Monolith vs Monocline
A monolith is a geological feature consisting of a single massive stone or rock.
A monocline is a step-like fold in rock strata consisting of a zone of steeper dip within an otherwise horizontal or gently-dipping sequence.
Mount Augustus is an inselberg or monadnock which is an isolated hill or small mountain that rises abruptly from a surrounding plain (literally ‘island mountain’). Geologically, it is an asymmetrical anticline. Uluru, however, is a monolith – mono (‘one’ or ‘single’) and lithos (‘stone’).
Mount Augustus is 2.5 times larger than Uluru (Ayers Rock), the world’s largest monolith.
Mount Augustus is often referred to as both a monolith and (or) a monocline. However, because Mount Augustus is composed of multiple rock types it is inaccurate to call it a monolith – meaning one rock type – or claim that it is the ‘world’s biggest rock’. Likewise, describing it as a monocline, meaning a one-sided slope connecting two horizontal or gently inclined strata (layers) is also inaccurate.
References:
https://parks.dpaw.wa.gov.au/park/mount-augustus
http://www.australiasomuchtosee.com/monoliths.htm