|Collection element||Original extent||Owned by WGNHS today||Brief description|
|Hand samples||~80,600||9,794||Rock samples taken from the field|
|Thin sections||~17,600||15,608||Microscope slides made from hand samples|
|Field notebooks*||491||464 (321 scanned)||Geologic and topographic notebooks, including drill hole logs|
|Thin section catalogs||3||3||Catalog correlating hand sample numbers with thin section numbers; ledger book|
|Chemical analyses||unknown||2||Chemical analyses of samples—not all are Lake Superior Division samples; ledger book|
|Photograph negative catalogs||unknown||1||List of photograph negatives including location taken and corresponding notebook and page number; ledger book|
|Specimen catalogs||24||24||Listing of specimens from 1 to 80,816, some with location information, thin section number, notebook number and page; ledger book|
|Lithological descriptions||9||6||Microscopic and macroscopic descriptions of samples written by Irving and Van Hise, organized by rock type; ledger book|
|Maps||unknown||67||Hand-drawn maps showing sample numbers and rock types, mostly of parts of Michigan’s Upper Peninsula|
*Some specimen catalog entries refer to notebook numbers preceded by a “C.” C1, C2, etc. We do not have these, and do not know what information they contain apart from sample descriptions.
The field notebooks and maps of the Lake Superior Divison use the Public Land Survey System (PLSS) to locate geological samples. This system can be confusing, especially when moving across states, as the system is not consistent throughout the U.S.A. For more information on the PLSS, please visit the USGS National Map.