The earth changes as time goes by: mountains are uplifted and eroded away, continents move, the magnetic poles move, volcanoes erupt and are eroded.
All of geology is consistent with standard processes applying over the standard geological time scale lasting some 4.6 billion years: there are no exceptions.
One explanation of the earth is based on uniformitarianism. One explanation of the earth is based on catastrophism: neither is a perfect fit to the facts.
Land forms have been shaped by factors such as weathering and erosion that we can see operating today: this is the principle called uniformitarianism.
One aspect of geological history is geomorphology, which studies the way in which geological forces that we see today have shaped the major landforms.
Uplift of rocks is followed by erosion, but equally, erosion is followed by isostatic uplift, since the crust of the planet floats on the mantle.
Erosion changes the surface of the planet, by wearing down hills and mountains, and by cutting new valleys, both with ice and with water carrying sediment away.
A gap in the geological record may be an unconformity, where one set of beds has been tilted, folded and eroded, before being overlain by later sediments.
A gap in the geological record may be represented by a disconformity, where the beds above and below a gap are in alignment, bet deposition stopped for a while.
Landforms may be determined by the underlying rocks, since more resistant beds will tend to remain, forming ridges that must be bypassed by rivers and glaciers.
The formation history of a sedimentary rock aeolian or alluvial deposits as may often be found in the rock, either in structures, or in the fossils
Wind erosion causes dust storms and sandhills, and given the right winds, has even been known to move fine sediments from one continent to another.
Ice or glacial erosion creates unusual landforms such as moraines, which allow us later to recognize the influence of ice in shaping the landscape.
Glacial valleys have a different shape from those cut by water erosion, because the grinding action of the valley-filling flowing ice makes a U-shaped valley.
The ratios of stable isotopes in fossils provide good evidence of past climates because they generally give an indication of past temperatures.
Tree rings provide good evidence of past climates, because the tree rings formed in good years are thicker. This is called dendroclimatology.
We can obtain evidence of past climates from fossil data of many sorts, anything which varied with the conditions such as temperature at the time.
We can gain evidence about past climates from palynology, the study of pollen grains, because the grains are distinctive to a particular species.