Deep-Water Processes Blog
Introduction
Dr. G.
Shanmugam is a person pf Indian origin. He emigrated to
the U.S. in 1970 and became a naturalized U. S. citizen in 1990. He is married
to Jean (1976–present). He is a pragmatic and an iconoclastic deep-water process
sedimentologist. His primary contributions are aimed at documenting the
volumetric importance of sandy mass-transport deposits and bottom-current
reworked sands in deep-water petroleum reservoirs worldwide and at dispelling
the popular myth that most deep-water sands are turbidites. His current
research includes not only sandy mass-transport processes and bottom currents,
but also oceanic internal waves, cyclonic waves, and tsunami waves.
The primary purpose of
this Blog is to share G. Shanmugam’s published works on deep-water processes.
He has also summarized his current views on selected topics
(Items # 13, 14, & 15) below.
In a companion Blog “G. Shanmugam's other
geological publications” <http://gshanshanmugam.blogspot.com/>, he has
shared his publications on various other topics, such as journal cover
photographs, oil generation from coal, erosional unconformities, porosity
in sandstones, braid deltas, tide-dominated estuaries, Appalachian tectonics,
manganese in marine carbonates, etc. with free PDF downloads of selected
articles.
Online Resources
UTA Profile: http://www.uta.edu/profiles/Ganapathy-Shanmugam
Blog (Deep-water processes): http://g-shanmugam.blogspot.com/
ResearchGate: http://www.researchgate.net/profile/G_Shanmugam/publications
Editorial
Board
Journal of
Palaeogeography: http://www.journalofpalaeogeography.org/EN/column/column340.shtml
Petroleum Exploration and Development: http://www.journals.elsevier.com/petroleum-exploration-and-development/editorial-board/
Research
His studies are based on sound theoretical, experimental, and empirical (rock-based) analyses. The underpinning objective is to arrive at the truth with conceptual clarity on complex issues. Notable contributions on modern and ancient systems in a multitude of topics are:
1. Sandy
mass-transport deposits in deep-water petroleum reservoirs: Elsevier books
(2006 & 2012)
2. New
perspectives on deep-water sandstones: Implications: Petroleum Exploration and
Development (2013)
3. Is the
turbidite facies association scheme valid for interpreting ancient submarine fan
environments? Geology (1985)
4. Perception
vs. Reality in deep-water exploration: World Oil (1996)
5. Deepwater
exploration: Conceptual models and their uncertainties: NAPE (Nigerian Assn. of
Petrol. Explorationists) Bulletin (1987)
6.
High-density turbidity currents: Are they sandy debris flows? JSR (1996)
7. Ten
turbidite myths: ESR (2002)
8. The Bouma
Sequence and the turbidite mind set: ESR (1997)
9. 50 years of
the turbidite paradigm (1950s–1990s): MPG
(2000)
10.
Experiments on sandy debris flows: MPG (2000) & GSA Bulletin (2001,
co-author)
11. Slope
failure using limit equilibrium analysis
in soil mechanics: AAPG Bulletin (2014)
12.
Reinterpretation of depositional processes in a classic flysch sequence in the
Pennsylvanian Jackfork Group, Ouachita Mountains: AAPG Bulletin (AAPG, 1995)
13.
Bottom-current reworked sands in deep-water petroleum reservoirs: Elsevier
books (2006 & 2012)
14.
Deep-marine tidal bottom currents in modern and ancient submarine canyons: MPG
(2003)
15. Deep-water
Bottom Currents and Their Deposits: Elsevier “Contourites” (2008, Chapter 5)
16. Process
sedimentology and reservoir quality of deep-marine bottom-current reworked
sands (sandy contourites): AAPG Bulletin (1993)
17. Sandy
debrites and tidalites of Pliocene reservoir sands, KG Basin, India: JSR (2009)
18. The
tsunamite problem: JSR (2006)
19. The
constructive functions of tropical cyclones and tsunamis: AAPG Bulletin ( 2008)
20.
Process-sedimentological challenges in distinguishing paleo-tsunami deposits:
NH (2012)
21. Modern
internal waves and internal tides along oceanic pycnoclines: AAPG Bulletin
(2013)
22.
Basin-floor fans in the North Sea: Sequence-stratigraphic models vs.
sedimentary facies: AAPG Bulletin (1995)
23. The
obsolescence of deep-water sequence Stratigraphy: GSL Spl. Publ. (1996) &
IJPG (2007)
24. Fan deltas
and braid deltas: Varieties of coarse‑grained
deltas: GSA Bulletin (1987, co-author)
25.
Tide-dominated estuarine facies, Sacha Field, Oriente Basin, Ecuador: AAPG
Bulletin (2000)
26. Analogous tectonic evolution of the
Ordovician foredeeps, southern and central Appalachians: Geology (1982)
27. Manganese
distribution in shallow- and deep-marine carbonates: SG (1983)
28.
Unconformity-related porosity enhancement in the Prudhoe Bay Field, Alaska:
AAPG Bulletin (1988)
29. Porosity development in sandstones beneath
erosional unconformities: WTGS (1989)
30. Significance
of coniferous rain forests and related Organic matter in generating commercial
quantities of oil, Gippsland basin, Australia: AAPG Bulletin (1985)
G. Shanmugam is grateful to his niece Geetha and
her spouse Vaideeswaran, who are professional computer technologists in
Atlanta, for their enthusiastic help during the initial stages of development
of this blog in 2013, which is still a work in progress.
Sedimentologic and Oceanographic Pioneers of the 20th Century
The following three pioneers made basic contributions that provided clarity to the understanding of deep-water
process sedimentology.
John
Essington Sanders (1926–1999)
Ph.D., Yale
University, 1953
Affiliation:
Yale University, Barnard College, Columbia University, and Hofstra University
(Differentiated
turbidity currents from debris flows)
Francis
Parker Shepard (1897–1985)
Ph.D.,
University of Chicago, 1922
Affiliation:
Scripps Institution of Oceanography
(Documented deep-marine
mass-transport processes and tidal currents in submarine canyons)
Charles
Davis Hollister (1936–1999)
Ph.D.,
Columbia University, 1967
Affiliation:
Woods Hole Oceanographic Institution
(Documented
deep-marine contour currents)
Process
Sedimentology
Process
sedimentology has always been the underpinning principle behind all his studies
(see Shanmugam, 2006, Chapter 1). Basic requirements of this discipline include
a combined knowledge of physics, soil mechanics and fluid mechanics (Sanders, 1963; Brush, 1965), application of
uniformitarianism, objective description of the rock, documentation of
excruciating details in sedimentological logs, interpretation of processes
using sedimentary structures, absolute exclusion of facies models, and the
routine use of the common sense.
The
late John Sanders’ pragmatic principles of process has been the foundation of G.
Shanmugam’s research. Sanders (1963, p.178) state that “Primary sedimentary
structures yield insights into fluid mechanics of moving currents in three
ways: (1) they substantiate the fundamental differences between the mechanisms
of suspension and traction that were pointed out by G. K. Gilbert in 1914; (2)
they emphasize the significance of the recent theoretical analysis of the
influence of cohesionless grains made by R. A. Bagnold, and (3) they illustrate
what may be the results of mass shearing effects between the fluid and sediment
along their common interface.” I have been an ardent advocate of Sanders’
approach in his lectures and printed publications.
References
Bagnold,
R.A., 1956, The flow of cohesionless grains in fluids. Phil. Trans. R. Soc.
Lond., Ser. A. Math. Phys. Sci. 249, 235-297.
Brush
Jr., L.M., 1965, Experimental work on primary sedimentary structures. In:
Middleton, G.V.
(Ed.), Primary Sedimentary Structures and their Hydrodynamic Interpretation,
SEPM Special Publication 12,
SEPM, Tulsa, OK, pp. 17-24.
Sanders,
J.E., 1963, Concepts of fluid mechanics provided by primary sedimentary
structures. J.
Sedimentary Petrol. 33, 173-179.
Gravity-driven deep-water processes
The world’s oceans and continental margins remain a
significant research frontier because of their importance to petroleum
exploration and their link to catastrophic submarine mass movements
(geohazards). Sediment failures near the shelf edge are the common cause of
gravity-driven downslope processes, which comprise slides, slumps, debris
flows, and turbidity currents. Mass-transport processes (i.e., slides, slumps,
and debris flows) exhibit elastic and plastic behaviors due to high sediment
concentration (25-100% by volume). Turbidity currents are not mass-transport
processes and they exhibit viscous fluid behavior due to low sediment concentration
(1-23% by volume) (Figure 1). In other words,
turbidity currents are innately low in flow density. A simple analogy to
high-volume sediment transport by mass-transport processes is the human
transport by a double-decker bus with a capacity to carry 73 passengers at a
time (Figure 2A). In contrast, low-volume sediment transport by turbidity
currents is analogous to human transport by a microcar with a capacity to carry
only two passengers at a time (Figure 2B). In this analogy, the concept of
“high-density turbidity currents” (HDTC) is like a microcar attempting to carry
73 passengers, which is impossible!
Figure
1. A. Schematic diagram showing four common types of
gravity-driven downslope processes (slides, slumps, debris flows, and turbidity
currents) that transport sediment into deep-marine environments. After Shanmugam et al. (1994). B. Sediment
concentration (% by volume) in gravity-driven processes. Note that turbidity
currents are low in sediment concentration (i.e., low-densitry flows). After
Shanmugam (2000). C. Based on mechanical behavior of gravity-driven downslope processes,
mass-transport processes are considered to include slide, slump, and debris
flow, but not turbidity currents (Dott, 1963).
D. The prefix “sandy” is used for mass-transport deposits (SMTDs) that
have grain (>0.06 mm: sand and gravel) concentration value equal to or above
20% by volume. The 20% value is adopted from the original field classification
of sedimentary rocks by Krynine (1948). From Shanmugam (2012).
Figure 2. Comparison of human transport on land with gravity-driven sediment
transport under water. (A) Difference between a double-decker bus with a
capacity to carry at least 73 passengers and a microcar with a capacity for
only two passengers. (B) Difference between mass-transport processes with high
sediment concentration (25-100% by volume) and turbidity currents with low
sediment concentration (1-23% by volume). Sediment mass transport = bus transport.
Turbidity current transport = microcar transport. Both bus and mass transport
are extremely efficient systems for high-volume transport (long arrow). SC =
Sediment concentration. From Shanmugam (2012).
Mass-transport processes occur in both subaerial and
submarine environments, whereas turbidity currents occur only in subaqueous
environments. Long-runout distances of up to 2500 km on Mars and 810 km on
Earth are known for mass-transport deposits (MTD). The synonymous usage of the
term ‘landslide ‘for all three mass-transport processes is incorrect. Seismic
profiles and bathymetric images of modern seafloor may be useful for
recognizing MTD as a general category; however, distinguishing a specific type
of depositional facies (e.g., sandy debrite) requires a detailed bed-by-bed
description of cm-scale features in core and outcrop. Among the 21 triggering
mechanisms of sediment failures (see Post # 14), short-term natural events that represent only
a matter of a few minutes to several hours, or days (e.g., earthquakes,
volcanic eruptions, meteorite impacts, tsunamis, tropical cyclones, monsoon
floods, etc.) are more important triggering mechanisms of sediment failures
than long-term sea-level lowstands that represent thousands of years. Empirical
data for emplacement of coarse sandy and gravelly deposits by mass-transport
processes in modern oceans are abundant, whereas observational data for sandy
turbidity currents are totally absent. Sandy mass-transport deposits (SMTD)
comprise major petroleum-producing sandstone reservoirs in the North Sea,
Norwegian Sea, Gulf of Mexico, offshore Brazil, West Africa, Russia, China, and
the Bay of Bengal (India).
Types of Bottom-currents
Bottom-current
reworked sands (BCRS) constitute important petroleum reservoirs (Shanmugam,
2012). In addition to gravity-driven downslope mass-transport processes and
turbidity currents, bottom currents are equally important in transporting and
depositing sediment in the deep sea. Bottom currents may flow parallel to the
strike of the regional slope, may flow in circular motions (gyres) unrelated to
the slope, or may flow up and down submarine canyons (tidal), whereas turbidity
currents commonly flow downslope (Figure 3).
Figure 3. Schematic diagram showing complex deep-marine sedimentary environments
occurring int water depths deeper than 200m (shelf-slope break). In general,
sediment transport in shallow-marine (shelf) environments is characterized by
tides and waves, whereas sediment transport in deep-marine (slope and basin)
environments is characterized by gravity-driven downslope processes, such as
mass transport (i.e., slides, slumps, and debris flows), and turbidity
currents. Bottom currents are composed of thermohaline contour-following
currents, wind-driven currents (circular motion), up and down tidal bottom
currents in submarine canyons (opposing arrows), and baroclinic currents
related to internal waves/tides (Figure 4). After Shanmugam (2003).
Figure 4. A
conceptual oceanographic and sedimentologic framework showing deposition from
baroclinic currents on continental slopes, in submarine canyons, and and on
guyots. On continental slopes and in submarine canyons, deposition occurs in
three progressive stages: (1) incoming
internal wave and tide stage, (2) shoaling transformation stage, and (3)
sediment transport and deposition stage. Continental slopes and submarine
canyons are considered to be environments with high potential for deposition
from baroclinic currents. In the open ocean, baroclinic currents can rework
sediments on flat tops of towering guyot terraces, without the need for three
stages required for deposition on continental slopes. In this model, basin
plains are considered unsuitable environments for deposition of baroclinic
sands. Not to scale. From Shanmugam
(2013).
References
Dott Jr., R.H., 1963,
Dynamics of subaqueous gravity depositional processes: AAPG Bulletin, v. 47, p.
104-128.
Krynine, P.D., 1948, The megascopic study and field classification of sedimentary rocks: The Journal of Geology, v. 56, p. 130-165.
Shanmugam, G., 2000, 50 years of the turbidite
paradigm (1950s–1990s):
Deep-water processes and facies models—A
critical perspective: Marine and Petroleum Geology, v. 17, p. 285–342.
Shanmugam, G., 2003,
Deep-marine tidal bottom currents and their reworked sands in modern and
ancient submarine canyons: Marine and Petroleum Geology, v. 20, p. 471–491.
Shanmugam, G. 2008, Deep-Water Bottom Currents and Their Deposits, in Rebesco, M., and
Camerlenghi, A., eds., Contourites: Amsterdam, Elsevier, Developments in
Sedimentology, v. 60, p. 59-81.
Shanmugam, G., 2012,
New perspectives on deep-water sandstones: Origin, recognition, initiation, and
reservoir quality: Amsterdam, Elsevier, Handbook of petroleum exploration and
production, v. 9, 524 p.
Shanmugam, G., 2013, Modern internal waves and
internal tides along oceanic pycnoclines: Challenges and implications for
ancient deep-marine baroclinic sands: AAPG Bulletin, v. 97(5), p. 767-811.
Shanmugam, G., L. R. Lehtonen,
T. Straume, S. E. Syversten, R. J.
Hodgkinson, and M. Skibeli, 1994, Slump and debris flow dominated upper slope
facies in the Cretaceous of the Norwegian and Northern North Seas (61º–67º N):
implications for sand distribution: AAPG Bulletin, v. 78, p. 910–937.
Biography
G.
(Shan) Shanmugam is a polemic and a pragmatic process sedimentologist. He is a
person of Indian origin and a naturalized U.S. citizen. He is married to Jean
(1976–present).
Email:
shanshanmugam@aol.com
Degree
|
Major
|
Institution
|
Year
|
Ph.D.
|
Geology
|
University of Tennessee, Knoxville, U.S.
|
1978
|
M.S.
|
Geology
|
Ohio University, Athens, U.S.
|
1972
|
M.Sc.
|
Applied Geology
|
Departrment of Civil Engineering,
Indian Institute of Technology (IIT)-
Bombay, India
|
1968
|
B.Sc.
|
Geology and Chemistry
|
Annamalai University,
Tamil Nadu, South India
|
1965
|
Research and Expertise
- Deep-water process sedimentology
- Mass-transport processes and bottom currents
- Oceanic waves (Internal, cyclonic, and tsunami)
- Sandstone petroleum reservoirs
- Tectonics and sedimentation.
- Flume experiments
- Sandstone diagenesis
- Source rock (organic geochemistry)
Doctoral
Research
Shanmugam, G., 1978,
The stratigraphy, sedimentology and tectonics of the Middle Ordovician Sevier
Shale basin in east Tennessee: Knoxville, TN, University of Tennessee:
Unpublished Ph.D. dissertation in Geology, 222 p. Adviser: Professor Kenneth R.
Walker. Field and laboratory study of shelf, slope, and basinal deposits with
an emphasis on deep-water sedimentation.
Masters
Research
Shanmugam, G., 1968,
Geology of Tankhala Area, Gujarat State: Bombay, India, Civil Engineering department,
Indian Institute of Technology: Unpublished
M.Sc. Dissertation in Applied Geology, 84 p. Adviser: Professor A.
Parthasarathy. Field, laboratory, and statistical analysis of fluvial and
shallow-marine strata of Cretaceous age.
1982‑1984 Senior Research Geologist
1984‑1985
Associate
Publications on Deep-Water
Processes
Shanmugam, G., 2012, New
perspectives on deep-water sandstones: Origin, recognition, initiation, and
reservoir quality: Amsterdam, Elsevier, Handbook of petroleum exploration and
production, v. 9, 524 p.
Shanmugam, G., 1997a. The
Bouma Sequence and the turbidite mind set. Earth-Science Reviews, v. 42, p.
201–229.
Shanmugam, G., 1997b,
Deep-water exploration: Conceptual models and their uncertainties: NAPE (NigerianAssociation
of PetroleumExplorationists) Bulletin, v. 12/01, p. 11–28.
Shanmugam, G., 2000, 50
years of the turbidite paradigm (1950s–1990s): Deep-water processes and
facies models—A critical perspective: Marine and Petroleum Geology, v. 17, p. 285–342.
Shanmugam, G., 2002. Ten
turbidite myths: Earth-Science Reviews, v. 58, p. 311–341.
Shanmugam, G., 2003,
Deep-marine tidal bottom currents and their reworked sands in modern and
ancient submarine canyons: Marine and Petroleum Geology, v. 20, p. 471–491.
Shanmugam, G., 2006, The
tsunamite problem: Journal of Sedimentary Research, v. 76, p. 718–730.
Shanmugam, G., 2007, The
obsolescence of deep-water sequence stratigraphy in petroleum geology: Indian
Journal of Petroleum Geology, v. 16 (1), p. 1-45.
Shanmugam, G. 2008a,
Deep-Water Bottom Currents and Their Deposits, in Rebesco, M., and Camerlenghi,
A., eds., Contourites: Amsterdam, Elsevier, Developments in Sedimentology, v.
60, p. 59-81.
Shanmugam, G., 2008b,
Leaves in turbidite sand: The main source of oil and gas in the deep-water
Kutei Basin, Indonesia: Discussion: AAPG Bulletin, v. 92, p. 127–137.
Shanmugam, G., 2008c, The
constructive functions of tropical cyclones and tsunamis on deep-water sand
deposition during sea level highstand: Implications for petroleum exploration:
AAPG Bulletin, v. 92, p. 443–471.
Shanmugam, G., 2009,
Slides, slumps, debris flows, and turbidity currents, in J.H., Steele, S.A. Thorpe, and K.K. Turekian, eds., Encyclopedia of Ocean
Sciences, 2nd ed: Waltham, Massachusetts,
Academic Press (Elsevier), p. 447-467.
Shanmugam, G., 2012,
Process-sedimentological challenges in distinguishing paleo-tsunami deposits, in
A. Kumar and I. Nister, eds., Paleo-tsunamis: Natural Hazards, v. 63, p. 5–30.
Shanmugam, G., 2013a,
Comment on “Internal waves, an underexplored source of turbulence events in the
sedimentary record” by L. Pomar, M. Morsilli, P. Hallock, and B. Bádenas
[Earth-Science Reviews, 111 (2012), 56–81]: Earth-Science Reviews, v. 116, p.
195–205.
Shanmugam, G., 2013b,
Modern internal waves and internal tides along oceanic pycnoclines: Challenges
and implications for ancient deep-marine baroclinic sands: AAPG Bulletin, v.
97(5), p. 767-811.
Shanmugam, G. 2013c,
Slides, Slumps, Debris Flows, and Turbidity Currents. In: Earth Systems and
Environmental Sciences Reference Module. Elsevier (online), to be published in
August or September 2013.
Shanmugam, G. 2013d. 深水砂体成因研究新进展 (New perspectives on deep-water sandstones:
Implications): Petroleum Exploration and Development, v. 40 (3), p. 294-301. DOI:
10.11698/PED.2013.03.05 (in Chinese).
Shanmugam, G., and G. L.
Benedict, 1978, Fine-grained carbonate debris flow, Ordovician basin margin,
Southern Appalachians: Journal of
Sedimentary Petrology, v. 48, p. 1233-1240.
Shanmugam, G., and R. J.
Moiola, 1982, Eustatic control of turbidites and winnowed turbidites: Geology,
v. 10, p. 231–235. Shanmugam, G., and R. J.
Moiola, 1988, Submarine fans: Characteristics, models, classification,
and reservoir potential: Earth-Science Reviews, v. 24, p. 383– 428.
Shanmugam, G., and R. J.
Moiola, 1995, Reinterpretation of depositional processes in a classic flysch
sequence in the Pennsylvanian Jackfork Group, Ouachita Mountains: AAPG Bulletin, v. 79, p. 672-695.
Shanmugam, G., J.E. Damuth,
R.J. Moiola, 1985, Is the turbidite facies association scheme valid for
interpreting ancient submarine fan environments? Geology, v. 13, p. 234-237.
Shanmugam, G., T. D.
Spalding, and D. H. Rofheart, 1993, Process sedimentology and reservoir quality
of deep-marine bottom-current reworked sands (sandy contourites): an example
from the Gulf of Mexico: AAPG Bulletin, v. 77, p. 1241–1259.
Shanmugam, G., L. R.
Lehtonen, T. Straume, S. E. Syversten,
R. J. Hodgkinson, and M. Skibeli, 1994, Slump and debris flow dominated
upper slope facies in the Cretaceous of the Norwegian and Northern North Seas
(61º–67º N): implications for sand distribution: AAPG Bulletin, v. 78, p.
910–937.
Shanmugam, G., R. B. Bloch, S. M. Mitchell, G.
W. J. Beamish, R. J. Hodgkinson, J. E. Damuth, T. Straume, S.E. Syvertsen, and
K. E. Shields, 1995, Basin-floor fans in the North Sea: Sequence-stratigraphic
models vs. sedimentary facies: AAPG Bulletin, v. 79, p. 477–512.
Shanmugam, G., S. K.
Shrivastava, and B. Das, 2009, Sandy debrites and tidalites of Pliocene
reservoir sands in upper-slope canyon environments, offshore Krishna-Godavari
Basin (India): Implications: Journal of Sedimentary Research, v. 79, p. 736–756.
Shanmugam, G., 2000, 50 years of the turbidite
paradigm (1950s–1990s):
Deep-water processes and facies models—A
critical perspective: Marine and Petroleum Geology, v. 17, p. 285–342.
Marr, J.G., Harff, P.A., Shanmugam, G., Parker, G.,
2001, Experiments on subaqueous sandy gravity flows: the role of clay and water
content in flow dynamics and depositional structures. Geological Society of America
Bulletin, v. 113, p. 1377-1386.
1997
(April) AAPG Convention Debate Panelist, Dallas, Texas
Topic: Processes of
Deep-Water Clastic Sedimentation and Their Reservoir Implications: What Can We
Predict?
Moderator: H. E.
Clifton.
Panelists: A.H. Bouma, J.E. Damuth, D.R. Lowe, G. Parker, and G. Shanmugam
Shanmugam, G., 2002. Ten turbidite myths:
Earth-Science Reviews, v. 58, p. 311–341.
Shanmugam, G., 2003, Deep-marine tidal bottom
currents and their reworked sands in modern and ancient submarine canyons:
Marine and Petroleum Geology, v. 20, p. 471–491.
All Outcrop/Field Studies
Deep-water deposits: Ouachita
Mountains (Arkansas and Oklahoma, USA)
Deep-water
deposits: Peira Cava area (SE France)
Coniferous rain forests:
North Island (New Zealand)
1995 (October), UK
Department of Trade and Industry (DTI), Edinburgh, Scotland
1998 (November), Petrobras,
Mobil, and Unocal, Rio de Janeiro, Brazil, South America
1999 (August), Petrobras, Mobil, and Unocal, Sao Mateus, Brazil, South America
2009 and 2010, Research Institute of Petroleum Exploration and Development (RIPED) of PetroChina,
2014: China University of Petroleum, Qingdao, China
2014: Yanchang Oil Field Research and Development Research Institute, Yan'an, China:
:
1985-1989
Research Associate
1989-1993
Senior Research Associate
1993-1996
Assoc. Geological Research Advisor
1996-2000
Geological Scientist (retired)
Duties in Mobil
Research on wide range of topics
(sedimentology, sequence stratigraphy, tectonics, diagenesis, paleobotany and
organic geochemistry) on petroleum exploration and production. Job duties also
included teaching, core and outcrop description worldwide.
Acknowledgement: G. Shanmugam is grateful to Mobil for its unprecedented generosity and enthusiasm in the
history of the petroleum industry for granting permission to publish data and
controversial concepts. In 2000, Mobil merged with Exxon and became ExxonMobil.
Courses taught at the University of
Texas at Arlington
- Spring 2003: Geology 3442
(Sedimentology and Stratigraphy)
- Fall 2003: Geology 5344 and 4305
(Clastic Depositional Environments)
- Spring 2004: Geology 3442
(Sedimentology and Stratigraphy)
His 330 publications
during 1970-2013), which include two Elsevier’s Handbook of Petroleum
Exploration and Production volumes on deep-water sandstones (2006 and 2012), cover a wide range
of topics (e.g., deep-water process sedimentology, sequence stratigraphy, phenomena of tsunamis,
cyclones, erosional unconformities, porosity in sandstones, Appalachian tectonics,
Mn distribution in marine strata, etc.).
Publications on Deep-Water
Processes
Books
Shanmugam, G., 2006, Deep-water processes and facies models: Implications
for sandstone petroleum reservoirs: Amsterdam, Elsevier, Handbook of petroleum
exploration and production, v. 5, 476 p.
Shanmugam, G., 2012, New
perspectives on deep-water sandstones: Origin, recognition, initiation, and
reservoir quality: Amsterdam, Elsevier, Handbook of petroleum exploration and
production, v. 9, 524 p.
Selected Journal Publications
Shanmugam, G., 1996a, High-density turbidity currents: Are they sandy
debris flows? Journal of Sedimentary Research, v. 66, p. 2–10.
Shanmugam, G., 1996b, Perception vs. Reality in
deep-water exploration: World Oil, v. 217, p. 37-41.
Shanmugam, G., 1997a. The
Bouma Sequence and the turbidite mind set. Earth-Science Reviews, v. 42, p.
201–229.
Shanmugam, G., 1997b,
Deep-water exploration: Conceptual models and their uncertainties: NAPE (NigerianAssociation
of PetroleumExplorationists) Bulletin, v. 12/01, p. 11–28.
Shanmugam, G., 2000, 50
years of the turbidite paradigm (1950s–1990s): Deep-water processes and
facies models—A critical perspective: Marine and Petroleum Geology, v. 17, p. 285–342.
Shanmugam, G., 2002. Ten
turbidite myths: Earth-Science Reviews, v. 58, p. 311–341.
Shanmugam, G., 2003,
Deep-marine tidal bottom currents and their reworked sands in modern and
ancient submarine canyons: Marine and Petroleum Geology, v. 20, p. 471–491.
Shanmugam, G., 2006, The
tsunamite problem: Journal of Sedimentary Research, v. 76, p. 718–730.
Shanmugam, G., 2007, The
obsolescence of deep-water sequence stratigraphy in petroleum geology: Indian
Journal of Petroleum Geology, v. 16 (1), p. 1-45.
Shanmugam, G. 2008a,
Deep-Water Bottom Currents and Their Deposits, in Rebesco, M., and Camerlenghi,
A., eds., Contourites: Amsterdam, Elsevier, Developments in Sedimentology, v.
60, p. 59-81.
Shanmugam, G., 2008b,
Leaves in turbidite sand: The main source of oil and gas in the deep-water
Kutei Basin, Indonesia: Discussion: AAPG Bulletin, v. 92, p. 127–137.
Shanmugam, G., 2008c, The
constructive functions of tropical cyclones and tsunamis on deep-water sand
deposition during sea level highstand: Implications for petroleum exploration:
AAPG Bulletin, v. 92, p. 443–471.
Shanmugam, G., 2009,
Slides, slumps, debris flows, and turbidity currents, in J.H., Steele, S.A. Thorpe, and K.K. Turekian, eds., Encyclopedia of Ocean
Sciences, 2nd ed: Waltham, Massachusetts,
Academic Press (Elsevier), p. 447-467.
Shanmugam, G., 2012,
Process-sedimentological challenges in distinguishing paleo-tsunami deposits, in
A. Kumar and I. Nister, eds., Paleo-tsunamis: Natural Hazards, v. 63, p. 5–30.
Shanmugam, G., 2013a,
Comment on “Internal waves, an underexplored source of turbulence events in the
sedimentary record” by L. Pomar, M. Morsilli, P. Hallock, and B. Bádenas
[Earth-Science Reviews, 111 (2012), 56–81]: Earth-Science Reviews, v. 116, p.
195–205.
Shanmugam, G., 2013b,
Modern internal waves and internal tides along oceanic pycnoclines: Challenges
and implications for ancient deep-marine baroclinic sands: AAPG Bulletin, v.
97(5), p. 767-811.
Shanmugam, G. 2013c,
Slides, Slumps, Debris Flows, and Turbidity Currents. In: Earth Systems and
Environmental Sciences Reference Module. Elsevier (online), to be published in
August or September 2013.
Shanmugam, G. 2013d. 深水砂体成因研究新进展 (New perspectives on deep-water sandstones:
Implications): Petroleum Exploration and Development, v. 40 (3), p. 294-301. DOI:
10.11698/PED.2013.03.05 (in Chinese).
Shanmugam, G., and G. L.
Benedict, 1978, Fine-grained carbonate debris flow, Ordovician basin margin,
Southern Appalachians: Journal of
Sedimentary Petrology, v. 48, p. 1233-1240.
Shanmugam, G., and R. J.
Moiola, 1982, Eustatic control of turbidites and winnowed turbidites: Geology,
v. 10, p. 231–235. Shanmugam, G., and R. J.
Moiola, 1988, Submarine fans: Characteristics, models, classification,
and reservoir potential: Earth-Science Reviews, v. 24, p. 383– 428.
Shanmugam, G., and R. J.
Moiola, 1995, Reinterpretation of depositional processes in a classic flysch
sequence in the Pennsylvanian Jackfork Group, Ouachita Mountains: AAPG Bulletin, v. 79, p. 672-695.
Shanmugam, G., J.E. Damuth,
R.J. Moiola, 1985, Is the turbidite facies association scheme valid for
interpreting ancient submarine fan environments? Geology, v. 13, p. 234-237.
Shanmugam, G., T. D.
Spalding, and D. H. Rofheart, 1993, Process sedimentology and reservoir quality
of deep-marine bottom-current reworked sands (sandy contourites): an example
from the Gulf of Mexico: AAPG Bulletin, v. 77, p. 1241–1259.
Shanmugam, G., L. R.
Lehtonen, T. Straume, S. E. Syversten,
R. J. Hodgkinson, and M. Skibeli, 1994, Slump and debris flow dominated
upper slope facies in the Cretaceous of the Norwegian and Northern North Seas
(61º–67º N): implications for sand distribution: AAPG Bulletin, v. 78, p.
910–937.
Shanmugam, G., R. B. Bloch, S. M. Mitchell, G.
W. J. Beamish, R. J. Hodgkinson, J. E. Damuth, T. Straume, S.E. Syvertsen, and
K. E. Shields, 1995, Basin-floor fans in the North Sea: Sequence-stratigraphic
models vs. sedimentary facies: AAPG Bulletin, v. 79, p. 477–512.
Shanmugam, G., S. K.
Shrivastava, and B. Das, 2009, Sandy debrites and tidalites of Pliocene
reservoir sands in upper-slope canyon environments, offshore Krishna-Godavari
Basin (India): Implications: Journal of Sedimentary Research, v. 79, p. 736–756.
First flume experiments on sandy debris flows (1996-1998)
For the first time, to understand mechanics of sandy
debris flows and their deposits, a Mobil-funded experimental flume study was
carried out at St. Anthony Falls Laboratory (SAFL), University of Minnesota
(1996-1998) under the direction of Professor G. Parker. Results were
published in two major articles.
Shanmugam, G., 2000, 50 years of the turbidite
paradigm (1950s–1990s):
Deep-water processes and facies models—A
critical perspective: Marine and Petroleum Geology, v. 17, p. 285–342.
Marr, J.G., Harff, P.A., Shanmugam, G., Parker, G.,
2001, Experiments on subaqueous sandy gravity flows: the role of clay and water
content in flow dynamics and depositional structures. Geological Society of America
Bulletin, v. 113, p. 1377-1386.
1997
(April) AAPG Convention Debate Panelist, Dallas, Texas
Topic: Processes of
Deep-Water Clastic Sedimentation and Their Reservoir Implications: What Can We
Predict?
Moderator: H. E.
Clifton.
Panelists: A.H. Bouma, J.E. Damuth, D.R. Lowe, G. Parker, and G. Shanmugam
1998 Field Verification of the Bouma Seuence at the Type Locality, Annot
Sandstone (Eocene-Oligocene), Peira-Cava area, French Maritime Alps, SE France
To verify the observational validity of the
vertical turbidite facies model, known as the Bouma Sequence (Ta, Tb, Tc, Td,
and Te divisions), a field study of the Annot Sandstone (Eocene-Oligocene), exposed
near Peira-Cava area-the type locality, French Maritime Alps, SE France was carried out in 1998 by Mobil geologists G.
Shanmugam, R. J. Moiola, and R. B. Bloch. Results were published in two major
articles and in a book.
Shanmugam, G., 2002. Ten turbidite myths:
Earth-Science Reviews, v. 58, p. 311–341.
Shanmugam, G., 2003, Deep-marine tidal bottom
currents and their reworked sands in modern and ancient submarine canyons:
Marine and Petroleum Geology, v. 20, p. 471–491.
Shanmugam, G., 2006,
Deep-water processes and facies models: Implications for sandstone petroleum
reservoirs: Amsterdam, Elsevier, Handbook of petroleum exploration and
production, v. 5, 476 p.
Awards and Achievements
- 1968: IIT Medal for the top-ranking student in
Applied Geology, Indian Institute of Technology, Bombay, India.
- 1995: Best paper award
from NAPE (Nigerian Association of Petroleum Explorationists) for his
paper “Deepwater
Exploration: Conceptual Models and their Uncertainties”
- 2000: Listed in the Millennium Edition
(2000-2001) of Marquis Who’s who in Science and Engineering among 470 geologists chosen from 40
countries.
- His paper ‘High-density turbidity currents: are they sandy debris flows?’ published in the Journal of Sedimentary Research in 1996, has achieved the status of the single most cited paper in sedimentological research published in three world-renowned periodicals - Journal of Sedimentary Research, Sedimentology, and Sedimentary Geology - during the survey period of 1996-2003 (Source: International Association of Sedimentologists Newsletter, August 2003).
- The above article was also ranked 46th among the top 50 most-cited JSR articles of all time. http://m.jsedres.sepmonline.org/reports/most-cited (accessed October 31, 2014)
- He was interviewed by SUN TV, Chennai, India
(Televised on December 30th 2003) on his controversial research papers on
turbidite sedimentation and their implications for petroleum reservoirs.
- He is an Emeritus Member
of SEPM (Society for Sedimentary Geology), member since 1970.
Rock description
worldwide used in deep-water research
His rock description
includes 35 case studies of deep-water systems that comprise many
petroleum-producing massive sands worldwide. Description of core and outcrop
was carried out at a scale of 1:20 to 1:50, totaling more than 10,000 m, during
1974-2011. These modern and ancient deep-water systems include both marine and
lacustrine settings. They are:
1.
Mississippi Fan, Quaternary, DSDP Leg 96 core, Gulf of Mexico, U.S.
2. Green Canyon,
late Pliocene, conventional core, Gulf of Mexico, U.S.
3. Garden Banks,
middle Pleistocene, conventional core, Gulf of Mexico, U.S.
4. Ewing Bank 826,
Pliocene-Pleistocene, conventional core, Gulf of Mexico, U.S.
5. South Marsh
Island, late Pliocene, conventional core, Gulf of Mexico, U.S.
6. South Timbalier,
middle Pleistocene, conventional core, Gulf of Mexico, U.S.
7. High
Island, late Pliocene, conventional core, Gulf of Mexico, U.S.
8. East
Breaks, late Pliocene-Holocene, conventional and piston cores, Gulf of Mexico,
U.S.
9. Midway
Sunset Field, upper Miocene, conventional core, onshore California, U.S.
10. Jackfork
Group, Pennsylvanian, outcrop, Ouachita Mountains, Arkansas, and Oklahoma, U.S.
11. Sevier
Basin, middle Ordovician, outcrop, Southern Appalachians, Tennessee, U.S.
12. Lagoa
Parda Field, lower Eocene, conventional core, Espirito Santo Basin, onshore
Brazil.
13. Fazenda
Alegre Field, upper Cretaceous, conventional core, Espirito Santo Basin,
onshore Brazil.
14. Cangoa
Field, upper Eocene, conventional core, Espirito Santo Basin, offshore Brazil.
15. Peroa´
Field, lower Eocene to upper Oligocene, conventional core, Espirito Santo
Basin, offshore Brazil.
16. Marlim
Field, Oligocene, conventional core, Campos Basin, offshore Brazil.
17. Marimba
Field, upper Cretaceous, conventional core, Campos Basin, offshore Brazil.
18. Roncador
Field, upper Cretaceous, conventional core, Campos Basin, offshore Brazil.
19. Frigg
Field, lower Eocene, conventional core, Norwegian North Sea.
20. Harding
Field (formerly Forth Field), lower Eocene, conventional core, U.K. North Sea.
21. Alba
Field, Eocene, conventional core, U.K. North Sea.
22. Fyne
Field, Eocene, conventional core, U.K. North Sea.
23. Gannet
Field, Paleocene, conventional core, U.K. North Sea.
24. Andrew
Field, Paleocene, conventional core, U.K. North Sea.
25. Gryphon
Field, upper Paleocene_lower Eocene, conventional core, U.K. North Sea.
26. Faeroe area,
Paleocene, conventional core, west of the Shetland Islands, U.K. Atlantic
Margin.
27. Foinaven
Field, Paleocene, conventional core, west of the Shetland Islands, U.K.
Atlantic Margin.
28. Mid-Norway
region, Cretaceous, conventional core, Norwegian Sea.
29. Agat
region, Cretaceous, conventional core, Norwegian North Sea.
30. Annot
Sandstone, Eocene-Oligocene, outcrop, Maritime Alps, Southeast France.
31. Edop
Field, Pliocene, conventional core, offshore Nigeria.
32. Zafiro
Field, Pliocene, conventional core, offshore Equatorial Guinea.
33. Opalo
Field, Pliocene, conventional core, offshore Equatorial Guinea.
34. Melania
Formation, lower Cretaceous, conventional core, offshore Gabon.
35.
Krishna-Godavari Basin, Pliocene, conventional core, Bay of Bengal, India.
Personal knowledge gained from this robust rock-based data set has
allowed Shanmugam to be consistent in his process interpretations. See Figure 5
below for locations.
All Outcrop/Field Studies
Deep-water
deposits (Ph.D. work): Southern Appalachians (Tennessee, USA)
Shallow-marine deposits: Qassim
area (Saudi Arabia)
Tide-Dominated Estuarine
deposits: Oriente Basin (Ecuador)
Fluvial and Sahallow-marine
deposits: Gujarat State (India)
2004 Indian Ocean
Tsunami-related deposits: Tamilnadu (India)
Coal deposits: Victoria
(Australia)
Limestone karst: Guilin
(China)
Organizer of Deep-Water Sandstone Workshops
1996 (November), Mobil,
Dallas, Texas
1997 (July), UK Department
of Trade and Industry (DTI), Edinburgh, Scotland, U.K.
1998 (June), Petrobras,
Mobil, and Unocal, Sao Mateus, Brazil, South America
1998 (August), Oil and
Natural Gas Corp. (ONGC), Dehra Dun, India
1999 (June), Mobil, Dallas,
Texas, U.S.A.
1999 (August), Petrobras, Mobil, and Unocal, Sao Mateus, Brazil, South America
2002, Hardy Exploration and
Production (India) Inc. Chennai, India
2002, 2004, and
2009, Oil and Natural Gas Corporation (ONGC), Chennai and Karaikal, India
2006, 2007,
2008, 2009, & 2010, Reliance Industries Ltd. Kakinada and Gadimoga,
India
2009 and 2010, Research Institute of Petroleum Exploration and Development (RIPED) of PetroChina,
2014: China University of Petroleum, Qingdao, China
2014: Yanchang Oil Field Research and Development Research Institute, Yan'an, China:
:
Invited Speaker
Lamont‑Doherty Geological Observatory of Columbia University (1980) – USA
Graduate School of Oceanography, University of Rhode Island (1980) ‑ USA
Saskatchewan Geological Society, Regina (1981) ‑ Canada
University of Texas at Arlington (1982, 1983, 1984, 1987) ‑ USA
University of Texas at Dallas (1982, 1983, 1984, 1985, 1987) – USA
University of Texas at Arlington (1982, 1983, 1984, 1987) ‑ USA
University of Texas at Dallas (1982, 1983, 1984, 1985, 1987) – USA
Southern Methodist University, Dallas (1984, 1985) ‑ USA
University of Victoria at Wellington (1983) ‑ New Zealand
University of Parma (1984) ‑ Italy
NATO Advanced Study Institute ‑ Conference on "Reading Provenance from Arenites" Calabria (1984) – Italy
University of Parma (1984) ‑ Italy
NATO Advanced Study Institute ‑ Conference on "Reading Provenance from Arenites" Calabria (1984) – Italy
Nigerian Association of Petroleum Explorationists, Annual Conference,
Lagos (1984) ‑ Nigeria
University of Bergen, Bergen (1985) ‑ Norway
Norwegian Petroleum Society, Stavanger (1985) – Norway
Norwegian Petroleum Society, Stavanger (1985) – Norway
Dallas Geological Society, Dallas (1985, 1986, 1990) ‑ USA
Abilene Christian University, Abilene (1985) ‑ USA
University of Tennessee, Knoxville (1985, 1987) ‑ USA
West Texas Geological Society, Midland (1986) ‑ USA
Fort Worth Geological Society, Fort Worth (1987, 1990) ‑ USA
Society of Exploration Geophysicists, Dallas (1987) – USA
AAPG Research Conference on "Prediction of Reservoir Quality through
Chemical Modeling," Park City, Utah (1987) ‑ USA
Abilene Geological Society, Abilene (1988) ‑ USA
COMFAN II, Parma
(1988) ‑ Italy
AAPG Research
Symposium on "Application of Chemical Modeling to the Prediction of
Reservoir Quality", San Antonio, Texas (1989) – USA
West Texas
Geological Society Symposium "Search for the subtle trap hydrocarbon
exploration in mature basins", Midland, Texas (1989)-USA
Dhahran Geological Society, Dhaharan (1990) ‑ Saudi Arabia
Geological Society of London Symposium: Diagenesis at Unconformities-
Implications for Reservoir Quality (1991), London-UK
Dallas Geological Information Library, Dallas (1991) - USA
Arthur Holmes Conference on Deep-water massive sands, Cefalu, Sicily
(1992) - Italy
Norwegian Petroleum Society, Stavanger (1993) – Norway
Lafayette Geological Society, Lafayette (1994) – Louisiana
Geological Society of London Symposium: Progress in Sequence Stratigraphy:
London (1994) - U.K.
AAPG International Conference and Exhibition, Nice (1995), France.
Azerbaijan Association of Petroleum Geologists 2nd Intl Conference, Baku
(1995), Azerbaijan.
Nigerian Association of Petroleum Explorationists 13th Annual Conference,
Lagos (1995), Nigeria
Geological Society of London Conference "Reservoir Modelling of
turbidite systems", London (1996) - U.K.
AAPG International Conference and Exhibition, Caracas (1996), Venezuela.
Tulsa Geological Society, Tulsa (1996) - Oklahoma
Society of Exploration Geophysicists, Denver (1996), Colorado
Houston Geological Society, Houston (1997), Texas
Bureau of Economic Geology, Austin (1997), Texas
AAPG International Conference and Exhibition, Vienna (1997), Austria.
Geoscience 98, Keele (1998), England
Petrotech -99, New Delhi (1999), India
AAPG, San Antonio (1999), Texas
Dallas Geological Society International Group (2002), Texas
Annamalai University, Annamali Nagar (2002), India
I.I.T., Institute Colloquium, Bombay (2002), India
Association of Petroleum Geologists, Mussoorie (2002), India
EMGI Distinguished Lecturers Symposium, Dallas (2003), Texas
Association of Petroleum Geologists, Kajuraho (2004), India
Association of Petroleum Geologists, Goa (2006), India
6th China National Petroleum Sequence Stratigraphy Conference:
Hangzhou (2010), China
8th International Conference & Exposition on Petroleum
Geophysics, “Hyderabad-2010”, SPG-India
AAPG Annual Convention and Exhibition, New Orleans (2010), Louisiana
CAPG (Chinese Association of Petroleum Geologists): Beijing (2011), China
Texas A&M University, College Station (2012), Texas
Journal and Special Volume Editors of G. Shanmugam’s Publications
G.
Shanmugam would like to acknowledge a select group of editors who published his
contributions on deep-water processes
and on other topics during the past 45 years (1970-2014):
1. J.
Southard (Journal of Sedimentary Research)
2. P.
McCarthy (Journal of Sedimentary Research)
3. C.
North (Journal of Sedimentary Research)
4. O.
Pilkey (Journal of Sedimentary Petrology)
5. A.D.
Miall (Sedimentary Geology and Earth-Science Reviews)
6. G.D.
Klein (Earth-Science Reviews)
7. G.M.
Friedman (Earth-Science Reviews)
8. R.
Steinmetz (AAPG Bulletin)
9. J.A.
Helwig (AAPG Bulletin)
10.
S.A. Longacre (AAPG Bulletin)
11.
K.T. Biddle (AAPG Bulletin)
12.
N.F. Hurley (AAPG Bulletin)
13.
E.A. Mancini (AAPG Bulletin)
14.
G.M. Gillis (AAPG Bulletin)
15.
S.E. Laubach (AAPG Bulletin)
16.
M.L. Sweet (AAPG Bulletin)
17.
D.G. Roberts (Marine and Petroleum Geology)
18.
E.M. Moores (Geology)
19.
H.T. Mullins (Geology)
20.
R.E. Arvidson and M.E. Bickford (Geology)
21.
R.D. Hatcher, Jr. and W.A. Thomas (GSA Bulletin)
22. P.
Carling (Sedimentology)
23.
A.J. Michael (Bulletin of the Seismological Society of America)
24. A.
Kumar and I. Nister (Paleotsunamis: Natural Hazards)
25.
B.W. Flemming and M.T. Delafontaine (Geo-Marine Letters)
26.
A.J. Van Loon (Geologos)
27. J.
Rodgers, J.H. Ostrom, and P.M. Orville (American Journal of Science)
28.
K.R. Walker and D. Roeder (Appalachian Geodynamic Research: American Journal of Science)
29.
A.H. Bouma, W.R. Normark, and N.E. Barnes (Submarine Fans and
Related Turbidite Systems: Springer-Verlag)
30.
G.G. Zuffa (Provenance of Arenites: D. Reidel Publishing Company)
31.
I.D. Meshri and P.J. Ortoleva (Prediction of reservoir quality through chemical
modeling: AAPG Memoir 49)
32.
G.C. Brown, D.S. Gorsline, and W.J. Schweller (Deep-Marine
Sedimentation: Depositional Models
and Case Histories in Hydrocarbon
Exploration and Development: SEPM Short Course No. 66)
33.
K.L. Kleinspehn and C. Paola (New Perspectives in Basin Analysis:
Springer-Verlag)
34.
S.P. Hesselbo and D.N. Parkinson (Sequence Stratigraphy in British Geology: Geological Society
of London Special Publication No. 103)
35.
R.D. Winn, and J.M. Armentrout (Turbidites and Associated Deep-
Water Facies: SEPM Core workshop No. 20)
36. D.A.V. Stow and M. Mayall (Deep-water
Sedimentary Systems: Marine and Petroleum Geology)
37. E. M. Moores and F. Michael Wahl (The Art of
Geology: GSA Special Paper 225)
38. J.H
Steele, K.K. Turekian, and S.A Thorpe (Encyclopedia of Ocean Sciences, 2nd
edition: Academic
Press-Elsevier)
39. M.
Rebesco and A. Camerlenghi (Contourites: Developments
in Sedimentology, v. 60, Elsevier)
40. S.
Lichen (Petroleum
Exploration and Development, Elsevier)
41. J.
Cubitt (Handbook of Petroleum Exploration and Production series, Elsevier)
42. Zeng-Zhao Feng (Journal of Palaeogeography)
Of over
300 reviewers who reviewed his papers,Shanmugam would like to single out (1)
the late Charles Hollister for his review of paper by Shanmugam, Spalding,
Rofheart on bottom-current reworked
sands (1993, AAPG Bulletin), and (2) the late John Sanders for review of paper
by Shanmugam on the Bouma Sequence and the
turbidite mind set (1997, Earth-Science Reviews).
