(Page Under
Construction in 2009)
Dr Ian P. Skilling
Assistant Professor (Volcanology)
Department of Geology and Planetary Science
200 SRCC
Email: skilling@pitt.edu
Tel #: +1 412 624 5873
Fax #: +1 412 624 3914
A dusty day in
the Kenyan Rift Valley
Please click here for pdf files of my
publications: http://skiling.geology.pitt.edu/pubs
and here for my latest resume: http://skilling.geology.pitt.edu/resume.html
Research Interests
My research interests include
volcanology and sedimentology, and are focused on documenting and understanding
the processes and products of the interaction of magma with ice, wet sediment
and water.
1) Volcano-Ice Interaction on Earth
I am particularly interested in
the interaction of volcanoes with former and existing ice sheets on Earth
(glaciovolcanism). This is the most
developed area of my research and also where I see that most of my future research
interests will lie. It is also the area
that I believe to be currently the most fundable as it has implications for
understanding past climates on both Earth and Mars. Glaciovolcanic rocks represent the only way
we can obtain direct data on the thickness of former ice sheets. Such rocks also commonly record evidence of
former terrestrial ice sheets, for which there may be no other evidence
preserved. Given the importance of
understanding past climates, they represent an important new, and largely
untapped, database on the extent and thickness of former ice sheets. Recent
work by John Smellie and co-workers (British Antarctic Survey) has demonstrated
the utility of this approach.
Glaciovolcanology is a new branch
of volcanology, for which there has been a considerable growth in the last few
years. In 2007 alone
there were four international meetings on volcano-ice interaction. In 2006, IAVCEI (International Association of
Volcanology and Chemistry of the Earth’s Interior) recognized this growth by
initiating a new Commission on Volcano-Ice Interaction. This increased interest reflects the fact
that glaciovolcanic rocks (1) record the presence and thickness of former ice,
(2) provide insight into ice sheet basal melting and sliding in volcanic areas
(please see the attached article from a recent issue of Nature Geoscience that
notes the importance of understanding volcano-ice interaction to model the
future behaviour of the West Antarctic Ice Sheet), and (3) are important
analogs for volcano-cryosphere interaction on Mars
My interest in volcano-ice
interaction began when I was employed as a volcanologist by the British
Antarctic Survey (1988-1993), have published several papers and organized two
international meetings (including initiating the first international conference
on Volcano-Ice Interaction in Iceland in 2000) on this topic. My 1994 paper on Brown Bluff, Antarctica was
one of the first (the first?) studies of glaciovolcanic rocks to use a detailed
approach of studying lithofacies and my 2002 paper on lava-fed deltas was the first
to describe in detail this very common suite of rocks at many basaltic
volcanoes that have interacted with ice.
My 2009 paper on Hlöðufell volcano,
The principal
goals of my research on volcano-ice interaction are to:
(1) develop
detailed conceptual models of the interaction of volcanoes with ice sheets. The
models illustrate the spatial distribution and temporal evolution of processes,
products and paleoenvironments.
(2) use the above
models to infer information about the presence and thickness of former
ice.
To attain both of
these goals requires detailed geologic mapping, GIS, remote sensing (mostly air
photography), field description and logging of volcanic and sedimentary
lithofacies, and sample collection.
Fieldwork is often in remote areas.
Field studies combined with textural study of the rocks in thin-section
and geochemical analysis, mostly for chemostratigraphy. I have also recently been collaborating with
Barry Cameron (
Important recent
results include the first data on the former thickness of the Cordilleran Ice
Sheet in northern British Columbia, using glaciovolcanic rocks (Edwards et al.,
2009) and the first account of ice-contact structures from basaltic lavas
emplaced beneath ice (Skilling, 2009)
2) Magma-Sediment Interaction (Peperite Formation)
My other main research interest
relates to the interaction of magma and wet sediments and particularly, how the
textures of the rocks produced (called peperites) can be used to constrain the
starting conditions for hazardous magma-water explosions. The explosive interaction of magma and water
is typically thought to begin with an intimate mix of magma and water called a
pre-mix. The development of this pre-mix
in natural settings is poorly understood, particularly the mechanisms of magma
break-up. Peperites are important rocks
in this regard. Interaction with wet
sediment rather than pure water is more common in natural environments, and
peperite textures also preserve evidence of how magma disintegrates into a
potentially explosive pre-mix.
The principal
goals of my research on magma-wet sediment interaction are:
(1) To document
in detail the processes and products of the interaction of magma with wet
sediment, and in particular to understand the processes of magma break-up
(2) Using the above to interpret the controls on
magma break-up and mingling with the sediment in order to determine exactly how
explosive pre-mixes are generated
This area of my
research is not as well developed as my glaciovolcanism research, but it is an
area I wish to pursue in more detail in the future. My review paper on peperite (Skilling et al.,
2002) is a widely cited paper, and I have also studied the products of
explosive magma-wet sediment interaction in
Future Research
I wish to continue my research on
volcano-ice interaction and in particular strengthening the research on the
paleoclimate aspects. Important
questions that need addressing are: 1) What are the detailed emplacement mechanisms
of basaltic lavas emplaced beneath ice, (2) How much variation in water and
carbon dioxide content is their within single sub-ice lava flows or even single
pillow tubes? (3) How do big ice-confined fissure-erupted complexes grow and
evolve and, (4) What are the processes, products and palaeoenvironments
associated with the interaction of large central caldera volcanoes and the
surrounding ice, and how do they record evidence of the former ice?
I am also enthusiastic about using
my knowledge of volcano-ice interaction on Earth to understand similar
processes on Mars, and wish to develop this area of my research in the
future. Important questions include: (1)
Can we recognize ice-contact basaltic lava flows on Mars? (2) How do
ice-contact basaltic lavas on Mars differ from those on Earth? and (3) What are
the controls on the development of structures such as ice-confinement surfaces
and ice-block meltout cavities on terrestrial basaltic lavas, that we can then
use to infer emplacement conditions of Martian ice-contact lava flows.
I have also recently rekindled an
interest in understanding the evolution of caldera volcanoes in the central
Kenya Rift Valley. I have published 3
papers on this area.. This is the field
area in which I did my doctorate at the University of Lancaster, UK. I am interested in understanding the
complexity of volcanological and petrological processes at the onset of caldera
collapse, and particularly the links between petrology and volcanology. In this regard, I have developed
collaboration with Libby Anthony (UT-El Paso) and am interested in pursuing
this research further in the future.
Some More Details about my Research Interests (Under
Construction):
Magma-Sediment
Mingling
Peperite is a rock
produced by sub-surface mingling of magma (of any type) and wet sediment (of
any type) (White et al., 2000). It is a
common rock that occurs in almost all volcanic environments, as most magmas
encounter at least some wet sediment.
The study of peperite offers
insight into how magma (especially degassed magma) fragments in most natural
settings (ie with wet sediment or wet friable rock) and helps us understand
fuel-coolant interaction “pre-mixing”.
Figure illustrating complex convoluted mingling of degassed basaltic magma (pale) intruded into wet
silt. Such textures illustrate multiple
separation and coalescence episodes.
Fragmentation is mostly by
ductile tearing accompanying this deformation and by other processes of ductile delamination along bleb
margins (Drakensberg Group,
Ice-Confined Volcanism (Glaciovolcanism)
My research on ice-confined volcanism is concerned with
processes, products and environments of basaltic subglacial to emergent
volcanoes. The research involves
detailed fieldwork that includes lithofacies mapping and sample
collection. Most of my recent fieldwork
has been in SW Iceland, but I have also worked on similar edifices in the
Antarctic Peninsula (Brown Bluff) and
Tuff Cone and Tuff Ring Processes and
Products
View of Koko Crater, O’ahu. Koko Crater is actually a pair of cones with
a higher NW margin on the larger northerly cone (due to SE trade winds at time
of eruptions). Koko Crater is composed
mostly of both dense wet “Surtseyan” fall deposits and wet
low-concentration pyroclastic density
current deposits
Suswa Volcano, Kenyan Rift Valley
My
doctoral research at the University of Lancaster (UK) was concerned with the
geologic evolution and physical volcanology of Suswa volcano, Kenya Rift
Valley. I have also worked at the
volcano next door to Suswa, Longonot Volcano.
An interesting aspect of these volcanoes is that we now know that their
first caldera collapsed at the “same time” (syncaldera tephra from Longonot is
interbedded with syncaldera 1 tephra from Suswa on the north flank of
Suswa. Both calderas (Longonot and Suswa
caldera 1) were accompanied by magma drainage at depth. These observations suggest that regional
extension is an important control on caldera collapse in such settings.
View of caldera at Longonot volcano,