ex1317 {Sleuth2} | R Documentation |
Dinosaur Extinctions—An Observational Study
Description
About 65 million years ago, the dinosaurs suffered a mass extinction virtually overnight (in geologic time). Among many clues, one that all scientists regard as crucial is a layer of iridium-rich dust that was deposited over much of the earth at that time. The theory is that an event like a volcanic eruption or meteor impact caused a massive dust cloud that blanketed the earth for years killing off animals and their food sources. Dataset has Iridium depths by type of deposit.
Usage
ex1317
Format
A data frame with 28 observations on the following 3 variables.
Iridium
Iridium in samples (ppt)
Strata
a factor with levels
"Limestone"
and"Shale"
Depth
a factor with six levels:
"1"
,"2"
, ...,"6"
Source
Ramsey, F.L. and Schafer, D.W. (2002). The Statistical Sleuth: A Course in Methods of Data Analysis (2nd ed), Duxbury.
References
Alvarez, W. and Asaro, F. (1990). What Caused the Mass Extinction? An Extraterrestrial Impact, Scientific American 263(4): 76–84.
Courtillot, E. (1990). What Caused the Mass Extinction? A Volcanic Eruption. Scientific American 263(4): 85–92.
Examples
str(ex1317)