1- Answer: The geological processes that shape Earth's features today
are basically the same as they were in the geologic past.
Explanation: We know that there are many geological processes that shape up or alter the surface of Earth. Some of these processes include Erosion, Weathering, Plate tectonics and Volcanic eruptions etc. These process are static, they were the same in the past thus giving us this Earth we see now with relatively different features and these processes will further bring changes to Earth's features. The processes remain the same only their intensity differs.
2- Answer: James Hutton proposed the principle of
Uniformitarianism
James Hutton.
Explanation: James Hutton was a renowned geologist, he gave the concept of
Uniformitarianism. This concept links with the answer of first part of your question, the only difference is that this theory talks about changes that occurs within the Earth crust, whereas the answer of first part discussed the visible Earth features. This theory states that the changes in earth crust occurs due to some static and ongoing geological processes, which we discussed earlier. Earth's features which we can see along with those which occurs within the Earth crust are both the consequence of geological processes which gradually bring changes.
3- Answer: According to the principle of cross-cutting relationships, an intrusive rock body is younger than the rocks into which it intrudes.
Explanation: To understand this answer you need to know what cross-cutting relationship of rocks is. Lets take an example of the volcano surrounded with volcanic rocks. Whenever, Magma from volcanoes flows down, they intrudes into the spaces or cracks present between the already existing rocks. After some time, when this magma cools down it becomes a rock, but this rock remains within those already existing rocks. This also explains that the newly made rocks within the already existing rocks are younger than the later. This is what we call a cross-cutting relationship.
