Radiogenic heat production in the crust from inversion of gravity and magnetic data

Ketil Hokstad,Zuzana Alasonati Tašárová,Rune Kyrkjebø,Kenneth Duffaut,Stephen Anthony Clark,Christine Fichler,Torgeir Wiik

doi:10.17850/njg97-3-04

Abstract

Radiogenic heat production in the crust from inversion of gravity and magnetic data

Highlights

The thermal state and thermal history of the subsurface are of major importance for the petroleum prospectivity of sedimentary basins
Kukkonen & Peltoniemi (1998) investigated 2700 core samples from Finland, and concluded that the correlation between heat production and other geophysical and petrophysical parameters were generally low. They argued that heat production is due to the presence of thorium, uranium and potassium in the rocks, whereas geophysical parameters such as density, velocity, susceptibility and resistivity are controlled by other factors
The heat produced within the crystalline crust and the mantle heat flow estimated at the Moho are discussed in detail below

Summary

Introduction

The thermal state and thermal history of the subsurface are of major importance for the petroleum prospectivity of sedimentary basins. 2017: Radiogenic heat production in the crust from inversion of gravity and magnetic data. Kukkonen & Peltoniemi (1998) investigated 2700 core samples from Finland, and concluded that the correlation between heat production and other geophysical and petrophysical parameters were generally low They argued that heat production is due to the presence of thorium, uranium and potassium in the rocks, whereas geophysical parameters such as density, velocity, susceptibility and resistivity are controlled by other factors. To estimate radiogenic heat production in the crust, and its contribution to heat flow, we apply a novel multi-geophysical inversion method. We apply the full workflow to gravity and magnetic data from the greater Barents Sea. The estimated basal and surface heat flow can be applied directly to compute temperature within the steady-state approximation. Our approach differs from other published forward modelling approaches, such as Guillou et al (1994), Zeyen & Fernàndez (1994), Afonso et al (2008) and Fullea et al (2009), by explicitly inverting for the RHP in the crust based on a specific work flow, rather than by assigning a certain value of the RHP to the crustal layers to match the measured surface heat flow

Methods and general workflow

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