1. What is the most logical past environment to have produced a deposit consisting of very little sand and mud, but instead lots of broken-up carbonate shells of marine organisms? 

1.delta 
2.sand dunes 
3.shallow-water carbonate area 
4.small-lake environment 
5.glacial valley

2. The structure that may form where a stream enters a lake: 

1. is called a delta. 
2.has nearly horizontal topset beds composed of gravel. 
3.has sloping forset beds of gravel and sand. 
4.has nearly horizontal silty bottomset beds on the lake floor. 
5.all of the above are true statements.

3. Which of the following sedimentary features is the surest indicator that the past environment there was subaerial (under air), not submarine (underwater)? 

1.turbidites 
2.mud cracks 
3.scour marks 
4.fossil marine clam shell imprints 
5.They are all indicators of a subaerial land surface. 

4. Sedimentary rocks form only at or near Earth's surface, never at great depths. 

1.True 
2.False