Sports FAQ
Home / Racing

Continental drift time

8 without a trace a trace2010-01-25 09:01:51 +0000 #1
continental drift is the number of years ago
412,296,1082010-01-25 09:12:42 +0000 #2
the idea of continental drift as early as the beginning of the 19th century appeared, initially put forward to explain the apparent correspondence across the Atlantic. Until 1915, German meteorologist Alfred Wegener (Alfred Wegener) "the mainland and the ocean form a" come out before the shock caused by the geological community. In this monumental work, the Wigner fit the mainland shape according to the ancient climatology, paleontology, geology, ancient polar migration is substantial evidence, made the Earth's surface there is a pan-Mesozoic continent (Pangea), the super - Antarctica was divided, after 200 million years of drift, the formation of today's oceans and land.

Because at that time by the right internal structure and dynamics of Earth's knowledge of the limitations of the mechanism and dynamics of continental drift is not of physics support. Wigner theory of misfortune is that he advocated the same time that the continental drift of the ocean at the end of stability. Until his death 20 years later, to abandon the ocean floor stability does not move the sea-floor spreading theory suggested that people's interest in continental drift has also re-meng.

Early map of the world have clearly shown that the coast of Africa and South America, the relative "jagged fit." Far in 1801, Humboldt (A. Humboldt) and his contemporaries of the famous scientists have proposed that both sides of the Atlantic coastline and rocks are very similar. Wegener first proposed, it should be with the deep edge of the continental slope continental fit. Carey (SWCarey) proved that the shape of the two continents in the sea below 2000 meters isobath is almost entirely fitting. Brad (E. Bullard), and others rely on computer calculations and found that both of 1000 meters or 2000 meters isobath little difference between the results of fitting. Recovery fitting work proved that the continent can be restored to form a super-continent, namely, Wigner named by "pan-continent." Pan-China is a Gondwana (southern continents plus India) and Laurasia (North America and Europe and Asia) a composite of ancient China.

Wegener first proposed continental drift point of view, a lot of evidence from his studies of ancient climate. He noted that the existence of a major land-based geological rock types were formed during the under modern conditions in the area should not occur: If the distribution in the polar regions are ancient coral reefs and tropical plant fossils; and in the equatorial regions of ancient ice found . The use of the ancient principles of this theory, Wigner to the center of activities on the glacier was very near the rotation, while the distribution of coral reefs and evaporite zone placed near the equator, determined in this way the ancient latitude on all continents at that time. Latitudes of the ancient and modern latitude comparison, Wegener arrived at the conclusions of continental drift.

Wegener believed that continental drift separated the modern from the major land-based marine fauna and flora significant similarity provides the best explanation. To Wigner and later investigators have obtained a number of impressive examples: South America and Africa can be seen with similar bone structure salamander freshwater reptiles in Long (Mesosaurus), it can not swim across the ocean; sides of the Atlantic Paleozoic marine invertebrate fossil assemblage is very similar; Antarctica, there are many terrestrial Triassic reptile fossils also exists in other continents; Permian Tongue Fern Group (a unique combination of plants) in seed fern fossils, found in the southern continents and India. Palaeontological evidence that has caused controversy over anyone's guess, Dietz (RSDietz) in 1967 on the argument that people made a comment on the evidence, including Holden (JCHolden) made a number of interesting map group.

Today, these arguments have a historical relic, from here we can see that the old framework of the collection of new facts in vain, the old theory to explain the fact that often lead to absurd.

South America, Africa, India and Australia, similar to the stratum 22, so that Wigner obtained a deep impression on him. Sides of the Atlantic geological phenomenon common to the mainland once more prove that two are linked.

2 in the North Atlantic on both sides of the mainland, there is a very significant ancient mountains, known as the Caledonian Mountains. Today, the east coast of Norway in the Atlantic Ocean to see the mountains of the western part, this mountain would seem that after adoption of the Irish under submerged in the Atlantic Ocean. However, in Newfoundland, Canada, there seems to an ancient mountain to climb from the Atlantic years ago, it and the Caledonian mountain range in Europe have much in common. The mountain ranges in North America occurs is called the old Appalachian Mountains. Wigner that the Appalachian Mountains in North America and Europe, once connected to the Caledonian Mountains. If you put together the mainland together to form a continuous mountain.

Rocks containing magnetic minerals in the Earth's magnetic field under the influence of the rock formation to be magnetized and thus preserve the shape of their time and place of the ancient Earth's magnetic field direction in magnetic recording. Recorded by the ancient rock tendencies and inclination of the magnetic field measurements, we can calculate the rock formation the location of the Earth's magnetic poles.

People from every continent where the strata of different ages measured by thousands of ancient pole position, to connect either a continent at different times of the ancient magnetic pole of the line, is that the mainland's apparent polar wander paths. Will all continents APWP comparison, the adjusted results showed that 2 billion years ago all the continents had been a co-continent - Pangea.

Wigner eventually died because the search for evidence, and his body was only found in the following year.

Reply

Name:
Content:


Other posts in this category