Information presented on hydrology of limestone and related rocks at the conferences of the Ground Water Branch at Mammoth Cave, Kentucky, March 27-31, 1956, and at Carlsbad, New Mexico, November 13-17, 1956.


                           UNITED STATES
                    DEPARTMENT OF THE INTERIOR
                         GEOLOGICAL SURVEY
                     Water Resources Division
                        Washington 25, D.C.

In reply refer to:                           December 10, 1956
                                             Code No. 4051 0001

GROUND WATER BRANCH MEMORANDUM NO. 57.21

To:       District Chiefs and Staff Officials, Ground Water Branch

From:     Chief, Ground Water Branch, Washington, D.C.

Subject:  Information presented on hydrology of limestone and
          related rocks at the conferences of the Ground Water
          Branch at Mammoth Cave, Kentucky, March 27-31, 1956,
          and at Carlsbad, New Mexico, November 13-17, 1956.

Each person who presented a paper or gave an informal talk at the
conferences at Mammoth Cave and Carlsbad should prepare, without
illustrations, at least the gist of the paper ar talk and send it
to this office by April 1, 1957, if he has not already done so.
After the papers have been reproduced for use within the Survey,
it is expected that at least some of them will be put in shape for
approval for publication, and at that time illustrations can be
included.

If you have already sent your paper to this office, but wish to
make some changes and revisions, please do so, and send to this
office the revised draft.

In addition to the papers which were presented at the conferences,
information is needed on the character, occurrence, and extent of
the limestones and related rocks which are known to be aquifers.
Therefore, it will be appreciated if each district supervisor will
have someone in his district prepare a memorandum which briefly
describes the principal aquifers of limestones and related rocks
in his district.  The memorandum should include references to the
literature.  Some of this information was given in papers at the
conferences; however, information is not given for many of the
States and therefore we would like to have papers to fill this gap
by April 1, 1957.



                                 (s) A. N. Sayre

Distribution:  A, B, GS, GFO