SELECT copper_age FROM table_23537091_1 WHERE ubaid_period_in_mesopotamia = "Hittite Old Kingdom , Minoan eruption"
Ketika kerajaan tua Het, letusan Minoan adalah periode Ubaid di Mesopotamia Berapa usia tembaga?
CREATE TABLE table_23537091_1 (copper_age VARCHAR, ubaid_period_in_mesopotamia VARCHAR)