Marine and Petroleum Geology 26 (2009) 1866–1878
Contents lists available at ScienceDirect
Marine and Petroleum Geology
journal homepage: www.elsevier.com/locate/marpetgeo
Martian mud volcanism: Terrestrial analogs and implications for formational
scenarios
James A. Skinner, Jr. a * , Adriano Mazzini b
a
b
U.S. Geological Survey, Astrogeology Team, 2255 North Gemini Drive, Flagstaff, AZ 86001, USA
Physics of Geological Processes, University of Oslo, Box 1048, 0316 Oslo, Norway
a r t i c l e i n f o
a b s t r a c t
Article history:
Received 26 June 2008
Received in revised form
23 January 2009
Accepted 14 February 2009
Available online 28 February 2009
The geology of Mars and the stratigraphic characteristics of its uppermost crust (mega-regolith) suggest
that some of the pervasively-occurring pitted cones, mounds, and flows may have formed through
processes akin to terrestrial mud volcanism. A comparison of terrestrial mud volcanism suggests that
equivalent Martian processes likely required discrete sedimentary depocenters, volatile-enriched strata,
buried rheological instabilities, and a mechanism of destabilization to initiate subsurface flow. We
outline five formational scenarios whereby Martian mud volcanism might have occurred: (A) rapid
deposition of sediments, (B) volcano-induced destabilization, (C) tectonic shortening, (D) long-term,
load-induced subsidence, and (E) seismic shaking. We describe locations within and around the Martian
northern plains that broadly fit the geological context of these scenarios and which contain mud
volcano-like landforms. We compare terrestrial and Martian satellite images and examine the geological
settings of mud volcano provinces on Earth in order to describe potential target areas for piercement
structures on Mars. Our comparisons help to evaluate not only the role of water as a functional
component of geological processes on Mars but also how Martian mud volcanoes could provide samples
of otherwise inaccessible strata, some of which could contain astrobiological evidence.
Published by Elsevier Ltd.
Keywords:
Mars
Mud volcano
Analogs
Surface processes
Astrobiology
1. Introduction
Pitted cones, mounds, and lobate flows are common landforms
on the Martian surface and are most generally interpreted as having
formed through an array of overlapping volcanic, glacial, periglacial, and/or impact processes (e.g., Frey et al., 1979; Lucchitta,
1981; Garvin et al., 2000; Dickson et al., 2008; Burr et al., 2008).
Other researchers have used terrestrial mud volcanism as an analog
for the formation of many of these features, primarily as an alternative to magmatic volcanism (Komar, 1990; Davis and Tanaka,
1995; Tanaka, 1997; Tanaka et al., 2003a,b, 2005; Farrand et al.,
2005; Kite et al., 2007; Skinner and Tanaka, 2007; Skinner et al.,
2007). However, dissimilar geologic processes commonly result in
landforms of broadly-similar shape (the geomorphological concept
of ‘‘equifinality’’). Inferring geologic processes based strictly on
geomorphology can implicate, both directly and indirectly, very
specific and often unintentional formational characteristics and
conditions.
It is unclear whether the current understanding of Mars’
geologic evolution reasonably supports the geologic conditions
implied by a mud volcano analogy. Terrestrial studies reveal that
mud volcanoes are geomorphologically variable and are subtly
affected by many overlapping processes and conditions. For
extraterrestrial studies, we are forced to rely heavily on remotebased geomorphological observations to interpret geologic
processes and history. Though mud volcanism may be a plausible
Martian geologic process based on gross morphologic similarities of
terrestrial and Martian landforms, the geologic implications of the
analogy have not yet been fully assessed.
Herein, we summarize the components of terrestrial mud
volcanoes and use these as a framework to examine the physical
characteristics whereby mud volcanoes may form on Mars. Because
a comprehensive summary of Mars’ exploration, datasets, and
geologic setting is not tractable in the following text, further
information is included as an Appendix.
2. Framework for terrestrial mud volcanism
* Corresponding author. Tel.: þ1 928 556 7043; fax: þ1 928 556 7019.
E-mail addresses: jskinner@usgs.gov (J.A. Skinner Jr.), adriano.mazzini@
fys.uio.no (A. Mazzini).
0264-8172/$ – see front matter Published by Elsevier Ltd.
doi:10.1016/j.marpetgeo.2009.02.006
The terminology that is used to describe the surface and subsurface
movements of large masses of sediments and fluids is broad and
sometimes misleading. For terrestrial studies, these terms include
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
1867
diapirs, diatremes, domes, mud intrusions, chimneys, pockmarks,
piercement structures, and mud volcanoes. Though such terms are
descriptive, they are often confusingly applied, resulting in an unintended divergence of consistent scientific discussion. Herein, we apply
a simplified definition of mud volcanoes as ‘‘geological phenomena
made manifest through the sudden eruption or quiescent extrusion of
sediment, rock, and fluid from deeper strata’’.
On Earth, the occurrence of a mud volcano implies not only
a suite of geologic conditions but also a sequence of events that
result from these conditions. Processes and conditions that can lead
to the growth of a mud volcano include (1) high rates of basin
sedimentation and/or subsidence, (2) illitization of clay minerals, (3)
expansion of pore fluids, (4) generation of hydrocarbon-rich fluids at
depth, (5) presence of impermeable (or low permeability) strata as
capping rock for pressurized units, (6) vertical or lateral compression of basin sediments, and (7) seismicity. When these conditions
are achieved, mud volcanism may occur through a sequence of
events that includes the build-up of pressure at depth (generally
driven by gas (methane) production), the brecciation of sedimentary
strata along a vertical conduit, and the eruption or extrusion of mud
(mud breccia) with water, oil, and/or gas. The geomorphic result is
generally a crater-shaped vent, perhaps located on a topographic
cone, mound, or ridge of various size and shape, that is composed
and surrounded by mud (mud breccia) flows (e.g., Khalilov and
Kerimov, 1981; Kholodov, 2002; Kopf, 2002).
Most terrestrial mud volcanoes form proximal to paleo-depocenters within structurally-controlled sedimentary basins that are
experiencing active tectonic deformation. As a result, mud volcanoes are frequently located along major geologic structures such as
faults and fold axes related to deformation of the sedimentary
sequence. Terrestrial mud volcanoes can occur both offshore (e.g.,
Black Sea, Gulf of Cadiz, Caspian Sea, and Mediterranean Sea) and
onshore (e.g., Azerbaijan, Indonesia, Trinidad), just to name the best
known and characterized fields (e.g., Jakubov et al., 1971; Barber
et al., 1986; Cita et al., 1996; Ivanov et al., 1996; Dia et al., 1999;
Pinheiro et al., 2003; Isaksen et al., 2007).
The most spectacular terrestrial mud volcanoes have a conical
shape with a summit crater, similar to magmatic equivalents. Some
mud volcanoes reach up to 5 km in diameter and 500 m in height.
The total volume of erupted mud breccia can be >12 km3 for single
volcanoes and up to 250 km3 for mud volcano complexes. Mud
volcano flows can cover areas as large as 100 km2 (e.g., Dimitrov,
2002). One of the most spectacular terrestrial eruptions occurs on
the Java Island at the Lusi mud volcano, which has erupted
continuously for more than two years (at the time of this writing)
covering >7 km2 (Mazzini et al., 2007).
A critical element of the extraterrestrial analogy for mud
volcanoes is what the morphology/morphometry of a potential
Martian mud volcano indicates about the underlying formational
conditions (e.g., Skinner and Tanaka, 2007). Such conditions
include tapping depth, fluid content, stratigraphic architecture, and
triggering mechanism. Size and morphology of terrestrial mud
volcanoes vary widely depending on factors such as eruption
frequency and vigor, lithology and water content of the erupted
mud breccia, type of meteoric erosion (e.g., wind, rain, bottom
currents), rates of basin subsidence, thickness of the affected
sequence, and character of the confining strata or structure. The
characteristics of these analogies and their known geologic settings
provide the framework for describing formational contexts and
scenarios of Martian mud volcanism.
Global physiography provides the most broad and basic
framework for understanding a planet’s evolutionary processes.
The form and arrangement of large-scale Martian surface features
provide a record of the planet’s geologic history. This record
includes impact, volcanic, fluvial, periglacial, and eolian resurfacing processes, all of which variously overlap and intercalate with
one another through time (Appendix A3). One of the most
dominant Martian physiographic features is the highland–lowland
boundary (HLB) scarp, a globe-encircling feature that elevates
more ancient, higher-standing and densely-cratered terrains by
1–5 km above younger, lower-lying and sparsely-cratered terrains
(Fig. 1). The Martian HLB establishes a globally-occurring topographic basin within which geologic processes can be examined
and analyzed.
The cratered highlands dominate the southern two-thirds of the
Martian surface and are chiefly composed of very ancient (older
than 3.5 Gyr; Tanaka, 1986; Hartmann and Neukum, 2001) impact
crater and basin lithologies that are intercalated, onlapped, and
buried by volcanic and sedimentary deposits (e.g., Scott and Carr,
1978; Scott and Tanaka, 1986; Greeley and Guest, 1987). By contrast,
the Martian lowlands dominate the northern one-third of the
Martian surface and are chiefly composed of (relatively) younger
(younger than 2.5 Gyr) sedimentary and volcanic deposits (e.g.,
Tanaka et al., 2005). These units fill and bury ancient topographic
and structural basins, which likely formed through both endogenic
and exogenic processes very early in Mars’ evolution (e.g., Nimmo
and Tanaka, 2005). The lowland basins appear to be temporally
equivalent to the oldest exposed highlands (Frey, 2006). However,
the ancient lowland surfaces are thoroughly buried by thick
sequences (Buczkowski, 2007) of impact ejecta, erosional detritus,
and volcanic rocks and sediment (Tanaka et al., 2003a, 2005),
forming the low-relief topographic undulations that characterize
the lowland plains (Fig. 1).
An important step toward evaluating Mars’ geologic history
includes framing the lowlands as a global-scale depocenter that
consists of multiple overlapping, albeit unique, topographic and
stratigraphic basins. This inherently implies that lowland processes
were spatially partitioned, an assertion at least partly supported by
recent geological maps (Tanaka et al., 2005). We suggest that these
physiographic characteristics helped to establish accommodation
space for the accumulation of sediments and development of
a stratigraphic framework for the potential growth of mud
volcanoes.
3. Framework for Martian mud volcanism
3.2. Stratigraphy
In the absence of field-based data, terrestrial analogs provide the
basis for deciphering the geologic history of extraterrestrial surfaces
The lowlands represent Mars’ largest and longest-lived depocenter for the accumulation of sediments eroded from adjacent
and inferring the conditions through which they form. For Mars,
orbiting spacecrafts have historically provided the most fundamental
datasets for investigating global and regional geologic characteristics
(Appendix A1). Herein, we summarize geomorphological characteristics of Martian features as they appear in selected topographic and
image datasets. For our characterizations, we viewed relevant
Martian datasets (Appendix A2) as spatially-registered layers in
a geographic information system (GIS). For morphological analogy,
we note that many of the imaging instruments orbiting Mars were
adapted from Earth-orbiting imaging instrument parameters,
including spectral range, band-pass, and resolution. As such, we use
terrestrial satellite images of Earth (supplemented by field-based
images) as comparative examples to Martian mud volcanoes (see
Fig. 6 caption for details on comparative images).
3.1. Global physiography
1868
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
Fig. 1. Global context maps of Mars. (A) Color shaded-relief image showing major topographic features. The lowlands (purple and blue hues) represent Mars’ preeminent depocenter for the long-lived accumulation of diverse material sequences. White circles and connecting white line denote generalized locations of conceptual stratigraphic columns
(Fig. 2). White boxes denote the locations of landforms described herein (Fig. 6). Stars denote recent surface lander locations: Mars Exploration Rovers (MER) A (‘‘Spirit’’) and B
(‘‘Opportunity’’) and Phoenix (PHX). (B) Generalized geologic map of Mars indicating key physiographic regions, lithotypes, and surface ages. The yellow hachured line identifies the
HLB, where exposed. Mollweide projection centered at 0 E longitude with a MOLA topographic base, artificially-illuminated from the northwest. Adapted from Nimmo and Tanaka
(2005).
highland (and lowland) outcrops (Appendix A4). Though internal
stratigraphy cannot be confidently resolved within the lowland
deposits, depth–diameter relationships of buried impact crater
populations suggest that they vary laterally in both thickness and
rheology (Buczkowski, 2007). Internal stratigraphy must be inferred by observing outcrops of the uppermost exposures of Martian
rock and sedimentary deposits (i.e., Walther’s Law applied in
reverse fashion; Middleton, 1973) and then accounting for variations based on a working knowledge of the geologic history of
spatially-separated locations.
In general, the Martian uppermost crust (mega-regolith) can be
interpreted as vertically-gradational stratigraphic zones that
consist of fractured crystalline basement rock overlain by a mélange of impact breccias overlain by (and intercalated with)
erosional detritus and volcanic rocks and sediments (Clifford, 1993;
MacKinnon and Tanaka, 1989; Appendix A4). These sequences
presumably have differing proportions and lateral extents due to
regional variations in topographic relief, latitude, material provenance, and proximity to geologic activity (Fig. 2). Surface impacts
are interpreted to be (mostly) random, resulting in a global
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
1869
Fig. 2. Perceived variations in the Martian mega-regolith that constitute basin-related sequences and assist in partitioning geologic processes. The Martian highlands are dominated
by uplifted crustal massifs (A) that grade laterally into high-standing cratered plains composed of intercalated sedimentary and volcanic units (B). With increased distance from
high-standing regions, the thicknesses of the ejecta and detrital zones increase with the thickest mega-regolith in depocenters (C and D). Idealized global locations are denoted in
Fig. 1.
thickness of impact breccia that is maximum where there is an
overall absence of long-term denudation (such as in topographic
lows). By contrast, the thickness of erosional detritus is likely to
increase as long as there are erosional processes, transport mechanisms, and a common base-level with sufficient accommodation
space. These considerations are important because each zone
within the mega-regolith is likely to have different and perhaps
contrasting physical and hydrogeologic properties (e.g., MacKinnon
and Tanaka, 1989; Skinner, 2005). We suggest that the stratigraphic
architecture of the Martian lowland deposits established
a spatially-variable hydrogeologic framework that assisted the
formation of Martian mud volcanoes.
control the stability of volatiles in the Martian mega-regolith are
latitude and elevation: low-elevation and high latitude regions
(such as the Martian lowlands) are more apt to have had stable
volatile reservoirs than high elevations and low latitudes. These
assertions are supported by recent observations of widespread
near-surface ice inventories by NASA’s Mars Phoenix Lander in the
northern lowlands (e.g., Mitrofanov et al., 2007; Mellon et al., 2008;
see PHX location in Fig. 1). We suggest that these hydrogeologic
characteristics and their associated processes transported and
sequestered fluids in the subsurface, providing a key component for
the growth of Martian mud volcanoes.
3.4. The Martian rock cycle
3.3. Hydrogeology
Physical, rheological, and spatial properties of terrestrial strata
direct migratory pathways for subsurface fluids and there is no
plausible reason to expect fundamentally discrepant behavior on
Mars. For example, thick and horizontally continuous layers of
buried impact breccia are interpreted to be low-permeability, highporosity (due to high clay content), and mechanically-weak
subsurface regions that help to partition Martian aquifers (MacKinnon and Tanaka, 1989). Subsurface fluids are critical components
for the initiation of terrestrial mud volcanism and similar components should be anticipated in order to reasonably apply the
process to Mars. There is abundant morphological evidence
(channels, stream-lined islands, and lobate flows; Carr, 1996) and
spectroscopic evidence (aqueous alteration mineralogies; Wyatt
et al., 2004; Poulet et al., 2005) that show water was at the very
least episodically present on the Martian surface (Appendix A5).
The presence of fluids in the Martian mega-regolith is expected to
have occurred through multiple processes (e.g., Clifford, 1993),
including overland flow and aquifer recharge, direct condensation
and/or precipitation, and atmospheric vapor diffusion (Fig. 3).
A critical element for understanding the geologic effects of the
Martian hydrogeologic cycle is the persistence and stability of
water and/or ice within the mega-regolith. Pressure and temperature relationships imply that the two most critical factors that
The transition from one major rock type to another is conceptually represented by the rock cycle. However, the familiar
Fig. 3. Conceptual mechanisms of enrichment and migration of water within the
Martian mega-regolith. These include: overland flow (1), supra-cryospheric groundwater flow (2), direct precipitation and/or condensation (3), atmospheric vapor
diffusion (4), polar ice layers (5), impact (6), cryospheric vapor diffusion (7), and
a leaking cryosphere (8). Locations of conceptual stratigraphic sections described in
Fig. 2 are indicated by arrows. Low-lying regions provide a sink for the accumulation of
subsurface volatiles and for volatile-assisted geologic processes.
1870
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
terrestrial rock cycle significantly contrasts with the Martian rock
cycle for several reasons. For example, on Mars, crustal materials
are interpreted to have thickened very early in the planet’s
formation, precluding the development of plate-driven processes of
any notable longevity or overt geologic significance (Sleep, 2000;
Nimmo and Tanaka, 2005; Appendix A5). As a result, one of the key
ingredients for crustal recycling on Earth (i.e., plate-driven tectonism; Sleep, 2000) may have been inconsequential on Mars for
much of its geologic history.
A fundamental lack of crustal recycling through tectonic
processes may have been substituted by recycling through surface
impacts (e.g., Melosh, 1989) and diagenesis through compaction,
volcanic heating, and aqueous alteration (e.g., McLennan et al.,
2007). It is well understood from surface observations of the
terrestrial planets as well as numerical modeling that impacts onto
planetary surfaces are capable of simultaneously redistributing
crustal outcrops, transforming target rocks and sediments, and
forming regional-scale topographic basins (see summaries by
Melosh, 1989 and Spudis, 1993). On Mars, for example, Argyre,
Isidis, Utopia, and Hellas basins (see Fig. 1) formed from separate
impact events (e.g., Schultz et al., 1982), resulting in the uplift of
basement rocks and the formation of topographic basins thousands
of kilometers in diameter. Subsurface and near-surface diagenesis
likely occurred episodically on Mars through various processes,
resulting in the weak induration of sediments (e.g., Wyatt et al.,
2004). Impact-based recycling and low-grade diagenesis, in addition to atmospherically-driven surface erosion, may be the most
significant components of the Martian rock cycle since early in
Mars’ evolution (Fig. 4).
The reduced gravitational field of Mars (relative to Earth) is
likely to have had a demonstrable effect on Martian depthdependent diagenetic processes. Diminished gravitational effects
on the compaction or lithification of Martian sediments may have
resulted in long-lived instabilities in the Martian mega-regolith.
Fig. 4. Conceptual representation of the Martian rock cycle. Non-essential or ‘‘inactive’’
processes are denoted by dotted lines and include tectonic recycling of the Martian
crust and mega-regolith. The bulk of Mars’ evolutionary history has been dominated by
the creation of sediments through the uplift and exposure by surface impacts. Topographic equilibrium can be theoretically achieved through erosion and infill.
The depths and lateral continuity of these buried zones may be
indirectly observed through the development and clustering of
surface landforms. We suspect that the described Martian rock
cycle was responsible for establishing instabilities in the megaregolith, resulting in upper-crustal sequences that were predisposed to compaction, mobilization, and ascent given certain
mechanical controls (Skinner and Tanaka, 2007).
4. Potential scenarios for growth of Martian mud volcanoes
Using broad-brush characteristics of the terrestrial mud
volcano process and perceived Earth–Mars parallels, we suggest
five geologically-plausible scenarios whereby mud volcanism (or
mud volcano-like) processes could occur on Mars. The intent of
the following sections is to provide an interpretive classification
scheme for previously-identified landforms based on inferred
geologic context and formational scenario. We present schematic diagrams in Fig. 5 and correlative terrestrial analogs in
Fig. 6.
4.1. Scenario A – Rapid sedimentation
This scenario of Martian mud volcanism entails the compaction
and de-volatization of volumetrically-massive flood deposits (e.g.,
Davis and Tanaka, 1995; Fig. 5A). Mud volcanoes of this formational
class may form preferentially where there are variations in the
deposit thickness (perhaps due to variations in the pre-existing
topography) and/or at the deposit margin where the sediments are
likely to be fine-grained, water-enriched, and relatively thin. We
interpret these units as rheologically homogenous and relatively
thin (tens of meters?) (Table 1). Furthermore, the inferred particle
sizes and pore space volumes of emplaced materials suggest that
erupted mud and mud breccia may have had a low viscosity.
Though mass flow deposits are inherently devoid of significant
confining layers, internal heterogeneities may develop within
rapidly-deposited sequences due to repeated outburst floods and/
or rheological layering due to deposition of contrasting units (e.g.,
flood deposits and lava flows).
On Mars, the low-lying plains of Isidis, Chryse, and Acidalia
Planitiae are interpreted to have formed through the catastrophic
deposition of sediments related to fluvial and volcanic events
(Baker and Milton, 1974; Christiansen, 1989; Tanaka, 1997). Isidis
Planitia is located within the floor of an ancient impact basin and is
surrounded by high-standing impact massifs and a large volcanic
province (Fig. 1). Chryse and Acidalia Planitiae are located at the
margins of the northern plains and proximal to the mouths of
massive fluvial outflow channels. Each of these regions contains
a high density (358 per 103 km2) of pitted cones and mounds
(Fig. 6A, Table 2) that have been interpreted as Martian mud
volcanoes that formed through the compaction of rapidly-deposited sediments (Davis and Tanaka, 1995; Tanaka, 1997; Tanaka et al.,
2003a). The Isidis features are generally cone- or mound-shaped
landforms that are a few hundreds of meters wide and tens of
meters tall (Fig. 6A). The pitted cones are often aligned into arcuate
ridges several to tens of kilometers in length, suggesting some
association with buried structures. Mound-shaped features are
common in Acidalia Planitia, some with subtle topographic
depressions that may be eruptive vents (Fig. 6B). Though most mud
volcano-like features in Chryse Planitia are similar to those
described above, the region also includes pancake-like landforms
that are several kilometers in diameter with shallow, ovoid central
craters (Fig. 6C). None of these features are overtly associated with
well-defined flows.
The Isidis, Chryse, and Acidalia features are morphologically
akin to terrestrial subaerial mud volcanoes and gryphons as well as
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
1871
Fig. 5. Formational scenarios through which mud volcanoes may form. In each case, we assume that affected sequences were volatile enriched and that instabilities were either
inherent within and/or induced upon the sequences through various mechanism or processes. Martian mud volcanoes may have formed due to overlapping scenario characteristics.
Table 1 describes our inferred physical characteristics of affected lithotypes for each scenario. (A) Scenario A – vertical compaction of rapidly-deposited sediments, such as
catastrophic flood deposits. (B) Scenario B – vertical compaction of subsurface units through volcano-related heating through the intrusion of magmatic dikes and sills. (C) Scenario
C – lateral compaction through tectonic shortening. (D) Scenario D – vertical compaction through long-term, load-induced subsidence. Mud volcanism due to the intrusion of
magmatic dikes and sills may provide an alternative or supplemental condition. (D) Scenario E – vertical compaction through seismic shaking.
dewatering features (e.g., Jakubov et al., 1971). Terrestrial gryphons
may not be associated with abundant mud flows but, rather, form
vertical vents for subsurface de-volatilization through smallvolume fluid extrusion and/or outgassing (Fig. 6D). The pitted cones
that form inside eruptive mud volcano craters result from
continued fluid and mud seepage after periodic eruptions. Moundshaped mud volcanoes form on Earth through repeated eruption of
mud breccia from a central vent (Fig. 6E) and multiple summit
depressions in Martian features may allude to multiple eruptions
(e.g, Fig. 6B). Landforms similar to the elongate, pancake-like
features of Chryse Planitia are also observed on Earth (Fig. 6F). Their
shape and/or location are usually controlled by tectonic features
such as shallow or deep faults or by large-scale anticlines. After
large-scale eruptions, the crater may collapse and subsequently be
affected by localized seepage (e.g., Hovland et al., 1997; Planke et al.,
2003; Mazzini et al., 2009).
Table 1
Formational scenarios, inferred characteristics, and potential locations of Martian mud volcanoes.
Scenario
Internal character
of affected materials
Viscosity of
erupted material
Thickness of
affected materials
Martian locations,
landforms observed
Martian locations,
landforms not observed
Rapid sedimentation
Volcanic/geothermal
destabilization
Tectonic shortening
Homogenous
Homogeneous or
heterogeneous
Heterogeneous
Low
Low to moderate
10’s meters
100’s meters
Isidis, Chryse, Acidalia
Galaxias Fossae
Hellas, central Utopia
Cerberus Fossae, Alba Patera
Low to high
Utopia HLB
Long-term, load-induced
subsidence
Seismic shaking
Homogenous or
heterogeneous
Homogenous or
heterogeneous (?)
100’s of meters
to kilometers
Kilometers
On most globally-occurring
tectonic ridges
Other large basin centers
(Utopia, Isidis, Hellas, Argyre)
?
High
Low to high (?)
Meters to
kilometers (?)
Scandia
Utopia HLB (?)
1872
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
Fig. 6. Examples of Martian mud volcano-like features formed through formational scenarios proposed herein (see Fig. 1 for locations). Panels are excerpts from Mars Orbiter
Camera narrow-angle images (w3 m/px resolution), Thermal Emission Imaging System (visible, 36 m/px and infrared, 100 m/px), and Mars Orbiter Laser Altimeter (MOLA) digital
elevation models (231 m/px) (image number noted on each panel). Each Mars image is aligned above morphologically-equivalent terrestrial mud volcanoes (see Section 3 for
summary). North is toward the top. Earth images are from Google Earth, unless otherwise noted. (A) Pitted cones of Isidis Planitia. Note partial alignment indicating some structural
or topographic control. (B) Typical mound-shaped landform in Acidalia Planitia. Note small depressions at summit that may be overlapping vents. (C) Pancake-shaped mound in
Chryse Planitia. Features form in channel floors and pre-date linear (desiccation?) fractures. (D) Field of seeping gryphons in Dashgil mud volcano crater, Azerbaijan. Fluid seepage is
ongoing, forming mud flows that spread inside the crater. (E) Circular crater of Bledug Kuwu mud volcano (Java, Indonesia) showing three main active vents where gas and mud
vigorously erupt. Size of the crater is w650 m. (F) Elongated and collapsed crater with concentric mud breccia flows and fluidized mud locally erupting inside the crater, east
Azerbaijan. Size of the crater w1.5 km. (G) Pitted cones, flows, and ridges in Galaxias Fossae. Smooth, light-toned flows flood irregularly-shaped depression. (H) Eastern Utopia
Planitia HLB. Mounds (arrows), some superposed with small pitted cones, form proximal to tectonic ridges. (I) Eastern Utopia Planitia HLB. Broad, low-slope mounds (arrows)
superposed by smooth plains materials. (J) Lusi mud volcano (Java, Indonesia), oblique aerial view during August 2006. Note the area covered by the low-viscosity, water-rich mud.
(K) Pitted cones of erupting gryphons at Dashgil mud volcano, Azerbaijan. Gryphon heights are w4 m. (L) Tang mud volcano, southeastern Iran. Mud flows radiate from a central pit.
Fig. 6. (continued).
Image size 2 km. (M) Falsely-illuminated hillshade of MOLA topography depicting mounds of the Scandia region (arrows). Note scale bar relative to other panels. (N) Scandia mound
(outlined). Note high-standing central peak (arrow). (O) Western Utopia Planitia HLB pitted cones. Note morphologic difference between pitted cones (outlined) and impact crater.
(P) Mud volcano in eastern Azerbaijan. Long axis of the crater is w3 km. (Q) Paint Hill, TX, which formed as a piercement structure above an ascending column of breccia that tapped
Tertiary strata. Note boulders on the crowning diapir. (R) Quickbird image of Bahar satellite mud volcano, Azerbaijan. Size of the crater is w100 m. Note morphologic similarity to
impact crater (c.f. Fig. 6O). (S) Western Utopia Planitia HLB pitted cones and rugged lobate features (flows?). Cross-cutting relationships indicate both features formed concurrently.
(T) Western Utopia Planitia HLB cone and smooth flows. Note association with narrow fractures (arrow). (U) Western Utopia Planitia. Pitted cones and lobate features. (V) Quickbird
image of Kotturdag mud volcano, Azerbaijan. Size of the crater is w200 m. The circular crater was breached by a large tongue of mud breccia. (W) Oblique Quickbird image of
Lokbatan mud volcano, Azerbaijan. Width of image is w3 km. Graben collapse controls mud flows and coincides with the direction of the anticline axis that hosts Lokbatan mud
volcano. (X) Photograph of edge of mud breccia flow from Lokbatan mud volcano, Azerbaijan. See oil wells in the background for scale.
1874
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
4.2. Scenario B – Volcano-induced destabilization
This scenario of Martian mud volcanism entails the thermal and/
or mechanical destabilization of volatile-enriched units through
volcanic activity, mostly likely through the intrusion of dikes and
sills (Fig. 5B). Models of volcano-ice interactions on Mars indicate
that the thickness of affected units may be hundreds of meters thick
(e.g., Wilson and Mouginis-Mark, 2003). The inferred tapping
depth and conduit stratigraphy lead us to speculate that the
erupted sediments in this formational scenario are low- to
moderate-viscosity mud (Table 1). Preferential mobilization of mud
and mud breccia along structural weaknesses may result in alignment of mud volcanoes and elongated depressions related to
surface subsidence. The inferred variability in the affected units
may result in diverse mud volcano morphologies and localized
deposition of mud flows. Spatial distributions and alignments may
reflect buried structural weaknesses that mimic regional stresses
associated with the growth of the adjacent volcanic province
(Appendix A5).
On Mars, several locations are likely to have evolved partly
through volcano–ice interactions. Galaxias Fossae is a fissure
system located in the lowlands along the eastern margin of Utopia
Planitia and adjacent to the Elysium volcanic province (Fig. 1). The
region contains a relatively moderate density (90 per 103 km2) of
mud volcano-like landforms including small pitted cones and
domes, lineaments, and flows. However, the features occur as highdensity clusters, particularly when they are located marginal to
bright, lobate deposits that fill shallow depressions (Fig. 6G).
Segmented, positive- and negative-relief lineaments occur within
and may be the source of the high-albedo surface units. The Galaxias landforms are aligned in the northwest–southeast direction,
parallel to regional fracture patterns (Hall et al., 1986; Tanaka et al.,
2005). They are a few hundred meters in diameter, often contain
central pits, and extend tens of meters above adjacent terrains
(Table 2).
Mud volcanoes similar to the features observed in Galaxias
Fossae are also observed on Earth. These ‘‘swamp-like’’ features are
characterized by low-elevation and water-rich mud, which erupt
for extended periods of time from a central vent. Erupted lowviscosity mud easily migrates away from the main crater and can
cover significant areas (depending on the original morphology of
the terrain). Some examples of this type of terrestrial mud volcanoes occur in Trinidad and Malaysia. Perhaps the best terrestrial
analog is the Lusi mud volcano in northeast Java (Fig. 6J), a waterdominated eruption that has been ongoing since May 2006, which
covers >7 km2. Similar to the hypothesized low-viscosity flows and
edifices of Galaxias Fossae, Lusi is located proximal to a magmatic
complex (Mazzini et al., 2007), which may provide a mechanism for
the initiation and longevity of the eruption. Lineated ridges
observed in the Galaxias region (Fig. 6G) may be similar to terrestrial sinter ridges produced by frictional heating of mud breccia
during eruption.
4.3. Scenario C – Tectonic shortening
This scenario of Martian mud volcanism entails the eruption of
mud and mud breccia along buried faults due to the compression of
volatile-enriched strata (Fig. 5C). We interpret the units affected by
this Martian mud volcano scenario to have been rheologically
heterogeneous due to the inferred high density of emergent faults
and the potential existence of heterogeneous layers to confine
subsurface pressures (Table 1). The source strata that produce mud
volcanoes through tectonic shortening are not required to be
rheologically layered. However, the presence of capping strata may
promote the growth of mud volcano-like landforms due to
increased subsurface pressures. Furthermore, compression ridges
may provide more pathways for the ascent of buoyant sediments.
Because Martian wrinkle ridges likely deform lithologic sequences
of significant thickness (Watters, 1993), we suggest that the tapping
sources for the growth of mud volcanoes in this scenario may be
hundreds of meters to several kilometers thick (Table 1). These
assessments are correlative to thickness estimates from depth–
diameter relationships of buried impact crater populations (Buczkowski, 2007) as well as gravitational assessments of basin infill
(Banerdt, 2004).
On Mars, the southern margin of Utopia Planitia is defined by
alluvial and colluvial plains related to the erosion of the ancient
highlands located to the south (Tanaka et al., 2003; Skinner and
Tanaka, 2007; Fig. 1). These sediments may be intercalated with
Elysium-derived volcanic rocks and sediments, particularly along
their eastern margins. The eastern Utopia Planitia HLB contains
several large tectonic ridges which are buttressed and superposed
by mounds that we interpret as having formed as mud volcanoes
due to tectonic shortening (Fig. 6H). The mounds have a low spatial
density within the region (1.04 per 103 km2), are circular to ovoid in
planform shape, and are between 2 and 12 km wide (Table 2).
Several have small (tens of meters wide) pitted cones located near
their center (Fig. 6H). Others are partly buried by smooth materials
of apparent similar origin (Fig. 6I), suggesting concurrent formation
of mounds and surrounding plains. However, lobate features that
are indicative of thick, widely-occurring mud flows are not
observed in current datasets.
The mounds that occur in the eastern Utopia HLB (as well as
some of those described in Section 4.1) are morphologically akin to
terrestrial subaerial mud volcanoes and gryphons where ‘‘pieshaped’’ features develop (Fig. 6K). On Earth, the latter can form as
the result of episodic eruption of water-rich mud breccia from
a central crater. Compared to the explosive eruptions that define
other mud volcanoes, ‘‘pie-shaped’’ mud volcanoes on Earth erupt
quiescently. The high fluid content (and resultant low viscosity) of
mud in these instances allows for significant lateral propagation of
mud flows with low-elevation lobate margins. This type of terrestrial mud volcano is common in mud volcano provinces; Dashgil
(see Fig. 2 of Mazzini et al., 2009) and Tang mud volcanoes (Fig. 6L)
are some of the examples observed in these regions.
4.4. Scenario D – Long-term, load-induced subsidence
This scenario of Martian mud volcanism entails the growth of
diapiric masses and piercement structures as the result of longterm compaction of thick, volatile-enriched sediments (Fig. 5D).
We interpret the subsurface units affected by this Martian mud
volcano scenario as rheologically homogenous or heterogeneous
due to the diverse (and generally unknown) nature of the affected
material as well as the diversity in size and geologic character of the
erosional watersheds that feed these large basins (Table 1). Extreme
depths of the source strata (kilometers?) can result in a lengthy
vertical conduit along which ascending sediment mass can entrain
rocks and sediment, resulting in the eruption of high viscosity mud
breccia. The resultant mud volcano may be formed through violent
eruptions (pitted cones or mounds) or passive extrusion (un-pitted
domes).
On Mars, the Scandia region occupies the lowest portions of the
lowland plains (Fig. 1). This region is characterized by large ovoid
and knobby mountains (termed ‘‘tholi’’) which may have formed
through mud volcano-like processes related to long-term, loadinduced subsidence (Fig. 6M and N; Tanaka et al., 2003a; Kite et al.,
2007). The Scandia Tholi are dissimilar to other mud volcano-like
landforms described herein because they are not cone or mound
shaped and they contain no obvious central vent or collapse
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
1875
Table 2
Morphological characteristics of potential Martian mud volcanoes.
Martian location
Postulated formational
scenario
Density
(#/103 km2)
Diameter
Height
Cone or mound
morphologies?
Associated with
flow materials
or morphologies?
Associated with
tectonic features?
(type)
Isidis, Chryse, Acidalia
Galaxias Fossae
Rapid sedimentation
Volcanic/geotherm al
destabilization
Tectonic shortening
Long-term, load-induced
subsidence
Seismic shaking
358
90
400–600 m
400–800
w10–20 m
w10–20 m
Both
Cones
No
Yes
No
Yes (fractures)
1.04
0.13
2–12 km
22–40 km
10–200 m
100–500 m
Mounds
Mounds
No
No
Yes (ridges)
Maybea (fractures)
0.76
4–8 km
100–300 m
Cones
Yes
No
Eastern Utopia HLB
Scandia
Western Utopia HLB
a
Though their extents in Scandia are not observed, graben from Alba Patera may focus the growth of the Scandia mounds; see text for discussion.
caldera. Rather, the Scandia features are large-diameter rugged
mountains and hillocks (Table 2). If vents existed, they have been
eroded or buried. Proximity to higher-standing regions, including
Alba Patera and Planum Boreum (Fig. 1) suggests contributions
from hydraulic pressuring through groundwater movement from
higher areas (e.g., Tanaka, 2005). Increased subsurface pressures
resulting from hydraulic forcing may have contributed to the
buoyancy of buried deposits at the lowest point within the
lowlands, supplementing subsidence-related pressures. Increased
subsurface pressure may also have been generated by episodic
inundation by flood deposits (Fairén et al., 2003).
The Scandia Tholi are similar in shape to some terrestrial
subaerial mud volcanoes (Fig. 6P) and piercement structures.
Piercement structures are emergent sedimentary diapirs that
pierce the land surface as the result of the long-term buoyant
ascent of low-density sediments. Several of these structures are
located above thick sedimentary sequences of the eastern Rio
Grande embayment in McMullen County, Texas (Freeman, 1968).
These mud volcanoes form circular to elongate domes that tend to
parallel major northeast–southwest-trending geologic contacts
and buried subsurface structures (Fig. 6Q). The resultant domes are
comprised of breccia and sediment and are commonly topped and
surrounded by meter-sized blocks (Freeman, 1968).
An additional or alternative interpretation regarding the Scandia Tholi is their growth in response to magmatic intrusions in the
form of dikes and sills, perhaps related to the Alba Patera shield
volcano located to the south (Tanaka et al., 2005; Fig. 1). Such
intrusions may have triggered metamorphic reactions and hydrothermal activity that resulted in violent eruptions. A similar
scenario was suggested by Svensen et al. (2004) to explain the large
craters observed on seismic images offshore Norway. This mechanism may explain the lack of clearly-defined craters associated with
each of the Scandia mounds as well as the presence of blocky
features observed across large areas (Fig. 6N). The past presence of
water at or near the Scandia surface is evidenced through anomalous concentrations of hydrated sulfides and gypsum in adjacent
regions (Langevin et al., 2005), which may further support the
presence of hydrothermal activity in case of magmatic intrusions
(e.g., Tanaka et al., 2008). A magmatic intrusion component for the
growth of the Scandia features would be similar to the formational
scenario described for the Galaxias Fossae features (Section 4.2),
with the key discrepancy being the inferred thickness of affected
units (see Table 1).
4.5. Scenario E – Seismic shaking
This scenario of Martian mud volcanism entails the fluidization
and buoyant ascent of volatile-enriched sediments due to seismically-induced destabilization and compaction (Fig. 5E). Mars is
predicted to be seismically active based on length and offset
measurements of tectonic graben, with Mars quakes of magnitude
>4 occurring at rates of >500/year (Knapmeyer et al., 2006).
Seismic energy can also be emitted by large impacts on adjacent
and antipodal surfaces (Melosh, 1989). As such, the internal rheological character, viscosity, and thickness of the subsurface units
feasibly extend the gamut of consideration (Table 1). This type of
scenario can be used to account for the formation of multiple
features on the surface of Mars, including irregularly-shaped
depressions and mass movements as well as the pitted cone,
mound, and flow morphologies of potential mud volcano origin.
On Mars, we identify mud volcano-like landforms in the
western Utopia Planitia HLB as potentially forming through seismically-induced mud volcanism (Tanaka et al. 2003b; Skinner and
Tanaka, 2007). This assertion is based on a lack of characteristics
that confidently place these materials in any of the aforementioned
formational scenarios. The western Utopia HLB features include
low-angle cones (with lobate flows) and mounds (Fig. 6O and S).
The conical features are 4–8 km in diameter and 100–300 m in
height (Table 2). The pitted cones are often associated with topographically-subdued fractures (Fig. 6T) and the surrounding plains
consist of overlapping, rugged, lobate flows (Fig. 6U).
The features that we observe in the southern Utopia HLB have
similar morphologies to terrestrial mud volcanoes. Similar largescale edifice and crater mud volcanoes are observed in Azerbaijan
such as Bahar satellite (Fig. 6R), Kotturdag (Fig. 6V), and Lokbatan
(Fig. 6W). These classic morphology examples of terrestrial mud
volcanoes form through periodic violent eruption of mud and mud
breccia and resultant collapse of the upper plumbing conduits.
They are oriented along subsurface anticline axes related to the
lateral compression of underlying sedimentary sequences. These
mud volcanoes are also associated with mud flows with lobate
margins (Fig. 6X), the surface texture of which can vary from
smooth to rugged similar to terrestrial lava flows.
5. Implications of Martian mud volcanism
We acknowledge that the formational scenarios and morphologic comparisons outlined herein are speculative. However, they
represent an improvement over past characterizations of mud
volcano-like landforms on Mars because they provide some weight
to formational specifics and geologic context. It is important to bear
in mind that Mars–Earth analogs require careful adaptation in
order to fully account for the implied geologic contexts and
conditions. We identify several key implications of using mud
volcanism as a viable Martian geologic process.
If proven to exist, an analysis of the origin and character of
Martian mud volcanoes can provide an improved understanding of the history of water on Mars and the potential for
the development of life on that planet. For instance, basinscale impacts such as those that form the Martian lowlands
form concentric basins separated by uplifted crustal massifs
(Spudis, 1993; Schultz et al., 1982). Both terrestrial impact
1876
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
studies and numerical modeling indicate that the bounding
systems of impact-related extensional faults are long-lived
focal points of hydrothermal activity. Though hydrothermal
settings on Mars may have been conducive to the development
of autotrophic life, their associated rock record is likely buried
deep within the stratigraphic succession. The unique ability of
mud volcanoes to transport rocks and sediments to the surface
from great depths implies that erupted mud and mud breccia
on Mars may contain ancient materials. Such deposits could
provide not only a survey of past depositional environments
but also astrobiological evidence that would otherwise be
inaccessible for exploration.
Terrestrial mud volcanoes are commonly associated with
hydrocarbon reservoirs and mud eruptions contain not only
rocks and sediment but also fluid, aqueous vapor, and gas (e.g.,
Ivanov and Guliev, 1988; Mazzini et al., 2007, 2009). Carbon
dioxide and mainly methane production from terrestrial mud
volcanoes may provide significant volumes of fossil hydrocarbon
gas to Earth’s atmosphere and oceans (Etiope and Milkov, 2004).
Recent details of methane plumes on Mars by Mumma et al.
(2009) similarly indicate modern episodic release of methane
and water vapor from discrete regions. Though the age of the
Martian methane plumes is unknown, it is possible that they
formed through the modern release of anciently-sequestered
gas, perhaps as the result of the dissociation of gas-clathrate
hydrate reservoirs (e.g., Kargel and Lunine, 1998). Even though
the modern methane plumes do not directly coincide with the
locations of postulated lowland mud volcanoes, the parallel
between methane production from terrestrial mud volcanoes
and potential production from Martian mud volcanoes is
compelling. A concerted examination of Martian mud volcanism
as a geologically feasible process that may contain geochemical
evidence of fossil life can assist in identifying candidate landing
sites for future Mars missions.
Identifying a range of formational scenarios for the formation of
Martian mud volcanoes helps underscore the concept that Martian
basins contain complex stratigraphic architectures that both
resulted from and subsequently controlled regionally-focused
geologic activities. The idea that the younger and better-preserved
Martian lowlands consist of multiple sedimentary deposits
provides an understanding of the history of those deposits (e.g.,
Tanaka et al., 2003a). If mud volcanism is appropriately interpreted
and applied, it serves to illustrate the stratigraphic and hydrogeologic character of those basins. For example, a complete stratigraphic reconstruction has been successfully complete on
Mediterranean mud volcanoes using a collection of surface mud
breccia clasts (Akhmanov, 1996; Akhmanov et al., 2003). Targeted
analysis of potential Martian mud volcanoes using high-resolution
surface and subsurface imaging instruments (Appendix A2) may
provide a comprehensive approach to reconstructing Mars’
subsurface stratigraphy at specific locations.
We note that the terrestrial mud volcanoes that we identify as
morphologic analogies only partly satisfy the formational scenario
with which they are identified. Our hypotheses implicate an overlap of scenarios that need to be more robustly explored. We identify
only those regions within and adjacent to the Martian lowland
plains because they represent the longest-lived depocenters on the
surface of Mars. However, there are other locations that may
potentially satisfy the formational characteristics proposed herein
(e.g., Table 1). We are compelled to study these regions to identify
whether our formational scenarios are realistically applicable. In
addition, we need to establish scientific confidence beyond
geomorphic analogy in order to develop the mud volcano
hypotheses for Mars, using geochemical analyses and numerical
modeling.
There are significant questions that are unresolved (yet tractable
for further research) that can firm our suggestive characterizations
and scenarios. What is the full suite of formational processes that
could produce mud volcano-like edifices on both Earth and Mars?
Is there a discernible relationship between morphology/
morphometry and tapping depth, sediment-fluid ratios, subsurface
structures, geologic unit, and formational age? Why are equivalent
landforms not everywhere observed in ‘‘predicted’’ regions, based
on the proposed formational scenarios? Numerical models can
significantly assist in reconstructing the mud volcano-like
processes and conditions through which the observed Martian
landforms may have formed. Can the formational scenarios presented herein be reasonably buttressed by numerical modeling?
Svensen et al. (2007) and Gisler et al. (2008) made an initial step in
this direction when they compared terrestrial piercement features
with numerical modeling of such eruptions on Mars. The results
revealed comparable morphologies between the simulated terrestrial and Martian mud volcano-like features, with the exception
that the latter were of much larger dimension. This effect is the
result of the lower atmospheric pressure on Mars, which allows for
more violent eruptions to manifest, fitting with the results
described in our article. We not only expect but encourage
improvements and corrections to the characterizations described
herein.
6. Summary
We find that the physical components that contribute to the
growth of mud volcanoes on Earth have substantive parallels on
Mars that warrant further consideration of mud volcanism as
a viable Martian geologic process. We suggest:
The physiographic, stratigraphic, hydrogeologic, and diagenetic
character of Mars implicates five geologically-plausible formational scenarios through which mud volcanoes may form.
These occur in regions that have undergone rapid sedimentation, volcano-induced destabilization, tectonic shortening,
long-term, load-induced subsidence, and/or seismic shaking.
We perceive these scenarios as end-members for the characterization of Martian mud volcanism and anticipate substantial
overlap in geologic context and process.
Mud volcano-like landforms exist in regions of the Martian
lowlands that at least partly satisfy the aforementioned formational scenarios: (1) Isidis, Chryse, and Acidalia Planitiae
(rapid sedimentation), (2) Galaxias Fossae (volcano-induced
destabilization), (3) the eastern Utopia Planitia highland–
lowland boundary (tectonic shortening), (4) the Scandia region
(long-term, load-induced subsidence), and (5) the western
Utopia Planitia highland–lowland boundary (seismic shaking).
The pitted cones, mounds, and flows observed within regions
within and marginal to the Martian northern plains are
generally consistent with the morphological and geological
criteria for terrestrial mud volcanoes.
Martian mud volcanoes, if proven present, may provide ideal
locations for surface exploration and sampling due to their
point-source gathering of a vertical section of geologic units. The
co-existence of water and past hydrothermal activity peripheral
to lowland impact basins suggests that Martian mud volcanoes
could provide evidence of past fossil life that would normally be
inaccessible to robotic or human explorers.
Acknowledgements
We are grateful to the editors M. Ivanov and O. Catuneaunu for
their support. We acknowledge the input of G. Akhmanov and one
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
anonymous reviewer who helped tighten the focus of this paper.
Thanks to C. Fortezzo (USGS), G. Gisler (PGP), H. Svensen (PGP) and
K. Tanaka (USGS) who each provided helpful discussions and
reviews. We gratefully acknowledge the instrument teams that
provided datasets used herein, including THEMIS (http://themis.
asu.edu/), MOC (http://www.msss.com/), and MOLA (http://mola.
gsfc.nasa.gov/). This work was supported, in part, by a grant from
NASA’s Planetary Geology and Geophysics program.
Appendix. Supplementary information
Supplementary information associated with this article can be
found, in the online version, at doi:10.1016/j.marpetgeo.2009.02.006
References
Akhmanov, G.G., 1996. Lithology of mud breccia clasts from the Mediterranean
Ridge. Mar. Geol., 151–164.
Akhmanov, G.G., Premoli Silva, I., Erba, E., Cita, M.B., 2003. Sedimentary succession
and evolution of the Mediterranean Ridge western sector as derived from
lithology of mud breccia clasts. Mar. Geol. 195 (1–4), 277–299.
Baker, V.R., Milton, D.J., 1974. Erosion by catastrophic floods on Mars and Earth.
Icarus 23, 27–41.
Banerdt, W.B., 2004. A gravity analysis of the subsurface structure of the Utopia
impact basin. Lunar Planet. Sci. XXXV abstract #2043.
Barber, A.J., Tjokosapoetro, S., Charlton, T.R., 1986. Mud volcanoes, shale diapirs,
wrench faults and melanges in accretionary complexes, eastern Indonesia.
Amer. Assoc. Petrol. Geol. Bull. 70, 1729–1741.
Buczkowski, D.L., 2007. Stealth quasi-circular depressions (sQCDs) in the northern
lowlands of Mars. J. Geophys. Res. 112, E09002, doi:10.1029/2006JE002836.
Burr, B.M., Bruno, B.C., Lanagan, P.D., Glaze, L.S., Jaeger, W.L., Soare, R.J., Wan Bun
Tseung, J.-M., Skinner Jr., J.A., Baloga, S.M., 2008. Meso-scale raised rim depressions (MRRDs) on earth: a review of the characteristics, processes, and spatial
distributions of analogs for Mars. Planet. Space Sci., doi:10.1016/j.pss.2008.11.011.
Carr, M.H., 1996. Water on Mars. Oxford University Press, New York, 229 pp.
Christiansen, E.H., 1989. Lahars in the Elysium region of Mars. Geology 17, 203–206.
Cita, M.B., Ivanov, M.K., Woodside, J.M., 1996. The Mediterranean Ridge Diapiric Belt.
Mar. Geol. 132 (Special issue), 273 pp.
Clifford, S.M., 1993. A model for the hydrologic and climatic behavior of water on
Mars. J. Geophys. Res. 98, 10,973–11,103.
Davis, P.A., Tanaka, K.L., 1995. Curvilinear ridges in Isidis Planitia, Mars – the result
of mud volcanism? Proc. Lunar Planet. Sci. Conf. XXIV, 321–322.
Dia, A.N., Castrec-Rouelle, M., Boulegue, J., Comeau, P., 1999. Trinidad mud volcanoes: where do the expelled fluids come from? Geochim. Cosmochim. Acta 63
(7–8), 1023–1038.
Dickson, J.L., Head III, J.W., Marchant, D.R., 2008. Late Amazonian glaciation at the
dichotomy boundary Mars: evidence for glacial thickness maxima and multiple
glacial phases. Geology 36, 411–414.
Dimitrov, L.I., 2002. Mud volcanoes – the most important pathway for degassing
deeply buried sediments. Earth-Sci. Rev. 59 (1–4), 49–76.
Etiope, G., Milkov, A., 2004. A new estimate of global methane flux from onshore
and shallow submarine mud volcanoes to the atmosphere. Environ. Geol. 46,
997–1002.
Fairén, A.G., Dohm, J.M., Baker, V.R., de Pablo, M.A., Ruiz, J., Ferris, J.C.,
Anderson, R.C., 2003. Episodic flood inundations of the northern plains, Mars.
Icarus 165, 53–67.
Farrand, W.H., Gaddis, L.R., Keszthelyi, L., 2005. Pitted cones and domes on Mars:
observations in Acidalia and Cydonia Mensae using MOC, THEMIS, and TES
data. J. Geophys. Res. 110, doi:10.1029/2004JE002297.
Freeman, P.S., 1968. Exposed Middle Tertiary mud diapirs and related features in
south Texas. AAPG Memoir 8, 162–182.
Frey, H.V., 2006. Impact constraints on, and a chronology for, major events in early
Mars. J. Geophys. Res. 111, E08591, doi:10/1029/2005JE002449.
Frey, H., Lowry, B.L., Chase, S.A., 1979. Pseudocraters on Mars. J. Geophys. Res. 84
(B14), 8075–8086.
Garvin, J.B., Sakimoto, S.E.H., Frawley, J.J., Schnetzler, C.C., Write, H.M., 2000.
Topographic evidence for geologically recent near-polar volcanism on Mars.
Icarus 145, 648–652, doi:10.1006/icar.2000.6409.
Gisler, G., Svensen, H., Mazzini, A., Polteau, S., Galland, O., Planke, S., 2008. Simulations of the Explosive Eruption of Supercritical Fluids through Porous Media.
EGU, Vienna.
Greeley, R., Guest, J.E., 1987. Geologic map of the eastern equatorial region of Mars.
USGS Misc. Inv. Ser. Map I-1802-B scale 1, 15M.
Hall, J.L., Solomon, S.C., Head III, J.W., 1986. Elysium region, Mars: test of lithospheric
loading models for the formation of tectonic features. J. Geophys. Res. 91,
11377–11392.
Hartmann, W.K., Neukum, G., 2001. Cratering chronology and the evolution of Mars.
In: Kallenback, R., Geiss, J., Hartmann, W.K. (Eds.), Chronology and Evolution of
Mars. Kluwer Academic Publishers, London, pp. 165–194.
1877
Hovland, M., Hill, A., Stokes, D., 1997. The structure and geomorphology of the
Dashgil mud volcano, Azerbaijan. Geomorphology 21, 1–15.
Isaksen, G.H., Aliyev, A., Barboza, S.A., Plus, D., Guliev, I.S., 2007. Regional evaluation
of source rock in Azerbaijan from the geochemistry of organic-rich rocks in
mud-volcano ejecta. In: Yilmaz, P.O., Isaksen, G.H. (Eds.), Oil and Gas of the
Greater Caspian Area. AAPG Studies in Geology, vol. 5, pp. 51–64.
Ivanov, V.V., Guliev, I.S., 1988. A physio-chemical model of mud volcanism. In:
Problems in the Oil and Gas Content of the Caucasus.
Ivanov, M.K., Limonov, A.F., van Weering, T.C.E., 1996. Comparative characteristics of
the Black Sea and Mediterranean Ridge mud volcanoes. Mar. Geol. 132 (1–4),
253–271.
Jakubov, A.A., AliZade, A.A., Zeinalov, M.M., 1971. Mud Volcanoes of the Azerbaijan
SSR. In: Atlas. Azerbaijan Academy of Sciences, Baku (in Russian).
Kargel, J.S., Lunine, J.I., 1998. Clathrate hydrates on Earth and in the Solar System. In:
Schmitt, B., de Bergh, C., Festou, M. (Eds.), Solar System Ices. Kluwer Academic
Publishers, Dordrecht, The Netherlands, pp. 97–117.
Khalilov, N.Y., Kerimov, A.A., 1981. Origin of mud volcanism and diapirism. Int. Geol.
Rev. 25 (8), 877–881.
Kholodov, V.N., 2002. Mud volcanoes, their distribution regularities and genesis:
Communication 1. Mud volcanic provinces and morphology of mud volcanoes.
Lithology and Mineral Resources, 37 (3): 197-209.
Kite, E.S., Hovius, N., Hiller, J.K., Besserer, J., 2007. Candidate mud volcanoes in the
northern plains of Mars. Eos Trans. AGU 88 (52) Fall Meet. Suppl., Abstract
V13B-1346.
Knapmeyer, M., Oberst, J., Hauber, E., Waehlisch, M., Deuchler, C., Wagner, R., 2006.
Working models for spatial distribution and level of Mars’ seismicity. J. Geophys. Res. 111, E11006.
Komar, P.D., 1990. Mud volcanoes on Mars. NASA Tech. Memo. 4300, 539–541.
Kopf, A.J., 2002. Significance of mud volcanism. Rev. Geophys. 40 (2).
Langevin, Y., Poulet, F., Bibring, J., Gondet, B., 2005. Sulfates in the north polar region
of Mars detected by OMEGA/Mars Express. Science 307, 1584–1586.
Lucchitta, B.K., 1981. Mars and Earth: comparison of cold-climate features. Icarus 45,
264–303.
MacKinnon, D.J., Tanaka, K.L., 1989. The impacted Martian crust: structure,
hydrology, and some geologic implications. J. Geophys. Res. 94, 17,359–
17,370.
Mazzini, A., Svensen, H., Planke, S., Guliyev, I., Akhmanov, G.G., Fallik, T., Banks, D.,
2009. When mud volcanoes sleep: insight from seep geochemistry at
the Dashgil mud volcano, Azerbaijan. Mar. Petrol. Geol., doi:10.1016/
j.marpetgeo.2008.11.003.
Mazzini, A., Svensen, H., Akhmanov, G.G., Aloisi, G., Planke, S., Malthe-Sørenssen, A.,
Istadi, B., 2007. Triggering and dynamic evolution of LUIS mud volcano,
Indonesia. Earth Planet. Sci. Lett., doi:10.1016/j.epsl.2007.07.01.
McLennan, S.M., Arvidson, R.E., Clark, B.C., Golombeck, M.P., Grotzinger, J.P., Jolliff, B.L.,
Knoll, A.H., Squyres, S.W., Tosca, N.J., 2007. LPI Contr., Report 1353, abstract
#3231.
Mellon, M.T., Arvidson, R.E., Marlow, J.J., Phillips, R.J., Asphaug, E., Searls, M.L.,
Martinez-Alonso, S.E., the HiRISE Team, 2008. Polygonally patterned ground
and sorted rocks on Mars as seen by HiRISE: the Phoenix landing site, northern
plains, and beyond. Lunar Planet. Sci. XXXIX abstract #1770.
Melosh, H.J., 1989. Impact Cratering: A Geologic Process. Oxford University Press,
New York, 245 pp.
Middleton, G.V., 1973. Johannes Walther’s Law of the correlation of facies. AAPG
Bull. 84, 979–988.
Mitrofanov, I.G., et al., 2007. Water ice permafrost on Mars: layering structure and
subsurface distribution according to HEND/Odyssey and MOLA/MGS data.
Geophys. Res. Lett. 34, L18202.
Mumma, M.J., Villanueva, G.L., Novak, R.E., Hewagama, T., Bonev, B.P., DiSanti, M.A.,
Mandell, A.M., Smith, M.D., 2009. Strong release of methane on Mars in
northern summer 2003. Sci. Exp. January, doi:10.1126/science/1165243.
Nimmo, F., Tanaka, K., 2005. Early crustal evolution of Mars. Annu. Rev. Earth Planet
Sci. 33, 133–161, doi:10.1146/annurev.earth.33.092203.122637.
Pinheiro, L.M., Ivanov, M.K., Sautkin, A., Akhmanov, G., Magalhães, V.H.,
Volkonskaya, A., Monteiro, J.H., Somoza, L., Gardner, J., Hamouni, N.,
Cunha, M.R., 2003. Mud volcanism in the Gulf of Cadiz: results from the TTR-10
cruise. Mar. Geol. 195 (1–4), 131–151.
Planke, S., Svensen, H., Hovland, M., Banks, D.A., Jamteit, B., 2003. Mud and fluid
migration in active mud volcanoes in Azerbaijan. Geo-Mar. Lett. 23,
258–268.
Poulet, F., Bibring, J.P., Mustard, J.F., Gendrin, A., Mangold, N., Langevin, Y.,
Arvidson, R.E., Gondet, B., Gomez, C., the OMEGA Team, 2005. Phyllosilicates on
Mars and implications for early Martian climate. Nature 438, doi:10.1038/
nature04274.
Schultz, P.H., Schultz, R.A., Rogers, J., 1982. The structure and evolution of ancient
impact basins on Mars. J. Geophys. Res. 87, 9803–9820.
Scott, D.H., Carr, M.H., 1978. Geologic map of Mars. USGS Misc. Inv. Ser. Map I-1083
scale 1, 25M.
Scott, D.H., Tanaka, K.L., 1986. Geologic map of the western equatorial region of
Mars. USGS I-1802-A scale 1, 15M.
Skinner Jr., J.A., 2005. Hydraulically-distinct, stratigraphic horizons in the southern
margin of the Utopia impact basin, Mars. Eos Trans. AGU 86 (52) Fall Meet.
Suppl., Abstract P23A-0180.
Skinner Jr., J.A., Tanaka, K.L., 2007. Evidence for and implications of sedimentary
diapirism and mud volcanism in the southern Utopia highland–lowland
boundary plain, Mars. Icarus 186, 41–47, doi:10.1016/j.icarus.2006.08.013.
1878
J.A. Skinner Jr., A. Mazzini / Marine and Petroleum Geology 26 (2009) 1866–1878
Skinner Jr., J.A., Skinner, L.A., Kargel, J.S., 2007. Re-assessment of hydrovolcanismbased resurfacing within the Galaxias Fossae region of Mars. Lunar Planet. Sci.
XXXVIII abstract #1998.
Sleep, N.H., 2000. Evolution of the mode of convection within terrestrial planets. J.
Geophys. Res. 105, 17,563–17,578.
Spudis, P.D., 1993. The Geology of Multi-Ring Impact Basins. Cambridge University
Press.
Svensen, H., Planke, S., Malthe-Sørenssen, A., Jamtveit, B., Myklebust, R., Eidem, T.,
Rey, S.S., 2004. Release of methane from a volcanic basin as a mechanism for
initial Eocene global warming. Nature 429, 542–545.
Svensen, H., Gisler, G., Polteau, S., Mazzini, A., Planke, S., 2007. Hydrothermal vent
complexes and the search of extra-terrestrial water. Lunar Planet. Sci. XXXVIII
abstract #2268.
Tanaka, K.L., 1986. The stratigraphy of Mars. J. Geophys. Res. 91, E139–E158.
Tanaka, K.L., 1997. Sedimentary history and mass flow structures of Chryse and
Acidalia Planitiae. Mars J. Geophys. Res. 102, 4131–4150.
Tanaka, K.L., 2005. Geology and insolation-driven climatic history of Amazonian
north polar materials on Mars. Nature 437, 991–994.
Tanaka, K.L., Rodriguez, J.A.P., Skinner Jr., J.A., Bourke, M.C., Fortezzo, C.M.,
Herkenhoff, K.E., Kolb, E.J., Okubo, C.H., 2008. North polar region of Mars:
advances in stratigraphy, structure, and erosional modification. Icarus 196,
318–358.
Tanaka, K.L., Skinner Jr., J.A., Hare, T.M., Joyal, T., Wenker, A., 2003a. Resurfacing
history of the northern plains of Mars based on geologic mapping of Mars
Global Surveyor data. J. Geophys. Res. 108 (E4), doi:10.1029/2002JE001908.
Tanaka, K.L., Carr, M.H., Skinner Jr., J.A., Gilmore, M.S., 2003b. Geology of the MER
2003 ‘‘Elysium’’ candidate landing site in southeastern Utopia Planitia, Mars. J.
Geophys. Res. 108 (E12), doi:10.1029/2003JE002054.
Tanaka, K.L., Skinner Jr., J.A., Hare, T.M., 2005. Geologic map of the northern plains of
Mars. USGS Sci. Inv. Map 2888 scale 1 15,000,000.
Wilson, L., Mouginis-Mark, P.J., 2003. Phreatomagmatic explosive origin of Hrad
Vallis, Mars. J. Geophys. Res. 108 (E8).
Watters, T.R., 1993. Compressional tectonism on Mars. J. Geophys. Res. 98,
17,049–17,060.
Wyatt, M.B., McSween, H.Y., Tanaka, K.L., Head III, J.W., 2004. Global geologic
context for subsurface alteration on Mars. Geology 32 (8), 645–648.