This is indirect evidence of photosynthetic organisms." (Armstrong Chapter 2, pp. 6). Thus, photosynthetic organisms have been evidenced to have existed well into the Precambrian.
Another source of data concerning life in the Precambrian comes from ancient stromatolites. Today, stromatolites can still be found in a handful of locations, and build upon each other by catching tiny particles of sediment. "Ancient stromatolites, dated to 3.5 gya, are constructed identically. Stromatolites, as unique geological structures formed by the actions of living organisms, are indirect evidence of ancient microbial communities dominated presumably by green photosynthetic organisms." (Armstrong Chapter 2, pp. 7). Together, these three portions of scientific information have generated a rough picture of life in the Precambrian.
Still more recent lines of reasoning continue to reveal information about life from this geologic period. The fossils, carbon dating, and stromatolite...
Since taconite iron ore can be attracted by magnets, it is called a magnetite. Magnetite is abundant in the Minnesota Iron Range as well as the Michigan Iron Range that is located next to Marquette as well as in the Penokee Range in Wisconsin, Minnesota. In Wisconsin-Minnesota's Gogebic-Penokee Range, the taconite iron ore deposits are concentrated on the bands that run from the Mellen area in Ashland County up
evolution of eukaryotic cells linked to the increase of atmospheric oxygen concentration during the Precambrian? Increase of atmospheric oxygen during the Precambrian period led to creatures which were more dependent on oxygen in the atmosphere. Oxygen levels in the atmosphere increased from 1% to 15% of the modern level of oxygen. The increase in oxygen in the air led to the evolution of more expansive lungs which were capable of
region's geologic formation from the Precambrian Era forward, as well as the glaciation processes that were primarily responsible for carving out and meltwater filling of the Great Lakes. The Great Lakes describes a group of five freshwater lakes located in central North America between the U.S. And Canada, and includes Lakes Huron, Ontario, Michigan, Erie and Superior. The Great Lakes watershed covers about 765,990 km2, with the area being home
Continental tropical (cT) air masses are hot, dry, unstable at low levels and generally stable aloft (upper-level ridge); they originate in northern Mexico. Continental polar (cP) or continental arctic (cA) air masses are cold, dry, and stable originating over northern Canada and Alaska as a result of radiational cooling. (Oklahoma Climatological Survey, 2004)" The greenhouse effect has been in the news for the last several decades especially with the resulting
ancient Michigan basin area and discuss a brief geological history of the area and how the mammals that lived during the Ice Age adapted to their environment over the years. Use at least 12 sources of information; use quotes Michigan experienced the great Ice Age and was covered by glaciers several times. These events in turn affected the mammals that inhabited what are now the Great Lakes region and the state
Pan-African Cratonization (about 800 to 680 Ma) Nehlig et al. (2002) conducted a study to review the Pan-African evolution of the Arabian Shield on the premise that new perspectives on the geologic history and structural evolution on the Arabian Shield had emerged. These new perspectives were brought by the extensive fieldwork as well as synthesis and review of structural, aeromagnetic, geochemical, geologic, and geochronological data. The geologic evolution of the Arabian
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