Inter- and supratidal sedimentology of a fjord-head estuary, south-western British Columbia

被引:14
作者
Gibson, JW
Hickin, EJ
机构
[1] Simon Fraser Univ, Dept Geog, Burnaby, BC V5A 1S6, Canada
[2] Simon Fraser Univ, Inst Quaternay Res, Burnaby, BC V5A 1S6, Canada
关键词
D O I
10.1046/j.1365-3091.1997.d01-60.x
中图分类号
P5 [地质学];
学科分类号
0709 ; 081803 ;
摘要
Detailed examination of inter-and supratidal delta and floodplain sediments exposed in eroding bank sections at 52 locations along the Squamish River estuary provides the basis for recognizing seven distinct facies within the 5500 m-long estuary. Estuary sedimentation is initially driven by the development of sand bar complexes along the seaward edge of the intertidal delta. Sedimentation continues within interdistributary bay environments as intertidal sandflats and then tidal marshes develop. Aggradation of the delta within interdistributary bay environments results in a gradual transition from delta to alluvial plain. Of the seven facies identified, only the intertidal sands and tidal marsh deposits provide evidence of their tidal origin. Examination of deposits throughout the riverine estuary reveals a number of gradual yet distinct changes of sediment size, structure, and sequence architecture. These trends record the changing nature of tidal and riverine control on sedimentation along the tidal gradient. Generally, with increasing distance up-estuary, sediment grain-size increases, the thickness of fine-grained overbank deposits decreases, and bedding changes from fine parallel bedding to higher energy bedforms. In addition, fining-upward successions become capped by coarser sands, facies contacts change from gradational to abrupt and occasionally erosional, and facies successions become increasingly complex and less predictable. Squamish River estuary has been divided into four zones based on sedimentological and stratigraphical evidence, each zone reflecting changes in the relative influence of tidal and riverine control on sedimentation. Each zone contains distinctly different facies sequences, although zone boundaries generally are gradational.
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页码:1031 / +
页数:23
相关论文
共 60 条
[1]  
Allen G.P., 1991, Clastic Tidal Sedimentology, V16, P29
[2]  
ALLEN GP, 1993, 5 INT C FLUV SED MOD, P5
[3]  
ALLEN JRL, 1970, J SEDIMENT PETROL, V40, P298
[4]  
BARWIS JH, 1978, CANADIAN SOC PETROLE, V5, P129
[5]  
BOSENCE D W J, 1973, Geologie en Mijnbouw, V52, P63
[6]   A GRAPHIC PRESENTATION OF THE FACIES MODEL OF SALT MARSH DEPOSITS [J].
BOUMA, AH .
SEDIMENTOLOGY, 1963, 2 (02) :122-129
[7]   DESCRIPTION AND INTERPRETATION OF FLUVIAL DEPOSITS - A CRITICAL PERSPECTIVE [J].
BRIDGE, JS .
SEDIMENTOLOGY, 1993, 40 (04) :801-810
[8]  
CALVERLEY A, 1984, THESIS U CALGARY ALB
[9]   SEDIMENTATION IN A RIVER DOMINATED ESTUARY [J].
COOPER, JAG .
SEDIMENTOLOGY, 1993, 40 (05) :979-1017
[10]  
Dalrymple R.W., 1991, Canada Clastic Tidal Sedimentology-Memoir 16, V16