Would you like to start a free subscription?
Remember me | Forgot password
For full content view: Log in Now!
Exactly when did that happen? Explorationists spend a lot of time correlating events. Over the last few decades, our ability to determine geological time frames has become much more refined, because we have better tools, such as the ion microprobe and the refinement of radionuclide parent-daughter relationships. Precision still requires two things to match up: the isotopic evidence (geochronology) and the depositional history and relative location of the sample (chronostratigraphy).
Most folks know that the end of the Cretaceous Period (K) and the beginning of the Tertiary Period, known as the K-T boundary, occurred about 66 million years ago, accompanied by the mass extinction of dinosaurs. The prevailing theory is that a massive asteroid slammed into the Gulf of Mexico, just offshore Yucatan, and triggered the extinction event. However, recent study of melted rock ejected far from the Chicxulub impact crater suggests that the impact was too early to have caused the mass extinction, about 300,000 years too early.
This area of the site is restricted.
In order to gain access, please either Log
In, or subscribe to World Oil.
Two options are available to you for creating an account.
1. Get a Free Trial Subscription to World Oil Magazine and gain immediate access to select content on World Oil Online.
Start a Free Trial Subscription and gain immediate access to the complete current issue of World Oil Magazine. Plus, you’ll receive 3 upcoming issues of World Oil Magazine in print or digital format.* You also receive access to the Energy Events Calendar, Industry Statistics and WO Wire’s news and industry coverage.
2. Purchase a subscription to World Oil magazine and gain immediate
and complete access to World Oil Online. As a Total Access subscriber
you will have access to all areas of the site available to registered users and
free subscribers as well as having access to such premium content areas as:
Physical copies of this content may be available for purchase. Visit the Reprints & Back Issues section.
If you are already a paid subscriber and do not have access, please email CustomerService@worldoil.com.
World Oil's specialized upstream Engineering Data Tables featuring the Drill Bit Classifier, Tubing Tables and more. Get Total Access today.
Houston, TX - November 4-5
The Woodlands, TX - November 17-17
Houston, TX - November 18-18
All material subject to strictly enforced copyright laws.
© 2014 World Oil. © 2014 Gulf Publishing Company.