『Abstract
Accretionary orogens throughout apace and time represent extremely
fertile settings for the formation and preservation of a wide
variety of mineral deposit types. These range from those within
active magmatic arcs, either in continental margin or intra-oceanic
settings, to those that develop in a variety of arc-flanking environments,
such as fore-arcs and back-arcs during deformation and exhumation
of the continental margin. Deposit types also include those that
form in more distal, far back-arc and foreland basin settings.
The metallogenic signature and endowment of individual accretionary
orogens are, at a fundamental level, controlled by the nature,
composition and age of the sub-continental lithosphere, and a
complex interplay between formational processes and preservational
forces in an evolving Earth. Some deposit types, such as orogenic
gold and volcanic massive sulfide (VMS) deposits, have temporal
patterns that mimic the major accretionary and crustal growth
events in Earth history, whereas others, such as porphyry Cu-Au-Mo
and epithermal Au-Ag deposits, have largely preservational patterns.
The presence at c. 3.4 Ga of (rare) orogenic gold deposits, whose
formation necessitates some from of subduction-accretion, provides
strong evidence that accretionary processes operated then at the
margins of continental nuclei, while the widespread distribution
of orogenic gold and VMS deposits at c. 2.7-2.6 Ga reflects the
global distribution of accretionary orogens by this time.
Keywords: Accretionary orogens; Mineral deposits; Metal endowment;
Plate tectonics; Lithosphere』
1. Introduction
2. Mineral deposit types of accretionary margins
2.1. Arc-related mineral deposits
2.2. Back-arc related mineral deposits}
2.3. Orogenic gold and base-metal deposits
2.4. Mineral deposits in far back-arc settings or deformed accretionary
margins
2.5. Mineral deposits in foreland basins
3. Role of lithosphere in the generation of mineral deposits in
accretionary orogens
3.1. Thin lithosphere and orogenic gold deposits
3.2. Thin lithosphere and VMS deposits
3.3. Mineral deposits at lithospheric boundaries
4. Role of lithosphere in the preservation of mineral deposits
in accretionary orogens
4.1. Evolution of sub-continental lithospheric mantle
4.2. Temporal patterns of mineral deposits in accretionary margin
settings
4.3. Selective preservation of mineral deposits in accretionary
margin settings
5. Evidence from mineral deposits for the earliest onset of plate
tectonics
6. Summary
Acknowledgements
References