Mesozoic rocks deformed during the Laramide orogeny. During regional metamorphism that occurs during the mountain building process (orogeny), limestone recrystallizes into marble. These metasedimentary rocks were later uplifted during the Alleghenian orogeny. Ages are approximated from the magmatic activity associated with the individual cycles of the orogeny. The Taconic orogeny, a major mountain-building episode, was well under way in Cambrian times. In North America it shows as later phases of the Acadian orogeny. Meanwhile, Baltica collided with Siberia and Kazakhstania which resulted in the Uralian orogeny and Laurasia. This was part of the Sevier orogeny. The southern part emerged during the Hercynian orogeny. The Anti-Atlas Mountains are believed to have originally been formed as part of Alleghenian orogeny. This results from the isostasy associated with orogeny (mountain formation). Granite appeared with the Variscan Orogeny. This was the final episode of the Taconic Orogeny. The Tasmanian terranes only accreted onto Gondwana in the Middle Devonian in the Tabberabberan Orogeny. Coincidentally they exist in three parallel folds or chains surviving from the orogeny.