GRAVITY-FIELD OVER THE SEA-OF-GALILEE - EVIDENCE FOR A COMPOSITE BASIN ALONG A TRANSFORM-FAULT

The Sea of Galilee (Lake Kinneret) is located at the northern portion of the Kinneret-Bet Shean basin, in the northern Dead Sea transform. T hree hundred kilometers of continuous marine gravity data were collect ed in the lake and integrated with land gravity data to a distance of more than 20 km around the lake. Analyses of the gravity data resulted in a free-air anomaly map, a variable density Bouguer anomaly map, an d a horizontal first derivative map of the Bouguer anomaly. These maps , together with gravity models of profiles across the lake and the are a south of it, were used to infer the geometry of the basins in this r egion and the main faults of the transform system. The Sea of Galilee can be divided into two units. The southern half is a pull-apart that extends to the Kinarot Valley, south of the lake, whereas the northern half was formed by rotational opening and transverse normal faults. T he deepest part of the basinal area is located well south of the deepe st bathymetric depression. This implies that the northeastern part of the lake, where the bathymetry is the deepest, is a young feature that is actively subsiding now. The pull-apart basin is almost symmetrical in the southern part of the lake and in the Kinarot Valley south of t he lake. This suggests that the basin here is bounded by strike-slip f aults on both sides. The eastern boundary fault extends to the norther n part of the lake, while the western fault does not cross the norther n part. The main factor controlling the structural complexity of this area is the interaction of the Dead Sea transform with a subperpendicu lar fault system and rotated blocks.