Relative age dating diagrams channing dating tatum

21 Jan

This principle is often stated as "the present is the key to the past".Prior to the late 17th century, geologic time was thought to be the same as historical time.Archbishop James Ussher of Armagh, Ireland, 1654, added up generations from the Old Testament and determined that Earth formed on October 23, 4004 BCE.In fact, sedimentary rocks are, in a sense, trash from the Earth's surface deposited in basins.Principle of Original Horizontality Sedimentary strata are deposited in layers that are horizontal or nearly horizontal, parallel to or nearly parallel to the Earth's surface.

From the beginning of this course, we have stated that the Earth is about 4.6 billion years old.

How do we know this and how do we know the ages of other events in Earth history?

The Grand Canyon is particularly good for this because different sedimentary rocks have different colors.

For example, the mudstone, sandstone and shale are cut by the basalt dike, so we know that the mudstone, sandstone, and shale had to be present before the intrusion of the basalt dike.

Principle of Uniformitarianism The principle of Uniformitarianism was postulated by James Hutton (1726-1797) who examined rocks in Scotland and noted that features like mudcracks, ripple marks, graded bedding, etc.

where the same features that could be seen forming in modern environments.

In either case, the inclusions had to be present before they could be included in the younger rock, therefore, the inclusions represent fragments of an older rock.

relative age dating diagrams-35relative age dating diagrams-37relative age dating diagrams-42relative age dating diagrams-62