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Ocean Floor Magnetic Reversals • Basalt on the ocean floor records the direction of the Earth’s magnetic field – The pattern of this is symmetrical – Indicates that mid-ocean ridges slowly create oceanic plates • Does it lose its magnetism? – No, basalt is not magnetic – The structure of the rock records the magnetic field when it cools

© Colin Frayn, 2008 Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

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Page 1: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Ocean Floor Magnetic Reversals• Basalt on the ocean floor records the

direction of the Earth’s magnetic field– The pattern of this is symmetrical– Indicates that mid-ocean ridges slowly

create oceanic plates

• Does it lose its magnetism?– No, basalt is not magnetic– The structure of the rock records the

magnetic field when it cools

Page 2: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Oil Pressure• Oil pressure is so high that it can only have been

in place for a few thousand years

• No, oil & gas are usually trapped by impermeable rocks– They can easily be held for millions of years

• An oil field can be much younger than the oil– Oil can migrate into new reservoirs– A weak reservoir may be young

Page 3: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Ice Core Science• Ice cores

– Taken in areas of low snowfall– Longest are over 3km long!

• Dating methods– Counting layers (for shallow cores)– Aligning with known global events

• E.g. volcanic eruptions– Chemical analysis

• Looking at element ratios over time– Modelling accumulation rates

• Deep core layers are too compressed to count individually– Modelling ice flow

• Examine how deep levels flow over time

Page 4: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Greenland Lost Squadron• Planes crashed in 1942• Discovered in 1988, 75m deep in ice

– Near the coast, where snowfall rates are very high (several metres/year)

– In a glacier that had moved ~2km

• Ice cores are taken in the inner parts of Greenland– Snowfall rates are much lower

• …or in Antarctica– Antarctica is technically a desert!– ~5cm of water falls annually

Page 5: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Ocean Salination• Salt enters the oceans from the land• If Earth is Old, then should oceans be saltier?

• No, because:– Salt is also removed from the oceans to balance the

input

Sea spray 6.7 x 1010 kg/yrCation Exchange 5.2 x 1010 kg/yrBurial of pore water 3.9 x 1010 kg/yrHalite deposition 4.0 x 1010 kg/yrAlteration of Basalt 14 x 1010 kg/yrZeolite Formation 2 x 109 kg/yr Biogenic output 5 x 109 kg/yr Collective Small outputs 3.6 x 1010 kg/yrTotal 38.1 x 10^10 kg/yr.

Page 6: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Niagara Falls• How old are Niagra falls?

– Probably less than 10,000 years

• So?

• Age of Niagara is not age of the Earth• Age of Earth is at least the age of the

oldest thing in Earth not the youngest!• Some rocks date to over 4 billion years

Page 7: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Erosion Rates of Mountains• Are erosion rates too high?

• Mountains erode quickly– Should last <14 million years– Present erosion rates are likely far higher than average

• We have more mountains than average

• … but new mountains are always being formed– Colliding continents create uplift

• New continental crust is always being formed– Volcanic activity– Sediment deposition

Page 8: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Stalactites and Stalagmites• How long do they take to form?

– They can grow very quickly– …with different chemistry e.g. gypsum– However, calcium carbonate stalactites take a

very long time to form• ~10cm / 1000 years maximum• ~0.1cm / 1000 years minimum

• Limestone caverns– These are etched out slowly by weak acid

erosion– They are not formed by physical erosion

Page 9: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Water under the crust• Where did the flood water come from?

– And where did it go?

• The Hydroplate theory suggests it was mainly under the crust, and went back there– Water would be easily detected by seismic surveys

• Water behaves very differently from rock• We don’t detect any large bodies of water under the crust

– Rock is much denser than water• The water would not be able to remain at depth

– At this depth, the water would be superheated• The ‘flood’ would have cooked everyone

– The water burrowing through the rock would erode fissures• The deposits would be scattered on the surface• Such sediments would be easy to find, and extremely obvious• Of course, they do not exist

Page 10: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Antarctic Leaves• Hovind quotes Webb, Harwood, McKelvey

– Found fossilised forests in Antarctica

• What Hovind doesn’t say…– They date to the late Pliocene

• Roughly 2 million years ago

• This is consistent with current models of tectonic drift– Antarctica would have been at warmer latitudes at this

time

Page 11: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

The Geologic Column• The accumulated layers of deposition over

geological time• Is the column real?

– It exists in its entirety in over 20 locations worldwide

• How do we know this was not made by a flood?– Wind-deposited sediments

• Such as desert sandstone• These grow very slowly• They can be hundreds of metres thick• They aren’t deposited by water

– Multiple salt beds within the column• Grow slowly by evaporation• Couldn’t have been formed by a rapid flood

Page 12: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Pangea• One single large land mass

– Existed up to ~250Myr ago

• Evidence– Geological strata

• Rock beds often seem to correspond with extraordinary accuracy in distant countries.

– Similar fossils• Similar fossils are found on coastal regions

of continents thousands of miles apart– Glacial deposits

• Similar glacial deposits of similar age occur on many of the continents, suggesting that they were all polar at a similar time

– Shapes• Continents see, to fit together

Page 13: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Diatomatious Earth• A fossilised whale was found in this

sedimentary rock– Near Lompoc, CA– Apparently cutting through the layers– Suggesting rapid deposition

• However…– The whale was at roughly 45 degrees– So were the rock beds– i.e. the whale fossilised flat on the beds

• It did not cut through them

– The beds were later lifted tectonically

Page 14: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Rapid Petrification

• Flour, Charcoal, Trees etc.

• Petrification can happen quickly

• So?

Page 15: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Berlingame Canyon• A canyon formed in 6 days

– Formed by a burst irrigation canal in 1926– Approximately 90 million times smaller than the Grand

Canyon

• Part of the 16,000 year old Touchet formation– Dated by looking at ash from periodic eruptions of Mount

St Helens between layers– Gravel and fine sediment (not solid rock)

• It is obvious, from looking at this canyon, that it has been created rapidly– It is reasonably straight (The Grand Canyon meanders)

– It has no side channels (The Grand Canyon has perpendicular tributaries)

Page 16: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Coal Formation• How long does it take to form coal?

– ‘Low quality’ Coal may form fairly quickly, given the right conditions

• Up to 1 metre in 100 years

– However, real coal deposits usually formed slowly

• We see evidence for slow deposition• River channels and root systems• High-quality anthracite coal requires much longer

timescales to form

– Coal usually occurs bedded with sandstones, limestones, shales

• All of which form very slowly

Page 17: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Oil Formation• Oil forms between 4-6 km underground

– Requires temperatures between 50-120 celsius to form

• It migrates very slowly upwards– Millions of years per km– Depends on the permeability of the rock

• Some oil reaches the surface– E.g. Alberta tar sands

• Some oil gets trapped– Forms a reservoir

Page 18: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Earth was never Molten• Why are dense elements (e.g. gold) found at the

surface?– They should have ‘sunk’ to the core

• They probably did– There isn’t much gold in the crust– Though the mixing was probably not very thorough

• Elements are being continually mixed by convection, volcanism etc.– Lots of gold deposits are in igneous rocks– Even though creationists often claim the opposite!

Page 19: © Colin Frayn, 2008  Ocean Floor Magnetic Reversals Basalt on the ocean floor records the direction of the Earth’s magnetic field –The pattern

Anecdotal Stories• Anecdotal evidence is totally worthless as a basis

for science.

• Newton Anderson– Allegedly found a bell inside some coal

• Max Han– Allegedly found a hammer head in sedimentary rock