摘要:

The Neptunist‐Vulcanist controversy has distorted the reputations of both James Hutton and Abraham Gottlob Werner. Among English‐speaking geologists, Hutton is often presented as the Father of Modern Geology, whereas Werner's views are seen as ‘palpably absurd’. Both men made major contributions to geology, but they were men of their age, the second half of the eighteenth century, and remote in their general ideas from those current since Lyell's day in the mid‐nineteenth. Werner was greatly admired by some of his ablest contemporaries, and their admiration becomes inexplicable if we regard his views as ‘palpably absurd’. Historical research in the last few years, reviewed here, is able to show how Werner's views arose and why they seemed persuasive at the time. Some examples of Neptunist observations in Australia in the 1820's are given to show the application and later modification of the theory.

ISSN:0016-7614    

DOI:10.1080/00167617308728824

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Sixteen unpublished analyses of Broken Hill manganese silicates (two pyrox‐mangite, one rhodonite, four hedenbergite, and nine bustamite) from the papers of the late Dr W. T. Schaller are presented. They have been complemented with additional analyses by the electron microprobe to define the compositional fields of these minerals. Data are provided on the relationship of these minerals with tephroite and garnet. The occurrence of roepperite (zincian tephroite) at Broken Hill is discredited, and its validity is doubtful. Dannemorite from Broken Hill has a composition close to Mn2(Fe,Mg)5Si8O22(OH)2, and can be considered a valid amphibole subspecies.

ISSN:0016-7614    

DOI:10.1080/00167617308728825

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

An updated* tectonic model for the Palaeozoic tectonic history of New South Wales, based on actualistic models of plate tectonics, has resulted from tectonic analyses and syntheses during the compilation of the Tectonic Map of New South Wales.

ISSN:0016-7614    

DOI:10.1080/00167617308728826

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Alkali basaltic rocks from the Southern Highlands, N.S.W., contain oxide phases of both high and low pressure origin. The two phases are readily distinguished using chemical and textural criteria.

ISSN:0016-7614    

DOI:10.1080/00167617308728827

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

The Daylesford Limestone is the basal formation of the Ordovician Bowan Park Group of central western New South Wales. The formation contains four main limestone types and minor intercalated terrigenous beds. Limestones are: (1) grain‐stone, (2) grey skeletal wackestone and packstone, (3) dark grey burrowed wackestone and packstone, and (4) dark grey burrowed lime mudstone. Grainstone and grey skeletal wackstone and packstone are dominant in eastern sections; they are laterally equivalent to, and interfinger with, dark grey muddy limestones that dominate western sections. Lithoclasts are abundant in the grainstone but are absent from muddy sections to the west except in thin beds above disconformities. The rock types of the Daylesford Limestone also tend to occur sequentially above some disconformities; the full sequence is: grainstone (or grey skeletal wackestone and packstone) grading up into dark grey burrowed wackestone and packstone and thence into dark grey burrowed lime mudstone. Each sequence is probably trans‐gressive and reflects deepening water.

ISSN:0016-7614    

DOI:10.1080/00167617308728828

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

摘要:

Several isolated outcrops of melanocratic leucitite lava in central New South Wales are interpreted as remnants of flows erupted in late Cainozoic time by small lava‐volcanoes. The general distribution of outcrops conforms to the regional structural trends of the Palaeozoic basement complex, characterized by a prolonged post‐orogenic stabilization history dominated by block‐faulting and multiple uplift. The lavas are generally microphyric to aphyric and essentially composed of olivine (Fa7–21), diopsidic pyroxene, leucite, and iron‐titanium oxide minerals, with subordinate titaniferous phlogopite and amphibole (richterite), nepheline, and alkali feldspar. The Colour Index is generally close to 70. Bulk‐rock analyses and electron microprobe data on the constituent phases show the unusual chemistry of the suite and its close affinities to the alkali ultrabasic lavas of the ‘stable’ continental regions. Compositional variations are similar, in, their predominant trends, to their analogues in the alkali olivine basalt series and may be interpreted in terms of crystal‐liquid equilibria. The leucitites are thought to have crystallized mainly above about 700°C under pressures lower than 2 Kb. The source magma probably originated in the mantle at a minimum depth of 100 km and reached the surface through several independent channelways, probably assisted by the regional tectonic activity.

ISSN:0016-7614    

DOI:10.1080/00167617308728829

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor

ISSN:0016-7614    

DOI:10.1080/00167617308728823

出版商:Taylor & Francis Group    

年代:1973

数据来源: Taylor