Which is older, the dark dike, or the lighter sedimentary rocks?
How would you do on this test (taken from a chapter in Carlson, Plummer and Hammersly's excellent Physical Geology: Earth Revealed
1. “ Geological processes operating at present are the same processes that have operated in the past” is the principle of a. correlation b. catastrophism c. uniformitarianism d. none of the preceding
2. “ Within a sequence of undisturbed sedimentary rocks, the layers get younger going from bottom to top” is the principle of a. original horizontality b. superposition c. crosscutting d. none of the preceding
3. If rock A cuts across rock B, then rock A is rock B. a. younger than b. the same age as c. older than
4. Which is a method of correlation? a. physical continuity b. similarity of rock types c. fossils d. all of the preceding
5. Eras are subdivided into a. periods b. eons c. ages d. epochs
6. Periods are subdivided into a. eras b. epochs c. ages d. time zones
7. Which division of geologic time was the longest? a. Precambrian b. Paleozoic c. Mesozoic d. Cenozoic
8. Which is a useful radioactive decay scheme? a. 238U-206Pb b. 235U-207Pb c. 40K-40Ar d. 87Rb-87Sr e. all of the preceding
9. C-14 dating can be used on all of the following except a. wood b. shell c. the Dead Sea Scrolls d. granite e. bone
10. Concentrations of radon are highest in areas where the bedrock is a. granite b. gneiss c. limestone d. black shale e. phosphate-rich rock f. all of the preceding
11. Which is not a type of unconformity? a. disconformity b. angular unconformity c. nonconformity d. triconformity
12. A geologist could use the principle of inclusion to determine the relative age of a. fossils b. metamorphism c. shale layers d. xenoliths
13. The oldest abundant fossils of complex multicellular life with shells and other hard parts date from the a. Precambrian b. Paleozoic c. Mesozoic d. Cenozoic
14. A contact between parallel sedimentary rock that records missing geologic time is a. a disconformity b. an angular unconformity c. a nonconformity d. a sedimentary contact
If you have a degree in geology, these questions on earth history should give you no problem; they represent basic principles in the science. If you are a student in a basic geology class, they would be challenging, but with a bit of study, you should get most of them right. And if given as an open-book test with no time limit, they should be no problem at all...except if you are a student in my distance learning class. They barely break 50% most of the time. It isn't that they are bad students; they do fine on most of the other chapters. It mystifies me why they do badly on this one chapter, year after year, but I suspect the reason lies in the student's previous K-12 education.
Earth history and evolution have always been a required part of the primary and secondary curriculum, especially in California, but I get the feeling they don't get a strong emphasis in the classroom, perhaps out of fear of controversy from creationist parents, or due to the beliefs of the classroom teachers themselves. Because we end up not teaching our students why science accepts the evidence for an ancient Earth, students are left with statements like "scientists believe the Earth is millions of years old" as if it were a 50-50 choice. It's this idea of belief in scientific findings that has brought us to this dismal moment in our country's history when we can't mobilize to fight global warming because politicians and their followers choose to believe it isn't happening. Because people like Rush Limbaugh, Glen Beck and Senator Jim Inhofe are accepted as climate experts. They aren't; they are appallingly ignorant or devastatingly cynical (or both).
There was an interesting moment last weekend at our Wild Planet Day celebration, though. A father was showing his daughter our skeleton of the sabertooth cat. She wasn't much more than 7 years old, but he said to her, "is this creature millions of years old, or thousands?" I kind of sat back, waiting for the assumed explanation of how scientists are wrong and that the earth is only 6,000 years old. But, to my surprise, he said "the dinosaurs lived millions of years ago, but the mammals like this sabertooth lived thousands of years ago". A small but satisfying moment to be sure. And too rare these days.
If you haven't had a class in geology, don't feel bad if you don't know the answers. I've listed them in the comments.
What do you think about the earth science education our children are getting these days? Am I totally off base?