PPT-N: Geologic Time 1. Geologic History

a Fossils 3 Geologic Time Scale 4 Geologic Belts 5 NC Geologic History How do we know geologic history Earths History Earths history spans over a length of 45 billion years Geologists have divided that time into units based on major geologic events and life forms. 01: . Geologic Time . Scale. Huge sections of time are broken down into smaller groups of time:. E. ons, Eras, . P. eriods, and . E. pochs. Eon. is the largest time block. . (kind of like what we would think of as years).. How long ago were the dinosaurs here? How do we even describe geologic time anyway?. EONS. which are divided into . ERAS. ,. which are divided into. . PERIODS. ,. which are divided into. . EPOCHS. It has been suggested that, sometimes, drastic changes that can form a new species . take . place.. Under this idea, a new species may form after a group becomes separated from the original population.. Who was James Hutton?. In the late 1700s, James Hutton began to question some of the ideas regarding the Earth.. He found fossils and saw them as evidence of life forms that no longer exist. . Different types of fossilized creatures were found in different layers of rock.. Geological “Clocks”. Geologic time determination is subdivided into 2 categories:. Relative Dating: simply determines whether or not an event occurs before or after another event (e.g. a granite dike is younger than the surrounding sandstone since it intrudes across the sandstone in an outcrop).. East-Central Idaho — . Metasedimentary. Strata, . Ore . Types, . Folds, Dikes, and Metamorphic Overprint. Art . Bookstrom. , Steve Box, Pam Cossette, . Tom Frost, and Shane . Kostka. . Regional Geologic Map showing the Mesoproterozoic Belt-Purcell basin and the Lemhi sub-basin . Jacob Bleacher. Goddard Space Flight Center. 3. rd. Affordable Mars Workshop. Dec. 2, 2015. Geologic field work can be loosely defined as the body of work necessary to:. Determine the spatial distribution, age and attitude of the rock types within an area. Section 12.1 Discovering earth’s history. Uniformitarianism – the idea that physical, chemical, and biological laws that operate today also operated in the past; the present is the key to the past.. Geologic Time and Evolution Earth Has a History Geologic materials record enormous changes. Earth is a complex, evolving system. Physical and biological systems continuously interact. Earth constantly changes and has done so through time. 99.9% of all living things that have ever existed on earth have gone extinct. earth has experienced 5 five extinctions . Geologic time scale. Era. Largest unit of geologic time . lasts tens to hundreds of millions of years and consists of two or more periods. . Normally we think of time in terms of days or years but geologists commonly refer to events that happened millions or billions of years ago. For example earth is approximately 4.6 billion years old. GEOLOGIC TIME. Absolute vs. Relative . Age. Relative Age. Determining the age of an object in relation to other objects. “Estimate”. Index Fossils, Rock layers. Example. : A friend tells you . he . has 2 brothers – one that’s older than . book for . testing purposes. Some pictures in this slideshow may show a slightly different version. Neither is right or wrong, just different interpretations.. Geologic time is divided into giant chunks of time called . What is it and Why do we care? . What is the geologic time scale? . . Geologic Time Scale:. A record of the Earth’s . history broken up into . various units of time that. are based on types of . fossils contained within .