an excavation for extracting minerals that is not very deep

metaphorically used to describe something lacking depth or substance

पृष्ठीय या सतही

English Usage: His shallow mine of knowledge made it hard for him to engage in deep conversations.

Hindi Usage: उसके ज्ञान की सतही खनन ने उसे गहरे चर्चाओं में शामिल होना कठिन बना दिया।