Introduction to Geology Mountain formation Erosion Different Rocks

Introduction to Geology: Mountain formation Erosion Different Rocks Fossils Dating

Formation of mountains – weathering, erosion.

Mountain Formation.

Mountain Formation.

Mountain Formation.

80 -50 Mya.

Mountain Formation.

Weathering, erosion, sedimentation:

Three different Rock types:

Fossils & fossilization:

Fossils: = Remains of past organisms. Ø Actual (or petrified) body (parts) Ø Excrements (coprolites) Ø Gastroliths (stomach stones) Ø Imprints (burrows, foot, feathers ) Ø molecular residues

Coprolites.

Fossilization:

Fossilization: 1. Remains in water (river, lake, ocean) 2. Sink to the bottom. 3. Get covered by sediment Fossils in sedimentary rock! Exceptions: a) tar pits (La Brea, Los Angeles) b) conifer amber c) sanddunes

Fossilization TIME

Nature 6 September 2012 vol 489 p 22 Xing Xu stands among the remains of duck-billed dinosaurs in Zhucheng, China

Dating Rocks Relative - Absolute

Relative Dating

Nicolaus Stenonis (1638 -1686).

Nicolaus Stenonis (1638 -1686). ". . . at the time when any given stratum was being formed, all the matter resting upon it was fluid, and, therefore, at the time when the lower stratum was being formed, none of the upper strata existed. ”

Steno’s Principle of Superposition (Prodromus, 1669) That is, in a sequence of strata, any stratum is younger than the sequence of strata on which it rests, and is older than the strata that rest upon it. ”

Nicolaus Stenonis’ Principle of superposition: