scaling relationships in fluvial depostional systems

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Scaling Relationships in Fluvial Depostional Systems*

Kristy Milliken1, Mike Blum

2, and John Martin

1

Search and Discovery Article #30245 (2012)**Posted August 20, 2012

*Adapted from oral presentation at AAPG Annual Convention and Exhibition, Long Beach, California, April 22-25, 2012

**AAPG 2012 Serial rights given by author. For all other rights contact author directly.

1ExxonMobil Exploration Company, Houston, TX

2ExxonMobil Upstream Research, Houston, TX ([email protected])

Abstract

Fluvial systems possess a range of scaling relationships that reflect drainage-basin controls on water and sediment flux. In

hydrocarbon exploration and production, scaling relationships for fluvial deposits can be utilized to constrain environmental and

sequence-stratigraphic interpretations, as well as predict the lateral extent of fundamental reservoir flow units. This study documentsthe scales of channel fills, point and channel bars, channel belts, and coastal-plain incised valleys from well-constrained Quaternary

fluvial systems.

Data on channel-fill and point-bar to channel-belt scales were compiled from published thicknesses for sinuous single-channel

systems, with spatial dimensions measured from GoogleEarth. Fluvial systems included in this database span 3 orders of magnitude in

drainage area, from continental-scale systems to small tributaries, and span tropical to sub-polar climatic regimes. Channel-fill andchannel-belt scales were measured upstream from backwater effects, so as to minimize inclusion of distributive, highly avulsivesystems. Scales of incised valleys were derived from well-constrained published examples that are known to have formed during the

last 100 kyr glacio-eustatic cycle.

All scaling relationships are represented by statistically-significant power laws, with absolute dimensions that scale to drainage area,

but distinct clustering occurs between channel fills, point bars and channel belts, and incised valleys. Mean width-to-thickness ratiosfor channel fills are ~10:1, whereas point bars commonly range from 70-250:1. Coastal-plain incised valleys from the last glacio-
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eustatic cycle range from 25-150 m in thickness, and a few kilometers to more than 80 km in width, with width-to-thickness ratios of~600-800.

Scales of Quaternary examples compare well with previous compilations of channel-belt scales interpreted in the ancient record, and

with theory. However, the smallest Quaternary incised valleys in our database reside in the uppermost part of the domain of publishedcompilations of ancient incised valleys, with ancient examples overlapping significantly with both interpreted channel fills andchannel belts. When interpreted within the context of this database from modern systems, we suggest many ancient examples may

have been overinterpreted, which in turn suggests a persistent lack of objective criteria for differentiating channel fills, channel belts,

and incised valleys.

References

Blum, M.D., M.J. Guccione, D.A. Wysocki, P.C. Robnett, and E.M. Rutledge, 2000, Late Pleistocene evolution of the lowerMississippi River valley, southern Missouri to Arkansas: GSA Bulletin, v. 112/2, p. 221-235.

Blum, M.D., J.H. Tomkin, A. Purcell, and R.R. Lancaster, 2008, Ups and downs of the Mississippi Delta: Geology, v. 36/9, p. 675-678.

Jackson, R.G., II, 1976a, Depositional model of point bars in the lower Wabash River: Journal of Sedimentary Petroleum, v. 46, p.

579-594.

Jackson, R.G., II, 1976b, Large scale ripples of the lower Wabash River: Sedimentology, v. 23, p. 593-632.

Kolla, V., H.W. Posamentier, and L.J. Wood, 2007, Deep-water and fluvial sinuous channels; characteristics, similarities and

dissimilarities, and modes of formation, in R.B. Wynn, and B.T. Cronin, (eds.), Sinuous deep-water channels; genesis, geometry andarchitecture: Marine and Petroleum Geology, v. 24/6-9, p. 388-405.

Miall, A.D., 2002, Architecture and sequence stratigraphy of Pleistocene fluvial systems in the Malay Basin, based on seismic time-

slice analysis: AAPG Bulletin, v. 86/7, p. 1201-1216.

Reijenstein, H.M., H.W. Posamentier, and J.P. Bhattacharya, 2011, Seismic geomorphology and high-resolution seismic stratigraphy

of inner-shelf fluvial, estuarine, deltaic, and marine sequences, Gulf of Thailand: AAPG Bulletin, v. 95/11, p. 1959-1990.


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Rittenour, T.M., R.J. Goble, and M.D. Blum, 2005, Development of an OSL chronology for late Pleistocene channel belts in theLower Mississippi Valley, USA: Quaternary Science Reviews, v. 24/23-24, p. 2539-2554.

Rittenour, T.M., M.D. Blum, and R.J. Goble, 2007, Fluvial evolution of the lower Mississippi River valley during the last 100 k.y.

glacial cycle; response to glaciation and sea-level change: GSA Bulletin, v. 119/5-6, p. 586-608.

Willis, B.J., S.L. Dorobek, and Y. Darmadi, 2007, Three-dimensional seismic architecture of fluvial sequences on the low-gradient

Sunda Shelf, offshore Indonesia: JSR, v. 77/3-4, p. 225-238.


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KT Milliken*, MD Blum, JM Martin

Exxonmobil Upstream ResearchHouston, TX 77252

* now at Chevron

Scaling Relationships in Fluvial Depositional Systems


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Milliken et al. (2012) AAPG Annual Meeting

FLUVIAL SCALING RELATIONSHIPS

Travis Peak Fm., Zone 1, original interpretation by R.S. Tye

reinterpretation by Miall (2006) using scaling relationships

50

m

well-spacing ranges from 0.8-2.2 km, with a mean of 1.54 km

50 km

7 m deep and 420 m wide

7 m deep and 1750 m wide

Channel-Belt Sand Bodies Significance of Scaling Relationships


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Milliken et al. (2012) AAPG Annual Meeting


Motivations Recent Compilation by Gibling (2006)

Compilation of scalesin published literature

Scale domains are

very different from

modern systems,

much larger range

Raises issue of how

original data were

interpreted, and

criteria that were used

Need to cross-check

with modern systems,

where dimensions are

an observation, not

interpretation


7/23Milliken et al. (2012) AAPG Annual Meeting


Goals Quantify Scales of 1stOrder Fluvial Elements

Construct a database of modern channel-belt and channel-fill scales

Google Earth Approach: Scour literature and global landsat / DEM mature point bars, recently cutoff or close to cutoff

point bars with thickness measurement, i.e. core through deposit,

measure width, thickness, asymetry

Construct dataset of Late Quaternary incised-valley scales

coastal-plain valleys with robust geochronological control

channel fills andchannel-belt margins

are fundamental barriers

to flow

after Jordan and Pryor 1992)

basal scoursurface

point-bar

sands

channel-fill

muds




Bar Accretion and Large-Scale Inclined-Strata Sets

5-7 m

exhumed acrretionary topography,

Triassic Chinle Formation,, Arizona

1 km

LIDAR Image,

False River,

Louisiana

large-scale incl ined strata set,

lower Eocene, Tremp-Graus basin

3d seismic slice, illustrating

accretionary signature

20 m

1 km

from Reijenstein et al. (2011)




bankfull

channel

channel fill

(a deposit)

Definitions Channels, Channel Fills, and Channel Belts

Qbf

large-scale incl ined strata sets




Channel-belt and channel-fill scales from 38 modern rivers

periglacial to tropical drainage areas = 250 to 3,000,000 km2

124 measured meanders

Incised-valley Scales from 10 Late Quaternary Systems

drainage areas = 50,000 to 3,000,000 km2

Dataset




Methodology: Wabash River Example

Thickness: 9 m

Point bar areal extent: 0.8 km

2

Abandoned Channel Width: 190 m

Translation Length: 1450 m

Non-translation length: 650 m

Drainage Basin: 75,700 km2

Jackson (1976)

GRAPHICCOLUMN




Drainage Area (km2)

1stOrder Relationship

BankfullDischarge(m

3/s)

Bankfull Discharge (m3/s)

1stOrder Relationship

Point-BarThickness

(m)

(bankfullchanneldepth)

Drainage Area (km2)

Point-BarThick

ness(m)

Point-Bar Thickness (m)

Point-BarWidth(m)

Derivative Relationship Production ScaleDerivative Relationship Exploration Scale

Scaling of Channel Belts

w/t ~ 200:1




1 m

Kolla et al., 2007Donselaar and Overeem, 2008Blackhawk Fm

Examples from other studies

Heterolithic Abandoned Channel Fills

ChannelWidth(m)

Seismic examplesKolla et al. 2007,

Willis et al. 2007,

Miall, 2002;

Reijenstein et al. 2011

Castlegate-Blackhawk

Channel Depth (m)

w/t ~ 10-15:1




Low-Net End Member

High-Net End Member

Highly heterolithic Ribbon sands and thin sheet sands

encased in muds

Dominated by avulsion processes

Highly aggradational stacking

Amalgamated sand bodies

Channel fills and channel-belt margins

are dominant barriers to flow

Dominated by channel-belt migration

Fluvial processes confined to discrete

valley

Degradational or low aggradationalstacking

Fundamental Contrasts in Channel-Belt Scales: Why??




Fundamental Contrasts in Channel-Belt Scales: Backwater Effects

15 4520 25 3530 40

14000

12000

10000

8000

6000

4000

2000

0

upstream

R2= 0.91

channelbeltwidth

channel belt thickness

1

23

4

5

6

14

12

13

7

11

88

9

downstream

R2= 0.76

back-

water

limits

10 km




Low-Net End Member

High-Net End Member

Highly heterolithic

Dominated by avulsion processes within

backwater length

Highly aggradational stacking

Distributary channel belts w/t = 20-50:1

Amalgamated sand bodies

Channel fills and channel-belt margins

are dominant barriers to flow

Dominated by channel-belt migration

Fluvial processes confined to discrete

valley

Degradational or low aggradational

stacking Channel belts w/t = 200:1, channel fi lls 15:1

Fundamental Contrasts in Channel-Belt Scales: Why??




Gibling (2006) data

Scales of Incised Valleys Published Ancient




Significance of Incised-Valley Scales to Interpretation

10 km

Vicksburg

Baton Rouge

New Madrid

Memphis

New Orleans

Mississippi

incised valley

lease

size

lease

size

50 km

LOWER MISSISSIPPI VALLEYTRINITY VALLEY





Coastal-Plain Incised Valleys - Lower Mississippi River

based on Blum et al. (2000), Rittenour et al. (2005, 2007), and Blum et al. (2008)

Vicksburg

Baton Rouge

New Madrid

Memphis

New Orleans

Mississippi

incised valley





A A

50-35 ka

33-24 ka

22-18 ka

>80 ka

Coastal-Plain Incised Valleys - Lower Trinity River, Texas

EJf onMobii

Upstream esearch

I

I

20

I

I High I

Modern

I

Middle

I Deweyville I

5

Alluvial

I

Deweyville

Terrace

m

I

r

Ridge

Terrace

I

10

'

g

::0

0

5

0

km

10

I I





Scales of Incised Valleys Published Ancient vs. Late Quaternary

-

E

.c

+ -

0

-

10000

1000

100

. --

EJf onMobii

Upstream esearch

Mississippi River -

Parana/Rio de la Plata -

I

Rhine River -

Colotcldo River Texas USA) _

-

o

River -

Trinity River Texas USA)

coastal/alluvial valleys

bedrock valleys

1 0 ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~

1

10 100

Thickness

m)

1000 10000





Scales of Incised Valleys, Channel Belts, and Channel FIlls

100000

10000

E

' - '

..c

1000

0

:

100

1

EJf onMobii

Upstream esearch

-:::;;

modern/coastal-platn

.

.

.

.

1 1

incised

valleys

/

{w t

700) / /

.

- :...

modern chaonei

belts

w:t.

..

/70-300)

. /

fIII

. modern

channel

fills w:t

-:.10:20)

/ Gibling 2006) Data

/ fistributary channel belts

/ meandering channel belts _

coastal/alluvial valleys

bedrock valleys

100

Thickness m)

1000 10000



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Summary

Fluvial stratigraphic elements exhibit scaling relations that

are consistent across a range of r iver system scales Channel-belt sand bodies range from ~100-300:1, with a mean of ~200

Distr ibutary channel-belts range from ~20-50:1

Abandoned channel-fills range from 10-30:1

Each element occupies the same thickness domain, because of scaling to

bankfull discharge, but differ in width domains due to lateral migration

Coastal-plain incised valleys range from 500-800:1

Scaling relations defined from modern systems commonly

differ from scales interpreted in the stratigraphic record Scaling relationships from modern systems are observations, not

interpretations, and tied to process-based understanding of system

parameters (discharge, sediment f lux)

Can be used as an additional set of recognit ion criteria to guide, cross-

check, or calibrate interpretations in outcrop or subsurface data

scaling relationships in fluvial depostional systems

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