Geological History and Meteorology I

Study Guide

Geological History

Correlation

· Tracing sedimentary layers directly

· Positioning layers in a sequence of strata

· Distinctive or uncommon minerals in a layer

· Fossils that form in layers

The fossil record provides the primary method for determining long range correlations between sedimentary layers.

Preservation of fossils – a biased process

· Rapid burial – keep soft parts from being destroyed, eaten or decomposed by bacteria

· Hard parts – are more likely to last, shells, bones, and teeth

Principal of Fossil Succession – Fossil organisms succeed one another in a definite and determinable order, and therefore any time period can be recognized by its fossil content.

Major ages by fossil record

· Trilobites

· Fish

· Coal Swamps

· Reptiles

· Mammals

Absolute Dating

Counting tree rings – this method can go back thousands of years

Attempts at estimating sedimentation rates – These have been unreliable and inaccurate

Radiological Dating – the best method we have found

Radioactive Isotope	Daughter Product	Decay Type	Half Lives
Uranium 238	Thorium 234	Alpha	4.5 billion years
Uranium 235	Thorium 231	Alpha	713 million years
Thorium 232	Radium 228	Alpha	14.1 billion years
Rubidium 87			47.0 billion years
Potassium 40			1.3 billion years
Carbon 14	Nitrogen 14	Beta	5730 years

Alpha Decay – Alpha particles are emitted carrying two protons and two neutrons

Beta Decay – An electron is emitted from the nucleus and a neutron is converted to a proton (The nucleus can also emit anti-electrons known as positrons.)

Electron Capture – An electron is captured by the nucleus and a proton is converted to a neutron

EON	ERA	PERIOD	EPOCH	AGE	TIME
P h a n e r o z o i c	Cenozoic	Quaternary	Holocene		0-10000yr
			Pleistocene		10000yr-1.6Myr
		Tertiary^*	Pliocene		1.65-5.2Myr
			Miocene	late	5.2-25.2Myr
				middle
				early
			Oligocene		25.2-36Myr
			Eocene		36-54Myr
			Paleocene		54-66.5Myr
	Mesozoic	Cretaceous			66.5-144Myr
		Jurassic			144-213Myr
		Triassic			213-248Myr
	Paleozoic	Permian			248-286Myr
		Carboniferous	Pennsylvanian		286-360Myr
			Mississippian
		Devonian			360-408Myr
		Silurian			408-438Myr
		Ordovician			438-505Myr
		Cambrian			505-544Myr
P r o t e r o z o i c	Late				544-1000Myr
	Middle				1000-1600Myr
	Early				1600-2500Myr
A r c h e a n	Late				2500-2900Myr
	Middle				2900-3400Myr
	Early				3400-3900Myr

	Eon	Era	Period		Epoch	Millions of Years	Plants and Animals
	Hadian					4500-3800	Origin of the Earth
	Archean	Early				3800-3400	First Single Celled Organisms
		Middle				3400-3000
		Late				3000-2500
	Proteroxoic	Early				2500-1600	First Multicelled Organisms
		Middle				1600-900
		Late				900-540
	Phanerozoic	Paleozoic	Cambrian		Age of Invertebrates	540-490	Shells, Trilobites, Fish
			Ordovician			490-443
			Silurian		Age of Fish	443-417	Land Plants, Fish, Insects
			Devonian			417-354
				Mississippian	Age of Amphibians	354-323	Amphibians, Coal Swamps, Reptiles, Extinctions of Trilobites
				Pennsylvanian		323-290
			Permian			290-248
		Mesozoic	Triassic		Age of Reptiles	248-206	Dinosaurs, Birds, Flowering Plants
			Jurassic			206-144
			Cretaceous			144-65
		Cenozoic	Tertiary		Paleocene	65.0-54.8	Extinction of Dinosaurs, Mammals, Humans
					Eocene	54.8-33.7
					Oligocene	33.7-23.8
					Miocene	23.8-5.3
					Pilocene	5.3-1.8
			Quaternary		Pleistocene	1.8-0.01
					Holocene	0.01-present

Chapter 16

Learning Objectives

After reading, studying, and discussing the chapter, students should be able to:

· Describe the science of meteorology.

· Explain the difference between weather and climate.

· List the most important elements of weather and climate.

· List the major and variable components in air.

· Describe the extent and structure of the atmosphere.

· Describe how the atmosphere is heated.

· Explain the causes of the seasons.

· List the factors that cause temperature to vary from place to place.

· Describe the general distribution of global surface temperatures.

Chapter Outline___________________________________________________________________

I. Weather and climate

A. Weather

1. Encompasses a short period of time

2. Constantly changing

B. Climate

1. Covers a long period of time

2. Generalized composite of weather

C. Elements of weather and climate

1. Properties that are measured regularly

2. Most important elements

a. Temperature

b. Humidity

c. Cloudiness

d. Precipitation

e. Air pressure

f. Wind speed and direction

II. Composition of the atmosphere

A. Air is a mixture of discrete gases

B. Major components of clean, dry air

1. Nitrogen (N₂)—78 percent

2. Oxygen (O₂)—21 percent

3. Argon and other gases

4. Carbon dioxide (CO₂)—0.036 percent —absorbs heat energy from Earth

C. Variable components of air

1. Water vapor

a. Up to about 4 percent of the air's

volume

b. Forms clouds and precipitation

c. Absorbs heat energy from Earth

2. Aerosols

a. Tiny solid and liquid particles

b. Water vapor can condense on solids

c. Reflect sunlight

d. Help color sunrise and sunset

3. Ozone

a. Three atoms of oxygen (O₃)

b. Distribution not uniform

c. Concentrated between 10 and 50 kilometers above the surface

d. Absorbs harmful UV radiation

e. Human activity is depleting ozone by adding chlorofluorocarbons (CFCs)

III. Structure of the atmosphere

A. Pressure changes

1. Pressure is the weight of the air above

2. Average sea level pressure

a. Slightly more than 1000 millibars

b. About 14.7 pounds per square inch

3. Pressure decreases with altitude

a. Half of the atmosphere is below 3.5 miles (5.6 km)

b. Ninety percent of the atmosphere is below 10 miles (16 km)