EESB15H3 Lecture Notes - Lecture 14: Diamictite, Rodinia, Superior Craton
11 Dec 2017
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Document Summary
Mountain-building episode resulting in the formation of the nena and arctica continents. Occurred in the southern margin of the superior province. Figure 2: simplified structure of the grenville province. Pan-african orogeny: parts of africa come together to form the continent gondwana (africa, south america, india, australia, antarctica) around 540 ga. Migration of gondwana to the southern hemisphere. The cryogenian rock record - the primary mysteries: Weird cap carbonates: are unusual sedimentary structures that suggest both rapid precipitation both inorganically, and mediated by algae. Form in shallow waters and warm temperatures. Diamictite: is a lithified sedimentary rock that consists of poorly sorted sediment containing particles than range in size, suspended in a matrix of mudstone or sandstone. Thick diamictite deposits are found at low equatorial paleolatitudes. Low-paleolatitude diamictite deposits are common in the neoproterozoic. Varves: are sediment layers that change in character as a result of seasonal sediment flux. Formations on the seafloor indicate bottom-water anoxia.
