I'm completing an assignment for Earth-Space Science and have come across a word that I do not know, it does not come up in the dictionary and is quite specific to geology. The word is struetural, and was used in the sentence "The rock making up the above—mentioned peak—forest is quartzose sandstone of the Late Devonian platform struetural layer." Also the article is "GEOTECTONIC CONDITIONS OF FORMATION OF THE WULINGYUAN PEAK- FOREST LANDFORM, CHINA" if that helps. If anyone can find this word used in any other article or give me any source that hints at its definition that would be greatly appreciated.