Compile and Make Digital the Lithologies for all NRRI Drill Logs, with Emphasis on the Duluth Complex Drill Holes (An Addendum to an Earlier NRRI Database)

Abstract

This report and associated databases are updates on many of the holes that have been recently logged by the Natural Resources Research Institute (NRRI) in the Keweenawan Duluth Complex, the Paleoproterozoic Biwabik Iron Formation of the Mesabi Iron Range, and the Archean Deer Lake Complex of northeastern Itasca County, Minnesota. The main emphasis of this project was to update some of the databases that were presented in an earlier NRRI report (Patelke, 2003) with regard to lithologies in Duluth Complex drill holes that were logged by the NRRI since 2003 (and discussed in Severson and Hauck, 2008). To date, all of the publically available drill holes (except for around 30 drill holes) have now been logged in the Duluth Complex by the NRRI. These 30 holes are all that are missing from either the databases in this report or the databases in Patelke (2003). It is strongly suggested that the databases herein be combined, at the user’s discretion, with corresponding databases in Patelke (2003) in order to make an all- encompassing database for lithologies for all NRRI logged drill holes in the Duluth Complex. A secondary goal of this project was to present a header file database for all the holes that were recently drilled in the Duluth Complex (post-2003). Most of these holes are not yet publically available, but data regarding drill hole locations can be gleaned from abandonment files. Combining Duluth Complex header files in this report with the similar header file in Patelke (2003) could provide an all-encompassing database of locations for all of the holes drilled to date in the Duluth Complex (pre-2010 data). This combining of the data is left to the user’s discretion. Lastly, additional goals of this project (time permitting) were to present lithologic databases for all holes logged by the NRRI in the Mesabi Iron Range and, to a much lesser extent, holes logged by the NRRI in the Deer Lake Complex. The database for the Mesabi Iron Range contains information for almost 300 drill holes (over 5,947 lines of lithologic data) in regard to the lithologic picks pertaining to informal members and submembers of the iron-formation. The data in this file is about 80% complete in that not all of the iron-formation submembers are presented for holes drilled at the Keetac Taconite mine or in the Coleraine, MN, area (the latter holes are discussed in Zanko et al., 2003).