The Science steering committee has identified these basic themes for the meeting:

[A] Current Issues and New Approaches in FT and (U-Th-Sm)/He dating

Advances generally seek to either: a) improve our knowledge of a particular system, thereby improving data accuracy, precision, and/or the quality of the resultant geological interpretation; or b) improve the economics (time and cost) of obtaining and interpreting data. Some advances achieve both of these goals. Ideally, advancements targeting economics do not significantly and negatively affect accuracy, precision, or the quality of the geological interpretation.

For fission-track we are interested in exploring: 1) personal and interlaboratory calibration, including track-length measurements; 2) new experimental data focused on pressure, alpha-emitter concentration and radiation damage, and overall chemical composition; 3) geological benchmark data with either low and high degrees of track annealing; 4) modeling and linking to other methods (measured parameters, modeling methods). New approaches to FT dating are rapidly moving the methodology forward. In this regard, we hope to focus on 1) LA-ICP-MS (and comparison to EDM); 2) computer-aided fission track counting; 3) track-length calibration.

For (U-Th-Sm)/He dating we are interested in exploring; 1) radiation damage; 2) alpha-particle ranges in minerals; 3) double dating techniques and approaches; 4) new minerals. This session will be at least one full day and will include talks, round-table discussion, and poster presentations.

[B] Regional Tectonic Studies

Low-temperature thermochronometry is routinely used to study the thermal signatures of tectonic and geomorphic processes. Over the past 25 years, fission-track analyses have been used widely to study most, if not all, of the major physiographic provinces of the world. More recently, (U-Th)/He thermochronometry has emerged as a major tool to supplement and advance these investigations. Despite the large number of published studies applying low-temperature thermochronometers to investigate tectonic problems, much remains poorly understood, especially in terms of detail and process. In essence, the big picture has emerged, yet specific details still remain unclear. This session will focus on low-temperature thermochronologic studies applied to specific tectonic and geomorphic settings, and will be subdivided into studies focused on:
1) Convergent and transform plate boundaries. Studies of the timing of deformation and exhumation in orogenic belts, as well as along transform and transpressional plate boundaries continue to be a major focus of research. As low-temperature thermochronometric techniques improve, so does the level of detail and precision of these studies.
2) Divergent plate boundaries, extensional settings, and stable crustal blocks. The timing of rifting and passive margin development, and the mechanisms, rates and nature of major extensional detachments, as well as factors affecting the physiographic expression of these regions continue to be of interest. Constraining the "age" of very old stable crustal blocks also remains a technical challenge.
3) Surface processes and active faults. One of the major emerging research fields in surface processes involves studies of how and to what extent factors such as fluvial and glacial erosion control landscape evolution. Several recent studies have explored the effects of climatic variations on exhumation rates and tectonic processes. Major questions that remain unresolved include whether or not climatic variations can directly affect tectonic rates and loci of deformation, and how erosion may both control and be controlled by interactions between climate, climate change and tectonics.

[C] Modeling and interpretation methods

This session will cover the technical and theoretical ground between collecting data in the laboratory and the field and using it to derive information of geologic interest. Conceptually, this can be divided into three categories.

First, there is understanding and quantifying the processes of annealing, diffusion, and etching, and how they may be modified by complicating factors such as radiation damage and chemical variability. It is noteworthy that proper calibration of both fission-track annealing and helium diffusion in apatite, the most-studied mineral, remains an area of active research. Work in these fields may in fact be approaching a convergence, in which annealing and diffusion must be considered in tandem to obtain a rigorous solution for each. Likewise, understanding of these processes in zircon continues to evolve, and much work is being done towards expanding both techniques to other minerals. Other anticipated topics include related techniques such as alpha recoil dating and argon diffusion.
Second, thermal history inversion modeling, in which calibrations are combined with field data to constrain the time-temperature paths that samples may have experienced, is commonly performed in modern studies. Active research in this field includes improving the statistical and algorithmic means by which histories are posed and evaluated, and combining sample localities and disparate thermochronometers into a single modeling framework. A particular topic of research and discussion will be the necessity of standardizing fission-track length data across laboratories, and its impact on inversion.
Third, numerical modeling of geologic processes while incorporating thermochronologic data has become increasing important in recent years. In particular, thermochronometers can impose meaningful constraints on numerical models of extension and erosion, in turn allowing the models to provide information on timing, mechanisms and pathways of exhumation. An important aspect of this topic lies in illustrating how field work and modeling can interact with and reinforce one another, such as in site selection.

[D] Detrital studies and sedimentary basins

Thermochronology, when applied to detrital minerals, can constrain provenance, rates, and patterns of source deformation and erosion, paleogeography, and basin thermal history. Detrital thermochronological studies can also provide fundamental insights into the relationship between tectonics and climate. In this session we welcome contributions where the application of zircon and apatite fission track and (U-Th)/He thermochronology can provide information about modes and rates of orogenic growth, tectonic exhumation and erosion, paleorelief, deformation within the source and the sink coupled system and basin burial temperatures.

Particular attention will be given to interdisciplinary approaches involving multiple low-temperature thermochronometers, statistical analyses of detrital ages and thermal modeling. The ultimate goal of the session is to bring together scientists interested in innovative ways of applying detrital thermochronology to different geological settings in order to answer a suite of questions pertinent to different but complementary disciplines such as isotope geochemistry, sedimentary and structural geology, tectonics and geomorphology.

[E] Thermotectonic Framework of Alaska and surrounding areas

As FT2008 is being held in Anchorage, Alaska the organizers wished to convene a separate session on thermochronology in Alaska, the Arctic and British Columbia. Alaska has incredibly diverse geology, ranging from a subduction-dominated southern margin to continental scale strike-slip faults to regions of extension nearer the Arctic. It is a natural laboratory for investigating fundamental processes in the Earth Sciences such as terrane accretion, flat slab subduction or intracontinental deformation.

Alaska is also home to North America's highest mountain, Mt. McKinley (6194 m) lying within the Alaska Range, as well as the Wrangell - St. Elias Mountains that has the highest relief (5000+ m) of any coastal mountain range in the world and is a classic example of a glacially-dominated orogenic wedge. There have been many excellent thermochronologic studies in Alaska, but a recent explosion of thermochronologic work emphasizes the importance of our science contributing to a greater understanding of earth sciences.

We encourage submission of thermochronologic and related contributions whether they are applied to tectonics, provenance, terrane movement, mountain formation, landscape evolution, the interaction of tectonics and climate, the translation and accretion of terranes, or the thermal evolution of sedimentary basins.

The Extended Abstract Volume can be ordered online for $50 USD. It is also available as a free download.

This document can be located from http://www.union.edu/ft2008

Copyright Geology Department, Union College, Schenectady N.Y. 12308-3107.All rights reserved. No part of the document can be copied and/or redistributed, electronically or otherwise, without written permission from J.I.Garver, Geology Department, Union College, Schenectady NY, 12308-2311, USA. (Except images from the Anchorage Visitors Bureau.)