Autori: Clift, P D., Giosan, L., Blusztajn, J., Campbell, I.H., Allen., C., Pringle, M., Tabrez, A.R., Danish, M., Rabbani, M.M., Alizai, A., Carter., A., Luckge, A.

Editorial: Geology, 36(1), p.79-82, 2008.

Rezumat:

Climate is one of the principal controls setting rates of continental
erosion. Here we present the results of a provenance analysis
of Holocene sediments from the Indus delta in order to assess climatic
controls on erosion over millennial time scales. Bulk sediment Nd isotope
analysis reveals a number of changes during the late Pleistocene
and early Holocene (at 14-20, 11-12 and 8-9 ka) away from erosion of
the Karakoram and toward more sediment fl ux from the Himalaya.
Radiometric Ar-Ar dating of muscovite and U-Pb dating of zircon
sand grains indicate that the Lesser Himalaya eroded relatively more
strongly than the Greater Himalaya as global climate warmed and
the summer monsoon intensifi ed after 14 ka. Monsoon rains appear
to be the primary force controlling erosion across the western Himalaya,
at least over millennial time scales. This variation is preserved
with no apparent lag in sediments from the delta, but not in the deep
Arabian Sea, due to sediment buffering on the continental shelf.

Cuvinte cheie: Indus, Pakistan, monsoon, tectonics, climate