5/18/15 1.Attendance 2.Review of Calendar 3.Show test grades. Pass Back and Go over tomorrow! 4.New Notes!

The Earth’s History

How long has the Earth existed? 4.6 Billion Years

Rocks provide clues to the Earth’s History.

Relative Age – older or younger

Uniformitarianism A principle that assumes that forces that acted upon the Earth’s crust in the past are the same as those forces that are active today. “The present is the key to the past.”

The Law of Superposition The rock layers on the bottom of an undisturbed rock exposure are usually the ______________ oldest.

The rock layer is always __________ than the process that changed it. older

Intrusions are _____________ than the rock they move through. younger

Extrusions are _________ than the rock that they move through. younger

Can U tell the sequence of events?

________ are naturally preserved remains or impressions of once living things. Fossils

Nautiloid Nautiloids are a large and diverse group of marine cephalopods (Mollusca) belonging to the subclass Nautiloidea that began in the Late Cambrian and are represented today by the living Nautilus. Nautiloids flourished during the early Paleozoic era, where they constituted the main predatory animals, and developed an extraordinary diversity of shell shapes and forms. Some 2,500 species of fossil nautiloids are known, but only a handful of species survive to the present day. cephalopodsMollusca Late Cambrian NautilusPaleozoic fossil

Trilobite Trilobites ( / ˈ tra ɪ ləba ɪ t/, / ˈ tr ɪ ləba ɪ t/; meaning "three lobes") are a well-known fossil group of extinct marine arthropods that form the class Trilobita. The first appearance of trilobites in the fossil record defines the base of the Atdabanian stage of the Early Cambrian period (526 million years ago), and they flourished throughout the lower Paleozoic era before beginning a drawn- out decline to extinction when, during the Devonian, almost all trilobite orders, with the sole exception of Proetida, died out. Trilobites finally disappeared in the mass extinction at the end of the Permian about 250 million years ago. The trilobites were among the most successful of all early animals, roaming the oceans for over 270 million years.[2]

Fossil sponge Sponges are animals of the phylum Porifera ( /p ɒˈ r ɪ fərə/; meaning "pore bearer").They are multicellular organisms which have bodies full of pores and channels allowing water to circulate through them, consisting of jelly-like mesohyl sandwiched between two thin layers of cells. Sponges have unspecialized cells that can transform into other types and which often migrate between the main cell layers and the mesohyl in the process. Sponges do not have nervous, digestive or circulatory systems. Instead, most rely on maintaining a constant water flow through their bodies to obtain food, oxygen and remove wastes.

Coprolite A coprolite is fossilized feces. Coprolites are classified as trace fossils as opposed to body fossils, as they give evidence for the animal's behaviour (in this case, diet) rather than morphology. The name is derived from the Greek words κοπρος / kopros meaning 'dung' and λιθος / lithos meaning 'stone'.fossilizedfecestrace fossilsGreek

What type of rock are fossils found in? Sedimentary

Geologic time is divided into time units based upon the ________ record. fossil

Correlation – matching up the rock strata

Index fossils : Have existed for a short period of time Are found over a wide geographic area Are easily recognizable

Heterotroph Hypothesis

___________ individuals that have traits that better suit them to their environment would survive longer and produce more offspring. Natural selection

Human Evolution

_______________ are buried erosional surfaces. Unconformities

__________________ is the age of a rock unit, fossil or an event expressed in units of time (the exact age) Absolute age

The regular rate of nuclear decay (half-life) of a radioactive isotope allows us to find the absolute age of rocks and fossils. Radioactive Dating

Radioactive dating is a way to determine the absolute age by comparing the amounts of _____________ to the amounts of _________ product. isotope decay

___________ are forms of an element that have more neutrons in the nucleus than normal. Isotopes

Draw this data table in the empty space of your note packet.