Z. Gvirtzman et Z. Garfunkel, THE TRANSFORMATION OF SOUTHERN ISRAEL FROM A SWELL TO A BASIN - STRATIGRAPHIC AND GEODYNAMIC IMPLICATIONS FOR INTRACONTINENTAL TECTONICS, Earth and planetary science letters, 163(1-4), 1998, pp. 275-290
The history of souther Israel during the similar to 100 Myr period bet
ween the Cretaceous and the Eocene is an example of epeirogenic moveme
nts which were controlled by magmatism and heating. Initially this reg
ion was uplifted and became a local swell; then it subsided more than
its surroundings and became a local basin. This study analyzes the sub
sidence history of the region during its cooling for two purposes: fir
st, to understand the relations between the tectonic patter of subside
nce and the resulting stratal geometry, and second, to constrain the v
olume of magmatism that intruded the lithosphere and perturbed the iso
static equilibrium. Our results show that lateral changes in the inten
sity of the tectonically-driven subsidence are not always expressed by
simple corresponding changes in the thickness of sedimentary units. T
he most prominent example of this was found in the Cenomanian section,
which thickens northward in absolute contrast with the tectonic patte
rn of subsidence during its deposition. The reason for this discrepanc
y lies in lateral differences in the compactibility of the substrate u
pon which these sediments were deposited. The two most important facto
rs controlling the compactibility of the substrate are the thickness o
f previously existing sediments and their history of uplift. Since sed
iments that are reburied after an uplifting phase do not compact signi
ficantly until they reach their previous maximal depth, we emphasize t
he need to reveal the amount of exhumation from the amount of erosion
hidden in unconformities. Our second aim was achieved only in part bec
ause we cannot distinguish the subsidence caused by midlithospheric in
trusions from secondary factors. One possible scenario that satisfies
the observations is a combination of midlithospheric intrusions equiva
lent to a 15-km-thick sill, plus thermal thinning of the lithosphere o
f the same order. (C) 1998 Published by Elsevier Science B.V. All righ
ts reserved.