Cryptic Family Reunion: It's been a long, long, long time

Question

The answer to this puzzle is a list of ten thematically related words or proper names or phrases. Each of these is clued cryptically, and the theme is to be determined. Since the definition part of a cryptic clue would give away the theme, these cryptic clues use a family member (e.g., mom, sister) to stand in for the definition part of the clue. So for example, if the theme of the puzzle were chemical elements, "Sister picking at nit" would clue "tin". I hope you enjoy!

1. Aunt Nora distressed about COVID, panicking irrationally at first (10)
2. Grandpa is rising to skewer vile racist (8)
3. Brother of German insurgency leader to interrupt university administrator (8)
4. Grandpa's canton has Swiss, Nazi, Teutonic bases (8)
5. Nephew, living in sin, spoke up (8)
6. Sister to create disruption in company, and America (10)
7. Uncle has Canadian rye shot after leaving New York (9)
8. Son to collect as I analyse sample (8)
9. Father ruptured hernia after trimming around estate (10)
10. Niece's C perhaps eliminating her top one...top two schools (12)

Answer 1

These are

Geological periods

and the answers are:

1. Ordovician, NO(COVID* + I)RA*
2. Triassic, RACIS(IS<)T*
3. Devonian, DE(VON + I)AN
4. Jurassic, JURA + 'S + ..S ..I ..C
5. Siderian, SI(AIRED*)N
6. Cretaceous, C(CREATE*)O + US
7. Ediacaran, CANADIANRYE* - NY
8. Ectasian, ...ECT AS I AN...
9. Statherian, ..STAT.. + HERNIA*
10. Carboniferous, CARBON + IF + ..ER + O.. + U'S (universities)