GLGY 493 Lecture 1: Midterm 2 Paleozoic Time Line
7 Dec 2016
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Document Summary
Deposition of sand and carbonate sediments farther from land. Upper-caledonian orogenic belt (same trend as taconic) north-eastern north america. Lower: volcanic ash deposits, later altered to bentonite clays. Volcanic island arc collided with north america craton. Consisted of red sandstones and shales, coarser and thicker to the east, closer to the source. Caledonian orogeny northeastern north america (collision of baltica and laurentia) Passive margin and subductive zone in western north america cordillera. Deep marine deposits in n. a and s. e usa. St. peters sandstone, pure quartz from reworked sedimentary rocks. Evaporation led to immense quantities of rock salt and gypsum >750m thick. Upper: most of na flooded by epicontinental seas. Volcanic island arc collided with western margin of na, caused thrust faulting in. Acadian orogeny, avalon terrain (aka carolina terrain) collides with eastern n. a. Gondwana in southern hemisphere near the north pole. Acadian highlands form continuous belt with caledonian mountains. Initial deposits of kakaskia sea are clean quartz sands.
