Regional heat flow variations in the northern Michigan and Lake Superior region determined using the silica heat flow estimator

Abstract

Conventional heat flow data are sparse for northern Michigan. The groundwater silica heat flow estimator expands the database sufficiently to allow regional variations in heat flow to be examined. Heat flow shows a pattern of alternating highs and lows trending ESE across the Upper Peninsula and Lake Superior. The informal names given to these features, their characteristic heat flow and inferred causes are listed: southwestern high > 40 mW m −2 High heat generation of basement rocks; central low < 40 mW m −2 Geohydrology (groundwater recharge) possibly coupled with low heat generation of basement rocks; northeastern high > 40 mW m −2 Geohydrology (groundwater discharge); northeastern low < 40 mW m −2 Low heat generation of basement rocks. The results suggest that, for the study area, regional variations in heat flow cannot be interpreted solely in terms of regional variations of the heat generation rate of basement rocks.