U.S. Geological Survey, Branch Of Acquisition and Federal Assistance, Box 25046, Denver Federal Center, Denver, CO 80225-0046

B -- OPTICALLY STIMULATED LUMINESCENCE DATING OF COARSE-GRAINED QUARTZ DUE 071600 POC Marilyn Hutchison, MS204B, (303) 236-5900, ext. 327 E-MAIL: USGS, CR, Acquisition and Federal Assistance, mhutchi@usgs.gov. Concerns having the ability to furnish the services described herein are requested to give written notification (including the telephone number for a point of contact) to the procuring office above within 45 calendar days from the date of this synopsis. The U.S. Geological Survey, Earth Surface Dynamics Program, has a requirement for Optically Stimulated Luminescence (OSL) dating of coarse-grained quartz from Nebraska and Colorado Loess Sediments and both coarse and fine-grained quartz from Colorado Plateau eolian sediments, using the latest developments in luminescence geochronology. A reliable, precise, and accurate procedure for Optically Stimulated Luminescence (OSL) dating of quartz must be employed in order to enable precision of better than 5% for the measurement of past dose exposures. Single aliquot dating procedures must provide an independent age determination, leading to high precision OSL dates when 10 or more results are combined. Identification of the age and sources of both coarse-grained eolian sediments and far-traveled, fine-grained eolian sediments within the same deposit is essential for understanding climate impacts on southwestern landscapes. Analyses to be done include: (1) field and laboratory based measurements of U, Th and K concentrations in the host sediment, (2) calculation of dose rate, (3) laboratory estimates of sediment moisture content, (4) laboratory measurements of optically stimulated luminescence on coarse-grained quartz (in loess samples from Nebraska and Colorado) and coarse and fine-grained quartz (in eolian sediment samples from the Colorado Plateau region) and (5) calculation of ages using data obtained in items (1) through (4). Data generated from the measurements described above will be reported to the project chiefs in the form of a spreadsheet (e.g., in Excel or comparable software) sent as an attachment file and in paper form. Results will be reported to the project chiefs within one year from date of award. Based on information available at this time, and in accordance with 41 U.S.C. 253(c)(1), implemented by FAR 5.302-1, the Government considers the item specified as a sole source from Aberystwyth Luminescence Laboratory of the University of Wales, Aberystwyth, Wales, United Kingdom, and proposes to negotiate a contract with that firm on that basis. However, should additional sources be identified, they will be considered. Firms who feel that they can furnish the required supplies are invited to submit in writing an affirmative response to this announcement, and such other materials which correspond to the required items stated herein. This information will be evaluated and used to determine if competitive opportunities exist. Since no solicitation document exists, requests for such documents without accompanying information will be considered non-responsive to this request without further consideration. This notice may represent the Government's only official notice of this procurement. See Note 22. Posted 06/01/00 (W-SN460470). (0153)

Loren Data Corp. http://www.ld.com (SYN# 0021 20000605\B-0003.SOL)