. ▁ ▁Gallery ▁ ▁See ▁also ▁▁▁ ▁Co at ▁of ▁arms ▁of ▁the ▁Is le ▁of ▁Man ▁ ▁Flag ▁of ▁Sic ily , ▁a ▁similar ▁flag ▁with ▁a ▁tr isk el ion ▁ ▁References ▁▁ ▁Category : Flags ▁introduced ▁in ▁ 1 9 3 2 ▁Flag ▁Category : National ▁flags ▁Is le <0x0A> </s> ▁The ▁Th aum asia ▁Pl ate au ▁is ▁a ▁vast ▁s lop ing ▁vol can ic ▁plain ▁in ▁the ▁western ▁hem is phere ▁of ▁Mars , ▁and ▁is ▁the ▁most ▁a ere ally ▁extensive ▁component ▁of ▁the ▁Th ars is ▁R ise . ▁Sy ria ▁Plan um , ▁Sol is ▁Plan um , ▁S ina i ▁Plan um , ▁and ▁Th aum asia ▁Plan um ▁are ▁the ▁constitu ent ▁se ctors ▁of ▁the ▁plate au , ▁which ▁s its ▁between ▁ 8   km ▁and ▁ 4   km ▁above ▁the ▁surrounding ▁southern ▁high lands . ▁It ▁is ▁bounded ▁by ▁v estig ial ▁bas ement ▁terra ins ▁that ▁pre date ▁the ▁formation ▁of ▁Th ars is . ▁This ▁area ▁has ▁been ▁proposed ▁to ▁be ▁a ▁d rain age ▁bas in ▁that ▁s our ced ▁the ▁flo od w aters ▁forming ▁the ▁out flow ▁channels ▁surrounding ▁Ch ry se ▁Plan it ia . ▁ ▁Context ▁ ▁The ▁Th aum asia ▁Pl ate au ▁lies ▁at ▁the ▁heart ▁of ▁the ▁Th ars is ▁R ise , ▁and ▁is ▁fr amed ▁to ▁the ▁north west ▁by ▁the ▁No ct is ▁Lab yr inth us ▁f ract ure ▁zone ▁and ▁the ▁Vall es