2010.1-2斑岩铜矿系统.pdf

©2010 Society of Economic Geologists, Inc.
Economic Geology, v. 105, pp. 3–41
Porphyry Copper Systems*
RICHARD H. SILLITOE†
27 West Hill Park, Highgate Village, London N6 6ND, England
Abstract
Porphyry Cu systems host some of the most widely distributed mineralization types at convergent plate
boundaries, including porphyry deposits centered on intrusions; skarn, carbonate-replacement, and sediment-
hosted Au deposits in increasingly peripheral locations; and superjacent high- and intermediate-sulfidation epi-
thermal deposits. The monly define linear belts, some many hundreds of kilometers long, as well as
occurring monly in apparent isolation. The systems are closely related to posite plutons,
at paleodepths of 5 to 15 km, which represent the supply chambers for the magmas and fluids that formed the
vertically elongate (>3 km) stocks or dike swarms and associated mineralization. The plutons may erupt volcanic
rocks, but generally prior to initiation of the systems. Commonly, several discrete stocks are emplaced in and
above the pluton roof zones, resulting in either clusters or structurally controlled alignments of porphyry Cu
systems. The rheology position of the host rocks may strongly influence the size, grade, and type of
mineralization generated in porphyry Cu systems. Individual systems have life spans of ~100,000 to several mil-
lion years, whereas deposit clusters or alignments as well as entire belts may remain active for 10 . or longer.
The alteration and mineralization in porphyry Cu systems, occupying many cubic kilometers of rock, are
zoned outward from the stocks or dike swarms, which prise several generations of intermediate
to felsic porphyry intrusions. Porphyry Cu ± Au ± Mo deposits are centered on the intrusions, whereas car-
bonate wall monly host proximal Cu-Au skarns, mon distal Zn-Pb and/or Au skarns, and,
beyond the skarn front, carbonate-replacement Cu and/or Zn-Pb-Ag ± Au deposits, and/or sedi