The results are discussed in relation to grazing experiments in Queensland, New South Wales, South Australia, and the north-west of Western Australia.


1983 ◽  
Vol 10 (1) ◽  
pp. 47 ◽  
Author(s):  
PB Copley

Petrogale xanthopus still occurs over most of its former range in South Australia. It is widespread in the Flinders Ranges, where almost 200 colonies are now known, and is locally common in areas of both the Rinders Ranges and Olary Hills. Six colonies are currently known in the western Gawler Ranges with an outlying population on Carriewerloo Station only 50 km west of Port Augusta. Seven colonies have been found in the Olary Hills, to the north and north-west of Olary. The species has suffered a major decline in abundance since European settlement, having become extinct locally throughout this range. Hunting for skins, competition with introduced herbivores for food and shelter, and predation by foxes seem to be the main reasons for this decline. However, it is still not possible to say whether the species currently has a decreasing population and is at risk, is in equilibrium, or is increasing. Information published in this paper and current studies in South Australia and New South Wales should soon determine this.


1878 ◽  
Vol 26 (179-184) ◽  
pp. 133-137 ◽  

A telegraph-cable was laid off the north-west of Spain in 1870, and a portion of it was recovered in 1876, in long. 9° 4′ W. and lat. 44° 6′ N. The depth from which the recovered portion came was from 522 to 550 fathoms; the ground was conglomeratic, and there was a deposit there of sticky foraminiferal mud. Much coral growth had occurred on the cable, and when it was fished up some living and dead forms, together with Echini , Pectens, and mud, came up from off the surrounding sea-floor. The growth on the cable consisted of numerous individuals of Desmophyllum Crista-Galli of different sizes and of many bush-shaped coralla of Lophohelia prolifera , var gracilis ; there were also small masses of Solenosmilia variabilis (nobis), a new Amphihelia , and a specimen of Caryophyllia cylindracea (Reuss), which were not attached, but which must have been fixed close by to stones.


1993 ◽  
Vol 21 (1) ◽  
pp. 45-49
Author(s):  
John Amadio

The Pitjantjatjara people in the north west of South Australia and the Yalata Community in the far west of the state identify as Anangu (the people) Anangu culture is very different in many ways from the mainstream culture largely associated with urban centres but some of the aspects in common include a desire to maintain their culture and lifestyle, wanting a favourable future for their children and their communities, and a desire to be self managing.


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