|Geologic Characteristic 1|
The primary focus of this field trip is low-sulfidation precious metal vein systems in the northern
Nevada rifts, Nevada. A secondary focus of the trip is on the history of exploration for these
deposits, exploration methods leading to discovery, and current exploration programs that
utilize yet to be proven methods. I hope the mix of historically producing and currently
producing mines, “within the fence” exploration, and future-minded grass roots exploration will
be interesting and thought provoking for all field trip participants.
The Sleeper Mine was not only a revelation with its discovery as an open pittable bonanza vein
deposit, but the initial discovery along a rangefront fault led to exploration programs for blind
mineralization under pediments. The edges of outcrop along valley margins were searched for
color anomalies, structural vectors, geomorphic anomalies, and any other features that justified
testing related blind targets. As pediment exploration evolved, geophysical indicators such as
gravity, magnetics, and resistivity were brought to bear in an effort to “see” through cover.
This property is currently undergoing extensive exploration within the fence for mineralization
that will lead toward a second phase of production. We will see the rocks, the data and the
interpretation that the New Sleeper Joint Venture is using to meet their goal of bringing Sleeper
back into production. The lesson may be that “the best place to find gold is where it’s been
found.” Many of the other historic producers are subject to similar “brown fields” exploration
The valley to the west of Sleeper has been worked (as have a number of other valleys
adjacent to deposits) as a test case for evaluating the volume of alluvium as material bearing
evidence for the existence of blind mineralization. Gary Clifton will be presenting some of this
work during the field trip.
The North Snowstorm Project will be presented by Win Rowe. Win’s story will begin with the
“why not?” question arising from claim density along intersecting known mineralization trends,
and the hypothesis that favorable rock types are buried below what has been thought of as
unmanageable sterile sand cover within sight of tens of millions of ounces of gold reserves.
An open mind, hands-and-knees mapping and sampling, and perseverance marked by using
all possible tools has resulted in a provocative case history. We’ll see evidence that the sand
cover isn’t as unmanageable as was previously thought, and that attention to stratigraphic and
alteration details have been valuable. Also, we’ll see how data organization and presentation
has been taken beyond a secretarial function to a critical exploration tool. Has North
Snowstorm identified the tail of an elephant?
The second day of the field trip will provide perspective into the evolution of exploration within
a district and will identify what’s been done with land positions containing different levels of
exposure in an area affected by a large hydrothermal system. Historic open pit production was
followed by exploration for lateral extensions, and for depth extensions. Mining methods,
exploration methods, mineralization models, and gold prices all have had an effect in the
evolution of exploration in this district.