Abrief, "first step" presentation of a work to be completed is called

I believe the answer is: Draft

Draft is a rough planning that we made before putting any specification on what we want to do for the presentation. In the draft, we would write the 'big picture' things that we wish to achieve without having to put a specified plan on how to achieve that 'big picture' goals.

explanation:

since the crust is readily accessible, scientists have been able to perform hands-on experiments to determine its composition; studies on the more distant mantle and core have limited opportunities samples. so scientists also rely on analyses of seismic waves and gravity and as well as magnetic studies.