Why Alaska?
There are only a few good references on the subject of Gold Deposit Models and the question remains, "Why Alaska?"
For those inquisitive prospectors haunted by this question, you have come to the right place!
The Big Nugget deposit model:
The Big Nugget Gold deposit has been there since the Late Cretaceous - Early Tertiary 65 to 145 million years ago. That is greater than one million lifetimes. The Big Nugget deposit was likely formed as most other gold deposits along the Tintina Gold Province.
There are on the order of twenty gold deposit models.
https://www.usgs.gov/search?keywords=Mi ... t%20Models
Tintina Gold Province deposit models focus primarily on Reduced Intrusion-Related Gold Systems (IRGS) and related orogenic gold models, tied to mid-Cretaceous and Late Cretaceous magmatic belts. Key defining features include reduced ilmenite-series plutons, specific bismuth-tellurium-tungsten geochemical signatures, and zoned mineralization styles.
Mid-Cretaceous magmatic evolution and intrusion-related metallogeny of the Tintina gold province, Yukon and Alaska
Including the Nulato and Ruby Quadrangles:
Quadrangle(s):Bettles; Big Delta; Charley River; Circle; Eagle; Fairbanks; Healy; Hooper Bay; Iditarod; Kwiguk; Livengood; Marshall; McGrath; Medfra; Melozitna; Mount Hayes; Nulato; Ruby; Russian Mission; Tanacross; Unalakleet
https://dggs.alaska.gov/pubs/id/28033
From the opening paragraph of the Astract of the DGGS reference:
"The Tintina Gold Province (TGP) comprises numerous (>15) gold belts and districts throughout interior Alaska and Yukon that are associated with Cretaceous plutonic rocks. With a gold endowment of ~70M oz, most districts are defined by their placer gold contributions, which comprise greater than 30 M oz, but four districts have experience significant increases in gold exploration with notable discoveries at Fort Knox (5.4 M oz), Donlin Creek (12.3 M oz), Pogo (5.8 M oz), True North (0.79 M oz), and Brewery Creek (0.85 M oz)."
From Google AI:
"This citation most notably refers to economic geologist Craig J.R. Hart's foundational 2005 work on Classifying, Distinguishing and Exploring for Intrusion-Related Gold Systems, or his co-authored benchmark study with R.J. Goldfarb et al., Distribution, Character, and Genesis of Gold Deposits in Metamorphic Terranes published in the Society of Economic Geologists One Hundredth Anniversary Volume."
https://www.researchgate.net/publicatio ... ld_Systems
Page 1 of this reference shows the Tintina Province. The big nugget project is east of the Illinois Creek.
Page 5 of this reference shows a small elongate pluton. The extended outward regions contain As (Arsenic) most commonly seen as Arsenopyrite.
Famous words, "Look and ye shall find"!
- Geowizard