Stratigraphy, sedimentology, and paleotectonic setting of the Gazelle Formation, eastern Klamath Mountains, northern California

The Gazelle Formation crops out over an area of 22 x 8 kilometers with a stratigraphic thickness of at least 1.25 kilometers. The Gazelle consists of shale, siltstone, siliceous mudstone, volcaniclastic sandstone, and chert-rich flysch, in decreasing order of abundance. Sediment gravity flows were the dominant sedimentary process during deposition of the Gazelle Formation. Petrographic analysis of sandstones from the Gazelle reveal that these strata were derived from both magmatic arc and subduction complex sources. These petrographic data are consistent with regional geological relationships indicating that the Gazelle Formation was deposited in some portion of an arc-trench system; The sedimentological, stratigraphic, petrologic, and structural aspects of the Gazelle Formation provide convincing evidence that the Gazelle Formation was deposited as trench-slope basin fill. This interpretation is consistent with the regional tectonic framework and the fact that the characteristics of the Gazelle Formation match those of modern and ancient trench-slope basins worldwide