The link doesn't work, try this one:
And tell me what do you think?
When talking about what has wiped out the dinosaurs, it appears it has been an asteroid impact combined with the eruption of Deccan traps, but the major question really is, how did dinosaur species survive volcanic eruptions from 250 million years ago to 65.5 million years ago-that is the real mystery, here is what tortures me:
Check out years of volcanic explosions, and Ma means "million years ago".
Ok, my question is how did dinosaur species survive that long, it doesn't make any sense to me.
Take a special look at years and quantities of eruptions of Large igneous provinces and explosive eruptions.
Take also a look at Ontong Java Plateau, Kerguelen Plateau, take all the years between 250 million years ago and 65.5 million years ago and tell me how did dinosaur specis survive that long???
Can anyone help me?
I really don't know anymore, when you look all of these volcanic eruptions, each and all of them should have killed the dinosaurs, I don't understand why these volcanic eruptions (with several exceptions) couldn't kill the dinosaurs.
It just doesn't make any sense.
That question has been debated for quite some time. All we have is age of rock and the fossil bearing strata that coincides with those ages. We have two great extinction events, Permian-Triassic (P-Tr) extinction event, the largest extinction of life in Earth's history, then the KT line that marked the end of dinosaur era. Both these periods are being attributed to large volcanic eruptions. ( Siberian trapps / Deccen Trapps)
But some research has found within the sediment layers/lava and repetitive layers, both bone fossil and eggs right up to the KT boundary, showing that dinosaurs lived and reproduced during the time prior to the massive ( and final) eruption of the deccens. And considering this volcanic area had been active for millions of years before the KT, it would suggest that not every surface area on earth was effected...given the continent configuration at the time.
Granted its all theory, but we have accepted the current dating system and fossil strata time lines, which clearly shows dinosaurs surviving during other volcanic periods.
I found the answer:
The reason why Siberian traps are truly responsible from mass extinction between 251-249 million years ago is next and what makes it different than Deccan traps eruptions during 30 000 years is next:
The immeadiate area would be affected by such things as lava and pyrocastic flows but how does this affect the other side of the world? The real power of the Siberian Traps was the climate altering potential by the emission of ash and gases. The Siberian Traps is recognized as having a large proportion of pyroclastic deposits relative to other flood basalts (including Deccan traps). This proves an explosive nature with much ash and gases being pumped into the atmosphere. All of this ash and gas has two main effects that, even though they are opposite to each other, act on differing timescales.
Initially sulfur aerosols and volcanic ash envelop the earths atmosphere blocking out sunlight and sending surface temperatures plunging . Ash and sulphur aerosols can remain in the upper atmosphere for 100's to 1000's of years which would be enough to cause a significant glaciation. At the end of the Permian period the biggest ever drop in sea level in history occurred. Two scientists named Holser and Magaritz in 1987 proposed that such a marine regression could be caused by a large scale glaciation.
The second major effect is the emission of greenhouse gases such as CO2, methane and also water vapour. Green house gases warm the climate by allowing sunlight to pass through, heat reflected by the Earth itself cannot penetrate the atmosphere so is retained. Greenhouse gases stay in the atmosphere much longer so their climate changing effects can last for millions of years.
The Siberian Traps have erupted via numerous vents over a period of roughly a million years or more, east and south of Norilsk in Siberia. Individual eruptions of basalt lavas could have exceeded 2000 km3 or even more. The giant Norilsk-Talnakh nickel–copper–palladium deposit formed within the magma conduits in the main part of the Siberian Traps. The presence of extensive tuff and pyroclastic deposits suggests that a number of large explosive eruptions occurred during or before the eruptions of basaltic lavas. The presence of silicic volcanic rocks such as rhyolite is also a proof of explosive eruptions.
Of course, it is known what kind of material was erupted from volcanoes, plus their effects on the planet's climate. Some of them have been observed (Mount Helen's eruptions, Mount Pinatubo, Krakatau, Tambora) so can get a very nice picture what an volcanic eruption can do to Earth's local and global climate.
That's more than enough rock-solid, irrefutable proof.
Last edited by Fut004; Oct 3rd, 2011 at 9:02 AM.
However, volcanic eruptions alone could not create mass extinctions, but combine them with asteroid/comet impacts and you'll get mass extinction, this is the one who fell on Antarctica 250 million years ago, 50 km wide and left nearly 500 km (482 km in diameter, to be precise) wide crater:
Plus, there is general consensus that asteroid did wipe out the dinosaurs 65.5 million years ago:
There are currently 1 users browsing this thread. (0 members and 1 guests)