Hello. And thanks for tuning in. My name's Mike Hudec. I'm a senior research
scientist at the Bureau of Economic Geology, which is a part of the University
of Texas at Austin. I'm also the principal investigator for an organization
called the Applied Geodynamics Laboratory, or AGL, which is an industry-funded
research consortium that studies salt tectonics.
This morning, I'm going to be talking to you about an area called the Selena
del Bravo, which is in northeast Mexico as part of the Gulf of Mexico. And I'll
be talking a little bit about the structures that make up the Selena del Bravo
Region, including the Bravo Trough, Sigsbee Canopy, and the Perdido Fold Belt,
and then also a little bit about how they evolved and what they all have to do
with each other.
Before beginning, I need to thank both TGS and CGG for agreeing to let me
use the seismic data that I'm going to be showing in this presentation, and
also the members of the Applied Geodynamics Laboratory, who funded the
To begin with, let's talk about where the Selena del Bravo Region is. It's
in the northwestern Gulf of Mexico. Now, the northwestern Gulf of Mexico is an
interesting place for a couple of reasons. First of all, from a plate tectonics
perspective, there is a big change in the style of opening of the Gulf of
Mexico that goes on in that area. In the eastern parts of the Gulf of Mexico,
most of the spreading center is spreading ridges separated by very short
segments of transform faults. However, as you go further to the west in the
basin, the style of opening changes. And when you get into the western part of
the Gulf of Mexico, you're looking at much more of a transform-dominated system
with very short spreading centers. So you're looking at much more strike-slip
deformation in the western part of the basin.
The second, when you get into the Northwestern Gulf of Mexico, the width of
the salt basin changes. The salt basin is about 500 miles wide in the central
parts of the northern Gulf of Mexico. But as you go west, the basin gets
narrower and narrower and also steeper and steeper. So we would expect some
changes in style as we get closer to the west.
And then finally, as you get towards the western part of the Gulf of Mexico,
you're getting closer to the Pacific margin, and you're starting to see some of
the compressional structures. And those are the blue lines on the image that
you're seeing there. And so you're starting to get caught up in the edges of
some of the compressional plate deformation that's going on in the area. So you
might expect to see some differences in the western part of the Gulf of Mexico
as compared to the rest of the basin.
We'll start off by just sort of going through in a little more detail
exactly where the Selena del Bravo is, and what are the main structures that
formed there. So the Selena del Bravo is the continental slope that's just
south of the US-Mexico border. So you start in offshore Texas, and you go
south, and you're in the Selena del Bravo. If we wanted to look at a seismic
line, showing some of the key structural elements across the Selena del Bravo,
the line that you're looking at goes on the left, from roughly the shelf edge,
out on to the continental rise on the right end of the section. And we can see
four main sets of structures that we're going to be talking about in the basin.
First of all, starting furthest up dip, you have the Bravo trough. The Bravo
trough is very thick accumulation of Cenozoic sediment. It's fairly tightly
folded, and the seismic imaging is not very good, leading us to suspect that
mostly it's filled with shale that's been tightly compressed and deformed.
Moving a little bit further outboard, what we see is the Sigsbee salt
canopy. The Sigsbee salt canopy is fed mostly from feeders at it's up-dip end.
However, there are a few feeders within the canopy as well. And it flows
seaward, out over the next main structural province, which is the Perdido fold
belt. The Perdido fold belt is detached on the low end salt, down at the
bottom, and its series of compressional folds, with a few very minor thrust
faults, but mostly folds, sitting at the seaward end of the system.
Now, underneath the Perdido fold belt, and at the seaward end of the Perdido
fold belt, you have the BAHA high. The BAHA high is a structural high in the
base of salt. You can see we're ramping up about 2 kilometers on to the BAHA
high. And what this seismic line doesn't show, but the next one will, is that
you drop back down about 1 to 2 kilometers off the other side of it. So it is a
major basement high at the down dip end of the system.
Now, what do those provinces all have to do with one another? Well, starting
with the BAHA high, you can see that the Perdido fold belt lies above the BAHA
high and on the up-dip side. And as we'll be discussing as this presentation
goes on, we're going to argue that the BAHA high formed a buttress, against
which the Perdido fold belt formed as sediments slid seaward down on the salt
Looking further up-dip, if we look at the seaward end of the Bravo trough, we
see a weld that is connecting up to the Sigsbee salt canopy. In places that
weld still has some salt in it, in which case it's not a weld, but in most
places along its length, what you're looking at is a weld connecting the Bravo
trough to the Sigsbee salt canopy.
Now, the relationship between the Sigsbee salt canopy and the underlying
Perdido fold belt is kind of interesting. In places, like is shown with the
arrow pointing at it, it's very clear that the Perdido fold belt folds the base
of the Sigsbee salt canopy. In other places, what you see is that the
structures of the Perdido fold belt are unconformably overlain by the canopy.
So we're seeing mutually cross-cutting relationships, suggesting that the
Perdido fold belt and the emplacement of the Sigsbee salt canopy are roughly
synchronous. Now, synchronous at what time? The age of the sediments
immediately under the Sigsbee salt canopy suggests that canopy emplacement and
Perdido fold belt formation are mostly Oligocenan Age, extending on into the Miocene
as well. So we're looking at an Oligo-Miocine event.
Let's talk a little bit more about the Bravo trough. This is another seismic
line in which we're looking at the Bravo trough on the left-hand side. And one
of the things that's interesting to see in that area is that the Mesozoic
section, which is the blue on there, pinches out underneath the Bravo trough.
And the overlying Cenozoic section expands greatly into the Bravo trough. And
in fact, the Mesozoic is thin or missing under most of the Bravo trough,
suggesting to us that there was actually a salt diapir there during the time of
its formation. So the Bravo trough had, as a precursor, the Bravo diapir, onto
which the Mesozoic section thinned.
So what do these all look like in map view? So this is a map of the Selena
del Bravo and surrounding areas. And what we can see is several of the
different structural trends that are important in the area. First in yellow, we
have the BAHA high at the seaward end of the system, which extends all the way
from the southern end of the salt basin, down at the bottom of the slide, up
into US waters. Now overlying that, and to the left of it, is the Perdido fold
belt, which are those lines. Those lines mark the axes of the anticlines in the
Perdido fold belt. And then finally, up dip of that, in the blue, is the Bravo
trough. So the Bravo trough, Perdido fold belt, and BAHA high all run roughly
parallel to one another along the length of the continental margin.
So from here, we're going to be starting to address the question of, well,
what do they all have to do to each other? But first, before we get into that,
let's talk about what exactly the fill inside the Bravo trough looks like.
We're going to be looking at a seismic line running from north to south down the
axis of the Bravo trough.
Now, at the north end of this, around the area where it shows the one,
actually, up in US waters, we do have one good deep well that goes into the
Bravo trough. And what the Bravo trough shows is it's filled mostly with shale.
And the well penetrated a thick Miocene section, and then more than 10,000 feet
of Oligocene without ever getting out of the bottom of the Oligocene.
So we think that most of the fill of the Bravo trough is Oligo-Miocene in
age. Now if that rings a bell, the age of the fill, Oligo-Miocene, is the same
as the age of both the Sigsbee salt canopy and the Perdido fold belt. So all of
the major structures in this part of the world seem to be roughly the same age.
So the question then comes, well, the salt was deposited in this area back
in the Jurassic. And so for more than 100 million years, the area sat
relatively inertly. Not much happened in the region. And then in Oligo-Miocene,
everything happened at once. So what happened in the Oligo-Miocene to transform
this and create all of these structures all at once?
Inside the Bravo trough you see that the fill is shingled from north to
south. I've labeled them as 1, 2, 3. So the sediments become progressively
younger to the south within the basin. The Bravo trough is named for the Rio
Bravo. But the shingled nature of the fill suggests that there's probably going
to be more than one river involved in filling this up. It suggests that really
there's a little bit more going on than we currently know about in terms of
Oligocene sediment transport systems in this part of the Gulf of Mexico.
OK. So those are the players. Now, let's talk about what happened-- how they
all worked and why everything happened in the Oligo-Miocene and what was the
source of the timing and the cause of deformation in the Selena del Bravo
All right. Let's look again at a map of the system. And this time, we will
focus on the deformation that lies to the west of the Selena del Bravo Region.
You can see that, even today, there's a pretty good looking mountain belt off
to the west. And those black lines are all structures in the Cordilleran
Orogen, a compressional orogen related to subduction of the Farallon plate
beneath western Mexico.
And this deformation in those mountains started in the late Cretaceous. The
structures to the west are the oldest. And then as you go to the east, across
those mountains, the deformation gets progressively younger and younger. And at
its easternmost limit, you're looking at Eocene. So late Cretaceous to Eocene
deformation forming the mountains.
Now, if we're looking for, in the Selena del Bravo Region, what impact did
all that compression off to the west have, we're going to focus on an area
called the Burgos Basin, which is just up dip of the Selena del Bravo Region,
and ask ourselves what are the first things that we see in the Burgos Basin
that tell us something about what's going on in the mountains off to the west.
So we're going to look at a stratigraphic cross-section across the Burgos
Basin. And what we see is during Eocene time we get the first hints that
something major is going on off to the west. We have a couple of major
unconformities that cut down eastward across the Burgos Basin. And above each
of those unconformities is a major prograding sequence. So we're starting to
get sediment supply from the growing mountains off to the west beginning in
Eocene time. Now, beyond that, we also see some interesting tilting in the
If we look at a map of surface exposures in the Burgos Basin, we can see
that sediments get progressively older going westward toward the mountains.
Along the coast, we see Miocene units exposed at the surface, then getting
older and older, all the way back to Paleocene along the western margin of the
basin. This geometry suggests that the basin has been uplifted and tilted
toward the Gulf of Mexico.
So the next question is, when did that tilting occur? Well, there has been
considerable work on uplift in the mountains, just to the west of the Burgos
Basin. And what you can see in those areas is that the uplift is oldest to the
south and gets progressively younger to the north. But if you look just to the
west of the Burgos Basin, we've got uplift beginning around 30 million years
ago, just to the west of the Burgos Basin.
Now, remember that the actual compressional deformation ended in the Eocene.
30 million years is Oligocene, which means that the uplift and tilting is
post-orogenic. The shortening had already stopped by the time the uplift began.
So how much uplift was there? What kind of unroofing and uplift and tilting
do we have going on just to the west? This is a plot showing the burial history
of rocks to the west of the Burgos Basin and points south. And what you can see
is that we reached a maximum burial depth here and started uplifting about 30
million years ago, for this particular sample. This is constrained by
potassium-argon dating, fluid inclusions, and apatite fission track-dating. And
at about 30 million years ago, we started uplifting and we're continuing to
uplift all the way to the present.
So uplift is still going on in the region, uplift and tilting. What's
particularly interesting is the magnitude of the uplift. Putting together all
the samples regionally, you're looking at about 5 to 7 kilometers of uplift and
erosion that have gone on just to the west of the Selena del Bravo Region.
So that's a lot of erosion and a lot of sediments that were supplied by the
mountains to the west. And we would argue that the final resting place of a lot
of those sediments is in the Bravo trough, further down dip. So what we've got
going on in the early part of the Cenozoic is major sedimentation sourced from
the mountains to the west. We're looking at tilting.
And so then the question becomes, well, there's a lot going on tectonically
at the time, so how did that play into building the Bravo trough, Sigsbee salt
canopy, and Perdido fold belt? Well, if you look what's updip of the Bravo
trough, you see onshore there a lot of little blue lines, OK? Those are normal
faults. So we're looking, when we tilted the basin and added all those
sediments, we evidently destabilized the margin. And everything started to
slide seaward. And those are the breakaway normal faults.
So at first glance, you'd say, well, OK, that makes this a fairly simple
system. What happens is you throw in a lot of sediment, you tilt the margin,
and you have breakaway extension updip, and the Perdido fold belt is the
congressional toe of that system. Well, it turns out to be not quite that
simple. Because if you look at a seismic line from onshore in the Burgos Basin,
you see that the normal faults are not detached down on the salt layer. In
fact, they're detached on a unit called the Mendez shale, which is at the top
of the Cretaceous.
Now, the Perdido fold belt downdip is detached on the salt layer, which is
down here. So if we're going to connect this updip extension to the downdip
shortening in the Perdido fold belt, we have to find some place where the
extension can ramp down from the Mendez shale on to the deeper salt detachment.
OK. Well, let's move a little bit further outboard. Now we're on the shelf,
so just a little bit downdip from the last seismic line. And what we see on the
shelf is actually even a little more complicated. We start to have shale
diapirism, which are the little red blobs that you're seeing in the right end
of the section. And you're getting multiple detachment levels. Not all of these
normal faults make it down to the Mendez shale. Many of them are detaching in
the Oligocene and the Miocene.
So we have multiple detachments being fed from onshore, none of which are
making it down to the salt layer. So somehow, if we're going to explain the
origin of the Perdido fold belt, we're going to have to get all of this
translation ramped down onto the basal salt detachment.
You can see the same story a little bit more regionally here. On this
seismic line, we see both some of the update extension, with the deeper
detachment fault coming downslope and, we would argue, ramping down onto the
salt detachment in the area of the Bravo trough.
There are also a number of shallower detachments up in here that don't make
it down onto the deep salt layer, but instead go into feeding shortening within
the Bravo trough. So some of the shortening that is sourced by the extension
updip is actually being absorbed inside the Bravo trough and give an
explanation for the complexity of some of the deformation there. And some of it
is actually ramping down onto the deeper detachment and, we would argue, going
out to feed deformation in the Perdido fold belt.
So in summary of our evolutionary model, this is the story that we suggest
is what's going on. So back at the end of the Mesozoic, not that much had
happened yet. The Mesozoic was a fairly quiet time. Most of what happened was
building the Bravo diapir. So we would argue, at the updip end of the deeper
salt basin, the salt basin that starts in about the center of the section, we
had one big diapir, the Bravo diapir, which was a major salt wall that ran up
and down the length of most of the basin.
Now, if you remember from the map how big the Bravo trough is, it's about
400 kilometers long by 100 kilometers wide. That would be the biggest salt
diapir in the world by quite a lot. We suspect that actually the Bravo diapir
had a series of relays in it and was more than one diapir and that subsequent
mapping will probably show some of the additional complexities of the system.
But for now, let's just treat it like it's one big diapir.
So at the end of the Mesozoic, there it sat, the Bravo diapir. Now, in the
early parts of the Cenozoic, what you had down in the bottom half of the image
was you had all the uplift and tilting started. So the present day is the
configuration that we see down on the bottom. And there are a couple of
interesting things about that.
First of all the sediments being sourced from the mountains that lie to the
west come in and they fill the Bravo trough. And what happens is the salt that
was in the Bravo trough gets squeezed up and out into the Sigsbee salt canopy,
which lies just downdip. So we would argue that the Bravo diapir is actually
the source of most of the salt that is presently in the Sigsbee canopy in this
part of the Gulf of Mexico.
Second, the tilting that goes on destabilizes the margin, and everything
starts sliding downhill. So the series of shallower detachments feed into the
Bravo trough and go into some of the shortening there. But the deeper
detachment along the Mendez shale, actually comes down to the updip end of the
Bravo trough, ramps down to the deeper salt layer there, and then goes out and
causes the deformation out in the Perdido fold belt.
So our argument is, is that the reason why the basin got destabilized in the
Oligo-Miocene is that that's when the effects of the shortening and uplift to
the west started to be felt in the basin. The compressional deformation further
updip sourced all the sediments that filled the Bravo trough and expelled salt
into the Sigsbee canopy. And the post-orogenic uplift in the region is what
tilted everything and caused the sliding down slope which made the Perdido fold
So that's an interesting model. And it's kind of plausible. But it's also a
little bit complicated, because there has to be a whole lot that's happening
all at once. We have to have tilting and sedimentation and extension and
everything ramping down onto the salt detachment. And so although it's kind of
a neat model, how do we know if it's physically plausible that all that could
be happening at the same time? Well, what we resolved to do was to try to test
it with a physical model, which is what I'm going to show you next.
So the setup of the physical model looks like this. We started off with a
salt basin, which is shown in red on the top cross section. And we vacuumed off
the cover over one little strip in the center of the model. And that caused
salt to flow in from both sides and build the equivalent of the Bravo diapir.
And so we build the Bravo diapir until it reaches the surface. So we've got our
big, pre-existing Bravo diapir.
Then we put in another shallow layer which is shown in purple right there,
which is going to be the equivalent of the Mendez shale. So that is the
shallower detachment. And then we start prograding sediments, shown in that
little wedge there, across our Mendez shale.
Now, if the experiment works, what we're expecting to see is that that
prograding wedge will start extending and stretching, detached on the Mendez
shale. You will get sliding along the Mendez shale until we reach the Bravo
diapir. And then that sliding will ramp down onto the basal salt layer and go
ahead and build the Perdido fold belt out to the right end of the model. At the
same time, continued progradation is going to eventually reach the area of the
Bravo diapir, is going to expel salt out from the Bravo diapir, creating the
equivalent of the Sigsbee salt canopy further down slope. So let's see if
that's actually what happened when we made the model.
What you're looking at now is an overhead view on the left-hand side and an
underside view on the right-hand side. The overhead view is just a camera
mounted on the ceiling. The underside view is actually a camera mounted on the
floor, looking up. Now the underside of our experimental rig is actually clear
plastic. So you can look up at the bottom of the model and watch it evolve. You
can see in the underside view the little label that says salt wall in the
middle of it, that's our Bravo diapir. So I'm going to be going back and forth
a little bit, talking about what's going on.
On the overhead view, what you're looking at in the blue, on the left side,
that's our Mendez shale, OK? And what you're going to see when the movie starts
is you're going to see a series of colors being prograded across that. You'll
see sort of quick changes of color, which is the new sediment wedges, each one
which is a different color, prograding across that Mendez shale. So let's start
And so now you're seeing progradation. And almost immediately, you're seeing
all that clear stuff extruding in the overhead view, out from in front of the
Bravo diapir. So salt in the Bravo diapir is being expelled out. You're looking
at the growth of the Sigsbee canopy. Now, if we look at the underside view,
what you're seeing is shortening to the right of the Bravo diapir. That's
actually the Perdido fold belt forming.
And at this point, you're also seeing some orange coming into view down at
the bottom of the Bravo diapir. That is the Bravo trough. That is the sediments
in the Bravo trough sinking down. You're looking at just about all of the salt
has been expelled. And off to the right, what we've seen is some shortening
going on. That panel off to the right has shortened quite considerably. And so
we have made the Perdido fold belt.
Well, so that's the overhead view. Let's look at the cross sections. Now,
before we start the animation, I should explain what you're looking at a little
bit. In the upper right, you have the picture of the overhead view at the very
end of the model. There is a white line down at the bottom of that which shows
the location of the cross section which is down at the bottom of the image.
Now, what's going to happen when we start the animation is that that white line
is going to sweep northward across the picture. And we're going to do a
fly-through of the model. So we're going to keep changing sections and look at
new sections every time.
So let's start the animation. You can see the white line moving. And we're
flying through the model. So let's just stop right here for a minute. And you
can see right in the middle what we've got is a big syncline, almost exactly in
the middle of the image. It's a big syncline with orange and yellow sediment
sunk all the way down to the bottom. That is the Bravo trough. That is the
former location of the Bravo diapir. Salt has now been expelled out from there
and is in this little thin skim at the top of the model off to the right. That
is the Sigsbee salt canopy.
Also noticed, at the right end, detached on the deeper salt level, we have
the Perdido fold belt. You see a big set of salt cord folds down there. And at
the updip end of the model, down along the Mendez shale detachment, you can see
a little couple of triangular diapirs. Those are extensional structures. And
that is the shallow extension detached on the Mendez shale.
So in short, the model seems to have worked. We get extension detached up on
the Mendez shale. It ramps down to the deeper salt level, which is what forms
the Perdido fold belt out in front. And at the same time, we have sediments
sinking into the Bravo diapir to form the Bravo trough and formation of the
Sigsbee salt canopy.
So let's move on and do a comparison between the seismic data on top and the
physical model in the center and our conceptual model down at the bottom. So in
the seismic, we see the location of the Bravo trough, seismically fairly
incoherent, mostly shale filled, intensely deformed inside of it. Then we see
the same structure in the physical model, which is the big sediment-filled
syncline sinking down to the bottom. And there it is in the conceptual model as
So we get the Bravo trough in all three models. We get the Sigsbee salt
canopy in the seismic, the physical model, and the conceptual model. And then
finally, at the seaward end of the system, we have the Perdido fold belt on
seismic model and conceptual model.
So we'd have to say that the physical model seems to be a success. Now, that
doesn't prove that the model is right. But it does prove that it's physically
reasonable, that we're not trying to call on some process that can't possibly
work. So at this point, we feel that the conceptual model that we've developed
offers a reasonable explanation for what seems to be going on in the Selena del
Well, at this point in almost any kind of scientific endeavor, you have to
stop and say, well, so what? I mean, it's kind of neat that we have a model.
But what are the implications of this model? And what kind of insight does it
give us as to larger questions in the Gulf of Mexico?
So first of all, let's talk about some of the structures that we see at the
north end of the Bravo trough, where it crosses into US waters. Now, this area
shown by the arrow on the map is notoriously difficult for seismic imaging in
the Gulf of Mexico. And in fact, the top seismic line is a line across that
area. And you can see that underneath the salt canopy, you see a whole lot of
nothing. And there has been enormous effort in both seismic acquisition and
processing spent on trying to get a better image out of this area.
What this work and this mapping suggests is that what's underneath the salt
in this area is the Bravo trough, which is made largely of shale without much
internal seismic impedance and is, in addition, very tightly deformed and
extremely steep dips and not a whole lot of continuity, lots of faulting going
on. So it is entirely possible that the effort that has been going on in
seismic acquisition and processing is to some extent wasted because you're
already seeing what's there. What's there is not really imageable. There's not
a lot of sand. There's not a lot of impedance. And it's very, very tightly
So actually, the seismic imaging in this area may be quite good. And the
unfortunate fact is there's just not a lot down there to image in this area. So
that's one implication of this work.
Now furthermore, to more regional scale, there is an interesting comparison
that you can make between the Perdido fold belt, which is the one we've been
looking at in the Selena del Bravo Region, and looking further south across on the
other side of the basin, the compressional structures in the Bay of Campeche.
Now, these are conjugate margins. The Perdido fold belt part of the basin
restores against the Bay of Campeche. And both of them are in deep water. And
they're both compressional fold belts. But there, the similarities stop.
They're actually quite different in a lot of ways.
So let's talk a little bit about what we've got down in the Bay of Campeche.
So here's a zoom in showing topography in the Bay of Campeche. And what you can
see, that the Bay of Campeche is actually in the foreland of the Sierra de
Chiapas, which is a big basement involved thrust system also related to
tectonics along the Western edge of Mexico, and that the thrust faults come up
toward the surface in that area and then detach on the salt layer and then
slide out on the salt, so that the shortening in the Bay of Campeche is
actually directly tied to plate compression, subduction along the western edge
If we look in at a map in detail of the structures in the Bay of Campeche,
all the black and blue little lines that we're seeing in there are
compressional folds, faults, pinched off diapirs, over-thrust diapirs, all
sorts of different compressional structures. You can see they make a broadly
arcuate shape. And there are a whole lot of them across pretty much the whole
So in this area, you're looking at more than 100 kilometers of shortening,
in all likelihood, in comparison with 10 kilometers or less in the Perdido fold
belt. So there is roughly an order of magnitude, more shortening going on in
the Bay of Campeche than there is in the Perdido fold belt.
So what we say is that, yes, they're both in deep water. Yes, they're both
on sort of passive margins, although you can make an argument about the Bay of
Campeche. But that's where the similarities stop. The Perdido fold belt, which
is shown on the top illustration, is at the toe of a gravity slide which is
coming off the eastern side of post-orogenic uplift related to all the plate
collision. So it's kind of indirectly tied to plate margin effects on the
western margin of Mexico. It's a gravity slide.
On the other hand, the Bay of Campeche is directly linked to plate
collision, that in fact the basement structures-- we've got the Sierra de Chiapas
at the left end of the section. The thrusting comes up out of the basement,
detaches on the salt, and then moves directly forward from there. So you're
looking at a direct manifestation of plate shortening in the Bay of Campeche.
So two really very different congressional provinces on opposite sides of the
So in summary, the Selena del Bravo Region is very interesting. It's got a
set of major structures in deep water. And those are the BAHA high, Perdido
fold belt, Sigsbee salt canopy, and Bravo trough. And we think that all of
those provinces are tied to the influx of sedimentation and tilting that
happened as a result of congressional deformation in central Mexico, the
Cordilleran orogeny, and that the sedimentation loaded the Bravo diapir,
expelled salt out into the Sigsbee canopy.
And the sedimentation plus tilting destabilized the margin edge and caused
extension at the updip end of the margin, all sliding downhill. Some of that
extension was absorbed by shortening within the Bravo trough. Some of it went
all the way out into the Perdido fold belt, depending on the detachment level.
And that the Perdido fold belt actually has a markedly different style than the
shortening we see in the Bay of Campeche on the other side of the basin.
So it's an interesting area. It's an area about which really very little is
known, outside of Mexican oil companies. They've had access to most of the
data. And as it's starting to come to light that other geologists outside of
Mexico can look at it, it's a fascinating province that teaches us a lot about
processes that are going on in the basin.
So I hope you've enjoyed your introduction to the geology in this part of
the world. I'd like to thank both AAPG and the AAPG Foundation for making the
Distinguished Lecture Series a possibility. And I look forward to seeing you
all at sometime in the future. Thank you.