In August 1882, the Morgan brothers recognised a mineral deposit, now known as the Mount Morgan Gold-Copper Deposit. The final production figures for the mine were 250 tonnes of gold and 360,000 tonnes of copper from 50 million tonnes of ore, making the average grades 4.99g/t gold and 0.72% copper.

Carbonate petrography — the study of limestones, dolomites and associated deposits under optical or electron microscopes —greatly enhances field studies or core observations and can provide a frame of reference for geochemical studies. Petrography is an especially powerful tool because it enables the identification of constituent grains, the detailed classification of sediments and rocks, the interpretation of environments of deposition, and the determination of the often complex history of post-depositional alteration (diagenesis).

This book is designed as a companion volume to AAPG Memoir 27. As with its predecessor volume, the purpose of this book is to provide identified illustrations of important grains, textures, cements, and porosity types for geologists who may not be specialists in the petrography of sandstones and associated sedimentary rocks.

Sandstone petrography is of particular interest to the explorationist for several reasons. First, it can provide valuable information on the detailed composition of sedimentary rocks. From this, one can often draw conclusions about the lithology, climate, and tectonic history of the source area, as well as predicting the response of such units to a variety of subsurface diagenetic environments. Second, one can acquire significant data on the grain size, sorting, and rounding of sedimentary grains. For lithified sediments this may be the only way to obtain such data, which may be useful in determinations of the transport mechanisms and depositional environment of the sediment. Third, information may be obtained on the postdepositional alteration history of sedimentary rocks. This may include data on compaction, cementation, leaching, fracturing, porosity types, and other factors. These are essential for a proper understanding of reservoir rocks and, commonly, petrography provides the only technique fort gathering accurate data on such diagenetic factors <...>

This atlas has been prepared for students of earth science, geology, mineralogy and physical geography who requ~re a text for practical classes on rocks and mInerals under the minoscope. While the book's prime purpose is as an introduction to the subject for college and university students as an essential part of their course, we hope that amateur geologists and mineralogists will also find it useful and attractrve.