what is depletion 
depletion is an accrual accounting technique used to allocate the cost of extracting natural resources such as timber minerals and oil from the earth like depreciation and amortization depletion is a non cash expense that lowers the cost value of an asset incrementally through scheduled charges to income where depletion differs is that it refers to the gradual exhaustion of natural resource reserves as opposed to the wearing out of depreciable assets or aging life of intangibles 