A Revision of Stratigraphic Nomenclature for Middle Precambrian Rocks in Northern Michigan

Cannon, William F.; Gair, Jacob Eugene

doi:10.1130/0016-7606(1970)81[2843:arosnf]2.0.co;2

Cited by 62 publications

(54 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…1; Cannon and Gair, 1970). For the Archean rocks north of the Marquette synclinorium, Van Hise and Bay ley (1897) introduced the name "northern complex"; the Archean rocks south of the synclinorium they named "southern complex.…”

Section: Geologic Settingmentioning

confidence: 99%

Great Lakes tectonic zone in Marquette area, Michigan: Implications for Archean tectonics in north-central United States

Sims¹

1991

View full text Add to dashboard Cite

Section: Geologic Settingmentioning

confidence: 99%

Great Lakes tectonic zone in Marquette area, Michigan: Implications for Archean tectonics in north-central United States

Sims¹

1991

View full text Add to dashboard Cite

“…It is bounded to the north and west by Archean granite and gneissic granitoids (Sims, 1980). To the south the Archean rocks of the belt are unconformably covered by or are in fault contact with sedimentary rocks of the Early Proterozoic Marquette Range Supergroup (Cannon and Gair, 1970).…”

Section: Geologic Settingmentioning

confidence: 99%

“…Early Proterozoic sedimentary rocks assigned to the Michigamme Formation of the Marquette Range Supergroup (Cannon and Gair, 1970), Early Proterozoic diabase dikes, and Middle Proterozoic (Keweenawan) diabase dikes occur within the northern block.…”

Section: Proterozoic Rocksmentioning

confidence: 99%

Archean geology of the northern block of the Ishpeming greenstone belt, Marquette County, Michigan

Johnson

Bornhorst

Sims³

et al. 1991

View full text Add to dashboard Cite

“…4A) in the Lake Huron area, the Huronian Supergroup of Canada, and a somewhat younger sequence in the Lake Superior region, the Marquette Range Supergroup and its equivalents in Minnesota (Sims and others, 1981;Morey, 1983;Cannon and Gair, 1970 northern Minnesota (Morey, 1973), was deposited over relatively nonstretched (stable) Archean greenstonegranite complexes on the north, whereas a much thicker (:::::6 km) succession of interlayered sedimentary and volcanic rocks accumulated on stretched Archean gneiss basement on the south. Sedimentation began with deposition of quartz-rich and carbonate rocks and continued with precipitation of major iron-formations.…”

Section: Early Proterozoic Epicratonic Sequencementioning

confidence: 99%

Contributions to mineral resources research, 1984

Bush¹

1987

View full text Add to dashboard Cite

Chemical and mineralogical studies of the Davis Formation show that very fine grained authigenic potassium feldspar, a major silicate, formed diagenetically at the expense of detrital vitric volcanic ash deposited in a marine environment The chemistry, mineralogy, and texture of the Upper Cambrian Davis Formation are consistent with the concept that its silicate minerals originated chiefly from vitric volcanic ash that was deposited in a marine environment and then altered during diagenesis to potassium feldspar. Dolomite, calcite, illitesmectite, chlorite, and sparse glauconite and pyrite in the Davis also formed diagenetically. Quartz occurs in some beds and is largely detrital. Very fine grained authigenic monoclinic potassium feldspar is the dominant mineral in all insoluble residue samples and constitutes as much as 60 percent of many of the residues; only minor amounts of detrital igneous orthoclase and microcline (to 60 J.A.m) are recognized in polished grain mounts and thin sections. By contrast, the authigenic potassium feldspar crystals are so small (0.03-5 J.A.m) that they can be conclusively identified by scanning electron microscopy, electron-microprobe, or X-ray diffraction methods. U.S. GEOLOGICAL SURVEY BULLETIN 1694 CONTRIBUTIONS TO MINERAL RESOURCES RESEARCH, 1984 CONTENTSThat the silicate minerals in the Davis Formation are authigenic is also suggested by the composition and distribution of nearby igneous rocks. The Davis is thickest in the region surrounding the core of Precambrian igneous rocks that now form the St. Francois Mountains. These Precambrian granites and rhyolites were also exposed during Davis deposition, yet they contributed only a minor local detrital component to the Davis Formation. Evidence for this conclusion includes (1) the very high K 2 0:Na 2 0 (weight percent) ratio of >55, and (2) K 2 0 contents of 10-11 percent for beds in the Davis; these values are large compared with those for the local Precambrian igneous rocks. In addition, the K 2 0, barium, zirconium, and boron concentrations for Davis samples differ significantly from the concentrations of these components in local Precambrian rocks. Further, the absence of quartz in some of the Davis samples, and the euhedral potassium feldspar grains smaller than 5 J.A.m, taken with the other evidence preceding, all suggest an authigenic origin for potassium feldspar in many beds in the Davis.The lower half of the marine Franconia Formation in Minnesota has been reported to contain nearly 50 percent authigenic potassium feldspar. These strata are age equivalent to the Davis Formation. INTRODUCTIONIn the past several years, highly potassic strata in which potassium feldspar is the major potassium-bearing mineral and also the major silicate mineral have commonly been considered to have originated from the diagenetic alteration of volcanogenic or tuffaceous debris. This interpretation has been applied to both lacustrine (Sheppard and Gude, 1965) and marine (Weiss, 1954) occurrences. Buyce and Friedman (1975) have emphasiz...

show abstract

A Revision of Stratigraphic Nomenclature for Middle Precambrian Rocks in Northern Michigan

Cited by 62 publications

References 0 publications

Great Lakes tectonic zone in Marquette area, Michigan: Implications for Archean tectonics in north-central United States

Great Lakes tectonic zone in Marquette area, Michigan: Implications for Archean tectonics in north-central United States

Archean geology of the northern block of the Ishpeming greenstone belt, Marquette County, Michigan

Contributions to mineral resources research, 1984

Contact Info

Product

Resources

About