G E O L O GY , M E T E O R O L O GY A N D A S T R O N O M Y

EARTH SCIENCE (PART 1)BY JESS CHRISTIAN RAMIREZ

MAY 2012

GEOLOGY

• GEO – EARTH• LOGOS – TO STUDY

• MINERALS• ROCKS• FORMATIONS• HISTORY

MINERALS

MINERALS

• N – aturally occuring• O – rdered Structure• I – norganic• S – olid• E – xact Chemical Composition

• They are the building blocks of rocks

ORDERED STRUCTURES

PROPERTIES OF A MINERAL

• HARDNESS – Refers to which materials a mineral can scratch, (Moh’s Hardness Scale**)• COLOR – A property referring to the light which is

reflected by the mineral to the human eye• STREAK – (Streak Plate**), refers to the color of

the mineral in its powder form. Note a minerals color may differ from its streak• CLEAVAGE – Refers to the number of cleaves or

breaks a mineral has. Aids in identification of minerals ordered structured as related to how it is broken into pieces.

MOH’S HARDNESS SCALE

ROCKS

• Formed due to the presence of one or more minerals• The rock cycle – refers to the processes that a

rock has undergone to obtain its present state• Has 3 major classification; IGNEOUS,

SEDIMENTARY, METAMORPHIC

THE ROCK CYCLE

IGNEOUS ROCKS

• IGNIS – Fire/Flame• Developed inside the Earth (Intrusive) or cooled

on the Earth’s surface (Extrusive)• Higher time of cooling = Larger crystals• Less time of cooling = Smooth, glassy features

EXTRUSIVE IGNEOUS ROCKS

• Obsidian

• Basalt

INTRUSIVE IGNEOUS ROCKS

• Pegmatite

• Diorite

SEDIMENTARY ROCKS

• EROSION• DEPOSITION• LITHIFICATION/DIAGENESIS• COMPACTION• CEMENTATION

• These SEDIMENTARY PROCESSES give us an idea of what type of environment the aggregate debris of these rocks has and its mode of transport

• Classified as; CLASTIC (cemented rock with clasts or pebble like mixed rocks), BIOCHEMICAL and CHEMICAL SEDIMENTARY ROCKS.

SEDIMENTARY ROCKS

METAMORPHIC ROCKS

• RESULT of the WEATHERING (either due to heat, pressure of both) or sedimentary or igneous rock(s).• FOLIATED OR NONFOLIATED• FOLIATION refers to the layers/bands found on

rocks

EARTHQUAKES

• Caused by rapid vibrations of the Earth releasing energy coming from the focus, associated with fractures called faults.

• Epicenter – Above the focus, on the “ground” where vegetation is found.

EARTHQUAKE WAVES

• Surface Waves: Travels along the outer layer of the Earth

• Body Waves: Travels through Earth’s interior• P waves: PUSH-PULL waves, fastest among waves. Can

travel on all medium• S waves: SHAKE waves, cannot travel on liquids

MEASURING THE “STRENGTH” OF AN EARTHQUAKE

• INTENSITY: compares strength relative to effect, ie. Swinging or lampshades, waking of asleep persons, etc.

• MOMENT MAGNITUDE: compares strength using energy release by the earthquake as measured by a seismograph

VOLCANISM

• VULCAN – Roman God of Fire

• Refers to any geological structure that has a crater(mouth) that emits and/or contains magma(molten rock) beneath the surface of the Earth.

• Basic classification includes: SHIELD(wide), CINDER(cone like) and COMPOSITE(steep)

COMPOSITION OF THE EARTH

COMPOSITION OF THE EARTH

• CRUST: thinnest layer of the Earth• MANTLE: thickest layer of the Earth.• OUTER CORE: liquid(higher temp, lower pressure)• INNER CORE: solid(high temp, high pressure)

• DISCONTINUITIES- Mohorovicic: “Moho”, Crust-Mantle- Gutenberg: Mantle - Outer Core- Lehmann: Outer Core –Inner Core

CHANGES IN THE EARTH’S SURFACE

1. Continental Drift Theorem: proposed by Alfred Wedgener• Pangea: Large land mass, evidences are as

follows• Puzzle like arrangement of Brazil and Africa• Fossil Evidences• Rock Structures• Ancient Climate

CHANGES IN THE EARTH’S SURFACE

2. Plate Tectonics Theory- Argued that the Continental Drift Theory- Separates Crust into Plate Boundaries

TYPES OF PLATE BOUNDARIES• Convergent: Plates move toward each other• Divergent: Plates move away from each other• Transform: Plates slide past from each other

GEOLOGIC TIME

• Nicolas Steno: pioneered the study of geological structures and relate them with computations regarding dates and other time related features.• STENO’S LAWS:• Law of Superposition: The fossil on top is younger than

the bottom• Principle of Original Horizontality: Layers are deposited

horizontally• Principle of Cross Cutting: When a fault cuts through

other rocks, the fault is younger than these rocks.

ANY QUESTION

S?

QUIZ

1. A mineral is defined as NOISE, give at least 2 def’ns.2. A rock is composed of several minerals that undergo the process

of _________3. An igneous rock that develop inside the Earth is called _____ and

develops ______ crystals, while that develop outside/surface of the Earth is called the ________ and develops ________ crystals.

4. A sedimentary rock relates its origin through ________5. The release of energy due to vibration of the Earth is the ______6. The source of 5, is the _____ and its reflection on the vegetation

is the _________7. The ______ measures relative effect on persons due to 5, and

______ measures energy due to 5 using a __________8. The father of Historical Geology is _______, he formulated the

______. Explain at least 2 of these 3 laws.