Gunflint formation
WebGunflint microfossils, assemblage of microscopic fossils uncovered in the Gunflint Iron Formation, a rock layer about two billion years old exposed in western Ontario, Canada. … WebThe Gunflint Formation of the late Paleoproterozoic Animiki Group comprises chemical, clastic, and volcaniclastic sedimentary rocks that are 100–160-m thick and which extend for 175 km along the Gunflint Range from northeastern Minnesota to the Thunder Bay area of Ontario, Canada. The Gunflint Formation is known for occurrence of various ...
Gunflint formation
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http://grippo.pazsaz.com/eco2.html WebDec 13, 2024 · The Late Proterozoic Gunflint Formation 2002). The microfossil assemblage of the Gunflint Formation is renowned among astrobiologists for its excellent preservation in stromatolitic and non-stromatolitic cherts and for its abundance and diversity of filamentous, coccoidal fossils and problematic forms that are reported only in iron …
WebOct 20, 2024 · The Gunflint Formation is a ~ 120 m thick sedimentary sequence that was unconformably deposited on granite-greenstone Neoarchaean basement rocks (Petrash et al., 2016). The northeast-southwest-trending exposed sections outcrop along the north shore of Lake Superior and to the west of Thunder Bay, ... WebMay 18, 2024 · We have imaged microfossils from the Schreiber Beach and Mink Mountain localities of the Gunflint Formation (1.88 Ga, Ontario, Canada), which present remarkably different assemblages and states of ...
WebSep 15, 2024 · The Gunflint Formation is a part of the Paleoproterozoic Animikie Group, which lies in the Lake Superior region of Canada and the USA. The group extends northeastward from the Mesabi Range in north-central Minnesota to the Gunflint Range in Ontario, Canada. WebSep 15, 2024 · The Gunflint Formation is a part of the Paleoproterozoic Animikie Group, which lies in the Lake Superior region of Canada and the USA. The group extends …
WebThis stromatolite is from the Gunflint Formation, a Paleoproterozoic chemical-clastic sedimentary assemblage outcropping to the immediate northwest of Lake Superior that became famous in 1954 for containing …
WebThe Late Proterozoic Gunflint Formation comprises 100–160-m thick iron-rich chemical, clastic, and volcaniclastic sedimentary rocks extending for 175 km along the Gunflint Range from northeastern Minnesota, USA to the Thunder Bay area of Ontario, Canada. The iron formation is well dated at 1878 ± 1.3 Ma by U-Pb on zircons (Fralick et al. 2002).The … parker 110a-071-as-0WebThe Gunflint iron formation is part of a Late Precambrian sedimentary-volcanic series that overlies with major unconformity an ancient granite-greenstone pediment surface. Iron- and silica-bearing rocks of the Gunflint were deposited in a marginal basin that bordered open sea water in a region of volcanic activity. Volcanism played a dual role ... parker 110a-106-asoWebAug 20, 2024 · However, the former passage of fluid hydrocarbons rarely leaves a trace, so evidence for this process in the early Precambrian rock record is sparse. Here, we report the widespread presence of... parker 10 micron breather filterWebSignificance of the Gunflint (Precambrian) Microflora: Photosynthetic oxygen may have had important local effects before becoming a major ... P.M., UNMETAMORPHOSED MINERALS IN THE GUNFLINT FORMATION USED TO TEST THE AGE OF THE ANIMIKIE, JOURNAL OF GEOLOGY 70: 489 (1962). Google Scholar. JAMES, H.L., … time value of money factor tablesWebOther articles where Gunflint Iron Formation is discussed: algae: Evolution and paleontology of algae: …Porphyridium are known from the Gunflint Iron Formation of … time value of money formula exampleWebMar 23, 2024 · The stratigraphic association of Gunflint-type microfossils and Palaeoproterozoic iron formation suggests that these fossils may record communities involved in iron metabolism or oxygen... time value of money excel spreadsheetWebThe 1.88-Ga Gunflint Formation occupies a key point in Earth’s history. It shortly predates the earliest widely accepted evidence for fossil eukaryotes ( 9) and the generally accepted timing of the transition from largely ferruginous to largely sulfidic ocean conditions ( 10, 11 ). time value of money formulas