In the spring of 1848 the first expeditions sailed in search of the lost Franklin expedition. Unfortunately Franklin and most of his men were already dead. Although this was unknown to the early relief expeditions, it must have seemed increasingly probable to the crews of the forty ships which followed during the next eleven years. Increasingly they felt free to turn their attention to the discovery of those unknown islands among which the expedition had so mysteriously disappeared. Before clear evidence of the tragedy was found, the northwest passage had been negotiated and most of the Canadian Arctic archipelago had been outlined. Today it is appropriate to look back a century and realize that these same inhospitable regions are the scene of activity such as they have not known in the intervening years. Spurred by no tragedy, assisted by aids unknown even a generation ago, the exploration, mapping and scientific study of the North American Arctic is now being pursued on a scale never before possible. What an unique opportunity it is! The world revolves about the polar regions. The magnetic poles, the aurora, the effects of continuous summer sunlight, the winter's cold are strange physical attributes that make the background to this exploration of the world's last undiscovered frontiers as fascinating today as it has ever been. Discovery was not the only achievement of the Franklin search, for it elicited world wide sympathy and support from many nations. Bellot Strait at the extreme northern boundary of the mainland was named for a French volunteer. The Danish and Russian governments assisted search parties. Henry Grinnell of Philadelphia equipped two expeditions which were commanded by United States Navy officers. Although De Haven and Kane did not find Franklin, their discoveries first aroused that American interest in Ellesmere Island and northern Greenland that led to later expeditions in search of the pole. All these efforts, inspired by noble motives, were happily marked by an absence of quarrelling and a generous recognition of the achievements of others. As an international, scientific society the Arctic Institute of North America can wish for no better guide to its conduct than these examples of international goodwill a hundred years ago. The small group of men who four years ago formed this private society and maintained control of it until it was established upon a secure foundation, are now anxious to see a larger number of those interested in the North American Arctic take an active part in the Institute's affairs. As a means of bringing this about they invite all persons interested to join the Institute; they have limited the number of times any Governor may be re-elected and they now launch this journal as a means of communicating information about the Arctic and the activities of the Institute to all its members and to the wider public that may be interested in the ends of the earth.
Oceanic islands increase in age from the mid-ocean ridges towards continents and the andesite line reaching a maximum known age of Upper Jurassic. The Seychelles appear to be a continental fragment. Several pairs of lateral aseismic ridges extend from islands on the mid-ocean ridge to adjacent continents. Their continental junctions mark points on opposite coasts which would also fit if the continents were reassembled according to the criteria used by Wegener. As Holmes has shown each pair of ridges tends to have distinctive chemical characteristics. One possible explanation is that convection currents in the mantle rising along the mid-ocean ridges and sinking beneath trenches have carried the crust apart across the Atlantic, India and East Pacific Oceans. The lateral ridges may be approximately streamlines. Although Darwin showed that most volcanic islands sink, a few have been uplifted. Most of these lie a few hundred kilometres in front of deep trenches, suggesting that they may be on the crest of a standing wave in front of the trenches and that the crust is rigid. Of eleven straight chains of young islands in the Pacific ten get older away from the East Pacific Ridge. They could also be streamlines, fed by lava rising from deep within convection cells with stagnant cores. The regularity of ridges suggests non-turbulent flow.
Romberger's (1992) paper suggests that deposition of 500 tonnes of gold in six unusually rich Nevada deposits was due to normal ore-bearing solutions flowing at a more rapid rate and for a longer period of time than usual through well-developed channels perpetuated by continual brecciation.
It is now understood that plate tectonics requires that 15 million years ago the Yellowstone mantle plume should have formed and begun to migrate eastward relative to the North American plate at a rate of approximately 35 km per million years. This paper proposes that the passage of the plume past the deposits coincided with the time of ore deposition, indicating that the plume was a factor in forming the ore bodies. It mentions some other reasons why plumes should be taken into account in economic geology.
'%3e%3cpath fill='%23012169' d='M0 0v30h60V0z'/%3e%3cpath stroke='%23fff' stroke-width='6' d='m0 0 60 30m0-30L0 30'/%3e%3cpath stroke='%23C8102E' stroke-width='4' d='m0 0 60 30m0-30L0 30' clip-path='url(%23b)'/%3e%3cpath stroke='%23fff' stroke-width='10' d='M30 0v30M0 15h60'/%3e%3cpath stroke='%23C8102E' stroke-width='6' d='M30 0v30M0 15h60'/%3e%3c/g%3e%3c/svg%3e)