Unit 1: Earth Materials
Cenozoic (creationist)
represents post-Flood deposits. They include the record of the dispersion from Babel which are the "cave-man" fossils.
Spheroidal Weathering
rocks becoming spheres
Rock Cycle
see "Igneous Rocks", slide 2
Igneous Rocks Chart
see "Igneous Rocks," slide 13
The Rock Cycle
see "Rock Cycle and Weathering," slides 2 and 3
Clastic Sedimentary Rocks
see "Sedimentary Rocks," slide 7
Plate Tectonics
slow process of movement
Weathering in Joints
streams find their way to already-existing weak spots and flow there
Paleozoic/Mesozoic (creationist)
the Flood is primarily represented by the Mesozoic and Paleozoic rocks. The Flood begins as tremendous erosion occurs on the continents (carving the Great Unconformity) and depositing vast amounts of marine rocks on the continents. Eventually land animals are also overcome to form the Mesozoic deposits.
Foliation vs Sedimentary Layering
the cause is different. Sedimentary is a settling of grains, mud, etc. Foliation results from actual mineral growth.
Conglomerate pieces:
the rounded pieces are "clasts" and the muddy stuff in between in the "matrix"
Lithification
turns sediment into a rock by hardening it 1. compaction 2. de-watering 3. cementation, with quartz, calcite, limonite, or hematite
Mechanical Weathering: Cavitation
vacuum bubbles imploding, happens with exceptionally fast-flowing water
Mechanical Weathering: Frost Wedging
water gets into cracks, then freezes and expands
Mechanical Weathering: Groundwater Sapping
water pushes rock out/off
Mechanical Weathering: Fire
water trapped in rocks heats up, steam pops open rocks, breaks them apart or creates little holes
Naturalism (1)
A scientific philosophy that only considers hypotheses that do not require any divine intervention
Perspectives
Biblical vs Naturalistic view
Mineral Group 2: Carbonates
Calcium Carbonite - (CO3)^-2 is the common ingredient (the carbonate ion) Calcite - CaCO3 (the main ingredient of limestone) Dolomite - CaMg(CO3)2
Precambrian (creationist)
Estimating from biblical chronologies, the date of creation was probably about 6,000 years ago (4004 BC according to Ussher). These rocks are devoid of animal fossils because no catastrophic processes were occurring to bury animal life. In order to be fossilized, organisms must be buried rapidly. In a Creation Geology model these rocks represent rocks dating from the Creation Week and the pre-Flood times.
Naturalism (2)
Everything happens by chance natural processes that can be explained with the laws of science including the origin of the universe and the origin of life
Naturalistic evolution over time
Evolution improvement/complexity should increase as time increases.
Naturalism (4)
Evolution of life forms over time from a single common ancestor
Predictions of Naturalism (4)
Evolution of new body plans with myriads of new species. (right now it's only the Cambrian Explosion)
How to Identify Minerals
Minerals are identified by their physical properties like streak, hardness, luster, cleavage, crystal shape, etc.
Naturalism (3)
Old age for the earth (4.6 billion) and universe (12 billion)
Evolution
Over time: things are getting better; simple to complex organic evolution
Common Elements in Earth's Crust
See "Minerals," slide 4
Mineral Group 1: Silicates
- 1/3 of all known minerals (over 4,000) are silicates - 95% of the Earth's crust is composed of silicates - Examples: quartz, feldspar, olivine, hornblende, mica (biotite and muscovite)
Chemical Weathering: Oxygen
- 4Fe + 3O2 ⇒ 2Fe2O3 - Iron and oxygen combine to make rust
Mineral Identification: Fluorescence
- A variety of minerals will fluoresce or glow under black light. - Fluorite is a common example.
Cleavage: Shape Description
- Basal - Cubic - Octahedral - Rhombic
Chemical Weathering: Carbonic Acid
- CO2 + H20 ⇒ H2CO3 - Carbon dioxide and water make carbonic acid - H2CO3 + CaCO3 ⇒ Ca++ + 2HCO3- - Carbonic acid dissolves calcite to make calcium and bicarbonate ions. - looks like "pock marks" but can even make caves
Mineral Identification: Cleavage
- Cleavage is the tendency of a mineral to break along certain preferred directions. - Some minerals break with clean mirror-like surfaces (perfect cleavage) and others break along a preferred plane, but the surface will be rough (good, fair, or poor). - Some minerals will cleave in specific shapes (basal, cubic, octahedral)
Mineral Identification: Color
- Color is usually the first property that is noticed - Sometimes color is relied upon too heavily for mineral identification - Some minerals like quartz can have a variety of colors (clear, white, black, purple, yellow, rose, etc.) because of slight impurities. - Other minerals always have a consistent color - Be very careful when identifying solely on color, try to come up with some other physical properties to confirm an identification.
Mineral Identification: External Crystal Form
- Crystal shape is an ordered geometric arrangement of faces with one another - Some of the common shapes are hexagonal and cubic - Crystals will not be perfectly formed unless they grow under special conditions, so this property may not be extremely helpful for the identification of most minerals
Mineral Group 6: Native Elements
- Elements that exist naturally on their own, without combination to other elements. - Sulfur (S) - Copper (Cu) - Gold (Au) - Silver (Ag) - Diamond (C) - Graphite (C)
Chemical Sedimentary Rocks (1)
- Evaporation of a body of water can lead to the concentration and precipitation of various salts like halite or gypsum. - Some minerals will precipitate out of solution around deep sea vents and springs. - These rocks do not typically contain fossils, but usually have characteristic layering as found in most sedimentary rocks. They can be identified by various mineral and chemical tests.
Igneous Rocks (Types)
- Extrusive (forms from lava) - Intrusive (forms from magma) - Creation Week (called into existence on Day 3 of the Creation)
Foliation
- Foliation results from minerals growing in preferred directions because of large amounts of pressure during metamorphism. - The minerals become "layered" in the rock because of foliation. Foliation can appear as bands of light and dark minerals.
Mechanical Weathering
- Frost wedging - Unloading - Root wedging - Abrasion - Hydraulic action - Cavitation - Wind - Fire - Groundwater Sapping
Course-grained rocks:
- Granite, light color - Diorite, darker color - Gabbro, dark color - Granite pegmatite - Diorite pegmatite - Gabbro pegmatite
Metamorphism Factors
- Heat - Pressure - Chemically Active Fluids - Parent rock
Cleavage: Plane Description
- How many planes of cleavage are there? - What is the quality of the plane? (perfect, good, fair, poor)
Mineral Identification: Chemical Tests
- Hydrochloric Acid (HCl) can be used to test for a variety of carbonate and sulfide minerals. - Calcite (CaCO3) will bubble vigorously when a drop of acid is applied to it. - Dolomite (CaMg(CO3)2) will only bubble if you scratch or powder the substance first. - Galena (PbS) will not bubble, but will smell (due to the production of H2S) when HCl is applied to it. The smell is similar to rotten eggs.
Evidence for Interventionalism
- Information contained in DNA - Lack of fossil Intermediates - Problem of the origin of life - Problem of the origin of new body plans - Evidence that suggests a young earth
Igneous Texture: Coarse grained (Phaneritic)
- Larger interlocking crystals (> 1 mm) - Thought to be due to longer periods of cooling - Usually formed from cooling of magma - A "pegmatite" has super big crystals (> 1cm)
Mineral Identification: Luster
- Luster is the quality and intensity of the light that is reflected from the mineral's surface. - It is difficult for a photograph to show this property. - Luster is compared to common substances like glass, wax, metal, and gem stones. - Luster can either be metallic or non metallic
Mineral Identification: Magnetism
- Magnetite (Fe3O4) is magnetic - A magnet, or a steel object such as a paperclip or thumb tack will stick to magnetite.
Metamorphism Characteristics
- Metamorphism is the process by which a rock is changed by heat and/or pressure. - The original minerals of the rock are recrystallized into new minerals during the process. - Melting is never a part of metamorphism. - The metamorphic product usually looks unrecognizable from its parent.
Mineral Identification: Hardness
- Not all minerals have the same hardness. - Some are very soft and can easily be scratched with your fingernail. - Mohs' scale of hardness is a standard for comparison of mineral hardness. - Common household objects can also be used to check hardness
Silicates (2)
- Olivine (single tetrahedron) - Pyroxene (single chain of tetrahedrons) - Hornblende (double chain) - Biotite (in mica group) (sheet of tetrahedrons) - Quartz (3 dimensional framework)
Mineral Group 5: Halides
- One of the halide elements from column VIIB of the periodic table is the common ingredient - (F-, Cl-, Br-, I-) - NaCl (halite, table salt) - CaF2 (fluorite)
Interventionism Terms:
- Plate Tectonics (fast, during Flood) - Evolution (fast, pre-designed diversification at various points in earth history) - Transitional forms (some within body plans, especially after the Flood)
Types of Metamorphism
- Regional (heat and pressure) - Contact or Thermal (heat) - Dynamic (pressure)
Minerals In New Jerusalem
- Rev 21:15-21 - transparent, pure gold - jasper, sapphire, chalcedony, emerald, sardonyx, carnelian, chrysolite, beryl, topaz, chrysoprase, jacinth, and amethyst
Fine-grained rocks:
- Rhyolite, pink - Andesite, gray - Basalt, really dark color - Obsidian (glassy) - Scoria (vesicular - frothy/bubbly), dark - Pumice (vesicular), gray
Mineral Group 4: Sulfides and Sulfates
- S^-2 is the common ingredient of the sulfides - PbS (galena) - a lead sulfide - (SO4)^-2 is the common ingredient of the sulfates - CaSO4.H20 (gypsum)
Predictions of Interventionism
- Separate, distinct kinds followed by diversification - Evidence for intelligent design - Extinction of body plans, with no new body plans arising
Evidence for Naturalism
- Sequence of vertebrate fossils - Sorting in the fossil record - Fossil reefs - Time required to cool igneous bodies - Radioactive Dating
Grades of Foliation
- Shale (a sedimentary rock) - Low grade: Slate (roofing material, foliation too small to see), Phyllite (minerals slightly bigger can barely be seen, more shiny that slate) - High grade: Schist (begin to identify minerals), Gneiss (all minerals are big, definite banding) - Migmatite (a partially melted rock, tends to have weird swirls)
Igneous Texture: Fine Grained (Aphanitic)
- Small interlocking crystals (< 1 mm) - Usually due to rapid cooling - Usually formed from cooling of lavas
Mineral Identification: Fracture
- Some minerals do not have specific cleavage directions, but instead break in random directions. This is referred to as fracture. - A special type of fracture is conchoidal fracture in which the mineral breaks like glass (large smooth, curved surfaces with sharp edges)
Mineral Identification: Specific Gravity
- Specific gravity refers to the density of a mineral. - Water is defined as having a specific gravity (density) of 1.0. - Some minerals will be noticeably light and others very heavy. - You can roughly determine specific gravity by performing a "heft" test in your hand.
Mineral Identification: Streak
- Streak is the color of the powdered or pulverized mineral and is the true color of the mineral. - A white porcelain streak plate is usually used to determine the streak. - Often streaks may be white or colorless which makes them difficult to detect on a white streak plate.
Bowen's Reaction Series (1928)
- Studied the order of crystallization of liquid rocks - He discovered that minerals in igneous rocks do not all form at the same temperature, but some form at high temperatures and others at lower temperatures. - see "Igneous Rocks," slide 23
Regional Metamorphism
- These rocks are commonly found in the cores of mountain ranges. They are not isolated to small areas, but occur "regionally." - The pressure in this type of metamorphism comes from great depths of burial and tectonic forces. - The temperature comes from depth of burial and friction from tectonic forces. - This is the most common type of metamorphism. Changes result because of large amounts of heat and pressure. - These rocks are foliated (layers of minerals w/in the rock).
Organic Sedimentary Rocks
- These types of sedimentary rocks are made from the remains of various plants and animals. - Limestone can be chemical, organic, or both. - Examples of organic sedimentary rocks include coal, limestone, and some types of chert.
Dynamic Metamorphism
- This type of metamorphism results from extremely high pressures in fault zones. - It is very localized. - The metamorphism occurs as pressures change and the existing minerals become unstable. - Mylonite is a common example.
Contact Metamorphism
- This type of metamorphism results from high temperatures - These rocks tend to be non foliated. - This type of metamorphism usually occurs in local areas. - This type of metamorphism can occur when hot liquid rock comes into contact with local bedrock. An aureole (see "Metamorphic Rocks," slide 27) is formed.
Magnetite
- aka lodestone - magnetic
Gypsum
- dry wall - cubic, crystal
Hematite
- is basically rust - reddish
Minerals
- one or more make up rocks - naturally occurring - inorganic (not from something living) - crystalline solid - definite chemical composition - characteristic physical properties
Mohs' Scale of Hardness: minerals
1 Talc 2 Gypsum 3 Calcite 4 Fluorite 5 Apatite 6 Feldspar 7 Quartz 8 Topaz 9 Corundum 10 Diamond
Sedimentary Rocks
1. Clastic or Detrital - sediment from weathering of any of the 3 rocks. Sandstone 2. Organic or Biochemical - sediment from broken up bits of organic matter. Limestone, Coal 3. Chemical - sediment from chemical sources (i.e. dried up salt water). Rocksalt, Halite
Igneous Rocks
1. Intrusive (magma) 2. Extrusive (lava) 3. Creation Week
Metamorphic Rocks (1)
1. Regional - transformed by heat and pressure. Slate 2. Contact (Thermal) - transformed by heat. Marble 3. Dynamic - transformed by pressure.
Mohs' Scale of Hardness: household
2.5 Fingernail 3.0 Copper penny 5.0 Knife blade 5.5 Glass 6.5 Steel file
Mineral Identification: Double Refraction
A clear piece of calcite will produce a double image.
Predictions of Naturalism (2)
Beneficial Mutations (that can cause the transitions).
Interventionism (2)
Can include, but not limited to: - A young earth - Catastrophic processes operating to produce much of the rock record - Diversification of life forms (within particular body plans) after an initial creative act. Ability to hybridize may give clues to original kinds or "baramins."
Limestone Types
Coquina: broken up shells Crystalline: chemical Oolitic: made of oolites, which are tiny balls that have a core of fecal material that gets a rind of calcite on it
Interventionist Timeline
Creation (about 4000 B.C. - 4004 BC?) The days of the Creation Week (1-7) The Fall of Satan The Fall of Man Noah's Flood (about 2350 B.C) The Tower of Babel (about 2250 B. C.) Birth of Abraham (about 2050 B.C.)
Prediction: Evolutionary Trees
Darwin first proposed this idea in The Origin of Species and it has grown to become a thoroughly developed tree/theory now. Paleontology should demonstrate this tree, but it doesn't. Instead there's about 40 discontinuous bushes.
Mineral Identification: Taste
Halite (NaCl) will taste salty, because it is what we use for "table salt."
Specific Gravities of Common Minerals:
Halite: 2.0 Quartz: 2.65 Feldspars:2.56-2.76 Magnetite: 5.2 Galena: 7.5 Gold: 19.3
Chemical Sedimentary Rocks (2)
Limestone (calcite): CaCO3 Dolomite (dolomite): (Ca,Mg)(CO3) - probably formed during Flood's extreme conditions Chert (quartz): SiO2 Rock Salt (halite): NaCl Gypsum (gypsum): CaSO4.H2O
Mineral Group 3: Oxides
O^-2 is the common ingredient Hematite - Fe2O3 Magnetite - Fe3O4
Parents of Metamorphic Rocks
Sandstone - Quartzite Limestone - Marble Organic rich shale or coal - Anthracite Shale - Slate Slate - Phyllite Phyllite - Schist Schist - Gneiss Granite - Gneiss
Silicates (1)
Silicon-Oxygen Tetrahedron: molecule is 1 silicone atom surrounded by 4 oxygen atoms
Conventional evolution timeline
The Big Bang (8-20 bya) The Origin of Earth and Solar System (4.6 bya) The Precambrian (4.6 bya to .542 bya) - almost no life/fossils The Origin of Life on Earth (3.8 bya) The Paleozoic [old life] Era (542 to 245 mya) The Cambrian Explosion (530 mya) - life suddenly appears The Mesozoic [middle life] Era (245 to 66 mya) - dinosaurs The Cenozoic [new life] Era (66 mya to present) Origin of Earliest Man (~ 5 mya) Origin of Modern Man (~ 0.5 mya)
Luster: Non-metallic
The mineral does not look like it is made of metal - glassy, vitreous, earthy, waxy, pearly, silky, or dull
Luster: Metallic
The mineral looks like it is made of some type of metal. It does not necessarily have to be shiny. It can have a dull metallic luster.
Interventionism (1)
The philosophy that accepts the possibility of Divine intervention in history, especially in regards to the origin of the universe and its life forms
Uniformitarianism
The present is the key to the past. Implies slow, gradual processes.
Predictions of Naturalism (3)
Things are getting better (evolutionary improvement)
Predictions of Naturalism (1)
Transitional Forms (in fossils, demonstrating evolution). We should see fish becoming amphibians, etc.
Boudinage:
a stretching process that occurs during some types of metamorphism. The result is a structure that looks like a long chain of sausage links. (high-grade metamorphism)
Why are they intrusive rocks?
because they intrude into other rocks as a liquid and then cools
Differences between Carbonates
carbonates such as Calcite, will react when HCl is applied to them (can't normally get a reaction from Dolomites)
Mechanical Weathering: Wind
carries dust or sand, basically abrasion. (Ventifact is a rock smoothed by wind's abrasion)
Mechanical Weathering: Unloading
deeply buried rock under lots of pressure. If the weight is removed by erosion, the rock expands and cracks parallel to the exposed surface. (sheet joints are created, top layers can exfoliate)
Granite:
each different color is a different mineral
Mechanical Weathering: Hydraulic Action
erosion by the sheer force of water
Sedimentary Rocks Layers
formed underwater, layers caused by the processes of formation. Makes up most of the earth's surface.
Interventionist Diversification
improvement/complexity decreases over time, because the best creatures would've been made at the beginning
Porphyritic Texture
is one in which magma first begins to cool in a magma chamber, below a volcano. Crystals form in the magma. Then, the volcano erupts, and the rest of the rock cools quickly.
Mechanical Weathering: Abrasion
like sand paper, smooths/rounds rocks: glacier or water with small rocks/sand sliding across big rocks and grinds against the rocks. (Pot hole formation: water swirls, carrying sand and gravel, drilling a hole into the rock)
Differential Weathering
one part of the rock is harder than the rest of the rock (mushroom rock protects "stem")
Mechanical Weathering: Root Wedging
plant roots grown in cracks and then expand
Prediction: Animal Phyla over time
predicted is a gradual increase in phyla, rather than the reality of the Cambrian Explosion.
Metamorphism
refers to change. (butterfly, Romans 12:1-2) the changed thing may look nothing like the original