Terms & Definitions written November 16th, 2005 for article: Effects of Volcanism: K/T Boundary

K/T Boundary

The K/T boundary marks the end of the Cretaceous and beginning of the Tertiary period.The mechanism of dinosaur extinction has long been debated between comet impact and excessive volcanism.

Greenhouse Effect

As volcanic activity through the cretaceous period, continuous eruptions had various effects upon the Earth’s atmosphere and climate.

The mechanism for extinction by excessive volcanism is built upon evidence of Carbon DiOxide, and other greenhouse gasses which rendered the Earth uninhabitable.

Traps

Hot Spots – a place in the Eath’s mantle which is unusually congested with lava. This is called a mantle plume.

Mantule Plumes – columns of bouffant molted rock material that rises through the lithosphere plates and erupts usually as basalt lavas.

Basalt lava – lava that covers a vast area of land.

Deccan Traps (India)

• Extremely active – still today on Reunion Island the volcano Piton deFournaise erupts between 100 and 300 times a year
• The lava left as black rock from 65 million years ago still covers over 500,000 square kilometers
• Estimated that at one point it covered over 203 million cubic kilometers – enough to release enough carbon dioxide to trigger a greenhouse effect

India’s “Smoking Gun”

1.  August 9th, 2005 American Geological Society released an articled called “India’s Smoking Gun: Dino Killing Eruptions” –
2. Hypothesis is that the majority of eruptions happened within 30,000 years
3. Sudden a 6,500-ft lava flow and gathered together other known dates from all over the traps
4. Used radiometric dating (looking at magnetic fields in the rocks)
5. Found a layer of iridium sandwiched between the lava. The iridium presumably came from the comet, which shows that the volcanism started before impact and continued after

Emissions from the Deccan Trap

The Deccan Traps are estimated to have alone produced:

• 33 trillion tons of Carbon Dioxide
• 6.6 trillion tons of sulfur66 billion tons of chlorine and fluorine molecules

The eruptions were so large scale that single Deccan Trap eruption caused an initial cooling of 5-9 degree (F) decline in atmospheric temperature.

Other Effects of Volcanism

Volcanism also caused:

• Acid Rain
• Acidic Layers of water on the surface of oceans
• Long-Term Effects of Volcanism

Long-term CO2 emissions caused CO2 levels to rise to 8 times of that found in today’s atmosphere. Global Temperature was increased by 9 degrees (F).

Effects of CO2 on Dinosaurs

It has been proven that below a certain atmospheric temperature, dinosaur eggs are born female, and above a certain temperature males are born.

Past Volcanic Extinctions

• 10 past events of extinction related to volcanism:
  Siberian – 250 millions years ago
  90%-95% marine species extinction
• 201 MYA – Triassic/Jurassic extinction

WORKS CITED

• Volcanoes & Climate
• Carbon dioxide emissions from Deccan volcanism and a K/T boundary greenhouse effect
• What Killed the Dinosaurs?

Terms & Definitions provided for article Excessive Volcanism: K/T Boundary via EarthToLove.org

OUTLINE – written November 13^th, 2005

Excessive Volcanism: K/T Boundary (outline)

Outline provided for article here: Excessive Volcanism: K/T Boundary