Historical Geology Understanding Our Planet\'s Past

Free ebooks ==> http://www.Ebook777.com water laden with sediment surged along the Mississippi River toward the Gulf of Mexic ...

peared from Australia. Meanwhile, giant ground sloths (Fig. 197), mastodons, and woolly mammoths (Fig. 198) disappeared from Nor ...

periods of glaciation over the past 2 to 3 million years, these large mammals succumbed to extinction following the Ice Age. Dur ...

by glaciers.The process is most active near the head of a glacier, where the ice deepens and flattens the gradient of the valley ...

deeply furrowed rocks, and great heaps of rocks marked the extent of former glaciers. Many of the northern lands are dotted with ...

The glacially derived sediments covered much of the landscape, burying older rocks under thick layers of till. Glacial till is n ...

The ridges dividing the two sides of a roche moutonnée are perpendicular to the general flow of the ice sheets. At the margins o ...

Drift is divided into two types of material. One is till deposited directly by glacial ice and shows little or no sorting or str ...

iers. They appear to represent sediment fillings of openings in stagnant ice. Many kames probably formed when streams flowed off ...

A fter taking a journey through geologic time, we can better appreci- ate the wide variety of life on Earth today. However, as s ...

abyss the deep ocean, generally over a mile in depth Acanthostega (ah-KAN-the-stay-ga) an extinct primitive Paleozoic amphibian ...

Historical Geology Archaeopteryx (AR-key-op-the-riks) a primitive Jurassic crow-sized bird characterized with teeth and a bony t ...

brachiopod (BRAY-key-eh-pod) a marine, shallow-water invertebrate with bivalve shells similar to mollusks and plentiful in the P ...

conodont a P aleozoic toothlike fossil probably from an extinct marine vertebrate continent a landmass composed of light,graniti ...

earthquake the sudden rupture of rocks along active faults in response to geologic forces within Earth East Pacific Rise a midoc ...

fissure a large crack in the crust through which magma might escape from a volcano fluvial(FLUE-vee-al) stream-deposited sedimen ...

greenstone a g reen, weakly formed, metamorphic igneous rock greenstone belt a mass of Archean metamorphosed igneous rock gypsum ...

lycopod(LIE-keh-pod) the first ancient trees of Paleozoic forests; today comprising club mosses and liverworts Lystrosaurus an a ...

Glossary Oort cloud a collection of comets that surround the Sun about a light-year away ophiolite(OH-fi-ah-lite) oceanic crust ...

Historical Geology pluton(PLUE-ton) an underground body of igneous rock younger than the rocks that surround it; it is formed wh ...