Unformatted text preview: 1/18/11 HISTORICAL GEOLOGY Geology 102 So what is the diﬀerence between GEO101 and GEO102? • In this class you will learn of the origin of the earth and the evoluJon of the land, atmosphere and all of its life. • And this is where you’ll need to learn the Geologic Time scale. • There will be a quiz on it on Tuesday, February 15. Dr. Stacey Verardo Spring 2011 Time scale Time scale Examples of the ScienJﬁc Method ScienJﬁc Method • Mediterranean Sea History • First, the quesJons… 1 1/18/11 Map Region Microfossils evidence ‐Foraminifera in study region changed abruptly 6 mya. WHAT EVENT HAPPENED? WHY DID EXTINCTION OCCUR? ‐Enormous gorge extends south of Rhone River. Similar found around the Mediterranean. HOW/WHY DID STREAM VELOCITY INCREASE TO ERODE GORGE? Diapirs Sedimentary Rock Layer ‐A hard layer of sedimentary rock is 100m below the sea ﬂoor ‐Domelike structures exist deep in the Mediterranean sea ﬂoor. WHAT IS THE ORIGIN OF THIS LAYER? ARE THESE SALT DEPOSITS? WHY ARE THEY THERE? GLOMAR CHALLENGER In 1970, Hsu and Ryan drillled the Mediterranean Sea To abempt to answer some of these quesJons. Next is the Hypothesis • Hsu and Ryan came up with the idea that the Mediterranean Sea was once a desert! • The strait of Gibraltar closed oﬀ and the sea slowly dried out. • Streams entering the Sea now had steep gradients as the water level dropped. • Then about 5.5 mya, the Strait opened again. 2 1/18/11 Then the Theory Hmmm.. What else will you learn? Plate Tectonics • This hypothesis has survived quesJoning and research and is on its way to be a THEORY. Absolute vs. RelaJve Age And ﬁnally you will learn about the EVOLUTION OF LIFE • Absolute age means we can more or less precisely assign a to the amount of Jme that has passed. Thus we can say how old something is. • RelaBve age means that we can determine if something is younger than or older than something else. RelaJve Jme does not tell how old something is, all we know is the sequence of events. Taxonomic classiﬁcaJon 3 ...
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- Spring '06
- Geology, Mediterranean Sea, time scale, • Hsu