UNITED STATES
                       SECURITIES AND EXCHANGE COMMISSION
                             Washington, D.C. 20549

                                 SCHEDULE 13G/A

                    Under the Securities Exchange Act of 1934
                                (Amendment No.6)*

                           DAWSON GEOPHYSICAL COMPANY
        -----------------------------------------------------------------
                                (Name of Issuer)

                                  Common Stock
        -----------------------------------------------------------------
                         (Title of Class of Securities)

                                    239359102
                              --------------------
                                 (CUSIP Number)

                                December 31, 2004
        ----------------------------------------------------------------
             (Date of Event Which Requires Filing of this Statement)

Check the  appropriate box to designate the rule pursuant to which this Schedule
is filed:

         / X /    Rule 13d-1(b)
         /   /    Rule 13d-1(c)
         /   /    Rule 13d-1(d)

*The  remainder of this cover page shall be filled out for a reporting  person's
initial filing on this form with respect to the subject class of securities, and
for any  subsequent  amendment  containing  information  which  would  alter the
disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed
to be "filed" for the purpose of Section 18 of the  Securities  Exchange  Act of
1934 ("Act") or otherwise  subject to the  liabilities of the section of the Act
but  shall be  subject  to all other  provisions  of the Act  (however,  see the
Notes).






                                 SCHEDULE 13G/A
                               CUSIP NO. 239359102

1.      Names of Reporting Persons.
        I.R.S. Identification Nos. of above persons (entities only).

        Quaker Capital Management Corporation
        ------------------------------------------------------------------------

2.      Check the Appropriate Box if a Member of a Group 

        (a)      -----
        (b)        X
                  -----

3.      SEC Use Only
                       ---------------------------------------------------------

4.      Citizenship or Place of Organization                        Pennsylvania
                                                                 ---------------

Number of         5.    Sole Voting Power                                0
Shares                                                           ---------------
Beneficially      6.    Shared Voting Power                              0
Owned by                                                         ---------------
Each Reporting    7.    Sole Dispositive Power                           0
Person With:                                                     ---------------
                  8.    Shared Dispositive Power                         0
                                                                 ---------------

9.      Aggregate Amount Beneficially Owned by Each Reporting Person

        0
        ---------

10.     Check if the Aggregate Amount in Row (9) Excludes Certain
        Shares
                --------


11.     Percent of Class Represented by Amount in Row (9)                 0%
                                                                       ---------

12.     Type of Reporting Person                                        IA
                                                                  --------------



                               Page 2 of 6 Pages



                                 SCHEDULE 13G/A
                               CUSIP NO. 239359102

Item 1.

         (a)      Name of Issuer

                  Dawson Geophysical Company
                  --------------------------------------------------------------

         (b)      Address of Issuer's Principal Executive Offices

                  508 West Wall, Suite 800, Midland, Texas 79701
                  --------------------------------------------------------------
Item 2.

         (a)      Name of Persons Filing

                  Quaker Capital Management Corporation
                  --------------------------------------------------------------

         (b)      Address of Principal Business Office or, if none, Residence

                  401 Wood Street, Suite 1300, Pittsburgh, PA  15222
                  --------------------------------------------------------------

         (c)      Citizenship

                  Pennsylvania, USA
                  --------------------------------------------------------------

         (d)      Title of Class of Securities

                  Common Stock
                  --------------------------------------------------------------

         (e)      CUSIP Number

                  239359102
                  --------------------------------------------------------------

                               
                               Page 3 of 6 Pages


                                 SCHEDULE 13G/A
                               CUSIP NO. 239359102


Item 3.        

          If  this  statement  is  filed  pursuant  to   ss.ss.240.13d-1(b)   or
          240.13d-2(b) or (c), check whether the person filing is a:

     (a)  /   / Broker of dealer  registered  under section 15 of the Act;

     (b)  /   / Bank as defined in section 3(a)(6) of the Act;

     (c)  /   / Insurance  company as defined in section 3(a)(19) of the Act;

     (d)  /   / Investment company registered under section 8 of  the Investment
                Company Act of 1940;

     (e)  / X / An  investment  adviser  in  accordance  with ss.240.13d-  1(b)
                (l)(ii)(E);

     (f)  /   / An employee  benefit  plan or  endowment  fund in ccordance with
                ss.240.13d-1(b)(1)(ii)(F);

     (g)  /   / A parent  holding  company or  control person in accordance with
                ss.240.13d-1(b)(1)(ii)(G);

     (h)  /   / A savings  association as defined in Section 3(b) of the Federal
                Deposit Insurance Act;

     (i) /    / A  church  plan  that  is  excluded   from  the   definition  of
                an  investment company  under section 3(c)(14) of the Investment
                Company Act of 1940;

     (j) /    / Group, in  accordance  with   ss.240.13d-1((b)(l)(ii)(J)

Item 4.  Ownership
         ---------

         (a)   The Reporting  Person no longer  beneficially  owns any shares of
               Common Stock of the Issuer.

         (b)   The shares  covered  by this  report  represent  0% of the Common
               Stock of the Issuer.

         (c)   The Reporting Person does not have voting  or  dispositive  power
               over any shares of Common Stock of the Issuer.

                               
                               Page 4 of 6 Pages



                                 SCHEDULE 13G/A
                               CUSIP NO. 239359102

Item 5.  Ownership of Five Percent or Less of a Class

                  If this statement is being filed to report the fact that as of
the date hereof,  the reporting  person has ceased to be the beneficial owner of
more than five percent of the class of securities, check the following:
                                                                          X
                                                                      ----------

Item 6.  Ownership of More than Five Percent on Behalf of Another Person

         Not applicable.

Item 7.  Identification and Classification of the Subsidiary Which
         Acquired the Security Being Reported on by the Parent
         Holding Company

         Not applicable.

Item 8.  Identification and Classification of Members of the Group

         Not applicable.

Item 9.  Notice of Dissolution of Group

         Not applicable.

Item 10. Certification

                  By signing  below I certify  that, to the best of my knowledge
and belief,  the securities  referred to above were acquired and are held in the
ordinary  course  of  business  and were not  acquired  and are not held for the
purpose of or with the effect of  changing  or  influencing  the  control of the
issuer of the  securities  and were not acquired and are not held in  connection
with or as a participant in any transaction having that purpose or effect.



                               Page 5 of 6 Pages



                                 SCHEDULE 13G/A
                               CUSIP NO. 239359102


                                    SIGNATURE

                  After  reasonable  inquiry and to the best of my knowledge and
belief,  I certify  that the  information  set forth in this  statement is true,
complete and correct.


                                           QUAKER CAPITAL MANAGEMENT CORPORATION


                                              February 9, 2005                  
                                              ----------------------------------
                                                            Date

                                              /s/ Mark G. Schoeppner            
                                              ----------------------------------
                                                         Signature


                                              Mark G. Schoeppner, President     
                                              ----------------------------------
                                                        Name/Title



                               Page 6 og 6 Pages