The International Basement Tectonics Association is a loosely organized, but dedicated, evolving group of earth scientists who are interested in all aspects of basement rocks. An early focus was on fracturing of the earth's crust, often early in geologic time, that affected and controlled more recent fracturing in all of its manifestations. The Association has expanded in scope to the study and understanding of all aspects of the crustal processes of basement rocks - their formation, history, rejuvenation; their effects on later rocks; and their utilization as both process and material to support societal needs. Location and expertise of the individual conference host suggests the focus of a meeting - from active process to records of origin, from plate tectonics to zircon overgrowth.

The evolution of the Association is mirrored in the proceeding volumes. The first conference was initiated and organized in 1974 by two industry geologists, S. Parker Gay, Jr. of Applied Geophysics, Inc., Salt Lake City, Utah, and Robert A. Hodgson, Gulf Oil Company. Analysis of the newly acquired satellite data documented that the earth's crust was highly lineated, an earlier conclusion of Gay, Hodgson and others. The rationale for the first basement tectonics conference relied heavily on the connection to lineaments.

THE FIRST INTERNATIONAL
CONFERENCE ON
THE NEW BASEMENT TECTONICS
is the first gathering of earth scientists to be devoted exclusively to geological lineaments. Numerous workers have recognized linear features of local or regional proportions on the earth's surface. These features are commonly called lineaments. The term "The New Basement Tectonics" implies that lineaments result from pervasive fracturing of the crystalline basement - fracturing which controls faulting during later periods of tectonism. "The New Basement Tectonics" has direct and far-reaching implications for all fields of geology - economic as well as academic. Convention themes will be: 1) to examine the evidence for, and the characteristics of, regional fracturing, and 2) to consider theories for the origin of this fracturing. The economic aspect will not be neglected, but will be emphasized to a greater degree at succeeding meetings. The conference will be interdisciplinary, and will include such topics as: Precambrian shear zones, jointing and joint patterns, air photo geology, space photo lineaments, aeromagnetic lineaments, side-looking radar lineaments and regional fracturing.


In later conferences, the theme of the IBTA broadened and the presentations matured to include both academic/scientific subjects to applications that more immediately benefited society. The statement from the 5th Basement Tectonics Conference in Cairo is reproduced as follows:

THE FIFTH INTERNATIONAL CONFERENCE
ON BASEMENT TECTONICS
The first conference on The New Basement Tectonics was held in 1974 in Salt Lake City, Utah, USA, and subsequently these Conferences have expanded in scope from the initial theme of origin and analysis of earth lineaments and fracture systems to the study and understanding of all aspects of fractured crystalline basement and basement effects on later geological events. Likewise, the studies presented at the meetings have expanded from largely academic-scientific interest in basement features to applications more immediately beneficial to society. The fifth conference will focus on the following :
    1. Field studies of:
      a - Basement terranes
      b - Deformed sedimentary rocks
      c - Exposed deep lithosphere
    2. Global tectonics, stratigraphic studies
    3. Theoretical analysis of basement deformation
    4. Geophysical studies of the basement and the nature and behavior of the lithosphere
    5. Laboratory and field studies of the mechanical behavior of rocks.
The conferences are held every two years (now in odd numbered years) at a location of particular interest to students of basement geology and are organized by institutions and individuals with a strong background in basement tectonics. This conference is no exception and indeed is fortunate in the high degree of experience in basement studies by the host country, Egypt, which has so generously provided its facilities, labours and enthusiasm to the 5th International Conference on Basement Tectonics.


The 10th Conference, held in 1992 , Duluth, Minnesota, situated on one of the world's larger basement cratons, focused on regional rifting and rejuvenation tectonics:

CONFERENCE THEMES

The tenth Conference emphasizes three main themes:
  • Shear Zones
  • Precambrian Basement Control on Phanerozoic Structures
  • Rifting

SUBTHEMES
  • Geometry and History of Late Precambrian-Early Paleozoic Rifting: Interior North America
  • Rift Geophysics: Patterns and Models
  • Rift Fill: Magmatism and Sedimentation
  • Rift Mineralization and Hydrocarbon Potential
  • Shear Zone Mineralization
  • Shear Zone Kinematics
  • Shear Zone Fluid Flow
  • Shear Zones / Tectonic Framework


The 13th Conference held in Blacksburg, Virginia in 1997, dealt in large part with studies of the Appalachian Mountains and its metamorphic rocks:

CONFERENCE THEMES

  • Economic Resources in Basement Terranes
  • Geophysical Studies of Basement Rocks
  • Plate Tectonic Models
  • Geochemical, Structural, Petrologic and
      Isotopic Record of Basement Rocks

The next Conference to be held, the 15th in A Coruña Spain, July 2000, will focus on Variscan-Appalachian Dynamics - Building the Upper Paleozoic Basement of northern Spain.

Thus, the themes of the many Basement Tectonics Conferences has varied with the location of the conferences over the years, but the prevailing thread that runs throughout is still control of younger fracture events by earlier ones. Field trips to view basement or basement-related structures have been an important part of all the conferences.

Additional information on past conferences may be obtained from the following published writeups:

      1. Geotimes, October 1975, p.16
      2. Geotimes, February 1977, p.21
      3. Geotimes, December 1990, p.18
      4. Skillings Mining Review, August 22, 1992, p.10


Membership in the IBTA

IBTA is not an annual dues society. The members are those professionals who attend and participate in the conferences and acquire membership in the Association until the next conference. At the conference, an open forum is held to discuss the affairs of the association and to plan for future meetings. Continuity and organization of the Association is provided the Board of Trustees.


Corporate Organization of the IBTA

The IBTA operates under a constitution and set of by-laws first registered in the State of Utah in 1978. The present by-laws were revised from the original under the direction of D.L. Baars in 1984. They specify a 5-person governing board consisting of a Chief Trustee, a Deputy Chief Trustee, a Deputy Trustee, an Associate Trustee/Treasurer and an Assistant Trustee/Secretary in decreasing order of rank. The Chief Trustee is responsible for the organization of the Basement Tectonics Conference that occurs at the end of his term and retires after that conference takes place. On the last day of the conference the five trustees choose a new Associate Trustee from the membership of the association and the remaining Trustees all advance one position in rank.

The executive offices of the association have remained at 661 South 400 East, Salt Lake City, Utah 84111, since the first conference in 1974, and Anna Mariea Gay has been Secretary/Treasurer of the association during this period.

Future Conferences

For those qualified institutions that may wish to hold a Basement Tectonics Conference it is necessary to contact the Board of Trustees of the Basement Tectonics Association. Preference is given to those organizations that have the financial capability to hold such a conference and those that have professional personnel with experience and reputation in basement studies and basement mapping. The location of the conference site and the ability to host field trips to important basement or basement-related geological features is also considered in the selection of Basement Tectonics host organizations.