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Source-linked reports with geographic coverage including Michigan.

At least 667 records · Page 37Linked to original sources
USGS1955

Zones of regional metamorphism in the Precambrian of northern Michigan

Precambrian rocks are exposed throughout an area of about 7500 square miles in northern Michigan. Of this area, approximately 3300 square miles is underlain by relatively unmetamorphosed Upper Precambrian (Keweenawan), about 2700 square miles by metamorphosed Middle Precambrian (Huronian), and about 1500 square miles by metamorphosed Lower Precambrian (“Archean”). Flat-lying or low-dipping strata of Paleozoic age overlap the Precambrian along the east margin of the area. The metamorphism, which is shown most clearly by mineralogic changes in the Hu-ronian sedimentary rocks, especially in the iron formations and the graywackes and slates, and in the post-Huronian basic intrusive rocks, occurred during a post-Huronian-pre-Keweenawan interval of orogeny and minor granite intrusion. At least one earlier period of major, intense metamorphism of pre-Huronian age (Algoman?) is recognized. In near-by areas of Wisconsin and Minnesota, a later thermal metamorphism is related to the intrusion of the upper Precambrian Duluth gabbro and equivalent masses;it is restricted to the immediate vicinity of the gabbroic bodies. Zones of metamorphic intensity delineated by chlorite, biotite, garnet, staurolite, and sillimanite isograds or their equivalents are partly or completely developed around four nodes, two of which lie in immediately adjacent parts of Wisconsin. The zones range in width from less than a mile to about 30 miles, and metamorphism of low grade is areally dominant over that of intermediate and high grade. The principal iron-ore deposits of the region—the “soft ores”—are restricted to the lower metamorphic zones, whereas the material considered suitable as low-grade concentrating ore (“taconite”) is restricted to the areas of high-grade metamorphism. The influence of metamorphism on grain size appears to be the controlling factor. Analysis of thermal gradients inferred from the metamorphic zonation indicates that the heat required for metamorphism must have been derived from subjacent bodies of magma, but the metamorphic patterns show no clear relation to regional structure or to the exposed granitic intrusions of the same orogenic cycle. The granite is most abundant in the areas of strongest metamorphism, but field evidence shows that most of the masses were intruded after the metamorphism. Field evidence also shows that deformation and metamorphism are independent variables in the orogenic scheme for this particular region.

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USGS1955

Geology of the Huron River pitchblende occurrence, Baraga County, Michigan

Small quantities of uranium-bearing minerals were discovered by a geologist of the Jones and Laughlin Ore Company during the summer of 1949 along the East Branch of the Huron River, sec. 1, T. 51 N., R. 30 W., Baraga County, Mich. Subsequent diamond drilling of the prospect by the Jones and Laughlin Ore Company and the Ford Motor Company disclosed only minor amounts of radioactive materials at shallow depths in the immediate vicinity of the surface showings. Pitchblende and secondary uranium minerals occur as very small, discontinuous stringers and pods in calcite and quartz cementing the breccia within a low-angle shear zone that dips about 10 degrees to the southwest. The shear zone has a thickness of 10 to 30 feet and cuts black, locally carbonaceous slates of the upper Huronian Precambrian Michigamme slate. Mineral deposition during two hypogene stages and one supergene stage was identified in polished sections. The first phase consisted of the introduction of quartz and minor hematite into the sheared slate. After fracturing of the quartz the second stage was initiated by deposition of calcite, pyrite, rutile, pitchblende, bornite, sphalerite, chalcopyrite, galena, and greenockite. The supergene stage consisted of the development of metatyuyamunite, chalcopyrite, chalcocite, covellite, cuprite, volborthite, malachite, and goethite.

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USGS1954

The White Pine copper deposit, Ontonagon County, Michigan

Copper, largely in the mineral chalcocite, is found in the lowermost beds of the Nonesuch shale over many square miles near White Pine, Ontonagon County, Mich. The Nonesuch shale, of late Keweenawan age, is about 600 feet thick and is composed largely of gray siltstone. It overlies 2,300 to 5,500 feet of red sandstones and conglomerates, the Copper Harbor conglomerate. This formation, in turn, overlies the middle Keweenawan Portage Lake lava series, in which occur the famous native-copper deposits of the south shore of Lake Superior. The White Pine mine is 45 to 70 miles west-southwest of the principal native copper mines.The copper-bearing beds at White Pine are primarily in the lower 20to 25 feet of the Nonesuch shale. This cupriferous zone is divided in local usage into four stratigraphic units, which are, in ascending order, the lower sandstone (the uppermost bed of the Copper Harbor conglomerate), the parting shale, the upper sandstone, and the upper shale. The sequence of beds is almost identical in the upper and parting shales, suggesting cyclic sedimentation. This sequence and the distribution of sedimentary facies are attributed to two submergences, separated by an emergence, of a deltaic area.Practically all the copper occurs in the upper and parting shales, except in a small area near the White Pine fault where it is abundant in the upper and lower sandstones. It is present in five different layers in amounts that average from 1 to 3 percent. The total amount of copper in each bed is generally higher where the bed is thick, and thickness, in turn, seems to be greatest in areas that were hollows away from the main channel or channels of the ancient delta. Copper content of the shale beds typically decreases as their sand content increases. The extent of individual copper-bearing beds 1 to 3 feet thick is measurable in square miles.The local occurrence of copper in the upper and lower sandstone beds can be reasonably explained as the result of hydrothermal transportation from the White Pine fault up the dip of the relatively permeable sandstone to the crest of an adjacent anticline. Distribution of copper in the parting and upper shales, on the other hand, seems to be completely independent of local structure, faults, and rock permeability. For the area as a whole the control is lithologic and stratigraphic. Probably the copper was dropped into or precipitated within the original mud; it may conceivably have replaced with exquisite detail something else that was so deposited.

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USGS1954

Water resources of the Grand Rapids area, Michigan

The Grand Rapids area, Michigan, has three sources from which to obtain its water supply: Lake Michigan, the Grand River and its tributaries, and ground water. Each of the first two and possibly the third is capable of supplying the entire needs of the area. This area is now obtaining a part of its supply from each of these sources. Of the average use of 50 mgd (million gallons per day) during 1951, Lake Michigan supplied 29 mgd; the Grand River and its tributaries supplied 1 mgd; and ground water supplied 20 mgd. Lake Michigan offers a practically unlimited source of potable water. However, the cost of delivery to the Grand Rapids area presents an economic problem in the further development of this source. Even without storage the Grand River can provide an adequate supply for the city of Grand Rapids. The present average use of the city of Grand Rapids is about 30 mgd and the maximum use is about 60 mgd, while the average flow of the Grand River is 2, 495 mgd or 3, 860 cfs (cubic feet per second) and the minimum daily flow recorded is 246 mgd. The quality and temperature of water in the Grand River is less desirable than Lake Michigan water. However, with proper treatment its chemical quality can be made entirely satisfactory. The city of Grand Rapids is actively engaged in a study that will lead to the expansion of its present water-supply facilities to meet the expected growth in population in Grand Rapids and its environs. Ground-water aquifers in the area are a large potential source of supply. The Grand Rapids area is underlain by glacial material containing a moderately hard to very hard water of varying chemical composition but suitable for most uses. The glacial outwash and lacustrine deposits bordering principal streams afford the greatest potential for the development of large supplies of potable ground water. Below the glacial drift, bedrock formations contain water that is extremely hard and moderately to highly mineralized. Thus the major sources of usable ground water are the glacial drift and some parts of the bedrock. Wherever the bedrock yields large quantities of water, the water is generally of inferior quality. Any development should be preceded by test drilling and careful hydrologic and geologic studies of the area under consideration and chemical analysis of the water found.

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USGS1954

Ground water resources of southeastern Oakland County, Michigan

The area covered by this report comprises a square which measures three townships on a side and enclose 318 square miles in southeastern Oakland County. The investigation of the ground-water resources of this area was made by the U.S. Geological Survey in cooperation with the Detroit Metropolitan Area Regional Planning Commission, the Michigan Department of Conservation, and the Michigan Water Resources Commission. In 1950 the population of this nine-township area exceeded 341,000, or more than 86 percent of the total population of Oakland County. This county ranks third in the state in number of industrial establishments and workers and is fifteenth in agricultural importance. Its numerous lakes and rolling uplands contribute to its top rank in the state in the number of recreational enterprises in rural or suburban areas. The climate is moderately humid. The average annual precipitation is 30 inches and the mean air temperature is 47.2° F. Snowfall averages 38 inches in the November-April interval. The growing season averages 151 days. The regional land surface slopes from northwest to southeast and has a total relief of 360 feet. Pitted outwash plains and morainal hills that are more than 1,000 feet above sea level in the northwest corner of the area give way southeastward to a sequence of terminal moraines and intervening till plains in the middle part. These give way to the broad lake plains that cover the southeastern third of the area. The area lies on the southeast edge of the Michigan Basin and the bedrock is composed of northwest dipping strata of the Devonian and Mississippian systems. The Antrim shale, of Lake Devonian and early Mississippian age, is the oldest formation cropping out beneath the mantle of glacial Berea sandstone, and Sunbury shale overlie the Antrim and are overlain by the Coldwater shale, their areas of outcrop beneath the drift lying successively farther northwest. These formations are of early Mississippian age. Throughout the area the bedrock is covered by glacial drift which ranges in thickness from 25 to more than 350 feet. The drift increases in thickness from southeast to northwest, but considerable relief on the underlying bedrock surface greatly modifies this trend. Extensive moraines, till plains, lake plains, and gravel outwash plains cover the area. In the northwestern third of the area an extensive upland of gravel plains is dotted with lakes ranging from a few feet to more than 100 feet in depth. Precipitation is the perennial source of all water in this area, whether on the surface of underground. The average annual rainfall on the nine-townships is equivalent to a continuous supply of 450 m.g.d. or 9 times the combined annual withdrawal from all wells in the area. About 53 percent of the area is drained by the Clinton River, 44 percent by the River Rouge, and the remaining 3 percent by the Huron River. Less than one-third of the annual precipitation reappears as surface discharge from the watersheds of this area. About two-thirds of the annual precipitation on the area is lost by evaporation from water and land surfaces and by transpirations from vegetative cover. A substantial part of this large annual water loss is from the many lakes and other exposed water surfaces and from contiguous lands where the depth to the water table is slight. Average annual water losses by evapotranspiration are equivalent to about 280 m.g.d. or nearly 6 times the combined withdrawal from all ground-water supplies in the area. The principal aquifers are the alluvial deposits bordering streams and the buried outwash deposits which represent alluvial fills in preglacial or interglacial stream channels. Intensive well developments in the urban areas have greatly lowered ground-water levels in the buried outwash deposits, have brought localized problems of declining well yield, and have induced migration of mineralized waters from the underlying consolidated formations. During 1952, withdrawals of ground water in the nine township area averages about 50 m.g.d., most of this quantity being pumped from municipal wells. This annual pumpage was distributed as follows: 60 percent in Pontiac and environs; 20 percent in Birmingham, Royal Oak and Troy Township; and the remaining 20 percent throughout the suburban and rural areas.

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USGS1953

Stratigraphic sections at White Pine copper mine, Ontonagon County, Michigan

The lithology and stratigraphy of the ore zones near the base of the Nonesuch formation in the vicinity of the White Pine copper mine, Ontonagon County, Michigan, are shown on preliminary stratigraphic sections that have been made available for examination. Partial logs of 91 holes, drilled by the Copper Range Company from 1937 to 1949 in an area of approximately 9 square miles, are graphically presented on 15 sheets. The stratigraphic sections, at vertical scale of 1 inch equals 4 feet, show lithologic details of composition, bedding, and color, in the lower 60 feet of the Nonesuch formation and in the top of the immediately underlying rocks. The stratigraphic sections of 7 drill holes long the line of the main service drift now being driven to develop the White Pine mine have copper assays (from records of the Copper Range Company) correlated with the lithology. These assays are representative of the area, and they illustrate the stratigraphic restriction of the ore and the persistent correlation between lithology and copper content. This open-file material, entitled "Stratigraphic sections at White Pine, Ontonagon County, Michigan", records the lithologic end stratigraphic classification of these drill cores by W. S. White end J. C. Wright, end copies are available for examination in the offices of the Geological Survey: Room 1033 (Library), General Services Administration Washington, D. C.; Room 213 Science Hall, University of Wisconsin, Madison 6, Wisconsin; and Calumet, Michigan; and at the office of the Geological Survey Division, Michigan Department of Conservation, Lansing, Michigan.

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USGS1953

Pre-Cambrian geology of the Norway Lake area, Dickinson County, Michigan

The Norway Lake area straddles the south margin of the Sagola basin, an embayment of Ruronian sedimentary rocks into the west side of a complex of crystalline and sedimentary rocks of pre-Ruronian age. The north part of the Norway Lake area is underlain by the Randville dolomite, an unnamed succession of slates, Vulcan iron-formation, and interbedded slates and graywackes of the Sagola basin. The Sturgeon quartzite has not been definitely recognized in the Norway Lake area. The Handville dolomite is more than 800 feet thick and can be subdivided into upper and lower dolomite members separated by a slate member. The Vulcan iron-formation and the footwall slates are exposed only in the Deerhunt exploration. A thick section of red and gray slates with interbedded graywacke, of probable Upper Huronian age, underlies the northwest part of the mapped area. The south part of the Norway Lake area is underlain by granite gneiss, an arkose series, and schists, all of pre-Huronian age. The principal structural elements of the Norway Lake area are high angle faults, and such faults form most of the boundary between Huronian and pre-Huronian rocks in the area. The structure of the Huronian rocks. particularly in the vicinity of the Deerhunt exploration, cannot be determined with certainty on the basis of information now available. Magnetic anomalies were found to be associated with the slate member of the Randville dolomite, basalt interbedded with the arkose series, and a magnetite-bearing member in hornblende schist. It is possible that economic deposits of iron ore occur within the mapped area. However, exploration will be tedious and costly because of the structural complexity of the area and the paucity of exposures. Furthermore, the absence of strong magnetic anomalies, such as typically are present in areas known to be underlain by Vulcan iron-formation, suggests that the iron-formation is not present in abundance; in fact, it may be limited to the immediate vicinity of the Deerhunt exploration. Field mapping and petrographic examination do not provide data to determine whether the granite gneiss formed from a magma. Chemical analysis of one sample suggests that it was formed from rocks of the earth's crust rather than by fractional crystallization of a basaltic magma. The original feldspars of the granite gneiss were probably anorthoclase and analbite. During uplift and denudation these were changed to microcline microperthite and albite. These feldspars were contributed to the arkose series. During regional metamorphism of the granite gneiss and arkose replacement type microperthite and secondary perthite were formed, probably by redistribution of feldspars already present tither than by metasomatism.

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USGS1952

Molting of northern yellow-throat in southern Michigan

During the summer of 1938, detailed studies were made of the molts of the Northern Yellow-throat, Geothlypis trichas brachidactyla , in southern Michigan. Observations of the post-natal molt were made each day on nestlings found near Geddes Pond, one mile east of Ann Arbor. Studies of the post-juvenal and post-nuptial molts were from fresh specimens collected at Portage Lake in Jackson County.

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