Snively Gulch, Malheur County, Oregon, USAi

Regional Level Types
Snively Gulch	Mineral Occurrence Area (Uncertain)
Malheur County	County
Oregon	State
USA	Country

Date: April 28, 2025

Location: This locality extends for about 50 metres along the western shoulder of Owyhee Lake Road (south of Ontario and Nyssa, Oregon), southeast of the Snively Hot Spring locality and paralleling the Owyhee River.

Coordinates: The center of the collecting area is at 43.716175, -117.192431.
The north margin of the collecting area is at 43.717000, -117.192117.
The south margin of the collecting area is at 43.715531, -117.192875.

Host Rock: The deposit is a mixture of several basalt flows, quite a bit of reddish welded tuff, sedimentary interbeds and accumulated fluvial material.

Mineral Species: A variety of low-temperature, primarily hydrothermally-deposited mineral species are found locally along the roadcut and in the debris between the road and the river. The species found to date include chalcedony (massive, surface coverings), opal (sparse, tiny hemispherical spheres to 2mm and as amorphous surficial coatings), the zeolites stilbite-(Ca) (up to 5mm in maximum dimension) and heulandite-(Ca) (up to 4mm in maximum dimension), goethite as tiny, black specks, and olivine as greenish crystals and crystalline masses present in the reddish tuff. Calcite and thomsonite, which occur abundantly at Snively Hot Spring, are absent here so far.

Author: Jon Gladwell

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