Geology and uranium deposits of the Caribou area, Boulder County, Colorado

Abstract

Paachblemde was diacoeeed la the Caribou miin., beuldS. Comsty, Cel a., ia 1468 by (eisrda'td CarIbou htIves Miam., lmcerpmratad, during the zeopetrg of the @4-levsl. Since 14. mall quwa-V I.. patChbhindS has bean produced %rm the Radlum vein dmring e4Xary work that wa doe am isd cinth.-d w~b the Atamic Imrpg Coummism.a The Carlbmn maes, primurlly a alive, mane. devekps-.w 'ei (Caribou, He Name,. Puorman, Sheraman and SIlver Do3laa) tha were homrly worked a repaint. mtaes. Thes father vea, the Radin, Elmsr. aud Nebsee, ame eapmd an th Cau~e. am only at and below the 1W-level. The general goepg of the Caribou area, hewn she 1661 as a llver dwtict, has beer, di~cered by lamtin and Hall (1917) and moe 'semly by Levering and Godderd (lSM0), Ia 1931, a deta 1.4 stsdy ti the petragraphy .1 the Caribou meek vas maade by Smiath (1166. ha 1166 mid 1161, K. U. KIng 'A6O) of the U. S. Geological Survey ev.aed the Caribou mie to evalas the aam depos. In 1Kf. D. M. Sheridan and. N. Hinricha of thes U. S. GeelagIupl $Srvey made a aadhoaetivity inemsaace of tti. mine dap at ~muand vicinkry. This .econmai..snee imlded exaerbeic of motof the accassabla working of the Car:.boa mine. Other reports em the area are lIbted ia the blbliography. As a result of Kiqgs prelamlnary ezamlanatlon and she later ezploration for saniam on tme proper. the t. S. Geologxca1 Survey i 1961 began a detailed Invesigarion of the Caribou area on bemal' of the Div:sioa of Raw Materials of the Atomic Energy Conmlisuiom, the priselpal perpree of which was to evalwae the man .um occurrences in the a-sa. The study was begam by E. P. Kaiser and W. S. Cavene wthc established a triangmaiataon met, wing a base line in Caribou Park for herasoetal control and a S, Geological Survey bench ,rmark on the top of CauiboL; Hill for vertical control. Upon the assigrment of Kaiser to another project in Augmut 1,61. the investigation was continued until November i90. by C. Moore and W. S. Cavender. Danag the study of the district the writers prepared a geolog.c miap a a scale of 1 inch to 100 feet of an area of about one square mile. The mapped area ancludm's mq~t of the mines in the Caribou district and embraces the eastern half of Caribou 11111 and adjacent a-eL 0o 'he .a' and north. In addition, all accessible underground workings were mapped at a scale of 1 ince 40 fe.et, The writers wish to acknowledge the cooperation of the staff of the Consolidated Caribc. Silver Mines, Incorporat-. !, who made the "2aribow mine available for examination at adl times inc a. 'ia-r sre maps and suggestions that were of great anistarce. Mr. A. E. Blakesley, owr.e: 0' the Corn:', k m~re wa' Mws mss coopexat1i. in making piusibl. the euammnauce of lus mine. 1 banks are 4d'e Di. t. L.. Warist rAI aE thme University of Colorado and to the Boulder Daily Camera to, the isa of thai, ilt. coaaru~. Ior matson on the Caribou mine, T. S. Lovering of rim U, 5. GeoLogical Survey made many valuabi' soggestions on the IdentifIcation of alteratIon pwndcu in thin section, LOCATION AND GENERAL FEATURES T...