Although skarn deposits occur throughout Alaska, skarns with appreciable gold production/reserves are largely limited to an arcuate belt that stretches through southeastern and southern Alaska to the Alaska Peninsula. Within this belt are nearly 100 known gold-bearing skarn prospects and deposits. They occur in a variety of tectono-stratigraphic terranes, with no consistent age or character of the host carbonate unit. These skarns are, however, characterized by specific geologic associations, including intrusives, alteration, ore and gangue mineralogy, and trace metals.

Intrusions associated with gold skarns are typically medium-grained, equigranular to slightly porphyritic members of gabbro-diorite-tonalite or diorite-quartz monzodiorite suites. Intrusive alteration, if present, consists predominantly of secondary albite, actinolite, and epidote, with little secondary quartz and sulfide and very rare secondary K-feldspar and muscovite. Typical "identifying" mineralogies include an abundance of epidote, chalcopyrite, and chlorite; the presence of pyrrhotite, "specular magnetite," idocrase, scapolite, hornblende, and albite; and the general absence of bornite, sphalerite, and galena. Generally, only minor amounts of sulfides and magnetite in gold skarns are present in the skarns per se or the associated plutons; most of the (gold-bearing) sulfide and agnetite is present at the marble front. Trace elements found at anomalous levels in gold skarns include Ni, Co, As, V, Mo, Sb, and Bi. Elements that are inevitably low in gold skarns include Zn, Pb, F, Sn, Be, W, and Ba. These elemental characteristics contrast strongly with those of gold-poor skarns and with metamorphosed volcanogenic massive sulfide deposits.

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Although gold skarns are generally small deposits (< 1 mmt), their consistent geologic characteristics make them relatively predictable ore-deposit targets in Alaska.

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