This article and a future article in the SEG Newsletter will serve as previews to an SEG-sponsored forum to examine and discuss the origins of gold deposits in the Carlin and Witwatersrand camps. The forum will be held in Reno, Nevada, on May 14, 2005, in conjunction with Geological Society of Nevada’s Symposium 2005 – Window to the World. Both districts have been the focus of major controversies. In this article, three short papers discuss the origin of Carlin-type deposits in north-central Nevada. Over the last few decades, Carlin-type deposits have been seen as shallow hot spring deposits, distal products of porphyry copper deposits, and the uppermost parts of deep mesother-mal systems. The first paper, by Jean Cline, provides an introduction to the characteristics of Carlin-type deposits and a framework for discussions of their origin. The second paper, by Marcus Johnston and Michael Ressel, argues for a magmatic origin for the deposits, and specifically that plutons are the source of heat and probably fluids and metals. The third paper, by Eric Seedorff and Mark Barton, discusses amagmatic models for the origin of Carlin-type deposits, as well as pointing out shortcomings in magmatic models. These authors will give talks at the May 2005 forum, which will be followed by panel and open discussions with the aim of identifying what we need to know to better understand and explore for these deposits.

During the past few years many experiments have been tried in the development of Manual Training Courses and much time has been spent in discussing of what lines of work they should consist. Wood and iron were the first materials used and are yet indispensable, but experience has led those who are developing this work to believe that there are other materials as well adapted to Manual Train¬ ing work in all its various forms. Clay, used not only for modeling but for ceramic work as well, leather, brass and copper are materials that have also been put to the test and found satisfactory in many ways

The inaugural edition of the Treatise on Geophysics published in 2007 included for the first time a geoscience volume specifically devoted to the dynamics in the Earth’s core. This Core Dynamics volume in the second edition of Treatise on Geophysics continues that tradition, offering an in-depth discussion of the dynamical processes that are active at the very heart of the Earth, some of which have impact far beyond the core itself. In the years since the first edition, there has been much in the way of progress, plus some revisions, as is inevitable in studying the most remote region of our planet. The overall trend is toward a more dynamical perspective of the core, in which energy production and dissipation are higher and the pulse of evolution is stronger, compared to our thinking just a few years ago. Evidence of this trend is found in the major new ideas, advances, concepts, and research directions that have appeared since the first edition, including the following: <...>

The Earth’s deep interior, being physically inaccessible, is difficult to study directly. The necessarily indirect methods used in its study are best pursued collaboratively in order to bring all possible sources of knowledge to bear on the topic, hence the need for interdisciplinary research. Over recent decades, there have been advances in investigating the dynamics of the Earth’s deep interior. In terms of experimental and observation work, there have been innovations in high-temperature and high-pressure experiments (employing diamond anvil cells and synchrotron radiation facilities), dramatically improved geochemical analyses aided by particle physics detectors, and seismic wave observations and theory. In terms of computational work, methodological innovations and increased computational power have facilitated theoretical calculations of mineral properties and fluid dynamical simulations at the micro and macro scale.