ORA-00907: missing right parenthesis on specifying 'ON UPDATE TIMESTAMP'

ORA-00907: missing right parenthesis on specifying 'ON UPDATE TIMESTAMP'

I need to have two columns - created_date and updated_date for every table
in the DB. I am trying the following SQL in Oracle, but its not working:
create table tmptmp (
id number(10),
created TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
updated TIMESTAMP DEFAULT CURRENT_TIMESTAMP ON UPDATE TIMESTAMP
);
The above gives the following error:
Error at Command Line:5 Column:42
Error report:
SQL Error: ORA-00907: missing right parenthesis
00907. 00000 - "missing right parenthesis"
*Cause:
*Action:
Any clue what is wrong here?