摘要:

Late Palaeozoic glaciation in Australia, discovered over a century ago, is now known to have covered a large part of the continent. In South Australia, tillite and outwash debris lie upon clearly striated pavements within glacial valleys, and show that ice sheets with valley tongues moved northward from sources now occupied by deep ocean south of the continent. These glaciers reached into the Cooper, Arckaringa, and Pedirka Basins at the end of the Carboniferous and laid down patches of till in the Early Permian, now preserved largely in the subsurface. In Tasmania, an ice sheet waxed in the latest Carboniferous from sources to the west of the island, and deposited till and “drop‐stones” into fossiliferous marine strata until well into the Late Permian. In Victoria, the ice cap laid down till on a striated floor, and here and there sequences of outwash, including boulder pavements. In New South Wales, continental glaciation expanded eastward to the sea early in the Permian, and left a record intercalated with volcanics and coal beds into the Late Permian. Bordering the Tamworth Trough of northern New South Wales, and occurring also in the highlands of New England, alpine glaciers left a record in the form of striated stones and dropstones, in very thick sequences of fluviatile, lacustrine, and marine clastic sediments. The mountains existed in Middle and early Late Carboniferous times, and were largely worn down to gentle relief when continental glaciers expanded northward in the Early Permian. A non‐glacial interval at the end of the Carboniferous therefore probably occurred in New South Wales. In Queensland, alpine glaciers occupied mountains at the western rim of the Bowen Basin at the end of the Carboniferous. Large blocks carried by icebergs from glaciers of unknown locations were dropped into Lower and Upper Permian strata of the Bowen Basin as well. In Western Australia Early Permian ice centres were located on the Yilgarn Block, east of the Perth Basin, on the Pilbara Block southwest of the Canning Basin, and on the Kimberley Block. Evidence for this glaciation consists mostly of ice‐rafted debris and fluvial‐glacial and glacial‐marine strata that reached as far north as the Bonaparte Gulf Basin.

ISSN:0016-7614    

DOI:10.1080/00167617108728730

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

In a sequence of fine‐grained, thinly bedded flysch of Lower Emsian (Lower Devonian) age, a sharpstone conglomerate, thought to be a proximal turbidite, is lithologically out of character and shows a different provenance.

ISSN:0016-7614    

DOI:10.1080/00167617108728731

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

All known Cambrian and Ordovician dendroids and hydroids of Tasmania are reviewed.Protohalecium hallianumChapman & Thomas is revised at both generic and specific levels.Archaeocryptolaria rectavar.flexilisChapman & Thomas is revised toProtohalecium flexilis. Archaeolafoea serialis(Chapman & Thomas) (Hydroidea) is transferred toMastigograptus(Dendroidea). The following species are described as new:Acanthograptus antiquus(Cambrian),A. banksi, Desmograptus thomasi(Ordovician).

ISSN:0016-7614    

DOI:10.1080/00167617108728732

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Interseam “sands” of Morwell form part of a sequence of brown‐coal seams, sediments and volcanic rocks which, together, make up the Tertiary Latrobe Valley Coal Measures. A detailed investigation and computer analysis of the “sands” show that they are fluviatile deposits which accumulated within the tectonically stable Latrobe Valley Depression.

ISSN:0016-7614    

DOI:10.1080/00167617108728733

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Twenty‐four mineral separates from the Arunta Complex, four from the metamorphosed Heavitree Quartzite (White Range Quartzite), and one whole rock sample of metamorphosed Bitter Springs Formation, all from the western part of the White Range Nappe of the Arltunga Nappe Complex, and two samples from the autochthonous basement west of the nappe have been dated by the K‐Ar method. The samples from the basement rocks form two groups. Those in the southern or frontal part of the nappe are of Middle Proterozoic (Carpentarian) age (1660–1368 m.y.), determined on hornblende, biotite, and muscovite. In the northern or rear part of the nappe, all but one of the muscovite samples and two biotites are of Middle Silurian to Early Carboniferous age (431–345 m.y.); the remainder of the biotite dates range from 1775 to 548 m.y. (including the two samples from the autochthon), and two hornblendes gave dates of 1639 and 2132 m.y. respectively. All the muscovite samples from the Heavitree Quartzite, and the whole rock sample from the Bitter Springs Formation gave Early to Middle Carboniferous dates (358–322 m.y.). The findings support the identification of the White Range Quartzite as the metamorphosed part of the Heavitree Quartzite, which in turn supports the interpretation of the structure of the area as a large, basement‐cored fold nappe. In addition, they date the time of the Alice Springs Orogeny as pre‐Late Carboniferous, which agrees with fossil evidence from elsewhere in the area. The Alice Springs Orogeny was accompanied by widespread greenschist facies meta‐morphism that progressively metamorphosed the Heavitree Quartzite and Bitter Springs Formation, and retrogressively metamorphosed the Arunta Complex. However, the basement rocks in the southern part of the nappe escaped this metamorphism and retain a Middle Proterozoic age, thus dating the time of the Arunta Orogeny in this region as Carpentarian or older.

ISSN:0016-7614    

DOI:10.1080/00167617108728734

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Rb‐Sr isotope measurements from the basement Houghton Inlier near Adelaide suggest that they were metamorphosed to upper amphibolite facies grade about 870 m.y. ago. One microcline mineral separate indicates that the minerals are grossly affected by the later Kanmantoo metamorphism (biotite grade in this region), but the total rock systems appear to have remained closed. The age of most of the Adelaide Supergroup is limited by this new result.

ISSN:0016-7614    

DOI:10.1080/00167617108728735

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

The Kielpa meteorite is a deeply weathered olivine‐bronzite‐chondrite with a high content of ferric oxide. The olivine composition is 21% Fa and the pyroxene is 21% FeSiO3. The petro‐chemical classification would be H5. The texture indicates a moderate amount of metamorphism and a small amount of shock, but with no penetrative stress.

ISSN:0016-7614    

DOI:10.1080/00167617108728736

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

摘要:

Corundum laths have been identified as exsolution products from both ilmenite and spinel in granulite facies rocks from central Australia. The exsolution is interpreted as having occurred during a decrease in the P‐T conditions under which the minerals initially crystallized. The ilmenite + corundum possibly indicate the existence of a former homogeneous iron‐högboemite. The spinel + corundum suggests that under conditions of high Ps‐T (granulite facies) and low fo2 there exists a field where aluminous spinel is stable.

ISSN:0016-7614    

DOI:10.1080/00167617108728737

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

ISSN:0016-7614    

DOI:10.1080/00167617108728738

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor

ISSN:0016-7614    

DOI:10.1080/00167617108728729

出版商:Taylor & Francis Group    

年代:1971

数据来源: Taylor