摘要:

The Bruinbun pluton is a small, massive, I‐type granitoid intruded into the meta‐sedimentary Hill End Trough, in eastern N.S.W. It is a multiple pluton representing two discrete magma pulses, the granodiorite core intruding the adamellite margin. A weak alignment of orthoclase megacrysts in the granitoids is best developed adjacent to both the internal and external intrusive contacts, and is considered by the writer to be a product of magmatic flow. Part of the northern contact and the southern and western contacts dip inward at moderate angles, whereas the eastern contact is vertical to outward‐dipping. The pluton is inferred to be mushroom‐shaped, and slightly tilted.

ISSN:0016-7614    

DOI:10.1080/00167618208729211

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

In an attempt to elucidate their ages, the often incomplete and poorly known early Permian marine faunas and sequences of India, Tibet, Pakistan, Afghanistan, Iran and Oman are compared with those of the Perth, Carnarvon and Canning Basins of Western Australia, where faunas are documented and in sequence, and stratigraphic relationships between units are clear. This comparison indicates that the faunas discussed are Latest Asselian or younger in age, and that most of the underlying glacial beds are probably Early Permian (Asselian) in age. By implication, the Permo‐Carboniferous boundary for Gondwana is considered to lie at or near the base of Unit II/Stage 2 and equivalent palynomorph zones throughout Gondwana.

ISSN:0016-7614    

DOI:10.1080/00167618208729212

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The results of in‐situ measurements, seismic studies of the Robertson Earthquake of 1961 and the Burragorang Earthquake of 1973, geological observations made during construction of Warragamba Dam and the Pipe Head‐Potts Hill Tunnel, and foundation investigations into dams in other catchment areas, do not indicate agreement as to the direction of maximum horizontal stress in the southern part of the Sydney Basin.

ISSN:0016-7614    

DOI:10.1080/00167618208729213

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The Toolebuc Formation, which is a potentially important source of oil shale in the Eromanga Basin of NW Qld, exhibits a marked gamma‐ray response that has long beeen used as a stratigraphic marker. At Julia Creek, a large area of the Formation contains low‐grade oil shale that is accessible to mining. Detailed investigation, by gamma‐ray spectrometry and neutron activation analysis, of drill core samples from this deposit and from the type section of the Toolebuc Formation at Boulia (BMR Boulia 3A stratigraphic drill hole) show that the Toolebuc gamma‐ray anomaly in the northern Eromanga Basin is due to the presence of uranium. Analyses for organic carbon and phosphorus show that the uranium is associated primarily with organic matter in the oil shales and with phosphatic skeletal fish debris in the accompanying coquinites.

ISSN:0016-7614    

DOI:10.1080/00167618208729214

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The 460 m‐thick Cliefden Caves Limestone Group is the oldest and best exposed, extensive body of limestone in N.S.W. Its Late Ordovician faunas and floras are comparatively well preserved and it has some excellent silicified horizons, especially in the upper part of the sequence. In the nominal type area at Cliefden Caves, the limestone has been subdivided into three formations—the Fossil Hill Limestone (lower), the Belubula Limestone (middle) and the Vandon Limestone (upper). Only the Belubula Limestone remains undifferentiated. The Fossil Hill Limestone has been further subdivided into six members (Gleesons, Kalimna, Wyoming, Taplow, Dunhill Bluff and Transmission Limestone Members, respectively), and the Vandon Limestone into two members (Trilobite Hill and Mount Lewin Limestone Members). Each of these subdivisions is defined herein, with a designated type section and a description of its content and distribution.

ISSN:0016-7614    

DOI:10.1080/00167618208729215

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

The age of formation of the Lapstone Monocline has been long considered to be late Pliocene/early Pleistocene (the Kosciusko Uplift) but it is now generally thought to be much older. Palaeomagnetic data from haematite‐rich beds within the Hawkesbury Sandstone on and about the monocline indicate that it formed before the oldest haematite was introduced to these beds. The age of this oldest haematite is 15±7 Ma. On the basis of these data, the age of the monocline is unlikely to be less than 8 Ma, probably exceeds 15 Ma, and could be older than 22 Ma.

ISSN:0016-7614    

DOI:10.1080/00167618208729216

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Measurements of 18 closely spaced beach profiles spanning Warilla Beach, N.S.W., over a 5‐year period have been examined for alongshore exchanges in beachface configuration. Horizontal slices of beach corresponding with berm, upper swash, upper and lower intertidal zones were examined by empirical orthogonal function (EOF) analysis. The first four EOF's for each of the four slices contain over 90% of the total variance for each slice. In each instance the first eigen‐function mode represents the onshore‐offshore component of beach response, and accounts for 50 to 60% of the variance. Subsequent modes describe alongshore exchange of sediment associated with large, standing, cellular water circulations of the embayment. Sediment shunts along each horizontal slice are determined by identification of nodal points in the eigen‐functions. These represent pivotal points through which sediment is transferred. The patterns of exchange vary considerably from slice to slice, reflecting change in the dominant beach processes from swash processes in the top of the beach to wave, tidal and current processes on the lower beach slope. Despite their disparity, similar periodicities are determined for the sediment exchanges in each slice. The amplitude spectra of the time series associated with each eigen‐function indicate that the exchanges take place at 24, 12 and 6 monthly periods.

ISSN:0016-7614    

DOI:10.1080/00167618208729217

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Fifty‐three sea‐floor samples close to Antarctica collected by Douglas Mawson during the Australasian Antarctic Expedition of 1911–1914 have beeen analysed for recycled palynomorphs. The distribution of the recycled microfossils provides a broad guide to the position of hidden sedimentary sequences on the Antarctic continental margin.

ISSN:0016-7614    

DOI:10.1080/00167618208729218

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Throughout most of the Early Carboniferous shelf sedimentation extended across the Tamworth Belt for a present distance of 35 km to near the eastern margin of the Belt. These sediments are dominated by muds and silts, with minor near shore sands, deposited by traction currents, along the western margin of the Belt. Much of the coarser sediment is inferred to have bypassed the shelf via channels, now comglomerate‐filled, to be deposited in base‐of‐slope environments east of the Tamworth Belt. The Texas and Sandon beds possibly represent these base‐of‐slope deposits. The New England Arch has not affected sedimentation in the Tamwortb Belt until post‐Visean (Late Carboniferous) times.

ISSN:0016-7614    

DOI:10.1080/00167618208729219

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor

摘要:

Two graptolite faunas are described from outcrops of the Wagonga Beds near Batemans Bay on the south coast of N.S.W. They are of late Eastonian and early Bolindian age. The faunas have been found in two geographically separate localities and, in spite of structural complexities, it is now suggested that the greater part of the Wagonga Beds was deposited in the Late Ordovician. The chert and volcanicrich Wagonga Beds were accumulated prior to, or as contemporaneous lateral facies equivalents of, the thick undifferentiated Upper Ordovician ‘slates and grey‐wackes unit’ that crops out in the same general region.

ISSN:0016-7614    

DOI:10.1080/00167618208729220

出版商:Taylor & Francis Group    

年代:1982

数据来源: Taylor