SQL> ed
Wrote file afiedt.buf

  1  create table dept_audit
  2  (
  3  old_DEPTNO NUMBER(2),
  4  old_DNAME  VARCHAR2(14),
  5  old_LOC    VARCHAR2(13),
  6  new_DEPTNO NUMBER(2),
  7  New_DNAME  VARCHAR2(14),
  8  new_LOC    VARCHAR2(13),
  9* timestamp date) -- you can change the date into timestamp 
SQL> /

Table created.

SQL> get trig_audit
  1  -- you can change the sysdate into timestamp column
  2  CREATE OR REPLACE TRIGGER TRIG_AUDIT
  3  AFTER INSERT OR UPDATE OR DELETE ON DEPT
  4  FOR EACH ROW
  5  BEGIN
  6  IF INSERTING THEN
  7     insert into dept_audit values
  8     (NULL,NULL,NULL,:new.deptno,:new.dname,:new.loc,sysdate);
  9  END IF;
 10  IF UPDATING THEN
 11     insert into dept_audit values
 12     (:old.deptno,:old.dname,:old.loc,:new.deptno,:new.dname,:new.loc,sysdate);
 13  END IF;
 14  IF DELETING THEN
 15     insert into dept_audit values
 16     (:old.deptno,:old.dname,:old.loc,NULL,NULL,NULL,sysdate);
 17  END IF;
 18* end;
 19  /

Trigger created.

SQL> insert into dept values
  2  (50,'newdep','FLORIDa');

1 row created.

SQL> update dept set dname='recentdep' where deptno=50;

1 row updated.

SQL> delete from dept where deptno=50;

1 row deleted.

SQL>  select * from dept_audit;

OLD_DEPTNO OLD_DNAME      OLD_LOC       NEW_DEPTNO NEW_DNAME      NEW_LOC       TIMESTAMP
---------- -------------- ------------- ---------- -------------- ------------- --------------------
                                                50 newdep         FLORIDa       02-jul-2002 10:08:00
        50 newdep         FLORIDa               50 recentdep      FLORIDa       02-jul-2002 10:08:35
        50 recentdep      FLORIDa                                               02-jul-2002 10:08:46