The Hanington coal occurrence is located along Hanington Creek approximately 110 kilometres south of Tumbler Ridge.
The region is underlain by an assemblage of sedimentary rocks consisting mainly of continental margin and shelf facies rocks. This assemblage was deposited on and to the west of the Ancestral North American craton. These sedimentary rocks, for the most part typical miogeoclinal continental margin slope and basin facies, range in age from Hadrynian to Upper Cretaceous. Structurally these rocks are part of the Foreland thrust and fold belt of the North American Cordillera.
Rocks of a sandstone unit underlie most of the northern and eastern portions of the Hanington property and are considered to correlate with the Upper Jurassic to Lower Cretaceous Minnes Group (ca. 1979, Coal Assessment Report 536). This is the only unit which contains any coal seams on the property. The sandstones that form the predominant lithology of this unit vary from fine grained and well laminated to coarse grained, massive and quartzitic. They also vary substantially in thickness from less than a metre to several tens of metres. Interbedded with these rocks are conglomerates, shales, siltstones and coal seams. The conglomerates are normally characterized by the presence of abundant black chert. This gives the rock a dark grey appearance, although lighter shades also occur due to either the weathering of the sandstone matrix or, less frequently, predominance of lighter shades of pebbles. The size of the pebbles varies from granular to large, whereas the matrix is commonly a medium- to coarse-grained sandstone. Conglomerate beds vary from 0.5 metre thick to zones, with interbedded sandstone and pebbly sandstone layers or lenses, up to 10 metres thick. Black shales and yellow-orange weathering siltstones up to a few metres in thickness are also present. Plant fossils are present in most of the shales and in the siltstones, which are found in proximity to coal seams. Some of the sandstones and conglomerates also contain large, carbonized ‘stems’ and/or coaly inclusions.
The coal seams range up to 1 metre in thickness but are usually between 0.10 and 0.30 metre thick. The coal is hard and sometimes argillaceous; it often has a high vitrain content. No coal seams or zones of economic potential have been found (ca. 1979, Coal Assessment Report 536).
Some chip samples taken from two thin seams in Hanington Creek have undergone proximate analysis and testing, with results of from 9.52 to 44.09 per cent ash, 26.12 to 35.96 per cent volatile matter, 28.58 to 52.98 per cent fixed carbon, 0.54 to 0.70 per cent sulphur and 7740 to 13 410 B.T.U.s (Coal Assessment Report 536).
The main structural feature in the area is a broad, roughly north- or northwest-trending syncline. The west limb of the syncline is cut by a north- to northwest-trending thrust fault (west-dipping) that places Triassic limestones against Cretaceous rocks close to the fault. The Minnes Group is tightly folded.
Work History
In 1979, Denison Mines Limited conducted an exploration program consisting of geological mapping and locating and sampling any coal seams that might be present.
