what type of rock is old harry made from
Old Harry Rocks The chalk of Old Harry Rocks used to be part of a long stretch of chalk between Purbeck and the Isle of Wight, but remained as a headland after large parts of this seam were eroded away. As the headland suffered hydraulic action (a process in which air and water are forced into small cracks by the force of the sea, resulting in enlarging cracks), first caves, then arches formed. The tops of the arches collapsed after being weakened by rainfall and wind, leaving disconnected stacks. One of these stacks is known as Old Harry. Old Harry's Wife was another stack which was eroded through corrosion and abrasion, until the bottom was so weak the top fell away, leaving a stump. Hydraulic action is the main cause of erosion (sheer force of the wave) that damaged the rock and caused it to fall away.
History of technology Human ancestors have been using stone and other tools since long before the emergence of Homo sapiens approximately 200,000 years ago.[3] The earliest methods of stone tool making, known as the Oldowan "industry", date back to at least 2.3 million years ago,[4] with the earliest direct evidence of tool usage found in Ethiopia within the Great Rift Valley, dating back to 2.5 million years ago.[5] This era of stone tool use is called the Paleolithic, or "Old stone age", and spans all of human history up to the development of agriculture approximately 12,000 years ago.