摘要:

This study of stratigraphy, chronology and sedimentology at Lake Amadeus, a major playa lake in central Australia, provides for the first time a Late Tertiary and Quaternary sedimentary sequence from the continent's centre. The Cenozoic sediments of the lake basin consist of two major units: the Uluru Clay; and the overlying Winmatti Beds. At least 60 m of Uluru Clay overlies Proterozoic dolomitic limestone and consists of uniform clay horizons with minor intercalated gypsum. The clay was deposited in a shallow lacustrine and fluvial environment. Conditions were periodically saline and frequently dry. The basal Uluru Clay is estimated to be over 5 Ma old.

ISSN:0812-0099    

DOI:10.1080/08120099308728059

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The Calliope Volcanic Assemblage, ranging from Late Silurian to Middle Devonian, is dominated by shallow marine volcaniclastic deposits and limestone, with small amounts of primary volcanic material. In the Rockhampton region, three stratigraphic units are recognized: the Early Devonian Mt Holly Formation and the Middle Devonian Capella Creek and Barmundoo Formations, with the Mt Morgan Tonalite (Late Devonian) considered as part of the assemblage.

ISSN:0812-0099    

DOI:10.1080/08120099308728060

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

The Clarence‐Moreton Basin contains abundant oil‐prone organic matter of terrestrial origin particularly in the Walloon Coal Measures and, to a lesser extent, in the Koukandowie Formation. This oil‐prone character is reflected in the petrographic composition, pyrolysis yields, kerogen elemental composition and extractable hydrocarbon yields of shale and coal. Maturation levels vary from immature to marginally mature in the west to overmature in the eastern part of the basin in New South Wales. Calculations based on Rock Eval data show that significant oil generation occurred in a narrow maturation range (0.8–1.0% vitrinite reflectance) and that migration has been highly efficient. Maturation modelling and fission track analyses indicate that hydrocarbon generation occurred 80–100 Ma during a period of high heat flow when the Tasman Sea spreading ridge was adjacent to the southeastern side of the Logan Sub‐basin. Despite the abundance of oil‐prone source rocks, the basin is considered to be largely gas‐prone because the drainage areas for many prospects are overmature.

ISSN:0812-0099    

DOI:10.1080/08120099308728061

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Aerial photogeological interpretation techniques have been used to map the geology, delineate the geological structures and identify the relict channels of three representative dryland salinized catchments in the wheatbelt of Western Australia. Much of the variation in groundwater salinity is explained by the distribution of geological structures (dykes, veins and basement highs) in relation to the alluvial systems and relict channels and their effect in modifying groundwater flow. Salinities in the relict channels are generally higher than in other areas of the catchment. Salinity also increases in the direction of groundwater flow along the relict channel. Salinity in groundwaters upstream of geological structures is without exception higher than in other parts of the catchment. The relict channels are found to have an important role in the storage and redistribution of salt in the landscape.

ISSN:0812-0099    

DOI:10.1080/08120099308728062

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

A combined GLORIA, Seabeam and high‐resolution seismic survey was conducted over a selected area of the southern Australian continental margin. The survey focused on the continental slope immediately seaward of the wide cool‐water carbonate shelf, in a region dissected by a suite of large submarine canyons. Examination of the data underscores the significance of mass‐wasting processes in the development of slope morphology. Slump scars and obvious sediment slides are virtually ubiquitous, in many cases being sourced immediately below the shelf break and connecting downslope with erosional channels. The channels themselves possess what appear to be degraded levee banks suggesting possible spill‐over of turbidity currents which themselves may have been triggered by the upper slope slides. The age of these large‐scale sediment movements remains uncertain, however, and it is currently unclear whether or not they relate to specific sea‐levels. A pair of east‐trending scarp‐like features dominates the mid‐slope region, possibly representing the surface expression of extensional normal faults related to the northwestern margin of the Otway Basin

ISSN:0812-0099    

DOI:10.1080/08120099308728063

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Structurally controlled gold mineralization in the Menzies‐Kambalda area of the Archaean Yilgarn Craton occurs in a wide variety of host rocks and structural settings. The dominant host rocks are Fe‐enriched basalt, and fractionated zones of mafic to ultramafic sills. However, other lithologies, including sedimentary and ultramafic rocks, are important host rocks in some mining camps and structural settings.

ISSN:0812-0099    

DOI:10.1080/08120099308728064

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

摘要:

Palaeomagnetic measurements indicate that the uraniferous Radium Ridge Breccias near Mt Painter in the northern Flinders Ranges of South Australia have been magnetized twice, both times in the Permo‐Carboniferous. The palaeomagnetic south pole for one remanence was estimated as 165.1°E, 65.7°S (A95= 11.5°). The direction for the other remanence was not well defined; however samples collected from diamictite bodies within the breccia gave 133.9°E, 33.1°S (A95= 6.9°) as the probable pole for the overprint. The latter is similar to overprint poles published from central Australia, which are generally attributed to the Alice Springs Orogeny.

ISSN:0812-0099    

DOI:10.1080/08120099308728065

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor

ISSN:0812-0099    

DOI:10.1080/08120099308728066

出版商:Taylor & Francis Group    

年代:1993

数据来源: Taylor