cryptovolcanic

cryptovolcanic

[¦krip·tō·väl′kan·ik]
(geology)
A small, nearly circular area of highly disturbed strata in which there is no evidence of volcanic materials to confirm the origin as being volcanic.
References in periodicals archive ?
Cryptovolcanic structure in Ohio of the type of the Steinheim Basin Geol Soc America Bull 32:74-5.
For many years these craters, including the startlingly well preserved Meteor Crater in Arizona, were said to have resulted from "cryptovolcanic" (hidden volcanic) activity, though some argued that this was impossible.