Recent geologic mapping has identified areas of extrusive basalts of the Middle to Late Triassic Nikolai Greenstone within the Wrangellia terrane that extend at least 80 km southwest of their previously known extent. Abundant dolerite sills of similar composition intrude Paleozoic and Mesozoic stratigraphy below the Nikolai throughout the central Talkeetna Mountains. The Talkeetna Mountains, therefore, have newly identified potential for copper, nickel, and platinum-group elements (PGEs) as disseminated, net-textured, or massive magmatic sulfide deposits hosted in mafic and ultramafic sill-form complexes related to emplacement of the Nikolai. Because of their potential high grades, similar magmatic sulfide targets have been the focus of increasing mineral exploration activity over the last decade in the Amphitheater Mountains and central Alaska Range, 100–200 km to the northeast. The Nikolai Greenstone, associated intrusions, and their metamorphosed equivalents also have potential to host stratabound disseminated “basaltic copper” deposits. Sedimentary and metasedimentary rocks overlying the Nikolai have the potential to host stratabound, disseminated, or massive “reduced-facies” type Cu-Ag deposits. Ultramafic rocks have been identified only in the extreme northeastern Talkeetna Mountains to date. However, coincident gravity and magnetic highs along the leading (northwestern) edge of and within Wrangellia in the Talkeetna and Clearwater Mountains suggest several areas that are highly prospective for ultramafic rocks related to extrusion of Nikolai lavas. In particular, the distribution, geometry, and composition of sills within the pre-Nikolai stratigraphy and the structural and tectonic controls on intrusive versus extrusive rock distribution deserve serious examination.

The Noril’sk volume is a valuable contribution to the economic geology profession. The translation which is a very literal one from the Russian original, has been ‘donated’ to the Society of Economic Geologists by Falconbridge and Inco . This is the first special publication for the Society. We have two successful series, Reviews in Economic Geology and our Guidebook series. When we were offered this translation we initiated this special publication series. It is hoped that we will continue to pursue and publish other monographs of direct economic interest for our members and the economic geology community at large. This volume and the accompanying figures (maps), tables and plates presents an excellent overview of the Noril’sk area and the mineralization specific to this region. Considerable awareness of the Noril’sk area has been available through various translations of Russian literature and ever increasing opportunities for western world geoscientists to visit the region. The Society is proud to have this opportunity to provide this comprehensive volume to economic geoscientists. Many individuals contributed their time, expertise and support. We would like to acknowledge A.J. Naldrett for his efforts in obtaining this translation from Inco and Falconbridge on our behalf. He was also our liaison with the original authors and was very supportive throughout the editing process. Falconbridge initiated the translation and G. Rylkova was contracted to produce a literal translation and we chose to substitute, or identify, a few nonfamiliar Russian terms with equivalent English language terms. However, the substance of the translation has not been changed. The editing concentrated on consistency, accuracy and limited grammatical re-interpretation. A location map and a stratigraphic section were added to the introduction. Suggestions for editing consistency were gratefully received from A. Craigie and R. Horn. Additional support for production and distribution was received from T. Thompson, J. Robertson, K. Clark. All figures, tables and plates were redrafted with their interpreted legends by Inco . W. Saftic and W. Peredery provided additional suggestions for drafting format and continuity. Inco and Falconbridge shared all drafting costs and donated this service to the Society of Economic Geologists as well as the translated text. P. Lightfoot gave permission to include the location map and the stratigraphic section in the introduction. The cover design was produced by C. Podashinsky and the WP formatting was contracted to Keystrokes Business Support Services. Production and printing of the volume was contracted to Citizen Printing Co. Inc. of Fort Collins.