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Abrupt increase in seasonal extreme precipitation at the Paleocene-Eocene boundary

Schmitz, Birger LU and Pujalte, Victoriano (2007) In Geology 35(3). p.215-218
Abstract
A prominent increase in atmospheric CO, at the Paleocene-Eocene boundary, ca. 55 Ma, led to the warmest Earth of the Cenozoic for similar to 100 k.y. High-resolution studies of continental flood-plain sediment records across this boundary can provide crucial information on how the hydrological cycle responds to rapidly changing CO2. Here we show from continental records across the Paleocene-Eocene boundary in the Spanish Pyrenees, a subtropical paleosetting, that during the early, most intense phase of CO2 rise, normal, semiarid coastal plains with few river channels of 10-200 m width were abruptly replaced by a vast conglomeratic braid plain, covering at least 500 km(2) and most likely more than 2000 km(2). This braid plain is interpreted... (More)
A prominent increase in atmospheric CO, at the Paleocene-Eocene boundary, ca. 55 Ma, led to the warmest Earth of the Cenozoic for similar to 100 k.y. High-resolution studies of continental flood-plain sediment records across this boundary can provide crucial information on how the hydrological cycle responds to rapidly changing CO2. Here we show from continental records across the Paleocene-Eocene boundary in the Spanish Pyrenees, a subtropical paleosetting, that during the early, most intense phase of CO2 rise, normal, semiarid coastal plains with few river channels of 10-200 m width were abruptly replaced by a vast conglomeratic braid plain, covering at least 500 km(2) and most likely more than 2000 km(2). This braid plain is interpreted as the proximal parts of a megafan. Carbonate nodules in the megafan deposits attest to seasonally dry periods and together with megafan development imply a dramatic increase in seasonal rain and an increased intra-annual humidity gradient. The megafan formed over a few thousand years to similar to 10 k.y. directly after the Paleocene-Eocene boundary. Only repeated severe floods and rainstorms could have contributed the water energy required to transport the enormous amounts of large boulders and gravel of the megafan during this short time span. The findings represent evidence for considerable changes in regional hydrological cycles following greenhouse gas emissions. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
keywords
carbon isotope excursion, hydrological cycle, fluvial megafan, greenhouse warming, Paleocene-Eocene boundary
in
Geology
volume
35
issue
3
pages
215 - 218
publisher
Geological Society of America
external identifiers
  • wos:000247627700006
  • scopus:33947328023
ISSN
0091-7613
DOI
10.1130/G23261A.1
language
English
LU publication?
yes
id
c1901bba-ebd3-45d5-a2ff-815158c8105c (old id 646490)
date added to LUP
2007-12-18 09:08:42
date last changed
2017-10-22 04:29:45
@article{c1901bba-ebd3-45d5-a2ff-815158c8105c,
  abstract     = {A prominent increase in atmospheric CO, at the Paleocene-Eocene boundary, ca. 55 Ma, led to the warmest Earth of the Cenozoic for similar to 100 k.y. High-resolution studies of continental flood-plain sediment records across this boundary can provide crucial information on how the hydrological cycle responds to rapidly changing CO2. Here we show from continental records across the Paleocene-Eocene boundary in the Spanish Pyrenees, a subtropical paleosetting, that during the early, most intense phase of CO2 rise, normal, semiarid coastal plains with few river channels of 10-200 m width were abruptly replaced by a vast conglomeratic braid plain, covering at least 500 km(2) and most likely more than 2000 km(2). This braid plain is interpreted as the proximal parts of a megafan. Carbonate nodules in the megafan deposits attest to seasonally dry periods and together with megafan development imply a dramatic increase in seasonal rain and an increased intra-annual humidity gradient. The megafan formed over a few thousand years to similar to 10 k.y. directly after the Paleocene-Eocene boundary. Only repeated severe floods and rainstorms could have contributed the water energy required to transport the enormous amounts of large boulders and gravel of the megafan during this short time span. The findings represent evidence for considerable changes in regional hydrological cycles following greenhouse gas emissions.},
  author       = {Schmitz, Birger and Pujalte, Victoriano},
  issn         = {0091-7613},
  keyword      = {carbon isotope excursion,hydrological cycle,fluvial megafan,greenhouse warming,Paleocene-Eocene boundary},
  language     = {eng},
  number       = {3},
  pages        = {215--218},
  publisher    = {Geological Society of America},
  series       = {Geology},
  title        = {Abrupt increase in seasonal extreme precipitation at the Paleocene-Eocene boundary},
  url          = {http://dx.doi.org/10.1130/G23261A.1},
  volume       = {35},
  year         = {2007},
}