The Geological Survey is engaged in many different kinds of investigations in the fields of geology and hydrology. These investigations may be grouped into several broad, inter-related categories as follows:

(a) Economic geology, including engineering geology

(b) Regional geologic mapping, including detailed mapping and stratigraphic studies

(c) Resource and topical studies

(d) Ground-water studies

(e) Surface-water studies

(f) Quality-of-water studies

(g) Field and laboratory research on geologic and hydrologic processes and principles.

The Geological Survey also carries on investigations in its fields of competence for other Federal agencies that do not have the required specialized staffs or scientific facilities.

Nearly all the Geological Survey's activities yield new data and principles of value in the development or application of the geologic and hydrologic sciences. The purpose of this report, which consists of 4 chapters, is to present as promptly as possible findings that have come to the fore during the fiscal year 1961 the 12 months ending June 30, 1961.

The present volume, chapter A, is a synopsis of the highlights of recent findings of scientific and economic interest. Some of these findings have been published or placed on open file during the year; some are presented in chapters B, C, and D; still others have not been published previously. Only part of the scientific and economic results developed during the year can be presented in this synopsis. Readers who wish more complete or more detailed information should consult the bibliography of reports beginning on page A-156 of this volume, and the collection of short articles presented in the companion chapters as follows:

Prof. Paper 424-B Articles 1 to 146

Prof. Paper 424-C Articles 147 to 292

Prof. Paper 424-D Articles 293 to 435

A list of investigations in progress in the Geologic and Water Resources Divisions with the names and addresses of the project leaders is given on pages A-110 to A-155 for those interested in work in progress in various areas or on special topics.

During the fiscal year 1961, the services of the Geologic and Water Resources Divisions were utilized, or supported financially in part, by the many Federal and State agencies listed on pages A-106 to A-109. The Geological Survey has also cooperated from time to time with other agencies, and some of the work described in these chapters stems from work of previous years in cooperation with agencies not shown on the list. All cooperating agencies are identified where appropriate in the individual short articles in chapters B, C, and D, and they are mentioned in connection with some of the larger programs summarized in chapter A; because of space limitations, however, their contributions are mentioned in many of the short summary paragraphs contained in chapter A.