This report is a continuation of an earlier work which can be viewed here: http://hdl.handle.net/10792/2850This 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)
