1.3 Strange Rocks

PALEONTOLOGY - the study of the history of life as reflected in the fossil record

Invertebrate Paleontology Micropaleontology Paleobotany

Taphonomy Evolutionary Biology Paleobiology/Paleoecology Biostratigraphy

FOSSIL - remains or traces of organisms that lived in the Geologic past and are preserved in the crust of the Earth. It’s not easy to become a fossil! Very few individual organisms are preserved out of the billions that have lived throughout geologic time!! Usually, its just the hard parts of organisms that are preserved.

What organism left fossil behind? It’s called an ammonite – a cephalopod related to modern-day squid It is at least 65 million years old.

Living Relatives of Ammonites Evolution of Cephalopods

What organism left these fossils behind? How did it become embedded in the sedimentary rock that is also solid? What was deposited first, the object or the strata below the object? Explain! These are sharks teeth

Five phases of fossilization: Death Deposition Preservation Uplift/Exposure Erosion

Types of Preservation 1) Preservation of Unaltered Remains Amber Entombment Tar Impregnation Original Skeletal Material Refrigeration Mummification

2) Preservation of Altered Remains Mineralization Trace Fossils (Ichnology) Mold and Cast Carbonization

What Do Fossils Tell Us? Mass Community Structure Evolutionary Relationships Mass Extinctions Biodiversity through Time Modern Paleozoic

Paleogeography Paleoclimatology

Rank the rock layers from oldest to youngest. Identify the unconformity.

versus Law of Superposition RELATIVE DATING: Determining which rock layers and fossils are older and which are younger (i.e. determining which era/period/epoch a fossil or layer belongs to). Law of Superposition Low of Original Horizontality Law of Lateral Continuity Law of Cross-Cutting Relationships versus Radiometric Dating ABSOLUTE DATING: Determining age (in years) of a rock layer or fossil

Determining which fossil species appeared in what order in time. Relative Dating Techniques - Fossil Succession Determining which fossil species appeared in what order in time.

Index fossils should be: common easily recognizable Relative Dating Techniques - Correlation Index Fossils: fossils that can help determine the relative ages of rocks and correlate rock sequences from different locations. Index fossils should be: common easily recognizable occurred over a large area relatively short time

William Smith (1769-1839)

The Grand Record

Forces of Catastrophe