With all this upheaval of drifting continental plates bumping into each other and tearing apart, there were dramatic effects at the boundaries. Where continental plates are bumping into each other, one tends to rise over the other to create huge mountain ranges along their edges as deep rock is forced to the surface. Some mountains are extremely old, having been created during the early stages of the Earth’s evolution.  An example is the Caledonide granite range passing through Scandinavia, Scotland and Ireland that is 3 billion years old, created when this region was a separate land mass. A more recent example is the Himalayas, some 40 million years old, between the plates containing India and Asia that is still rising at 5mm per year. Along the edges of these continental plates, either those separating or bumping into each other, volcanoes occur that also throw deep rock onto the surface.

The plate containing Africa had been drifting north and was quite late on the scene. Sixty million years ago there were no Alps, Carpathians or Pyrenees. These were created as the Africa plate met the European plate creating the Tethys Sea (later the Mediterranean Sea) and the still-growing mountain ranges to its north. One remarkable result of this collision was the formation of natural dams across the gap between Morocco and Gibraltar (presently 14km apart) – perhaps on ten occasions over millions of years. This resulted in the cessation of the flow of water from the Atlantic into the Mediterranean so that evaporation caused its level to fall until after about 1,000 years it practically dried out. Rivers such as the Rhone would have appeared as the Grand Canyon does today, as they cut deep into the rock to reach the shoreline. Further movements would cause the dams to collapse, causing enormous waterfalls that would take 100 years to re-fill the Mediterranean. The continental plates are still drifting a few centimetres a year, and are still building mountains and causing volcanic activity and earthquakes.

Because of all this continental plate activity, volcanoes and much surface sinking due to fractures in the Earth’s crust, instead of having neat layers of different rock (sandstone and limestone), coal and salt, they have been buckled and broken, buried and pushed to the surface over millions of years to the positions we see them today. Also rain dissolves soluble rocks such as limestone, creating caves, and wind erosion shapes rock formations.

The changes in the Earth’s climate have had a huge impact on the evolution of man. The mechanisms that produce the major climate changes are 1. the ovality of the Earth’s orbit round the sun; 2. the tilt of the Earth’s axis of rotation; and 3. the time of the year when the earth is nearest the sun. These have cycles of 95,000, 42,000 and 21,000 years, respectively. If all these factors are in the same direction, the Earth’s climate swings to an extreme of glacial (cold) or interglacial (warm) condition. At present we are in an ice age that began 40 million years ago. During the past 700,000 years the ovality cycle has been predominant, giving a major glaciation approximately once every 100,000 years, and today we are in one of the warm interglacials.

Ice Age Temperature Cycles – source Wikipedia

Another factor which could affect ice ages is the absorption of CO2, together with changes in wind patterns, by newly created mountain ranges, as there is some evidence that ties an ice age to the creation of the Appalachian Mountains 450 million years ago, and our present ice age to the creation of the Himalayan Mountains 40 million years ago.