Friday, December 03, 2010

Do you believe in Chicxulub?

Dinosaurs went extinct 65 million years ago after an asteroid hit Chicxulub, Mexico, near Cancun. My 12-year old son said that's what they learned in their secular textbook at Christian school today.

Dr. Donald DeYoung, a Creationist Geologists, debunks the whole theory of the big bad asteroid that caused dinosaurs to die out.

Selections from Chicxulub and the Demise of the Dinosaurs, by Donald B. DeYoung, PhD.

(This excerpt by Marko is from the article published in Impact #334, Institute for Creation Research, April 2001, http://www.icr.org/article/453/).

There have been nearly one hundred different dinosaur extinction theories offered in recent decades. These range from poisonous plants to mass suicide by dinosaur herds. One particular extinction theory has gained wide acceptance since the 1980s. It involves a major earth impact by an asteroid or comet. This catastrophe is thought to have extinguished up to two-thirds of all animal and plant species living at the time.

Around 1990, a particular formation of faulted rocks received major attention, located at the northern end of Mexico's Yucatan peninsula. The geologic formation is called Chicxulub (pronounced CHEEK-shoe-lube) after a nearby village. The roughly circular feature is 100-200 miles in diameter. It is buried a kilometer below ground, about half on land and half below the sea floor.

Scientific support for the dinosaur-collision hypothesis is not unanimous.
 
First, why did the alleged impact kill off the dinosaurs while many other forms of life remained healthy? Some of the least mobile creatures (tortoises, snakes, crocodiles) and also the most sensitive to climatic change (birds, fish) are still with us today. Some shallow marine bottom-dwelling invertebrates survived, while others became extinct. Plants also survived the cataclysm in great abundance.
 
Second, the fossil record does not show an instantaneous demise of the dinosaurs. Some dinosaurs died out within the Cretaceous period while others apparently survived well into the Tertiary period, millions of years later in evolutionary thinking (Rigby, et al., 1987; Sloan, et al., 1986).
 
Third, it is not certain that Chicxulub is an actual impact site. Practically all the data in support of a collision have alternative explanations. For example, the iridium concentration in the K-T layer could have resulted from volcanic processes. Igneous material includes traces of iridium, especially when derived from the deep mantle (Gunter, 1986). A large region in western India (called the Deccan Traps) experienced massive volcanism at a similar relative time in history. Some experts attribute dinosaur death to climatic events related to this massive outpouring of lava in India.
 
Several dramatic movies have portrayed deadly asteroids or comets pummeling the earth and endangering humanity itself in the years to come. The creation view is far more optimistic about the future, realizing that there is a definite future plan for mankind. We are not the result of chance, nor do we, or the earth's animal and plant life, face imminent extermination from a random space collision.
 
References (selected)
 
Gunter, F. 1986. Principles of Isotope Geology. John Wiley and Sons. New York.
 
Rigby, J. K., K. R. Newman, J. Smit, S. Vander Kaars, R. E. Sloan and J. K. Rigby. 1987. Dinosaurs from the Paleocene Part of the Hell Creek Formation, McCone County, Montana. Palaios 2: 296-302.
 
Sloan, R. E., J. K. Rigby, Jr., L. Van Valen and D. Gabriel. 1986. Gradual Dinosaur Extinction and Simultaneous Ungulate Radiation in the Hell Creek Formation. Science 232: 629-633.