Also known as Montana or Dumont district. Ag, Au, Cu, Pb, Zn.
The Lawson-Dumont district occupies about 10 square miles in the south-central part of the Central City quadrangle. It lies along Clear Creek between the Idaho Springs and Empire districts, includes the towns of Lawson and Dumont, and extends for about 1 mile south and 2 miles north of the creek.
ORE DEPOSITS
The ore deposits or the Lawson-Dumont district are of two types, lead-silver and pyritic gold. The lead-silver ores are very similar to those or the Georgetown-Silver Plume district, and the pyritic gold ores resemble closely those or the Central City- Idaho Springs district; both show the same general mineral content and paragenesis. The lead-silver. veins have a general northeasterly trend and are round chiefly in the western part or the district. A few lead-silver veins or various trends also occur near Dmmont. The pyritic gold veins are limited to the eastern part of the district in the vicinity or Dumont. The majority of the veins have an east-west trend, but some strike north-east and some northwest. In a few of the pyritic veins some lead-silver ore also is found, but such occurrences are rare.
The chief minerals or the lead-silver veins are galena, sphalerite, and pyrite. Silver minerals, such as proustite, pearcite, and polybasite, occur in varying amounts, and are abundant in the high-grade silver ores. These ores in general range in tenor from about 50 to 1,000 ounces or silver to the ton, from a few percent to 50 percent of lead, and from a few percent to 20 percent of zinc. Their gold content is generally very low, commonly a few hundredths or an ounce. Quartz is the chief gangue mineral, although some siderite is usually present. Chalcopyrite is found in some or the ores but is rarely abundant enough to be of commercial importance. In general the sequence of mineral deposition is (1) the massive sulfides comprising galena, sphalerite, and pyrite, with some chalcopyrite, (2) the silver minerals, such as polybasite, proustite and pearcite, and (3) very small amounts of chacopyrite, galena, and sphalerite.
The chief constituents of the pyritic gold ores are pyrite and quartz. Chalcopyrite is generally present and in places is abundant enough to be of commercial interest. Gold seems to be contained chiefly in the chalcopyrite, though in places it is associated with fine-grained pyrite. The gold content of this ore is commonly 1 to 10 ounces to the ton, but the silver content is generally low, ranging from a few ounces to 16 ounces to the ton. Galena and sphalerite are present in a few places but are usually unimportant. In general the veins of the Lawson-Dumont district have had a relatively small output compared with those of the Silver Plume-Georgetown district or the Central City-Idaho Springs district, but a few, such as the J 0 Reynolds and the veins or the Red Elephant group, have had an output of more than a million dollars.
U.S. Geological Survey Professional Paper 223
Mineral List
Mineral list contains entries from the region specified including sub-localities
The above list contains all mineral locality references listed on mindat.org. This does not claim to be a complete list. If you know of more minerals from this site, please register so you can add to our database. This locality information is for reference purposes only. You should never attempt to
visit any sites listed in mindat.org without first ensuring that you have the permission of the land and/or mineral rights holders
for access and that you are aware of all safety precautions necessary.
References
U.S. Geological Survey Professional Paper 223
This page is currently not sponsored. To sponsor this page click here.
Mineral and Locality Search
