1. Mineral Resources
2. Online Spatial Data
3. National Mineral Resource Assessment 1998

Mineral assessment tracts in Big Delta (1:250,000 Alaska quadrangle in USGS Quadrangles)

[Additional scientific data in this geographic area]

AK-EC04: Epithermal vein, generic (25) (Cretaceous - Tertiary) , covers 7 % of this area

The number of undiscovered deposits in this tract was not estimated.

AK-EC07: Low-sulfide Au-quartz veins (36a) (Cretaceous - Tertiary) , covers 97 % of this area

90%	50%	10%	5%	1%
2	8	15	20	30

AK-EC13: Porphyry Cu, BC-Ak type (17) (Cretaceous - Tertiary) , covers 80 % of this area

90%	50%	10%	5%	1%
1	2	4	8	10

AK-EC14: Plutonic porphyry Au (43) (Cretaceous - Tertiary) , covers 86 % of this area

90%	50%	10%	5%	1%
1	3	5	9	13

AK-EC15: Placer Au (39a) (Cenozoic) , covers 97 % of this area

The number of undiscovered deposits in this tract was not estimated.

AK-EC18: Polymetallic vein (22c) (Mesozoic - Tertiary) , covers 97 % of this area

The number of undiscovered deposits in this tract was not estimated.

AK-SC07: Au-Sb veins (36c) (Cretaceous - Tertiary) , covers < 0.1 % of this area

90%	50%	10%	5%	1%
2	4	10	10	10

AK-SC14: Kuroko massive sulfide (28a) (Devonian - Mississippian) , covers 2 % of this area

90%	50%	10%	5%	1%
3	5	25	25	25

AK-SC20: Porphyry Cu, BC-Ak type (17) (Cretaceous - Tertiary) , covers < 0.1 % of this area

90%	50%	10%	5%	1%
1	5	7	7	7

AK-SC24: Plutonic porphyry Au (43) (Cretaceous - Tertiary) , covers < 0.1 % of this area

90%	50%	10%	5%	1%
1	5	7	7	7

AK-SC25: Placer Au (39a) (Cenozoic) , covers < 0.1 % of this area

The number of undiscovered deposits in this tract was not estimated.