* Astronomy

Members Login
Username 
 
Password 
    Remember Me  
Home -> Astronomy News -> Meteorite News -> Chicxulub event
Post Info TOPIC: Chicxulub event
Blobrana


L

Posts: 131433
Date:
K-T boundary
Permalink  
 

Zumaia (Spanish: Zumaya) is a small town in the north of Spain in the Basque Country.
The town has two beaches (Itzurun and Santiago), which are of interest to geologists because they are situated among the longest set of continuous rock strata in the world. Known locally as the "flysh" they date from the mid-cretaceous period to the present, a time period of over 100 million years. The K-T boundary is present at the Itzurun beach, and fossils can be found, notably of ammonites.
Source

__________________
Blobrana


L

Posts: 131433
Date:
RE: Chicxulub event
Permalink  
 

Title: Re-igniting the Cretaceous-Palaeogene firestorm debate
Authors: Claire M. Belcher

Nearly 30 yr since Alvarez et al. (1980) detected an enrichment of iridium at the Cretaceous-Palaeogene (K-Pg) boundary (65 Ma), the events that lead to the demise of the dinosaurs have become a feature of considerable scientific and public debate. It is generally accepted that an extraterrestrial body collided with the Earth 65 m.y. ago and that the 200-km-wide Chicxulub Crater on the Yucatan Peninsula, Mexico, is the mark of this impact (Hildebrand et al., 1991). This impact blasted melted asteroidal and target rock debris across the planet, depositing the K-Pg boundary impact rock layers. The environmental consequences of the impact, and particularly the amount of thermal radiation it delivered, remain the hottest topic of the K-Pg debate.

Read more (136kb, PDF)

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

The asteroid impact that ended the age of dinosaurs 65 million years ago didn't incinerate life on our planet's surface - it just broiled it, a new study suggests. The work resolves nagging questions about a theory that the impact triggered deadly wildfires around the world, but it also raises new questions about just what led to the mass extinction at the end of the Cretaceous period.
Read more

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

In the hills behind the historic homestead in Waipara, north Canterbury, about 45 minutes drive north of Christchurch in the South Island, are limestone canyons and riverbeds yielding precious remnants of that catastrophic event when New Zealand was still under the ocean.
The Waipara riverbed is rich in the element iridium, also found mainly in Denmark and Italy. Iridium is rare on earth but abundant in meteorites.
Scattered across the Waipara property are massive rounded rocks, weighing over a tonne each, which Goord calls God's marbles.
Read more

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

The asteroid impact that many researchers claim was the cause of the dinosaur die-off was bad news for marine life at the time as well. But new research shows that microalgae - one of the primary producers in the ocean - bounced back from the global extinction in about 100 years or less.

Read more

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

Mass Extinction Event Spared Europe (Mostly)
When a comet crashed into the Yucatan Peninsula 65 million years ago, all hell broke loose. Scientists have guessed at the scene: a world enshrouded in ashen darkness leftover from the cosmic impact that left almost nothing -- including the dinosaurs -- standing.
But a new study shows that in western Europe at least, the effects were far less terrifying.
Fossil leaves from four million years after the impact show that plants and insects had made a full recovery.

Read more

__________________
Blobrana


L

Posts: 131433
Date:
Chicxulub crater
Permalink  
 

What do dinosaurs and the Maya have in common?
One of the world's most famous asteroid craters, the Chicxulub crater, has been the subject of research for about twenty years. The asteroid impact that formed it probably put an end to the dinosaurs and helped mammals to flourish. Together with an Anglo-American team, an ETH Zurich researcher has studied the most recent deposits that filled the crater. The results provide accurate dating of the limestones and a valuable basis for archaeologists to research the Maya.

Read more

__________________
Blobrana


L

Posts: 131433
Date:
RE: Chicxulub event
Permalink  
 

Title: Geological and archaeological implications of strontium isotope analysis of exposed bedrock in the Chicxulub crater basin, northwestern Yucatán, Mexico
Authors: Adrian Gilli, David A. Hodell, George D. Kamenov and Mark Brenner

The surface geology of the site of the Chicxulub impact crater in northwestern Yucatán, Mexico, has not been studied extensively since the discovery of the crater almost two decades ago. Strontium isotope (87Sr/86Sr) measurements in carbonate rock outcrops reveal near-uniform strontium signatures of 0.70905 inside the ring of cenotes (water-filled sinkholes), which represents the rim of the crater basin. Measured strontium isotope ratios were used to infer rock ages, employing the marine Sr isotope curve. We estimate the age of the exposed limestone within the Chicxulub crater basin to be late Miocene to early Pliocene, representing the age of the youngest sediment fill. Discovery of a large terrain of near-uniform strontium isotope ratios in northwestern Yucatán offers new geoarchaeological opportunities to track ancient Maya migration and determine sources of manufactured goods. Our results have implications for applying the Sr isotope method to Maya archaeological sites, such as Mayapán, the last Maya capital, and Chichén Itzá.

Source

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

A burst of carbon monoxide triggered by an asteroid impact may have been a key factor in the mass extinction which saw off the dinosaurs 65 million years ago.
The claim comes from Japanese scientists who have simulated the impact that created the massive crater at Chicxulub on Mexico's Yucatán Peninsula.

Read more

__________________
Blobrana


L

Posts: 131433
Date:
Permalink  
 

A Princeton University geoscientist who has stirred controversy with her studies challenging a popular theory that an asteroid wiped out the dinosaurs has compiled powerful new evidence asserting her position.
Gerta Keller, whose studies of rock formations at many sites in the United States, Mexico and India have led her to conclude that volcanoes, not a vast meteorite, were the more likely culprits in the demise of the Earth's giant reptiles, is producing new data supporting her claim.

Read more

__________________
«First  <  1 2 3 4 5 … 7  >  Last»  | Page of 7  sorted by
Quick Reply

Please log in to post quick replies.
Home -> Astronomy News -> Meteorite News -> Chicxulub event


Create your own FREE Forum
Report Abuse 		Powered by ActiveBoard