The barite-zinc-lead Cirque Deposit and other major showings in the Gataga district are part of an Upper Devonian to Mississippian sequence of basinal shales and submarine fan deposits of chert pebble conglomerate which were derived from the northwest. This sequence is preserved in the Akie, Pesika, and Gataga troughs, and unconformably overlies Ordovician to Silurian slope and basinal facies of the Kechika trough. The Akie trough is host to all known potentially economic barite-zinc-lead deposits in the district.

Both regional and detailed linear elements of the Cirque Deposit trend northwesterly and are asymmetric normal to the strike line. The background depositional unit is a soft gray aluminous shale which grades into black and carbonaceous shale to the southwest. An envelope consisting of diagenetically silicified fine carbonaceous clastic units was formed about the deposit. The outermost part of the diagenetic envelope consists of ribbon-bedded porcellanite with blebby and laminated massive barite on the northeast. Silicified platy poker chip shales with calcareous siltstone laminae are between the ribbon porcellanites and ore. The core of the cycle consists of up to 70 m of barite and sulfides on the axis of the deposit. Laterally, the ore section interfingers to the northeast with an e ual thickness of flaggy to blocky bedded silicified black shale containing abundant finely laminated pyrite. Pb:Zn ratios increase northeasterly, and ore isopachs are asymmetric toward the northeast with the thickest zone being on the southwest edge of the deposit.

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Genetically the barite-sulfide accumulations are considered to result from exhalative activity restricted to regionally developed basement faults. Accumulation occurred within a minor trough with resultant facies asymmetries being related to different topographic and paleochemical conditions during sedimentation and diagenesis.

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