The Himalayas, organic carbon burial, and climate in the Miocene

American Geophysical Union (AGU) - Tập 9 Số 3 - Trang 399-404 - 1994
Maureen E. Raymo

Tóm tắt

Cooling ages of rock in the Himalayas imply that rapid exhumation between the Main Central thrust system and the South Tibetan detachment system occurred between 21 and 17 Ma. The generation of relief and enhanced weathering which followed this event may have resulted in a pronounced increase in the delivery of dissolved strontium, carbon, phosphorus, and other chemical weathering products to the ocean (Richter et al., 1992). The increased supply of nutrients stimulated productivity in oceanic upwelling zones and expansion of the oxygen minimum zone leading to enhanced burial and preservation of organic matter in the Monterey formation and other deposits from this interval. A downdraw of atmospheric CO2 associated with enhanced chemical weathering rates and organic matter burial may have led to global cooling and the expansion of the Antarctic ice sheet by 15 Ma. The above scenario differs from the “Monterey hypothesis” of Vincent and Berger in that CO2 downdraw is primarily via silicate weathering rather than organic carbon burial and that organic carbon burial is driven by increased delivery of nutrients to the ocean rather than by stronger upwelling. A carbon mass balance calculation which assumes that river fluxes have been increasing over the last 40 Ma predicts that absolute organic carbon burial increased over this interval while, at the same time, the fraction of carbon buried as organic matter versus carbonate decreased. This implies that the organic carbon cycle has acted as a net source of CO2 to the atmosphere over the late Cenozoic.

Từ khóa


Tài liệu tham khảo

Armstrong R. L., 1971, Glacial erosion and the variable isotopic composition of strontium in sea water, Nature, 230, 132

Arthur M. A., 1991, Estimates of pCO2 for the last 120 Ma based on the δ13C of marine phytoplankton organic matter, Eos Trans. AGU, 72, 166

10.1126/science.249.4975.1382

10.2475/ajs.283.7.641

10.1016/0016-7037(92)90302-Y

10.1038/357578a0

10.1038/361344a0

10.1130/0091-7613(1990)018<1227:PAWOSS>2.3.CO;2

10.1016/0012-821X(87)90224-X

10.1029/PA003i002p00137

10.1130/0016-7606(1991)103<0112:HRSISA>2.3.CO;2

10.1126/science.258.5088.1594

10.2475/ajs.292.2.81

10.1029/92GB00190

10.1029/GD003p0111

Garrison R. E., 1981, The Monterey Formation and Related Siliceous Rocks of California, Spec. Publ., Soc. Econ. Paleontol. Mineral, 45, 1

Garrison R. E., 1990, Phosphate Deposits of the World, 285

10.1126/science.255.5052.1663

Hodell D. A., Variations in the strontium isotopic ratio of seawater during the Miocene: Stratigraphie and geochemical implications, Paleoceanography

Hodell D. A., 1990, Variation in the strontium isotopic composition of seawater (8 Ma to present): Implications for chemical weathering rates and dissolved fluxes to the oceans, Chem. Geol., 80, 291

10.1126/science.258.5087.1466

Isaacs C. M., 1987, Siliceous Sedimentary Rock‐Hosted Ores and Petroleum, 83

10.1016/S0070-4571(08)70094-3

10.1016/0012-821X(92)90087-C

10.1130/0091-7613(1983)11<578:LOMGRO>2.0.CO;2

Leckie R. M., 1985, Late Paleogene and early Neogene foraminifers of the Deep Sea Drilling Project site 270, Ross Sea, Antarctica, Initial Rep. Deep Sea Drill. Proj., 90, 1093

LeFort P., 1989, Tectonic Evolution of the Tethyan Region, 289

10.1029/90PA01941

10.1038/346029a0

Oslick J. S., Oligocene‐Miocene strontium isotopes: Stratigraphie revisions and correlations to an inferred glacioeustatic record, Paleoceanography

Pisciotto K. A., 1981, Lithofacies and depositional environments of the Monterey Formation, California, Spec. Publ., Soc. Econ. Paleontol. Mineral., 15, 97

10.2475/ajs.289.4.436

10.1038/360647a0

10.1038/342163a0

10.1029/91PA00321

10.1016/0012-821X(93)90177-B

10.1130/0091-7613(1991)019<0344:GESTCC>2.3.CO;2

10.1038/359117a0

10.1130/0091-7613(1988)016<0649:IOLCMB>2.3.CO;2

10.1016/0012-821X(92)90070-C

10.1144/GSL.SP.1987.026.01.27

Sorkhabi R. B., 1993, Rise of the Himalaya: A geochronologic approach, Geol. Soc. Am. Today, 3, 86

10.1038/363149a0

10.1016/0277-3791(91)90026-Q

10.1029/GM032p0455

10.1130/MEM163-p103

10.2475/ajs.289.10.1158

10.1029/91PA02561

10.1126/science.212.4495.665

Thông tin
Thông tin xuất bản

American Geophysical Union (AGU)

Tập 9 Số 3

399-404

Thông tin tác giả