Down-Hole Temperature Measurements, Deep Sea Drilling Project, Leg 42A

Abstract

Heat-flow measurements were made in DSDP boreholes at five sites in the Mediterranean and Aegean seas. AbnormalUy high heat flow was observed in the Algero-Provençal Basin, and in the Tyrrhenian and Aegean seas. Much lower heat flow was observed through the Central Ionian Sea and on the Florence Rise southwest of Cyprus. The heat-flow data from the DSDP holes are in excellent agreement with nearby conventional heat-flow values. High heat-flow through the Tyrrhenian and Aegean seas suggests, but does not require, that these basins are back-arc basins associated with the Calabrian and Cretan island arcs. The explanation of high heat flow through the Algero-Provençal and Balearic basins, and of low heat flow through the entire eastern Mediterranean Sea, may be related to thermal and chemical differences in, and horizontal and/or vertical displacements of, the asthenosphere beneath the converging African and Eurasian plates.

Thermal history of deep‐sea sediments as a record of recent changes in the deep circulation of the eastern Mediterranean

“…The temperature profiles both in the water column and in the sediments were dramatically different from what we expected from the few scattered heat flow measurements [ Erickson , 1970; Erickson et al , 1977; Haenel , 1972; Erickson and von Herzen , 1978; Della Vedova and Pellis , 1986, 1992; Camerlenghi et al , 1995] and regional oceanographic data available in the Jonian Sea [ Nittis et al , 1993]. Changes in the observed profiles, although scattered in space and unevenly sampled in time, can be evaluated at weekly, monthly, and interannual timescales.…”

Boron isotope geochemistry ofNa‐bicarbonate,Na‐chloride, andCa‐chloride waters from theNorthernApennineForedeep basin: other pieces of the sedimentary basin puzzle

“…sampled in the Messinian stratum of the DSDP site 372, the measured temperature values were between 24-28°C (Erickson & Von Herzen 2007) and their shift to low d 11 B is compatible with the presence of illite in the sediments (Chamley et al 2007). The mean temperatures determined by chemical and/or isotope geothermometers have been reported for French (Millot et al 2011), Gulf Coast (Land & Macpherson 1992;Williams et al 2001c) and our SM brine samples Boschetti 2013).…”

“…The reservoir temperature, or the temperature measured at depth of the samples shown in Fig. Concerning the two porewaters (Vengosh et al 2000), formation brines from France (Millot et al 2011), median values of the siliciclastic formation brines from the Gulf Coast (Land & Macpherson 1992;Land 1995), site 808, Nankai Trough mud volcano representative of the stress-induced B release (You et al 1996), and present-day seawater (Vengosh et al 1992 sampled in the Messinian stratum of the DSDP site 372, the measured temperature values were between 24-28°C (Erickson & Von Herzen 2007) and their shift to low d 11 B is compatible with the presence of illite in the sediments (Chamley et al 2007). 6B.…”

The effects of sedimentation and compaction on oceanic heat flow

“…The corrections were also calculated using plate model initial conditions; the curves follow the same pattern, although the final fluxes are 1-2 per cent higher. A further two western Mediterranean heat flow surveys reported by Hutchison et al (1985) gave alterations to 83-87 per cent (Balearic basin) and 92-96 per cent (southern Tyrrhenian Sea); these compare with the values of 33-60 per cent for the Balearic and 60-90 per cent for the Tyrrhenian estimated by Erickson & Von Herzen (1978) from an analytical approach.…”