lias
/ˈlaɪəs/noun
1the Lias
- Geology the earliest epoch of the Jurassic period, lasting from about 208 to 178 million years ago【地质】里阿斯统（约从2.08亿年前持续到1.78亿年前的早侏罗纪时代）。
1.1
- the system of rocks deposited during this epoch, consisting of shales and limestones rich in fossils里阿斯岩（由富含化石的页岩和石灰岩组成）。
1.2
- （亦作blue lias）[mass noun] a blue-grey clayey limestone derived from marl deposited in the Lower Jurassic, found chiefly in SW England蓝里阿斯岩。
派生词
liassic
adjective词源
late Middle English (denoting blue lias)： from Old French liais 'hard limestone'， probably from lie （see LEES）.