Definition of "tarnations"

Girl (wryly, as she moves to r. of Marnitski, looking at all the medicine). Oh, gracious me ! Oh, you poor thing ! King. Tarnations and thunderbolts !

1947, Paul Vincent Carroll, Guy Robertson, Plays for juvenile performers, page 22

Hell and tarnations, I've known them for muddleheads and blockheads half my life, and firsthand, but I sure didn't expect them to take leave of their senses, insulting our office of President, making our Party into a white demagogue's party, slapping the Negro vote in the face.

1964, Irving Wallace, The Man, page 537

Tarnations! You should be a cloth merchant with that blanket You're making it a hot thing and I'm cold.

1971, Pamana, page 40