Continental Drift To Plate Tectonics

Phanerozoic

"visible life" beginning of complex life form

Devonian period

(age of fishes)

Mesozoic-Cenozoic boundary

(age of reptiles) "middle life"

Mesozoic

(age of reptiles) split from Africa and Europe

Cambrian period

(earliest complex life forms)

Stromatolites

a calcareous mound built up of layers of lime-secreting cyanobacteria and trapped sediment, found in Precambrian rocks as the earliest known fossils

Focus

a central point, as of attraction, attention, or activity

blocks

a chunk of rock that is ejected (thrown) from a volcano.

cinder cones

a cone formed around a volcanic vent by fragments of lava thrown out during eruptions.

pyroclastic flows

a dense, destructive mass of very hot ash, lava fragments, and gases ejected explosively from a volcano and typically flowing downslope at great speed.

fissure eruptions, where are they found in the US

a linear volcanic vent through which lava erupts, usually without any explosive activity/ Hawaii

Tsunamis

a long high sea wave caused by an earthquake, submarine landslide, or other disturbance.

lava flows

a mass of flowing or solidified lava.

Radiometric dating

a method of dating geological or archeological specimens by determining the relative proportions of particular radioactive isotopes present in a sample.

Foreshocks

a mild tremor preceding the violent shaking movement of an earthquake.

Volcanic necks

a narrow part of something, resembling a neck in shape or position. a column of solidified lava or igneous rock formed in a volcanic vent, especially when exposed by erosion.

Seismogram

a record produced by a seismograph.

How tsunamis work

a series of waves travelling across the ocean due to a sudden displacement of a large body of water.

Aftershocks

a smaller earthquake following the main shock of a large earthquak

Earthquake

a sudden and violent shaking of the ground, sometimes causing great destruction, as a result of movements within the earth's crust or volcanic action.

pumice

a very light and porous volcanic rock formed when a gas-rich froth of glassy lava solidifies rapidly.

principle of superpoisition

all linear systems, the net response at a given place and time caused by two or more stimuli is the sum of the responses which would have been caused by each stimulus individually.

Seismograph

an instrument that measures and records details of earthquakes, such as force and duration.

Mid-ocean ridges

an underwater mountain range, formed by plate tectonics. This uplifting of the ocean floor occurs when convection currents rise in the mantle beneath the oceanic crust and create magma where two tectonic plates meet at a divergent boundary.

shield volcanoes

built almost entirely of fluid magma flows.

Three types of unconformities

disconformities, nonconformities, and angular unconformities.

Secondary complications from earthquakes

earthquake hazards are those that are caused by the primary hazards, and may often be more catastrophic: tsunami seiche flooding fire

amber encasement

fossilized resin from ancient forests

Nuee ardantes

highly destructive, fast-moving, incandescent mass of gas-enveloped particles that is associated with certain types of volcanic eruptions.

Landslides

is a form of mass wasting that includes a wide range of ground movements, such as rockfalls, deep failure of slopes, and shallow debris flows.

Liquefaction

is a phenomenon in which the strength and stiffness of a soil is reduced by earthquake shaking or other rapid loading.

principle of faunal succession

is based on the observation that sedimentary rock strata contain fossilized flora and fauna, and that these fossils succeed each other vertically in a specific, reliable order that can be identified over wide horizontal distances.

Eons

largest

Main Shocks

largest earthquake in a sequence, sometimes preceded by one or more foreshocks, and almost always followed by many aftershocks.

bombs

mass of molten rock, formed when a volcano ejects viscous fragments of lava during an eruption.

petrified wood

minerals, wood gets fully replaced/rot (solid rock)

Divergent boundaries: what occurs there

occurs beneath oceanic lithosphere, the rising convection current below lifts the lithosphere producing a mid-ocean ridge.

Plate boundaries: convergent

plates are coming together

Plate boundaries: divergent

plates spreading apart

cinders

pyroclastic material. Cinders are extrusive igneous rocks. Cinders are similar to pumice, which has so many cavities and is such low-density that it can float on water.

lapilli

rock fragments ejected from a volcano.

Glacial evidence: Striations

scratches or gouges cut into bedrock by glacial abrasion

Eras

second largest

periods

smallest time period

composite cones

sometimes called stratovolcanoes, are typically deep-sided, symmetrical cones of large dimension built of alternating layers of lava flows, volcanic ash, cinders, blocks, and bombs and may rise as much as 8,000 ft above their bases.

Cenozoic

sometimes called the Age of Mammals, because the largest land animals have been mammals during that time.

principle of cross-cutting relationships

states that an igneous intrusion is always younger than the rock it cuts across.

principle of lateral continuity

states that layers of sediment initially extend laterally in all directions

Precambrian time

the largest span of time in Earth's history before the current Phanerozoic Eon

Crust

the outermost layer of a planet. The crust of the Earth is composed of a great variety of igneous, metamorphic, and sedimentary rocks.

Epicenter

the point on the earth's surface vertically above the focus of an earthquake.

Polar "wandering"

the slow and erratic, real or apparent, movement of the earth's rotational or magnetic poles relative to the continents throughout geological time, due largely to continental drift.

Bishop Ussher and Catastrophism

the theory that changes in the earth's crust during geological history have resulted chiefly from sudden violent and unusual events.

molds and casts

three dimensional and preserve the surface contours of the organism.

Geologic time scale

understanding different time periods

Glacial evidence: Till

unsorted glacial sediment

What violance of eruption depends on

viscosity and gas content.

gases

volcanic gas is water vapor, which is harmless. However, significant amounts of carbon dioxide, sulfur dioxide, hydrogen sulfide and hydrogen halides can also be emitted from volcanoes.

Haiti earthquake

was a catastrophic magnitude 7.0 Mw earthquake, with an epicenter near the town of Léogâne (Ouest), approximately 25 kilometres (16 mi) west of Port-au-Prince, Haiti's capital.

Principle of original horoizontality

was proposed by the Danish geological pioneer Nicholas Steno (1638-1686). This principle states that layers of sediment are originally deposited horizontally under the action of gravity.

Phreatic explosions

water beneath the ground or on the surface is heated by magma, lava, hot rocks, or new volcanic deposits

burrows and tracks

worms will stir up mud

Calderas and where are they found

A caldera is a large cauldron-like volcanic depression, a type of volcanic crater formed by the collapse of an emptied magma chamber.

Magnetic reversals

A change in the Earth's magnetic field resulting in the magnetic north being aligned with the geographic south, and the magnetic south being aligned with the geographic north. Also called geomagnetic reversal.

Fault

A fault is a crack in a rock along which slippage has occurred.

Glossopteris

A fern fossil (plant)

Mountain ranges/ Rock similarities

Across North America, Scotland, Noraway. Same type, same ages.

Fit of coastlines

Africa and South American fit together

Lithosphere

All solid rock, the rigid outer part of the earth, consisting of the crust and upper mantle.

What layer plates move on

Asthenosphere

carbon film

Carbon films are thin film coatings which consist predominantly of the chemical element carbon

uniformitarianism vs. catastrophism

Catastrophism is the theory that the Earth has been affected in the past by sudden, short-lived, violent events, possibly worldwide in scope. This was in contrast to uniformitarianism (sometimes described as gradualism), in which slow incremental changes, such as erosion, created all the Earth's geological features.

Cenozoic fossils in Florida: time period

Cenozoic Era

What plates are and about how many there are

Continental and oceanic. Pieces of earth/about 15/Chunks of Lithosphere

Difference between continental and oceanic lithosphere

Continental: weighs less Oceanic: weighs more

Alfred Wegener's idea of continental drift

Continents were not always in the places that they are today, they were once all joined together (pangea)

New data revived the ideas

Deep sea data from WW2 By 1968, "plate tectonics" theory accepted

Core

Denses part of the earth

Mesosaurus

Dinosaur that lived in Africa/South America

Plates

Earth is broken up into plates/made out of the lithosphere

difference between granitic and basaltic magmas

Granitic magma is acidic and basaltic magma is basic in reaction.Granitic magma is highly viscous, with a high melting point and have a high percentage of silica.Basaltic magma is highly fluid, rich in iron and magnesium but poor in silica.On cooling, granitic magma gives rise to coarse grained rocks but basaltic magmas give rise to fine grained rocks.

Hydrothermal vents and black smokers

Hydrothermal vents are commonly found near volcanically active places, areas where tectonic plates are moving apart, ocean basins, and hotspots. Hydrothermal vents exist because the earth is both geologically active and has large amounts of water on its surface and within its crust. Hydrothermal vents may form features called black smokers.

Paleozoic

It is the longest of the Phanerozoic eras, and is subdivided into six geologic periods (from oldest to youngest)

Sea floor spreading

Land is spreading apart

Mantle

Lies between Earth's dense, super-heated core and its thin outer layer, the crust.

Where you can find mid-ocean ridges

Mid Atlantic ridge (St. Helena) & Iceland (Land of fire and ice)

Mt. St. Helens/ 2005 reactiviation

Mount St. Helens experienced major activity again on March 8, 2005 at about 5:30 P.M. PST, when a 36,000-foot (11 km) plume of steam and presumably ash was witnessed emerging from the volcano, accompanied by a tremor that measured about magnitude 2.5. The plume was visible from the metropolitan areas of Seattle, Washington, to Salem, Oregon, but only lasted for about 20-30 minutes.

Continental-continental

Nimalayah, no water or volcanoes

Wegener's idea criticized

No Mechanism No evidence of actual motion

Transform boundaries

Ocean ridge increases with lithosphere, transform Plate Boundaries are locations where two plates slide past one another.

Plate boundaries: transform

Plates going sideways

Why the asthenosphere is a critical layer

Plates move on

pyroclastics: ash

Pyroclastic flows are high-density mixtures of hot, dry rock fragments and hot gases that move away from the vent that erupted them at high speeds. They may result from the explosive eruption of molten or solid rock fragments, or both.

What is needed for fossil preservation

Rapid burial, Possession of hard parts

Northridge earthquake

Ray Hudson reacts as a friend's home goes up in flames after a 6.7-magnitude earthquake hit the San Fernando Valley area of Los Angeles on January 17, 1994.

Magma source and how it occurs

Source: upper mantle Occurs: lowering of pressure

Connection between earthquake epicenters and plate boundaries

Tectonic Plates, Earthquakes, and Volcanoes. According to theory of plate tectonics, Earth is an active planet — its surface is composed of many individual plates that move and interact, constantly changing and reshaping Earth's outer layer.

Indian Ocean tsunami

The 2004 Indian Ocean earthquake occurred at 00:58:53 UTC on 26 December with the epicentre off the west coast of Sumatra, Indonesia. The shock had a moment magnitude of 9.1-9.3 and a maximum Mercalli intensity of IX.

Japan tsunami

The 2011 earthquake off the Pacific coast of Tōhoku was a magnitude 9.0 (Mw) undersea megathrust earthquake off the coast of Japan that occurred at 14:46 JST (05:46 UTC) on Friday 11 March 2011, with the epicentre approximately 70 kilometres (43 mi) east of the Oshika Peninsula of Tōhoku and the hypocenter at an underwater depth of approximately 30 km (19 mi).

Oceanic-continental

The Continent-ocean boundary (COB) or continent-ocean transition is the boundary between continental crust and oceanic crust on a passive margin.

Indian subcontinent and its collision into Asia

The Indian Plate or India Plate is a major tectonic plate straddling the equator in the eastern hemisphere.

Marianas Trench

The Mariana Trench or Marianas Trench is the deepest part of the world's oceans. (34-36,000 ft)

Earthquake and volcano patterns (Pacific Ring of Fire)

The Ring of Fire is a ring of volcanoes around the Pacific Ocean that result from subduction of oceanic plates beneath lighter continental plates. Most of the Earth's volcanoes are located around the Pacific Ring of Fire because that the location of most of the Earth's subduction zones.

Loma Prieta earthquake

The earthquake was triggered by a slip along the San Andreas Fault. Its epicentre was in the Forest of Nisene Marks State Park, near Loma Prieta peak in the Santa Cruz mountains, northeast of Santa Cruz and approximately 60 miles (100 km) south of San Francisco. It struck just after 5:00 pm local time and lasted approximately 15 seconds, with a moment magnitude of 6.9. San Fransico, California

Elastic Rebound theory

The elastic rebound theory is an explanation for how energy is spread during earthquakes. As rocks on opposite sides of a fault are subjected to force and shift, they accumulate energy and slowly deform until their internal strength is exceeded.

hard parts

The most common body fossils found are from the hard parts of the body

aa vs. pahoehoe

The pahoehoe flow has a comparatively smooth or "ropy" surface. The surface of the aa flow consists of free chunks of very angular pieces of lava. This difference in form reflects flow dynamics. Aa forms when lava flows rapidly.

principle of inclusions

The principle of inclusions states that inclusions found in other rocks (or formations) must be older than the rock that contain them.

Two main types of earthquake waves

The two main types of waves are body waves and surface waves. Body waves can travel through the earth's inner layers, but surface waves can only move along the surface of the planet like ripples on water. Earthquakes radiate seismic energy as both body and surface waves.

Ages of sea floor

The two parts of the oceanic plate are pulled apart, and magnetic stripes become older as they move away from the mid-ocean ridge.

Asthenosphere

The upper layer of the earth's mantle, below the lithosphere, in which there is relatively low resistance to plastic flow and convection is thought to occur.

From oldest to youngest:

Triassic (252.17 to 201.3 million years ago) Jurassic (201.3 to 145 million years ago) Cretaceous (145 to 66 million years ago)

Unconformities: mission strata

Unconformities are gaps in the geologic record that may indicate episodes of crustal deformation, erosion, and sea level variations.

Oceanic-oceanic

Underneath of oceanic continental subduction

Hot spots

Volcanic regions thought to be fed by underlying mantle that is anomalously hot compared with the surrounding mantle. They may be on, near to, or far from tectonic plate boundaries

What plate tectonics is responsible for

Volcanos, Earthquakes, Mountains