Re: How do Geological Overthrusts figure into Evolution?

Dear James,

Your question seems to ask about two different areas of the Earth 
Sciences:  the dating of rocks and the Earth, and mountain building.  I 
will answer each part in turn.

We can provide absolute dates to rocks and events in Earth history using 
radioactive isotopes that occur naturally in igneous rocks.  Using this 
technique the oldest rocks so far found on Earth, which are found in 
Canada and western Australia, have been dated at between 4.0 and 4.1 
billion years old.  The Earth itself is confidently dated to about 4.55 
billion years old, based on dates obtained from carbonaceous chondrites, a 
type of meteorite thought to be left-over, primitive material from the 
birth of the solar system.  Most events in Earth history have been dated 
using radioactive isotopes, and the techniques are being refined 
constantly so that our dating of all geological events is becoming more 
and more accurate.  There has been ample time for the evolution of life 
into the millions of species on the Earth today to take place, and for all 
of the great geological events in Earth history, such as the building and 
destruction by erosion of mountain belts, to occur.

Mountain chains are constructed by immensely powerful compressional forces 
that can squeeze and thicken the Earth’s crust.  In the process 
sedimentary rocks are often folded and whole slices of the crust can be 
thrust up and over adjacent areas of the crust.  Overthrusting takes place 
along a type of fault called a low-angle thrust.  Sometimes thrusting 
results in older rocks lying on top of younger rocks; a good example is in 
the eastern Canadian Rockies, where marine rocks of Palaeozoic and even 
Proterozoic (PreCambrian) age have been thrust over the top of much 
younger Mesozoic sedimentary rocks.  Ultimately the engine that drives 
mountain building is the movement of the great plates of the Earth’s 
crust, driven by processes arising deep in the Earth’s mantle.  The 
continents ride on the plates, and as the plates have moved they have 
often brought continents into collision with each other; the collision of 
continents is the source of the compressional forces that form mountain 
chains.  This process is still happening in many parts of the world:  the 
Himalayan Mountains, for example, started to form about 55 million years 
ago when the Indian subcontinent began to collide with southern Asia, and 
the Himalayas are still rising today.

The processes involved in mountain building, including the development of 
thrust faults, has been and continues to be studied intensely by 
geologists, so that our understanding of them is improving all the time.  
Neither the immensity of geological time nor geological processes such as 
mountain building nor the reality of biological evolution are considered 
to be far-fetched by scientists because the evidence amassed by 
generations of geologists and natural scientists supports the truth of 
these ideas.