The Molly Marie Prospect is a group of 20 contiguous mining claims located in Maricopa County, Arizona. This website describes the Prospect that has a large, fully intact, IOCG (Iron Oxide Copper Gold) ore deposit located in a previously unrecognized submarine caldera over one mile in diameter. The IOCG has been overprinted by several large quartz breccia orebodies (not veins).
Below is a photo showing the extents of the iron-oxide altered breccias of the deposit on the west side of the caldera and the two largest Quartz Breccia orebodies identified. Please note the State highway located approximately only 600 yards to the west of the caldera.
Below are photos of some of the quartz breccias. There are many styles and types found in the quartz breccia orebodies. Assays of up to .05 opt Au are found in Breccia #2 in the above diagram and in silicified basalt. Chip samples of a smaller Quartz Breccia orebody not shown assayed as high .07 opt Au (see conclusion).
The igneous rock exposed at the neck is an magnetic, brick-red, Rhyodacite porphyry as shown below. This rock also underlies the entire west end of the Superstition Mountains, although it is mostly aphanitic there. The west end of the Superstition Mountains is a large Rhyodacite dome, and this dome, the Molly Marie Caldera, and the Goldfield Caldera were part of the same volcanic field.
Accompanying this deposit, located near the foot of the Superstition Mountains, is a subject that must be breached:
An entire “missing” mining district, which contained the Peralta Mines.
The location of these legendary mines has commonly been thought to be deep inside the Superstition Wilderness area, but it’s just outside its boundaries. The hundreds of stories told about lost mines in the Superstitions during the past 130 years have one thing in common; they do not have the geology to back them up. The geology of the District is shown within and it proves the existence of an IOCG deposit and large quartz orebodies within it. Proof that the District was extensively mined by the Spanish and Mexicans (also shown within with matching historic documents) demonstrates logically that the quartz orebodies must be exceptionally rich.
Proof that the Spanish and Mexicans mined the District also helps explain why a deposit so immense could go undiscovered; all of the most obvious outcrops indicating ore were simply removed and the pits (and shafts) were filled back in. But, intense alteration zones still betray their locations.
The nearby Goldfield mining District, 2-1/2 miles away, has geologic features similar to that of the Molly Marie Prospect, including a caldera with breccias on its margin. Significant gold ore was mined there at the Mammoth Mine, in breccias, that assayed hundreds of ounces of gold to the ton (struck at only 35 feet in depth). 50,000 ounces of gold was mined (reported) from the little Mammoth Mine, which at today’s gold price is worth over 200 million dollars! The volume of quartz breccias at the Molly Marie caldera is multitudes greater than those at Goldfield.
Below is a silica mound that remains on the northeast portion of the prospect that “caps” a portion of the deposit with the west end of Superstition Mountain in the background.
Below is an exposure of silica beds on the south side of the north mound. All of this material is very magnetic.
Below is Chrysocolla found at the base of the northern mound. There is Chrysocolla scattered throughout the property. It is suspected that most surface Chrysocolla was gathered on the property by prospectors in the 1960’s. A bathtub was found on the claims that was commonly used for do-it-yourself heap leaching and making sponge copper.
Some veinlets of Chrysocolla remain that weren’t found by past prospectors.
In the photo below, fossilized microbial mat can be see to the right of the barnacle. It is suggested that this life did not thrive around a black smoker or a white smoker, but a RED smoker, because of the large amount of hematite. Abundant fossils like those shown below are proof that the orebodies formed under a shallow brine sea or lake which is arguably the best environment for rich gold deposits (the great Eskay Creek deposit was formed under shallow sea water) .
Below is another piece of quartz covered by fossilized barnacles.
In the land of porphyry copper, a new type of orebody can be found, and after 20 years of study and fieldwork, there is now enough evidence to present the mines that used to be, and where new mines could be.
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(cover photo is a view of the Superstition Mountains from the southern end of the Molly Marie Prospect)