Geobulletin alpha

Airliner Chronicles: When Disaster Arrived from the Heavens 

I thought briefly of making this one of those "What is it?" kind of posts, but it seemed kind of obvious. We were flying home from our weekend in St. Louis, and without a GPS, I was trying to get myself situated correctly into the geography that was drifting by slowly far beneath us. I was not too particularly successful at orienting myself while over the "flyover" states of Oklahoma, Kansas

Mortoniceras sp. ammonite from the Duck Creek formation of Texas 

Before I started on my adventure in Oklahoma I landed in Dallas and drove north to a site that a good friend had suggested I visit. It was a creek that exposed the Duck Creek formation (Cretaceous, Albian stage) in a couple of spots. Having never collected in Texas before, but seeing plenty of field reports from those who had, I knew the Duck Creek formation should produce some nice fossils. I was not wrong. I found four specimens of the ammonite Mortoniceras sp. washed out in the creek bed. [...]

Glyptorthis costella brachiopod from the Viola formation from Oklahoma 

The last, identifiable, fossil that I found during my brief visit to the roadcut in Oklahoma that exposed the Viola formation, is the brachiopod Glyptorthis costella. It has a subrectangular shape with valves that are equally convex and decorated with many fine, closely spaced striae. The margin of the valves is flat with no obvious fold/sulcus structure. The posterior of the shell has a nearly flat, wide interarea. Both valves are recurved in the umbo with the brachial valve moreso than the [...]

Hindia sphaeroidalis sponge from the Viola formation of Oklahoma 

I found one specimen of the sponge fossil called Hindia sphaeroidalis. in the Viola formation roadcut south of Sulphur, OK. This species spans many millions of years and is known in rocks from the Ordovician up through the lower Devonian. I've also found examples of this species from the lower Devonian aged Kalkberg formation of New York, but there they seemed to get much larger. The shape of the fossil is like a large pea with many small openings on all surfaces. The round shape seems to [...]

Oxoplecia gouldi brachiopod from the Viola formation of Oklahoma 

Among the rubble that was the eroding rock of the Viola formation I found a few good examples of the brachiopod Oxoplecia gouldi. The shell is subrectangular to suboval in outline with both valves roughly equal in size and depth. There is a wide, shallow fold and sulcus structure present along with fine, widely spaced radiating striae on the surface of the valves. The pedicle valve extends out and curves back over the brachial valve. There is a wide, triangular interarea on the pedicle valve [...]

Oklahoma Roadcut through Ordovician strata near Sulphur, OK 

As I was driving through Oklahoma, on US 177 south of Sulphur, I approached a large roadcut and stopped to investigate. This roadcut had been a target of mine when I was planning my trip. It appeared to be exposing Ordovician aged rocks and my research told me that the cut exposed the Viola formation which overlies the Bromide formation. Having never sampled either unit I was hopeful to find some fossils. Here is a panorama of the east side of the cut, North is to the left. Click the picture [...]

Misc. fossil bits and pieces from the Bois D'Arc formation 

To close out this series of posts featuring fossils I found in the Bois D'Arc formation of Oklahoma, I have a few pieces left from my finds that don't merit a full blog post entry so I'm consolidating them here. They are each interesting in their own right and deserve at least a mention.This is a piece I kept as a curiosity. It appears to be the mold from some sort of epitheca that belongs to a coral (like Favosites conicus) or Bryozoan (like Lichenalia sp.).  There is some sort of [...]

Huntoniatonia sp. trilobite from the Bois D'Arc formation of Oklahoma 

From my experience collecting in the Bois D'Arc formation, I think that Huntoniatonia sp. (also sometimes called Huntonia) trilobites are possibly the most common trilobite to be found. I'm referring to the isolated parts of the trilobite not whole specimens. While there were a large number of whole Paciphacops sp. and Kaniops sp. fossils that I found I think I came across more detached pygidiums and cephalopns of Huntoniatonia sp. than anything else.I did find a few [...]

Platyceras sp. gastropod from the Bois D'Arc formation of Oklahoma 

As Platyceras sp. gastropods were abundant during the Devonian, it is no surprise to find one in the Bois D'Arc formation. This specimen has some added interest as there is a crinoid holdfast anchored to it.  The Platyceras shell is spiral shaped with a roughly rectangular cross section. The whorls are offset from the central axis and slightly angled. The exterior of the shell is decorated with wavy growth lines and some regular crenulations that follow the curve of the spiral. The crinoid [...]

Streptelasma (Enterolasma) strictum ? coral from the Bois D'Arc formation of Oklahoma. 

I can't find very much info on the corals that are found within the Bois D'Arc formation so I have been comparing what I found with similar examples from the Kalkberg formation of New York which is of equivalent age. I found numerous examples of a small, conical rugose coral that had prominent raised lines running along the flanks.  It looks very similar to Streptelasma (Enterolasma) strictum from the Kalkberg formation.Specimen #1Specimen #2I found the specimens shown on this page in [...]

Levenea subcarinata pumilis brachiopod from the Bois d'Arc formation of Oklahoma 

One of the more common brachiopods that I found in the Bois d'Arc formation is Levenea subcarinata pumilis. It is similar to Rhipimelloides oblata except for a few key features. The hinge line is wide and straight and the presence of a wide, shallow fold/sulcus structure. Otherwise they share some similar traits like the rounded shape to the shell and the  pedicle valve extending slightly past the brachial valve. Another difference are the fine costae on the valve surfaces which on L. [...]

Unknown Rhynchonellid brachiopod from the Bois d'Arc formation of Oklahoma 

This next brachiopod is a bit of a mystery to me. I can not find any decriptions or images that match it in Amsden's "Stratigraphy and Paleontology of the Hunton Group" papers nor in Hall's "Paleontology of New York". It is a triangular to sub-pentagonal shaped shell with slightly convex to flat valves. There is a slight sulcus and fold but they are mostly expressed near the anterior margin. The pedicle valve's beak extends beyond the brachial valve and recurves so that the umbo opening is [...]

Nucelospira ventricosta from the Bois d'Arc formation of Oklahoma 

This little, rounded shell appears to be a Nucleospira based on the shape.  I found it in the Bois d'Arc formation in Oklahoma. The brachial valve is slightly smaller and less convex than the pedicle valve but both are nearly perfectly circular. My fossil is smooth on the surface of the valve, at least in the areas where there is still shell, but it should be covered with lots of tiny, needle like spines. They likely either did not preserve well or were weathered away. There is a small [...]

Oklahoma is now officially the most dangerous place in the world for earthquakes 

Reference Yes, that's right.  As Susan Hough says: "Holy Crap!" Who knows what the units really mean?  They have totally mucked seismic hazard and risk.  Anyway, this place is due for New Madrid II, within a couple of years.  They live in the dream that they have calmed things down by cutting down the injection, but that was cut down ever since cheap oil.  I can make up plans for a

Kozlowskiellina (Megakozlowskiella) velata brachiopod from the Bois d'Arc formation of Oklahoma 

This highly decorated shell has a very long name: Kozlowskiellina (Megakozlowskiella) velata. It is related to Kozlowskiellina perlamellosa which is found in the Helderberg fauna of New York. The shell is triangular to half moon shaped with each convex valve featuring coarse plications (generally three on each side of the fold and four on each side of the sulcus). The shell is further decorated with strong concentric growth lamellae. The pedicle valve recurves, extends past the brachial [...]

Oklahoma experiences deep mantle movement 

A deep M3.6 earthquake indicates lower mantle motion.  More than that - the past few weeks have shown very deep earthquakes, and unusual activity at New Madrid.  Last December, a remarkable series of large earthquakes also rang New Madrid, which is the best strain gauge available in the area. In active areas, these deep strain events happen all the time, and don't mean anything.  But

Pelecypod molds and casts from the Bois d'Arc formation of Oklahoma 

As I mentioned in the previous post, I found a few specimens of pelecypod in the Bois d'Arc formation that are just casts or molds that I can't really ID. This specimen looks like it may belong to the genus Nucula or Grammysia.This next specimen looks similar to a Modiomorpha sp.This last specimen is a real mystery to me. There is no surface ornamentation preserved but both valves are present. It has very convex valves with what appears to be a flat hinge line.I found the specimens shown on [...]

Actinopteria sp. pelecypods from the Bois d'Arc formation 

I found a few pelecypod mold and casts during my hunt among the rocks of the Bois d'Arc formation in Oklahoma. All are without shell material and some have little detail with which to help identify them. One group of specimens does have some detail and appears to belong to the genus Actinopteria and may be A. textilis. The fossils I found are all of single valves but show impressions of the interior or exterior of the left or right valves. The shells have an overall rectangular outline with a [...]

Wild Proboscidea in Oklahoma 

I’m just back from a 10-day research trip to Oklahoma. I’ll have more pictures to post soon, of all kinds of cool things. One of the most surprising and interesting things I discovered on the trip was Proboscidea – not the mammalian order of elephants and their relatives, but the genus of plants with wacky

Coelospira virginia brachiopod from the Bois d'Arc formation of Oklahoma 

When I'm out collecting I often pick up anything that looks like it might be a fossil and sometimes I know what it is while other times it just looks similar to another shell. Such is the case with Coelospira virginia. This is a very small shell that I probably thought was an Atrypina sp. when I tossed it into my collecting bag. It wasn't until I got home and really looked closely at it that I saw there was a difference. White it does have the same rounded shape as Atrypina sp. with a wide fold [...]