Geology Reports⌕ Search

Geology topics

William F. Cannon

Publications and source records attributed to William F. Cannon.

At least 55 records · Page 3Linked to original sources
USGS1997

Potential for new nickel-copper sulfide deposits in the Lake Superior region

Scientists from the U.S. Geological Survey are evaluating the potential for undiscovered sulfide deposits containing varying amounts of nickel, copper, platinum-group metals, and cobalt in the Lake Superior region as part of an ongoing effort to assess the mineral potential of the United States. Similarities between rocks of the Midcontinent rift and rocks that host the Voisey Bay nickel-copper-cobalt deposit in Labrador, Canada, and the Noril'sk nickel-copper-platinum-group-metals deposits in Russia suggest a high potential for such sulfide deposits in rocks associated with the 1.1-billion-year-old Midcontinent rift in the Lake Superior region.

Lake Superior↗
USGS1992

Geology of Keweenawan Supergroup Rocks near the Porcupine Mountains, Ontonagon and Gogebic Counties, Michigan

This field trip examines the geology of rocks of the Keweenawan Supergroup (1 .1 Ga) and related intrusive rocks of the Midcontinent rift system (MRS) in the western part of the northern peninsula of Michigan. The combination of stops includes all formations of the Keweenawan Supergroup in this region. Examination of all described localities requires more than a single day and participants are encouraged to use this guidebook on their own to supplement the localities that will be visited on our one-day trip. Because of uncertainties of weather, road conditions, and remaining snow pack in early May in this region of very heavy snowfall, the stops that we will visitwill not be known until the date of the trip. Stops are numbered in stratigraphic order, from oldest to youngest, not in the order in which they will be visited.

Michigan↗
USGS1984

International Strategic Minerals Inventory summary report; manganese

Major world resources of manganese, a strategic mineral commodity, are described in this summary report of information in the International Strategic Minerals Inventory {ISMI). ISMI is a cooperative data-collection effort of earth-science and mineral-resource agencies in Australia, Canada, the Federal Republic of Germany, the Republic of South Africa, and the United States of America. This report, designed to be of benefit to policy analysts, contains two parts. Part I presents an overview of the resources and potential supply of manganese on the basis of inventory information. Part II contains tables of some of the geologic information and mineral-resource and production data that were collected by ISMI participants.

Circular↗
USGS1983

Mineral resource assessment of the Iron River 1° x 2° quadrangle, Michigan and Wisconsin

The Iron River 1? x 2? quadrangle contains identified resources of copper and iron. Copper-rich shale beds in the north part of the quadrangle contain 12.2 billion pounds (5.5 billion kilograms) of copper in well-studied deposits including 9.2 billion pounds (4.2 billion kilograms) that are economically minable by 1980 standards. At least several billion pounds of copper probably exist in other parts of the same shale beds, but not enough data are available to measure the amount. A small amount, about 250 million pounds (113 million kilograms), of native copper is known to remain in one abandoned mine, and additional but unknown amounts remain in other abandoned mines. About 13.25 billion tons (12.02 billion metric tons) of banded iron-formation averaging roughly 30 percent iron are known within 500 feet (152.4 meters) of the surface in the Gogebic, Marquette, and Iron River-Crystal Falls districts. A small percentage of that might someday be minable as taconite, but none is now believed to be economic. Some higher grade iron concentrations exist in the same iron-formations. Such material was the basis of former mining of iron in the region, but a poor market for such ore and depletion of many deposits have led to the decline of iron mining in the quadrangle. Iron mines of the quadrangle were not being worked in 1980. Many parts of the quadrangle contain belts of favorable host rocks for mineral deposits. Although deposits are not known in these belts, undiscovered deposits of copper, zinc, lead, silver, uranium, phosphate, nickel, chromium, platinum, gold, and diamonds could exist.

Michigan, Wisconsin↗
USGS1981

The potential for diamond-bearing kimberlite in northern Michigan and Wisconsin

Between 1876 and 1913, diamonds were found in at least seven localities in southern and central Wisconsin. All were found in Pleistocene glacial deposits or Holocene river gravel. The bedrock kimberlite source for the diamonds is unknown but has been presumed to be in northern Canada, the only area north of Wisconsin previously known to contain kimberlites. Recently, a kimberlite pipe, here named the Lake Ellen kimberlite, has been found in Iron County, Michigan. That find suggests the possibility that drift diamonds in Wisconsin have come from a more local source--kimberlites in northern Michigan and Wisconsin. The Lake Ellen kimberlite is very poorly exposed, but a strong positive magnetic anomaly indicates that it is roughly circular in plan and about 200 m in diameter. Although the kimberlite is entirely surrounded by Precambrian rocks, it contains abundant inclusions of fossiliferous dolomite, probably from the Ordovician Black River Group that overlay the area when the kimberlite was intruded. The post-Ordovician age of the kimberlite leads us to suspect that other possible cryptovolcanic structures in Paleozoic rocks in the region were formed over kimberlite pipes that are not yet exposed by erosion. Such structures include Limestone Mountain and Sherman Hill, in Houghton and Baraga Counties, Michigan; Glover Bluff, in Marquette County, Wisconsin; and possibly an area along the Brule River south of Iron River, Michigan. No diamonds are known in the Lake Ellen kimberlite, but it has not been adequately sampled. The cryptovolcanic structures could not be the source of the drift diamonds in Wisconsin because even if the structures are caused by kimberlites, those kimberlites have not yet been exposed by erosion. Elsewhere in the world, kimberlite is seldom found as a single isolated body; clusters of bodies are more common, and the presence of one kimberlite implies that others may exist nearby. The discovery of additional kimberlites may be very difficult because of the extensive cover of glacial drift and the typical small size of kimberlite bodies. If all are magnetic, they might be found by detailed aeromagnetic surveys. However, the magnetism of the Lake Ellen kimberlite appears to be caused by secondary magnetite formed during serpentinization of olivine, so an unserpentinized kimberlite may not be strongly magnetic. We suggest that one or more diamond-bearing kimberlites may exist in northern Michigan or Wisconsin, but the discovery of such bodies is unlikely unless a very thorough search is undertaken.

Circular↗
USGS1978

Summary of the estimated iron resources of the Marquette and Gogebic Iron Ranges of Michigan

The U. S. Geological Survey in cooperation with the Geological Survey Division of the Michigan Department of Natural Resources has recently completed detailed studies of iron-bearing rocks in the Marquette and Gogebic iron ranges in the northern peninsula of Michigan. The study included mapping the surface distribution of the iron-bearing rocks over a period of nearly 20 years. During that time, much information in the form of more than 4,000 drilling records and maps of mine workings detailing the subsurface distribution of the rocks was obtained from mining companies. We have used this information to better our understanding of the long- and short-term iron resource base of the region.

Michigan↗