Core libraries contain wealth of information

A wealth of geological knowledge is stored across the province in eight Ontario government drill core libraries. The facilities are much like regular libraries, but instead of books, they contain diamond drill core.

Collectively, the libraries house more than one million metres of core. Laid end to end, the core could stretch from Toronto to Montreal and back. At today’s drilling costs, this represents a $40-50 million resource. The libraries, under the jurisdiction of the Ministry of Northern Development and Mines (MNDM), were established to collect, store and catalogue drill core from various sources across Ontario.

The first core libraries were established in June, 1984, in Timmins and Kirkland Lake. Since then, others have been built in Kenora, Thunder Bay, Sault Ste. Marie, Bancroft, Tweed and London.

The London library contains mostly Paleozoic and Mesozoic sedimentary core that was drilled by oil companies exploring for hydrocarbon deposits in southwestern Ontario. The core facility is affiliated with the Ontario government’s Petroleum Resources Library.

Each library is staffed by a core library geologist and an assistant. It has an office area, a laboratory for cutting, polishing and staining, inside and outside storage, and a core logging area. Operation is supervised by the resident geologist for the area.

Drill core sizes range from X-Ray (1.9 cm) up to HQ (6.3 cm). In Kirkland Lake, the library also houses sonic drill core from the Ontario government’s Kirkland Lake incentives overburden drilling program (KLIP). The oldest drill core on record is stored in the Timmins library. The hole is from a gold property in Bristol Twp. and dates back to 1928. In the late 1980s, so much drill core had been collected or donated that internal storage at most of the libraries had reached maximum capacity. Many of the libraries then began storing core outside on pallets. Because of a severe lack of storage space, the Timmins library was forced to “telescope” drill holes. Under this policy, several representative holes would be selected from a property and stored. Any remaining holes would be shortened or “telescoped.” However, when holes were telescoped, any features such as mineralized zones, alteration zones or geological structures were kept intact.

The practice of telescoping holes has since been discontinued. To allow for future expansion, each library is now building an off-site storage facility. Construction of the off-site facilities is being funded by a $1.2-million grant from the Jobs Ontario Capital Fund. Off-site storage areas are also being established in Red Lake, Sioux Lookout, Geraldton and Hemlo. These storage sites will be maintained by the local resident geologist’s office.

Johial Newsome, manager of MNDM’s Northeastern Ontario Region, told The Northern Miner that the off-sites should provide enough storage for the next 15-20 years at the present levels of collection.

The new off-site storage areas should prove timely. As more companies close their regional offices, large amounts of drill core are being donated to the libraries. The Timmins library collects on average 10,000-15,000 metres of core per year. In some of the less active regions such as Sault Ste. Marie, only about 1,500 metres are collected per year.

If the core is donated by a company, the company can request a 1-year period of confidentiality. If the core is filed for assessment, it becomes part of the public record immediately and a company can claim 4% of its drill costs for assessment purposes. All core donated or filed for assessment must be accompanied by location maps and drill logs.

Chris Hamblin, core library geologist in Timmins, said that each facility is attempting to collect drill core from all the ore deposit types that are found in its region. All of the drill core filed is available for relogging and sampling. In many instances, the holes are often re-evaluated for different commodities. The libraries can also be used by companies to log and sample core from ongoing exploration programs.

Newsome says that the core libraries represent a valuable resource and they add important information to the Ontario geoscience database. In most areas, the facilities are under-used. The Timmins facility, for example, had just under 1,000 visitors last year, mostly geologists and prospectors. Each core library produces a catalogue listing all of the drill holes on file. The library inventories are also available in digital form.