Curie point depth in Venezuela and the Eastern Caribbean

Aeromagnetic, gravity, and Differential Interferometric Synthetic Aperture Radar analyses reveal the causative fault of the 3 April 2017 Mw 6.5 Moiyabana, Botswana, earthquake

“…The CPD beneath the M w 6.5 earthquake epicenter is deepest in the area (~25 km). The depth to the base of the magnetized crust is directly related to the Curie point (550–580°C), being the typical range of temperatures at which magnetic minerals lose their ferromagnetism [ Arnaiz‐Rodrigues and Orihuela , ]. The brittle‐ductile (BD) transition zone within the Earth's crust is typically 250–400°C [ Scholz , ].…”

Thermal perturbations beneath the incipient Okavango Rift Zone, northwest Botswana

“…Figures and show that shallower CPD values (<15 km) and elevated heat flow values (>55 mW m −2 ) occur within the rift zone, whereas deeper CPD values (>15 km) and lower heat flow estimates (<50 mW m −2 ) values occur outside the rift beneath the surrounding Proterozoic mobile belts. Arnaiz‐Rodrigues and Orihuela [] classified the CPD values into two groups based on their position relative to the Moho depth: (1) CPD values shallower than the Moho are usually associated with areas with high heat flow resulting from crustal thinning due to extension/rifting, and (2) CPD values deeper than the Moho are typical of tectonically and isostatically stable areas with low heat flow such as shields and cratons. Therefore, variations in the CPD values can be correlated with the tectonic processes, especially thermal processes driving rift initiation.…”

“…The depth to the base of the magnetized layer is therefore directly related to the CP, and variations in this depth can be correlated to either heat flow and geothermal gradient or thermal properties of the lithosphere [Aboud et al, 2011;Arnaiz-Rodrigues and Orihuela, 2013]. The CPD is largely influenced by the regional tectonic setting such as old stable cratons versus more active tectonic regimes including subduction and rift zones [Arnaiz-Rodrigues and Orihuela, 2013]. The CPDs can be used as a proxy for imaging the thermal structure of the lithosphere [Ross et al, 2006].…”

Eight good reasons why the uppermost mantle could be magnetic

“…Up to now this idea has been rejected based on the conclusions of Wasilewski et al (1979) and Wasilewski and Mayhew (1992) that mantle rocks are too weakly magnetic and too hot to contribute to LWMA. This view, however, is increasingly at odds with a growing number of studies suggesting that the source of some LWMA lies in the lithospheric 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 4/39 mantle ( Figure 1): for example, in oceanic basins such as the Ligurian Sea (Chiozzi et al, 2005), the Caribbean Sea (Counil et al, 1989;Guevara et al, 2013;Arnaiz-Rodriguez et al, 2013), in the forearc mantle such as the Cascadia arc (Bostock et al, 2002;Blakely et al, 2005) and other oceanic regions (Harrison and Carle, 1981;Arkani-Hamed and Strangway, 1986;1987;ArkaniAhmed, 1993;Dyment et al, 1997;Bronner et al, 2011;Popov et al, 2011;Ravat et al, 2011).…”