Evolution of the Appalachian orogen spanned the Paleozoic and Mesozoic Eras. Within the confines of the northern Appalachians of the United States (the New England States - Maine, New Hampshire, Vermont, Massachusetts, Connecticut and Rhode Island - and New York), the sequence of known major Appalachian tectonic events is late Proterozoic rifting of the protoNorth American craton; Ordovician subduction accompanied by destruction of the Iapetus Ocean and by obduction of tectonostratigraphic sequences; Devonian deformation, accretion, plutonism, and metamorphism, of uncertain plate tectonic context but likely related to a continent continentcollision; formation of late Carboniferous transtensive (oblique strikeslip) basins in which coal formed; and late Carboniferous to Permian thermal, plutonic, and metamorphic events. During the Mesozoic, the New England Appalachians underwent crustal extension associated with both alkalic and tholeiitic magmatism. These extensional processes (11-7, V-l)~/ reflect the opening of the North Atlantic Ocean and the creation of a passive margin, which remains today.<...>

The process of terrane accretion is vital to the understanding of the formation of continental crust. Accretionary orogens affect over half of the globe and have a distinctively different evolution to Wilson-type orogens. It is increasingly evident that accretionary orogenesis has played a significant role in the formation of the continents.

Nonrenewable energy resources available in very large quantities are limited to heavy hydrogen and dry geothermal energy. Large-scale renewable resources are solar and atmospheric electricity (Moody, 1978). These four may be regarded as the ultimate energy sources, but they are unlikely to contribute significantly to the total energy budget for at least the next few decades. Synthetic fuels are already in production, but widespread conversion is being held back by economic and environmental considerations. Wind, water, and biomass conversion will play an enlarged, but still relatively minor, role. This leaves coal, uranium, and petroleum to provide the bulk of the immediately foreseeable energy requirements.

The extraction of fossil fuels and mineral resources has grown exponentially since the early 20th century and far from decelerating, it is expected to increase in the coming decades. “The Limits to Growth” (Meadows et al., 1972) already alerted that if demand of metals and fossil fuels maintained the same trend, mankind would sooner or later be close to collapse. The book provoked a strong controversy between those that considered that the Earth was plentiful of non-renewable resources (technooptimists) and those who believed in the need for a rational management of the planetary mineral endowment.