Tim Minchin's "Storm"

If you haven't heard this yet, you need to listen to it right now.

LNJ

I Hate My Stupid Lungs...

...but my difficulties pale compared to those of Adam Yates, who is going through some genuinely terrifying parental shit. If you haven't already, you might want to drop by and leave a kind comment, as a great many people already have.

I caught the latest form of the flu last week. After a couple unpleasant days, the fever broke Wednesday. Unfortunately, it turned out that all the viruses, rather than leaving my body, had just moved to my lungs, and are renting the bronchioles out to bacteria. I haven't had either the clarity of mind or mood to write a new good post, and probably won't for a few more days, even assuming my lungs don't just come up in bloody chunks over the weekend. I'll probably be continuing on the science and religion thread.

LNJ

Jeff Is Reforming His Ways

Ok, here is the deal.

I have certainly enjoyed blogging thus far, and tremendously amused myself (and perhaps one or two other people).

However, I am currently seeking gainful employment within academia. On the advice of a friend, I have decided to review my previous postings and perform some...surgical alterations. Words substituted, posts removed, cartoons ommitted, that sort of thing. I have to think of the children now.

What Science Is

[Blogger's comment: the first paragraph of this post originally referred to a prior post which never actually existed. It was never here. I want you to forget about it].

However, I want to turn to an even more fascinating and relevant topic, specifically the nature of science itself. The question “What Is Science?” has recently been raised by a few science bloggers, and I want to throw in my two cents. Here is my working definition:

“Science is a methodology for determining reality that recognizes, and attempts to compensate for, human fallibility and delusion.” Simply put, the entire scientific “method” is built around the recognition that human beings are often not very good as seeing reality clearly.

We have been described as the “rational animal,” but this is baloney. We are the IMAGINATIVE animal. Creativity comes so naturally to us that some humans build careers just out of making shit up (e.g. painters, musicians, fiction writers, theologians), and even the least creative of us dream. We often take for granted just how incredibly bizarre dreams are. Not only do our brains conjure up vivid and bizarre hallucinations involving fictitious and often nonsensical storylines, but our dreaming mind completely understands and accepts it as reality. Dreams are arguably the most extreme expression of human creativity and capacity for self-delusion, and they require no effort at all. They come to all of us naturally, almost every night.

Rationality, however does NOT come naturally to us. It is a discipline that has to be developed, not an innate tendency. This discipline partly involves learning to use evidence to construct logical arguments that hold together on scrutiny, but also involves developing a certain type of emotional toughness. It is difficult and distressing to accept ideas that may be unappealing or difficult to understand, and the natural human tendency is to warp reality in their mind to fit what they are most comfortable believing.

Imagination is still very important, as it provides essential raw material for scientific hypotheses, but science recognizes that imagination only hits reality occasionally. Science recognizes that what we are comfortable believing has no bearing on what is actually true, and provides is a filter for our creative ideas to determine which represent reality. Speaking metaphorically, we are all intellectual paraplegics, but scientists use wheelchairs; a lot people are flopping around on the ground thinking they are walking.

This is why hypotheses have to be TESTED, and we are not content to simply let claims about reality be accepted without evidence. It is also why we have peer review, a process by which other individuals who may not share our particular biases, and who possess knowledge we do not, can catch shortcomings in our logic and evidence (and to help us improve our writing).

If we recognize how fundamentally the human capacity for self-delusion is built into the scientific process, I think it raises fairly obvious objections to the claim that science and faith have no inherent conflict. Almost everyone recognizes that a comforting idea may be completely wrong, but we have an unfortunate tendency to partition our reasoning. Most of us would consider the statement "I don't have cancer because I find the belief that I don't more spiritually fulfilling, so I am not seeking treatment" to be suicidally absurd, but a surprising number of people are willing to apply the same sort of reasoning to other subjects if they can get away with it without getting killed. I want to explore the significance of science towards religion in the next few blogs.

LNJ

A Deeply Personal Piece of Work

Hello neighbors.

I’m going to take an indefinite hiatus from the Petrified Forest thread. I have quite frankly gotten a little bored re-writing stuff I’ve already written and re-written to work into publishable form, and I’m not really in the mood to start revisiting my dissertation yet. I may get back to it later, but for right now I need to shift gears. I’ve already laid our most important cards on the table, so it will be an interesting experiment to see what, if anything, happens.

I may delve a little into the nature of science, and the relationship between science and religion, which are subjects I have been interested in for some time. But not today. Bill is posting the Triassic reconstructions I am doing for Petrified Forest (I am doing research for some potentially really cool and useful ones right now), so I want to share a piece of subjective and non-technical artwork, just in case there was any doubt that there is something seriously wrong with me.

We all pass through difficult times, particularly when our lives are either going through major changes, or not changing nearly enough. These periods may involve angst and ennui (e.g., getting through the last year of your thesis/dissertation), or anger and frustration (e.g. dealing with various corrupt liars and moral cowards while trying to get a sensible and objective ruling on ethical misconduct).

And then there are periods of such intense emotion that they completely tear you apart, where you experience something incredible and unexpected and end up getting completely burned alive with a mountain of stress and guilt piled on top and the resulting pain and turmoil and total sense of loss and need is so intense that you are literally frightened you might be loosing your mind, and for months after you are terrified of running across ANYTHING that might remind you of it because you aren't even sure how to deal with it.

Well, perhaps not you. I mean me. I went through one of these periods once. It was some really fucking crazy shit, I can assure you, and the weird part it, I'm not sorry for it. Not even a little bit. Buried under all the bad stuff and things I wish had happened differently was something brief but truly amazing that I never want to forget.

Anyhow, I am only bringing up this bullshit is because I recently completed a piece of fine art on which I have been laboring on for several weeks to commemorate this interesting episode in my life. I chose to work in monochrome, and to use metaphorical symbolism to express the overpowering nature of the experience. I have to warn you not to view it if you are squeamish and easily offended; although a minimalist and abstract piece, I have chosen a fairly graphic metaphor. I feel that it has captured the general feeling quite accurately. It may have personal application for you as it deals with universal themes of life and the human condition, so I wanted to make it freely available.

Here it is.

Is is not beautiful? Stay safe this weekend,

LNJ

We Are Still On Our Own

I am NOT as optimistic as most of my academic colleagues seem to be about how completely awesome things are going to be from now on.

Yes, it was a lot of fun to watch Middle America throw the Republican Party down the reactor shaft, screaming and spewing burnt-ground rhetoric, ignorance, and thinly-veiled bigotry like blue lightning all the way down. Nonetheless, Obama is but a man. The expectations on him are ridiculously high, and candy and free money will not really rain from the sky every day of his administration. He is a politician, and politicians lie and manipulate to get elected.

My biggest concern is not that Obama will suck horribly as president; it is that he will simply do a mediocre job without making America into the mythic Land of Prosperity, Rationality, and Good Feelings All Around, and that his supporters will become disillusioned and defensive to the point that they can't be objectively critical of him any more than Bush's supporters were. We can't trust any President under any circumstances; just tolerate him and parcel out carefully rationed praise as long as he seems to be doing a good job.

It might actually be better if Obama sucked. Like, really, really sucked. If the American people get to the point that they would rather slit their wrists than vote for a Democrat OR Republican president, than they might actually give other parties and independents a look. It continuously frustrates me that America won't evolve past being a two party system just because we can't think of it any other way. Whenever I hear someone complaining about "spoilers," I want to [I previous described what I would like to do here, but have removed it due to grammatical errors].

All politicians and political parties suck. It was therefore a real breath of fresh air to find The Beast, a site that holds both the left and right in complete scathing contempt.

Today Is The Day That Music Dies

This is not science related, but I need to talk about this. In talking about it, I can begin to heal.

I am sitting in a coffee house in Flagstaff listening to a guy play guitar and sing. He is a competent enough player, but his singing...

He sounds like he is being tortured. Specifically he sounds like he is being tasered in the head and strangled at the same time. He may be trying to imitate Native American singing, but it is not an effective imitation. People are trying to look polite.

Right now he is doing "Heat Wave."

I am going to drink myself into a puking stupor tonight.

LNJ

The Petrified Forest Project, Part 4: Fixing Vertebrate Biostratigraphy in PEFO

To recap from the last couple blogs:

1. Tracing the traditional Sonsela sandstone bed from the area around Agate Mesa to the south clearly shows that it is NOT correlative with Flattops sandstone number one as claimed by Heckert and Lucas (2002) and Woody (2006), but lies about 30 meters below it, as claimed by nearly all previous workers.

2. The traditional Sonsela sandstone bed (which we call Jasper Forest Bed following Raucci et al., 2006) is probably correlative with the Rainbow Forest Bed, as advocated by a handful of workers over the years.

3. These correlations have the impact of splitting the unit described by Heckert and Lucas (2002) and Woody (2003) as the “Jim Camp Wash beds” into two stratigraphically distinct packages: the type section of the Jim Camp Wash beds lies between the Jasper Forest/Rainbow Forest Bed and Flattops sandstone number one, and what we refer to as the “Lot’s Wife beds” lies below the Jasper Forest and Rainbow Forest Beds.

4. There is a very distinctive zone of silcrete (the “persistent red silcrete zone”) in the lowermost Jim Camp Wash beds, variably occurring about 4-6 meters above both the Jasper Forest Bed and Rainbow Forest Bed. These silcretes are commonly deep red on the outside (one outcrop is shown below), sit at a slight depositional hiatus, and at least in places seems to have been formed by badly distorted and decaying petrified wood killed by fungal infection (Creber and Ash, 1990). Woody (2006) mistakenly identified silcretes in the Lot’s Wife beds as being the same unit. However, the silcretes in the Lot’s Wife beds are much more discontinuous and never have the deep red color or the thickness (commonly almost 10 cm, and in one place over 1 meter) often seen in the stratigraphically higher "persistent red silcrete zone."

From Paleo Errata

So what impact do these revisions have on vertebrate biostratigraphy? Recall that Long and Ballew (1985) recognized two distinct vertebrate faunas in Chinle Formation of the park, one below the traditional Sonsela sandstone, and one above it. Several other workers, notably Charles Camp (1930) and Long and Padian (1986) also recognized or hinted at this faunal transition in Petrified Forest National Park and the surrounding area. Colbert and Gregory (1957) and Gregory (1972) had identified these faunas elsewhere in the western United States, and also identified two additional faunas, one above these two, and one below. These faunas were distinguished primarily based on phytosaur and aetosaur taxa, although there were other important faunal differences noted by these workers.

Lucas and Hunt (1993) subsequently named these four faunas, from oldest to youngest, the “Otischalkian, Adamanian, Revueltian, and Apachean land vertebrate faunachrons," and a surprising number of people seem to think they figured them out themselves (technically as defined these are units of time bounded by the appearances of faunal elements rather than the faunas themselves, but we will treat them as faunas here). The two faunas recognized by Long and Ballew (1985) in the park correspond to the Adamanian (below the traditional Sonsela sandstone) and the Revueltian (above it). Long and Ballew (1985) did not recognize any significant biostratigraphic overlap between the characteristic taxa of the Adamanian and Revueltian, and neither did most other workers (e.g. Long and Padian, 1986; Lucas, 1998).

This changed after Heckert and Lucas (2002) and Woody (2003, 2006) correlated the traditional Sonsela sandstone bed to Flattops one, and consequently the type Jim Camp Wash beds to the Lot’s Wife beds. Suddenly, there was a major faunal overlap across most of the “Sonsela Member” (Woody and Parker, 2004; Hunt et al., 2005, Parker, 2006), leading Hunt et al. (2005) to name a “Lamyan sub-faunachron” of the Adamanian, and even provide revised boundary definitions for the faunachrons. However, Parker (2006) noticed one really odd thing about this overlap: you never find diagnostic Revueltian and Adamanian taxa at the same locality. Their supposed stratigraphic equivalence is based solely on the revised lithostratigraphic correlation.

Once we pry these units apart properly, we find that the Adamanian and Revueltian faunas pop apart, and the solution to the “overlap” becomes clear: the Adamanian fauna occurs in the Jasper Forest Bed (traditional Sonsela sandstone), Lot’s Wife beds, and Camp Butte beds, and the underlying Blue Mesa Member, and the Revueltian fauna occurs in the Jim Camp Wash beds, Martha’s Butte beds (including the Flattops one sandstones) and overlying Petrified Forest Member.

Moreover, we have pinned down the exact placement of the boundary to within a few meters. It sits right at the persistent red silcrete zone, in the lowermost Jim Camp Wash beds. The stratigraphically lowest occurrence of the phytosaur Pseudopalatus (which defines the Revueltian according to Lucas’ 1998 definitions) and the lowest occurrence of the characteristically Revueltian aetosaur Typothorax coccinarum both occur almost immediately above the silcrete. Hunt et al. (2005) claimed that some of these Typothorax osteoderms belonged to the putative species T. antiquum, but Bill and I can’t distinguish them from T. coccinarum. Our only Rioarribascoopus osteoderm comes from above this level, consistent with its occurrence with Typothorax and Pseudopalatus in the Snyder Quarry in New Mexico (Zeigler et al., 2003).

The stratigraphically highest occurrences of the phytosaur Leptosuchus (the lowest occurrence of which defines the Adamanian) and the characteristic Adamanian aetosaur taxon Stagonolepis both occur a few meters below the silcrete. Paratypothoracisine aetosaurs, including Paratypothorax, seem to mostly occur in the Adamanian (especially high up), although they run a little bit into the Revueltian. Our only Trilophosaurus and Poposaurus material comes from the Camp Butte beds [my revisions to the lithostratigraphy of the Cooper Canyon Formation in Texas has pushed all known occurrences of Trilophosaurus into the Adamanian, which the exception of the single tooth Kirby (1989) described from the Owl Rock Member of the Chinle Formation]. We have no identifiable dicynodont material from the park yet, so we aren’t sure how high they really made it in western North America.

Except for Poposaurus, rauisuchians seem to span both faunachrons; a few large rauisuchian elements probably referrable to Postosuchus are found at localities scattered throughout the Adamanian and Revueltian, and shuvosaurid material is pretty common. Diverse dinosauromorph assemblages are also known throughout the sequence.

In summary, the faunas and the rough stratigraphic placement of the faunal turnover fit pretty well with what most workers were saying prior to about 2000. This just goes to emphasize the importance of getting your lithostratigraphy nailed down before making any claims about biostratigraphy...and obviously, any claims you make about faunal change and extinction depend on your biostratigraphic information being accurate. In my next blogs, I'll discuss how the vertebrate biostratigraphy of the park compares with that of other areas including the Dockum Group in southern Garza County, West Texas, where I did my dissertation….and what this MAY tell us about faunal change in the Late Triassic in western North America.

REFERENCES

Camp, C.L. 1930. A study of the phytosaurs with description of new material from western North America. Memoirs of the University of California, vol. 10 (June), 174 pp.

Colbert, E.H., and Gregory, J.T. 1957. Correlation of continental Triassic sediments by vertebrate fossils. In Reeside, J.B., Jr., Applin, P.L., Colbert, E.H., Gregory, J.T., Hadley, H.D., Kummel, B., Lewis, P.J., Love, J.D., Maldonado-Koerdell, M., McKee, E.D., McLaughlin, D.B., Muller, S.W., Reinemund, J.A., Rodgers, J., Sanders, J., Silberling, N.J., and Waagé, K. 1957. Correlation of the Triassic formations of North America exclusive of Canada. Bulletin of the Geological Society of America, vol. 68 (November), pp. 1451-1514.

Creber, G.T., and S.R. Ash. 1990. Evidence of widespread fungal attack on Upper Triassic trees in the southwestern U.S.A. Review of Palaeobotany and Palynology, vol. 63, pp. 189-195.

Gregory, J.T. 1972. Vertebrate faunas of the Dockum Group, eastern New Mexico and West Texas. In Kelly, V.C., and Trauger, F.D. (eds.), Guidebook of East-Central New Mexico, 23rd Field Conference (Albuquerque, New Mexico Geological Society), pp. 120-130.

Heckert, A. B. and S. G. Lucas. 2002. Revised Upper Triassic stratigraphy of the Petrified Forest National Park; pp. 1-36 in A. B. Heckert and S. G. Lucas (eds.), Upper Triassic Stratigraphy and Paleontology: New Mexico Museum of Natural History and Science Bulletin 21.

Hunt, A.P., Lucas, S.G., and Heckert, A.B. 2005. Definition and correlation of the Lamyan: A new biochronological unit for the nonmarine Late Carnian (Late Triassic) Geology of the Chama Basin, New mexico geological Society Guidebook, 56th Field Conference.

Kirby, R.E. 1989. Late Triassic vertebrate localities of the Owl Rock Member (Chinle Formation) in the Ward Terrace area of northern Arizona. In S.G. Lucas, and A.G. Hunt (eds.) Dawn of the Age of Dinosaurs in the American Southwest, pp. 12-29. University of Albuquerque Press, Albuquerque, NM.

Long, R.A., and Ballew, K.L. 1985. Aetosaur dermal armour from the Late Triassic of southwestern North America, with special reference to the Chinle Formation of Petrified Forest National Park. In Colbert, E.H., and Johnson, R.R. (eds.) The Petrified Forest Through the Ages: Museum of Northern Arizona Bulletin 54:45-68.

Long, R. A., and K. Padian. 1986. Vertebrate biostratigraphy of the Late Triassic Chinle Formation, Petrified Forest National Park, Arizona: preliminary results. In Padian, K. (ed.) The Beginning of the Age of Dinosaurs: faunal change across the Triassic-Jurassic boundary, pp. 161-169. Cambridge University Press, Cambridge, MA.

Lucas, S.G. 1998. Global Triassic tetrapod biostratigraphy and biochronology. Palaeogeography, Palaeoclimatology, Palaeoecology vol. 143, pp. 347-384.

Lucas, S.G., and Hunt, A.P. 1993. Tetrapod biochronology of the Chinle Group (Upper Triassic), western United States. In S.G. Lucas and M. Morales (eds.), The Nonmarine Triassic. New Mexico Museum of Natural History and Science Bulletin 3, pp. 327-329. Albuquerque, NM.

Parker, W.G. 2006. The stratigraphic distribtuion of major fossil localities in Petrified Forest National park, Arizona. In Parker, W.G., Ash, S.R., and Irmis, R.B. (eds.) A Century of Research at Petrified Forest National Park 1906-2006. Museum of Northern Bulletin no. 62, pp. 46-62. Flagstaff, AZ.

Raucci, J.J., R.C. Blakey, and P.J. Umhoefer. 2006. A new geologic map of Petrified Forest National park with emphasis on members and key beds of the Chinle Formation. Pp. 157-159 in W.G. Parker, S.R. Ash, and R.B. Irmis (eds.), A Century of Research at Petrified Forest National Park 1906-2006: Museum of Northern Arizona Bulletin 62.

Woody, D. T. 2006. Revised stratigraphy of the Lower Chinle Formation (Upper Triassic) of Petrified Forest National Park, Arizona; pp. 17-45 in W. G. Parker, S. R. Ash, and R. B. Irmis (eds.), A Century of Research at Petrified Forest National Park 1906-2006: Museum of Northern Bulletin 62.

Woody, D.T., and W.G. Parker. 2004. Evidence for a transitional fauna within the Sonsela Member of the Chinle Formation, Petrified Forest National Park, Arizona. Journal of Vertebrate Paleontology vol. 24, suppl. to no. 3, p. 132A.

Zeigler, K. E., A. B. Heckert, and S. G. Lucas. 2003a. The vertebrate fauna of the Upper Triassic (Revueltian) Snyder Quarry; pp. 71-79 in K. E. Zeigler, A. B. Heckert, and S. G. Lucas (eds.), Paleontology and Geology of the Snyder Quarry: New Mexico Museum of Natural History and Science Bulletin 24.

The Triassic For 2008

It was a busy year for us Triassic enthusiasts, oh yes.

In addition to me and a couple other colleagues finally getting our union tickets, and Bill and I nailing down the lithostratigraphy and biostratigraphy in the southern part of PEFO, it has been eventful in other ways. Bill has posted the year's publications over at Chinleana, and Microecos has covered some of the other interesting developments.

It occurs to me I might have been overly glib about a guy with obvious psychological problems getting mauled by an alligator. I sincerely apologize. I'm also not certain that my analogy between opposition to evolution and homophobia really holds up to scrutiny. I clearly need to be medicated. Barhopping in Flagstaff this weekend for me.

LNJ

This One Is Going On My Wall, Possibly Framed.

I was just looking for alligator photographs on Google, and found possibly the best headline ever.

Then I felt really bad about the guy being hurt and wondered if he had recovered, so I entered his name into Google and found a follow up. Ouch. I particularly liked him insisting that he was wearing clothes.

And it gets better. This man clearly has a destiny.

The Petrified Forest Project, Part 3: Hey, Are We Going To Get Scooped?

I hope you enjoyed your holidays. I ate a lot and got a new external hard drive, which is now home to a ridiculously huge collection of Mesozoic-related pdfs and some other things. I call it "the magic box,” and it has completely eliminated my need to depend on other members of the human species for emotional fulfillment. What are you sniggering about? Don't be disgusting.

A funny feeling is coming over me. I may be psychic! An in-house published bulletin is going to come out in which an unpredictable combination of authors who revise their previously published ideas on Chinle Formation stratigraphy! The Sonsela sandstone and Flattops sandstone number one are NOT the same unit after all! The Jim Camp Wash beds and the strata below the Sonsela sandstone are NOT really correlative! They figured it out, independently, after we just told everyone! Scooping is a weird form of flattery I suppose; it basically admits that they need to borrow someone else’s competence and hard work.

Anyway, enough negativity. We live in a world with helper monkeys after all.

I was talking about our revisions to the Sonsela Member. We now recognize five units, instead of the three identified by Heckert and Lucas (2002) and Woody (2003, 2006). These are, from lowest to highest, the Camp Butte beds, Lot’s Wife beds, Jasper Forest Bed/Rainbow Forest Bed, Jim Camp Wash beds, and Martha’s Butte beds. The lower part of the Sonsela Member is best exposed at Blue Mesa, Agate Mesa (including Jasper Forest), King’s Throne, Lot’s Wife, and the cliffs north of Crystal Forest (all well north of the Flattops). The upper part of the Sonsela Member is exposed around Mountain Lion Mesa, the Flattops, the Jim Camp Wash drainage, and along the cliffs north of Rainbow Forest. Here is a quick and dirty revised strat section for the Chinle Formation within the park:

From Paleo Errata

This photograph was taken at Blue Mesa, and shows the lower part of the Sonsela Member:

From Paleo Errata

The Camp Butte beds: These are generally light colored (yellowish, white, or light gray) and often conglomeritic sandstones forming the base of the Sonsela Member, interbedded with the dark purple mudstones of the Blue Mesa Member. Woody (2006) called these the “Rainbow Forest beds”, but they are not in fact correlative with the Rainbow Forest sandstone bed, but occur lower in the section; he also alleged there were only two discontinuous sandstone units in this unit, although there are actually several, and they cannot be individually traced between Agate Mesa, Lot’s Wife, and Blue Mesa. These beds are mostly exposed around the bases of these landmarks, although one of these discontinuous lenses caps Camp’s Butte. These sandstones and conglomerates represent bedload-dominated channels, marking a major shift in the depositonal pattern from the Blue Mesa Member (Woody, 2003, 2006; Herrick, 1999).

The Lot’s Wife beds: These beds were mistakenly correlated with the Jim Camp Wash beds, the type section of which is higher in the section northeast of Rainbow Forest (Heckert and Lucas, 2002). These beds consist of complexly interbedded sandstone and mudstone. A very distinctive sequence occurs in most places (though not everywhere) where these beds are exposed north of the Flattops, in which the lower Lot’s Wife beds are dominated by purple mudstone with horizontal layers of light-colored sandstone, and the upper part is dominated by mostly light gray and reddish sandstone with lesser interbedded mudstone showing extensive cut and fill architecture. These beds were interpreted by Woody (2003, 2006) and Herrick (1999) as channel and overbank deposits, with the lower purple overbank beds being overbank deposts associated with the Camp Butte beds.

The Jasper Forest Bed/Rainbow Forest Bed: The Jasper Forest Bed is the unit traditionally referred to as the Sonsela sandstone bed north of the Flattops, capping Agate Mesa and Blue Mesa, and the cliffs north of Crystal Forest. The Rainbow Forest Bed occurs at the base of cliffs capped by Flattops one sandstones at and around Rainbow Forest. These very distinctive and probably conglomeritic sandstones produce all the reddish and multi-colored petrified wood in the park, as alleged by a few authors, including Heckert and Lucas (1998) (all other units produce petrified wood, but it is usually orangish and whitish and shows a very different preservation). At Crystal Forest, and at Mountain Lion Mesa, the Jasper Forest Bed becomes a more friable and un-conglomeritic sandstone, which forms most of the Battleship; this facies change can be observed almost due west of Crystal Forest. This facies change, and the fact that neither unit can be traced around the Flattops within the park, suggest that these units may not by physically continuous, although they occur at the same stratigraphic level. For this reason, we retain separate names for them. These units are generally accepted to represent bedload dominated braided river channel deposits (e.g. Deacon, 1990; Herrick, 1999).

4. The Jim Camp Wash beds: The type section for these beds was designated by Heckert and Lucas (2002) north of Rainbow Forest, but occurs above the Rainbow Forest Bed. Like the Lot’s Wife beds, this unit consists of complexly interbedded sandstone and mudstone. Although mudstone is usually more common lower in the section, there is not the sort of striking distinction seen between the lower and upper Lot’s Wife beds. Since this is a fairly complex and heterogeneous package, we prefer Woody’d (2006) informal plural modifier “beds” to Heckert and Lucas’ (2002) formal singular “Bed.” Woody (2003, 2006) interpreted these as channel and interbedded overbank deposits, as with the Lot’s Wife beds.

One stratigraphic interval within the Jim Camp Wash beds is especially worth mentioning; low in the unit, about 4-6 meters above the top of the Jasper Forest Bed and Rainbow Forest Bed is a distinctive zone of (usually) reddish silcrete. Silcretes have been observed elsewhere in the section, but these are unusually persistent, commonly a deep red color on the outside, and in places particularly thick (usually no more than 10 cm, but at one place, over a meter). This silcrete zone, which we call the "persistant reddish silcrete zone" locally contains plant badly damaged petrified wood which was interpreted by Ash and Creber (2000) as having been killed by fungal infection. Moreover, this silcrete usually occurs at a horizon which is clearly unconformable in some places, and shows evidence of extensive pedogenic development in others, suggesting it indicates some sort of depositional hiatus. This is also suggested by a difference in the vertebrate faunas found just above and below it (hint hint!)

5. The Martha’s Butte beds: This package of resistant ledge-forming sandstones and more friable sandstones and mudstones was called the “Camp Wash zone” by Roadifer (1966), who was clearly NOT applying the name to the strata directly above the Jasper Forest/Rainbow Forest Beds identified as the “Camp Wash zone” by Billingsley (1985) and the “Jim Camp Wash Bed/beds” by Heckert and Lucas (2002) and Woody (2006). Billinglsey (1985) called the resistant sandstones “Flattops sandstone number one”, but walking out the contacts of these sandstones has revealed that these sandstones occur at slightly different levels within the Martha’s Butte beds, as other workers have noted. It can sometimes be hard to precisely place the contact between the Jim Camp Wash beds and the Martha’s Butte beds, especially along the east side of Jim Camp Wash (I think I have done it, but tracing the contacts all the way around is REALLY difficult). The Flattops one sandstones are often very blocky weathering tan or yellowish sandstones, which are not like those found in the Jim Camp Wash beds, although there are also grayish hoodoo-weathering sandstones in both units. These sandstones were probably deposited in a meandering river system, an imporant change from the deposition pattern seen lower in the Sonsela Member, which continues into the Petrified Forest Member (=Painted Desert Member).

This photograph is Heckert and Lucas' (2002) type section for the Rainbow Forest Bed, Jim Camp Wash beds, and the "Agate Bridge Bed" (one of the Flattops one sandstones, which we use to identify the base of the Martha's Butte beds; be think we can trace this contact all the way to the Flattops). The units refer to those in Roadifer's (1966) secton; unit 4 is probably the "persistant red silcrete", although it looks pretty different here than it usually does.

From Paleo Errata

This photograph is Martha's Butte, near the Flattops, which is our reference section for the Martha's Butte beds. Three of sandstones Billingsley (1985) identified as Flattops sandstone number one actually meet here, and the contact between the top of the Martha's Butte beds and the "monotonous purple mudstone" (see below) is pretty obvious.

From Paleo Errata

Heckert and Lucas (2002) and Woody (2003, 2006) identified the top of the Sonsela Member at the top of Flattops sandstone number one. However, as already noted, this is not a single sandstone. Moreover, there is another, very distinctive, and easily correlatable contact right at the top of the Martha’s Butte beds. In most places, the top of the Martha’s Butte beds consists of red and gray “candy stripped” friable sandstone (sometimes with a mottled purple zone at the top with lots of pedogenic carbonate nodules), which have been interpreted as representing point bar deposits (Espregen, 1985). In most places, these beds are unconformably truncated, and there is a zone of monotonous purple mudstone between the Martha’s Butte beds and Flattops sandstone number two. This contact is easily identified, and traceable all over the southern part of the park. We are using it as the Sonsela Member-Petrified Forest Member (=Painted Desert Member) contact.

Next I will discuss the impact of these lithostratigraphic revisions on vertebrate biostratigraphy and the so-called “Tr-4 unconformity.”

REFERENCES

Billingsley, G.H. 1985. General stratigraphy of the Petrified Forest National Park, Artizona. Museum of Northern Arizona Bulletin 54, pp. 3-8.

Creber, G.T., and S.R. Ash. 1990. Evidence of widespread fungal attack on Upper Triassic trees in the southwestern U.S.A. Review of Palaeobotany and Palynology, vol. 63, pp. 189-195.

Deacon, M.W. 1990. Depositional analysis of the Sonsela sandstone bed, Chinle Formation, northeast Arizona and northwest New Mexico. Unpublished Master’s thesis, Northern Arizona University, Flagstaff, 128 pp.

Espregen, W.A. 1985. Sedimentology and petrology of the Upper Petrified Forest Member of the Chinle Formation, Petrified Forest National Park and vicinity, Arizona. Unpublished Master’s thesis, Northern Arizona University, Flagstaff, 228 pp.

Heckert, A.B., and S.G. Lucas. 1998a. Stratigraphic distribution and age of petrified wood in Petrified Forest National Park, Arizona. Pp. 125-129 in V.L. Santucci and L. McClelland (eds.), National Park Service Paleontological Research: Technical Report NPS/NRGRD/GRDTR 98/01.

Heckert, A.B., and S.G. Lucas. 2002. Revised Upper Triassic stratigraphy of the Petrified Forest National Park, Arizona, U.S.A. Pp. 37-42 in A.B. Heckert and S.G. Lucas (eds.), Upper Triassic Stratigraphy and Paleontology: New Mexico Museum of Natural History and Science Bulletin 21.

Herrick, A.S. 1999. Telling time in the Triassic: biochronology and stratigraphy of the Chinle Formation in Petrified Forest National Park, Arizona. Unpublished Master’s thesis, University of Rhode Island, RI, 93 pp.

Roadifer, J.E. 1966. Stratigraphy of the Petrified Forest National Park, Arizona. Unpublished Ph.D dissertation, University of Arizona, Tuscon, 152 pp.

Woody, D.T. 2003. Geologic reassessment of the Sonsela Member of the Chinle Formation, Petrified Forest National Park, Arizona. Unpublished Master’s thesis, Museum of Northern Arizona, Flagstaff, 205 pp.

Woody, D.T. 2006. Revised stratigraphy of the Lower Chinle Formation (Upper Triassic) of Petrified Forest National Park, Arizona. Pp. 17-45 in W.G. Parker, S.R. Ash, and R.B. Irmis (eds.), A Century of Research at Petrified Forest National Park 1906-2006: Museum of Northern Arizona Bulletin 62.

Helper Monkeys Are Real

My friend Jonathan Weinbaum and I have spent some time discussing why everyone needs a trained monkey to be their personal friend and assistant. Monkeys are, as Jonathan calls them, “nature’s little tricksters”, and they have many admirable qualities. They can be trained to bite people, and are small and agile enough to climb up onto people and bite them right on the face. They can also perform a variety of odd jobs, such as getting toilet paper when you are in a jam, squeezing down storm drains to get your car keys, making sure you get up on time in the morning by licking your face, embarrassing people who’s dog humps your leg by doing the same to them, keeping the cat in its place with nonstop harassment (e.g. dominance mounting), etc… the list goes on. They are also refreshingly comfortable with their bodily functions.

Deep down, everyone loves monkeys. The antievolutionists who deny our relationship to them are like homophobes who actually want to tea bag the gay men they claim to hate. They know, deep down, how wonderful monkeys are. If everyone had a special monkey assistant, the world would be a more magical place.

We thought we were kidding. We never dared to dream that this world could be a reality, but then I saw THIS.