iPedia Free Information Center

Information about Gunflint Chert

The Gunflint chert (2.51 Ga) is a sequence of banded iron formation rocks that are exposed in the Gunflint Range of northern Minnesota and western Ontario along the north shore of Lake Superior. The black layers in the sequence contain microfossils that are 1.9 to 2.3 billion years in age. Stromatolite colonies of cyanobacteria that have been converted to jasper are found in Ontario. The banded ironstone formation consists of alternating strata of iron oxide-rich layers interbedded with silica-rich zones. The iron oxides are typically hematite or magnetite with ilmenite, while the silicates are predominantly cryptocrystalline quartz as chert or jasper, along with some minor silicate minerals.

Stanley A. Tyler examined the area in 1953, and noted the red-colored stromatolites. He also sampled a jet-black chert layer which, when observed petrographically, revealed some life-like small spheres, rods and filaments less than 10 micrometres in size. Elso Barghoorn, a paleobotanist at Harvard, subsequently looked at these same samples. Barghoorn concluded that "they were indeed structurally preserved unicellular organisms."[1] In 1965 the two scientists published their finding, and named a variety of the Gunflint flora.[2] This created an academic "stampede" to explore Precambrian microfossils from similar Proterozoic environments.

See also

References

1. ^ Past lives: Chronicles of Canadian Paleontology [1]
2. ^ Barghoorn, E.S. and Tyler, S.A., 1965: Microorganisms from the Gunflint Chert. Science, vol. 147, p. 563-577.
Annum is a Latin noun meaning year. It is the accusative singular of the second declension masculine noun annus (nominative), anni (genitive) [1] .

As a unit of time, it is defined as exactly 365.
..... Click the link for more information.
Banded iron formations (also known as banded ironstone formations or BIFs) are a distinctive type of rock often found in primordial sedimentary rocks. The structures consist of repeated thin layers of iron oxides, either magnetite or hematite, alternating with bands
..... Click the link for more information.
The Gunflint Range is an iron ore deposit in northern Minnesota in the United States and western Ontario, Canada. The range extends from the extreme northern portion of Cook County, Minnesota into Canada.

See also

  • Gunflint Chert

..... Click the link for more information.
State of Minnesota

Flag of Minnesota Seal
Nickname(s): North Star State,
The Land of 10,000 Lakes, The Gopher State
Motto(s): L'Étoile du Nord (French: The Star of the North)

Capital Saint Paul

..... Click the link for more information.
Ontario


Flag Coat of arms
Motto: Ut Incepit Fidelis Sic Permanet (Latin: Loyal she began, loyal she remains)

Capital Toronto
Largest city Toronto
Official languages English (de facto)
Government
..... Click the link for more information.
Coordinates Coordinates:
Lake type Rift lake
Primary sources Nipigon River,
St.
..... Click the link for more information.
Micropaleontology (also sometimes spelled as micropalaeontology) is that branch of paleontology which studies microfossils. Microfossils are fossils generally not larger than four millimeters, and commonly smaller than one millimeter, the study of which requires the
..... Click the link for more information.
Stromatolites (from Greek strōma, mattress, bed, stratum, and lithos, rock) are defined as "attached, lithified sedimentary growth structures, accretionary away from a point or limited surface of initiation.
..... Click the link for more information.
''This is a biological article:
''For a territory administered by another territory see: Colony


''For a group attempting to affiliate with a Fraternity or Sorority see: Colony (fraternity)


In biology, a colony
..... Click the link for more information.
Cyanobacteria

Orders

The taxonomy is currently under revision.[1]

Cyanobacteria (Greek: κυανόs (kyanós) = blue + bacterium) also known as Cyanophyta
..... Click the link for more information.
JasPer is a project to create a reference implementation of the codec specified in the JPEG-2000 Part-1 standard, (ie. ISO/IEC 15444-1). The project was started by Image Power, Inc. and the University of British Columbia.
..... Click the link for more information.
Ironstone is a fine-grained, heavy and compact sedimentary rock. Its main components are the carbonate or oxide of iron, clay and/or sand. It can be thought as a concretionary form of siderite. Ironstone also contains clay, and sometimes calcite and quartz.
..... Click the link for more information.
stratum (plural: strata) is a layer of rock or soil with internally consistent characteristics that distinguishes it from contiguous layers. Each layer is generally one of a number of parallel layers that lie one upon another, laid down by natural forces.
..... Click the link for more information.
Ferruginous redirects here. For the bird, see Ferruginous Hawk


Altogether there are sixteen known iron oxides.[1] These compounds are either oxides (Wüstite, Hematite, β-Fe2O3, Maghemite, γ-Fe2O
..... Click the link for more information.
silicon dioxide, also known as silica or silox (from the Latin "silex"), is the oxide of silicon, chemical formula SiO2, and has been known for its hardness since the 16th century.
..... Click the link for more information.
Hematite, also spelled hæmatite, is the mineral form of Iron(III) oxide, (Fe2O3), one of several iron oxides. Hematite crystallizes in the rhombohedral system, and it has the same crystal structure as ilmenite and as corundum.
..... Click the link for more information.
Magnetite is a ferrimagnetic mineral with chemical formula Fe3O4, one of several iron oxides and a member of the spinel group. The chemical IUPAC name is iron(II,III) oxide and the common chemical name ferrous-ferric oxide.
..... Click the link for more information.
Ilmenite is a weakly magnetic titanium-iron oxide mineral which is iron-black or steel-gray. It is a crystalline iron titanium oxide (FeTiO3). It crystallizes in the trigonal system, and it has the same crystal structure as corundum and hematite.
..... Click the link for more information.
Cryptocrystalline is a rock texture which is so finely crystalline, that is, made up of such minute crystals that its crystalline nature is only vaguely revealed even microscopically in thin section by transmitted polarized light.
..... Click the link for more information.
Quartz (from German Quarz   (help info ) [1]) is the second most common mineral in the Earth's continental crust, feldspar being the first.
..... Click the link for more information.
Chert (IPA: /ˈtʃəː(r)t/) is a fine-grained silica-rich cryptocrystalline sedimentary rock that may contain small fossils.
..... Click the link for more information.
JasPer is a project to create a reference implementation of the codec specified in the JPEG-2000 Part-1 standard, (ie. ISO/IEC 15444-1). The project was started by Image Power, Inc. and the University of British Columbia.
..... Click the link for more information.
Petrography is that branch of petrology which focuses on detailed descriptions of rocks. Someone who studies petrography is called a petrographer. The mineral content and the textural relationships within the rock are described in detail.
..... Click the link for more information.
Elso Sterrenberg Barghoorn (1915-1984) was an American paleobotanist best known for his discoveries in South African rocks of fossils which pushed back the estimates of the origin of life to more than 3.
..... Click the link for more information.
Harvard University (incorporated as The President and Fellows of Harvard College) is a private university in Cambridge, Massachusetts, USA and a member of the Ivy League.
..... Click the link for more information.
microorganism (also spelled as microrganism) or microbe is an organism that is microscopic (too small to be seen by the human eye). The study of microorganisms is called microbiology.
..... Click the link for more information.
microorganism (also spelled as microrganism) or microbe is an organism that is microscopic (too small to be seen by the human eye). The study of microorganisms is called microbiology.
..... Click the link for more information.
Precambrian (Pre-Cambrian) is an informal name for the supereon comprising the eons of the geologic timescale that came before the current Phanerozoic eon. It spans from the formation of Earth around 4500 Ma (million years ago) to the evolution of abundant
..... Click the link for more information.
Micropaleontology (also sometimes spelled as micropalaeontology) is that branch of paleontology which studies microfossils. Microfossils are fossils generally not larger than four millimeters, and commonly smaller than one millimeter, the study of which requires the
..... Click the link for more information.
Proterozoic (IPA: /ˌprəʊt(ə)rəˈzəʊɪk/) is a geological eon representing a period before the first abundant complex life on Earth. The Proterozoic Eon extended from 2500 Ma to 542.
..... Click the link for more information.


This article is copied from an article on Wikipedia.org - the free encyclopedia created and edited by online user community. The text was not checked or edited by anyone on our staff. Although the vast majority of the wikipedia encyclopedia articles provide accurate and timely information please do not assume the accuracy of any particular article. This article is distributed under the terms of GNU Free Documentation License.
Herod_Archelaus


page counter