Final answer:
Compaction and cementation of 1.5 centimeter diameter particles would form a clastic sedimentary rock known as conglomerate. This process involves layering of sediments followed by compaction and cementation, where minerals precipitate and bind the grains together.
Step-by-step explanation:
The compaction and cementation of particles that are 1.5 centimeters in diameter would likely result in the formation of a type of clastic sedimentary rock known as conglomerate. The process begins with the weathering and erosion of pre-existing rocks that produce the sediment. These particles are then transported and eventually settle when the carrying medium (water, wind, or ice) slows down enough. Over time, layers of sediment build up and the weight of the overlying materials causes compaction that reduces the spaces between the sediment.
During compaction, the mineral-rich water within the sediment is squeezed out, precipitating minerals such as quartz, calcite, and occasionally pyrite in the pore spaces. This precipitate acts as a cementing agent, thus cementation occurs, binding the sediment grains together. The large size of the particles, in this case 1.5 centimeters, is a characteristic feature of conglomerates, distinguishing them from finer-grained sedimentary rocks like sandstone, siltstone, or shale.