• Paleogeography

  
  
  Figure 29.1 Fossil hash (Ocala Fm.) near Perry, GA.
  
  
  
  
  Figure 29.2 Cambro-Ordovician sea floor life.
  
  
  

• Paleoclimatology

• Relative time scale

  
  
  Figure 29.3 Faunal succession. Selected members of the long-extinct group, trilobites, indicate changing styles with time (from The Changing Earth - Introduction to Geology (2nd ed.), by Mears, Jr., D. Van Nostrand Co., 1977).
  
  
  

• Evolution of life

• Correlating rocks, etc.

  
  
  Figure 29.4 Correlation by fossils. Certain index fossils are keys to matching sedimentary strata in widely separated outcrops (from The Changing Earth - Introduction to Geology (2nd ed.), by Mears, Jr., D. Van Nostrand Co., 1977).
  
  
  

• Extrusive igneous rocks

  
  
  Figure 29.5 Lava lake in Surtsey crater (Iceland).
  
  
  
  
  Figure 29.6 Home and car destroyed by lava near Hawaiian village of Kapolo (6 Mar., 1965).
  
  
  
  
  Figure 29.7 Cast of a dog produced by the nuées ardente of the 79 AD erruption of Mt. Vesuvuis.
  
  
  

• Low grade metamorphics

  
  
  Figure 29.8 Highly contorted gneiss.
  
  
  

• Sedimentary rocks

  
  
  Figure 29.9 Bronsweiler River near Clam Lake, WI.
  
  
  
  
  Figure 29.10 Toe of Athabuska Glacier (cars for scale) between Banff and Jasper Parks, Alberta, CN.
  
  
  
  
  Figure 29.11 Sedimentary laminations in Precambrian slates near Wausau, WI.
  
  
  

• Ancient Greeks recognized fossils as remains of past life.

• In the Middle Ages, fossils were the work of the Devil to produce living forms in rock.

• In 15th century, Leonardo da Vinci recognized fossils as the remains of organisms.

• A total of perhaps 500 million species may have lived since life began.

• Ca. 200,000 fossil species are recognized with new fossils still being discovered.

• Most of the 1.4 million species estimated to have lived in the recent past were invertebrates (95%) including insects (75%).

Figure 29.12 Fossils and some types of preservation (from The Changing Earth - Introduction to Geology (2nd ed.), by Mears, Jr., D. Van Nostrand Co., 1977).

1. Direct preservation of remains
   • bogs, oil seeps, tar pits, frozen ground

     
     
     Figure 29.13 Bronsweiler River near Clam Lake, WI.
     
     
     
     
     Figure 29.14 Tollund (DK) man buried in a peat bog for over 2,000 years. He had been executed by strangling with a noose for either a crime or sacrifice.
     
     
     
     
     Figure 29.15 Fly reserved in amber for over 3 million years.
     
     
     

   • desiccation

     
     
     Figure 29.16 Inca Snow Boy - freeze dried remains of an Inca boy (ca. 6 years old) who had been buried alive in an Andean cave as a sacrifice over 500 years ago.
     
     
     

2. Carbonization
   • conversion to coal

   • carbon film impressions

     
     
     Figure 29.17 A leaf (left) and an insect (right) preserved as a carbonaceous film (from General Geology (5th ed.), by Foster, Merrill Publishing Co., 1988).
     
     
     

3. Petrification
   • replacement & perimineralization

   • calcite, silica, pyrite, dolomite, hematite, galena, fluorite, etc.

     
     
     Figure 29.18 Petrified tree near Mammoth Hot Springs, Yellowstone Nat'l Monument, WY. Example of perimineralization with silica filling voids.
     
     
     
     
     Figure 29.19 Petrified tree showing woody texture near Mammoth Hot Springs, Yellowstone Nat'l Monument, WY.
     
     
     
     
     Figure 29.20 Tree trunks with deformed sandstone over compacted Penn. shale along the turnpike, WV.
     
     
     

4. Molds and casts

   
   
   Figure 29.21 Mold of a lower Cambrian trilobite.
   
   
   
   
   Figure 29.22 Cast of a Pompeii citizen killed by the nuées ardentes from the 79 AD erruption of Mt. Vesuvius.
   
   
   

5. Tracks and burrows

6. Coprolites

7. Gastroliths