TY - JOUR
T1 - Stable isotopes of surface water across the Longmenshan margin of the eastern Tibetan Plateau
AU - Xu, Qiang
AU - Hoke, Gregory D.
AU - Jing, Liu Zeng
AU - Ding, Lin
AU - Wang, Wei
AU - Yang, Yang
PY - 2014/8/1
Y1 - 2014/8/1
N2 - Characterization of the stable isotope compositions (δ18O and δD) of modern-day surface waters traversing mountain ranges and bordering continental plateaus is important for refining climate models and establishing modern isotope-elevation gradients along mountain ranges. The Longmenshan margin of the Tibetan Plateau is a steep, 4 km topographic front situated near the boundaries between westerlies and Asian monsoon moisture sources, and is previously unexplored with respect to the variation in water isotopic composition with elevation. This study reports stable isotope data from 101 water samples collected from streams, springs, and ponds along the Min River (Minjiang) watershed, which traverses the Longmenshan margin. Local meteoric water lines, d-excess values, and surrounding precipitation and river water data sets suggest that precipitation across the Longmenshan margin is dominated by the East Asian summer monsoon. The increase in d-excess values with increasing catchment elevation breaks down as local moisture recycling becomes important at elevations > 3 km a.s.l. Along the Min River, however, the δ18Ow and δDw values decrease with increasing catchment elevation, which fit second-order polynomial curves and are well-approximated by a simple Rayleigh fractionation processes. The temperature-corrected oxygen values in authigenic carbonates from the Pleistocene Zoige Basin, north of the Min River watershed, yield elevations equivalent to present by the oxygen isotope-elevation relationship of the Longmenshan margin.
AB - Characterization of the stable isotope compositions (δ18O and δD) of modern-day surface waters traversing mountain ranges and bordering continental plateaus is important for refining climate models and establishing modern isotope-elevation gradients along mountain ranges. The Longmenshan margin of the Tibetan Plateau is a steep, 4 km topographic front situated near the boundaries between westerlies and Asian monsoon moisture sources, and is previously unexplored with respect to the variation in water isotopic composition with elevation. This study reports stable isotope data from 101 water samples collected from streams, springs, and ponds along the Min River (Minjiang) watershed, which traverses the Longmenshan margin. Local meteoric water lines, d-excess values, and surrounding precipitation and river water data sets suggest that precipitation across the Longmenshan margin is dominated by the East Asian summer monsoon. The increase in d-excess values with increasing catchment elevation breaks down as local moisture recycling becomes important at elevations > 3 km a.s.l. Along the Min River, however, the δ18Ow and δDw values decrease with increasing catchment elevation, which fit second-order polynomial curves and are well-approximated by a simple Rayleigh fractionation processes. The temperature-corrected oxygen values in authigenic carbonates from the Pleistocene Zoige Basin, north of the Min River watershed, yield elevations equivalent to present by the oxygen isotope-elevation relationship of the Longmenshan margin.
KW - Longmenshan margin
KW - Min River
KW - Tibetan Plateau
KW - paleoelevation
KW - stable isotopes
UR - http://www.scopus.com/inward/record.url?scp=84907931853&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84907931853&partnerID=8YFLogxK
U2 - 10.1002/2014GC005252
DO - 10.1002/2014GC005252
M3 - Article
AN - SCOPUS:84907931853
VL - 15
SP - 3416
EP - 3429
JO - Geochemistry, Geophysics, Geosystems
JF - Geochemistry, Geophysics, Geosystems
SN - 1525-2027
IS - 8
ER -