I grew up in central Kansas and as a kid, and an enthusiastic collector of “natural” items---rocks, minerals, new and old bones, projectile points (arrowheads in the vernacular), etc.---I was always looking for something a little bit more exciting. The area around my home had exposures of the Dakota Formation (Cretaceous) but little else, and it was not fossiliferous. My friends and I were always exploring for caves (but no carbonates around), “Indian relics”, and new “catfish holes” in the Saline River. We were not very successful in our hunt except for the latter! When we did find the fish we tried a variety of methods to extract them including traditional hook and line using prepared bait such as Catfish Charlie© or our favorite---stinky chicken (Jack Rabbits also worked) livers left in a closed jar in order to “season”. If those methods did not work, or we got bored, then it was time to noodle (I presume the statute of limitations has passed). This method involved walking or wading along the bank and sticking our hands under old tree stumps “feeling” for fish. When one was located we attempted to grab it via a thumb in the mouth and fingers in the gills—it did not always work, and our thumbs were often covered with scabs. I know these activities might sound gross to some readers; however, it was a different time and a different place and most of the kids were very outdoor-oriented. In my case, this devotion to the outdoors led me to a career in geology.
Later in life a person told me about a place perhaps 20 miles from my home where one could collect concretions shaped like roses. This was news to me so off I went on a new journey—borrowed the family car from my father. I was able to collect a few of these strange concretions and assumed they were from the same sandstone and shale that cropped out near my home town---the Dakota Formation. Only later did I learn the concretions were Barite Roses from the underlying Kiowa Formation (also Cretaceous). In many localities the Kiowa is very difficult to distinguish from the Dakota and I certainly did not know the difference as a teenager. In fact, I still have trouble today!
Barite Rose collected many years ago near the hamlet of Bavaria, Kansas. Essentially small quartz grains cemented by barite. Width ~6 cm.
I was fascinated by my find and have a single concretion left---probably the earliest-collected specimen among my many treasures.
Several types of minerals form roses or pseudocrystals. Common examples include: gypsum (Desert Roses from western Oklahoma and St. David, Arizona---see Blog posting on February 4, 2013) and calcite (sand crystals from South Dakota and Wyoming---see Blog posting on December 11, 2011). I believe celestine/celestite also forms “flowers” but I have yet to examine examples.
Oklahoma is probably the Barite Rose Capital of the U. S. as thousands have been excavated from Permian rocks (Garber Sandstone) cropping out in the central part of the state. In fact, the State Legislature has declared Barite Roses as the State Rock.
Not all barite roses look like blooming “flowers” and some have shapes more reminiscent of nuts such as walnuts or hickory. Others resemble---well nothing, just concretions. In Oklahoma, there have been reports of roses reaching nearly 20 inches length/width.
In the Kansas roses or nodules barite ( BaSO4), the cementing agent, probably had a primary source in the underlying Permian rocks and was dissolved by “salt waters” was re-precipitated in voids of the Kiowa sediments—perhaps shortly after deposition. This cementation created radiating or divergent blades (the petals of the flower) rotating around a central axis.
A Barite Rose recently acquired at an estate auction. The label is quite old (Allen Collection) and states Bavaria, Kansas. Width ~ 5 cm.
In describing the sand calcite crystals, I noted these crystals are a crude representative of calcite scalenohedradons. However, barite crystals are tabular orthorhombic while the “petals” of the barite flower are sort of rounded disks. This shape may be connected to differential growth as the barite formed.
London (2008) has studied extensively the formation of barite roses in Oklahoma and has constructed the following scenario that may apply to the Kansas specimens: the Permian rocks contain barium and sulfur in their saline solutions and are acidic. As these brines rise upwards into overlying rocks and sediment they encounter the vadose zone of oxygenated water. The sulfides in the water would then then oxidize to sulfate, and barite would begin to immediately precipitate. Other organic components of the brine solution may act as a “poison” on barite growth and cause the round crystals. I am not a geochemist by any stretch of the imagination but could believe this is the process by which the Kansas roses formed---Permian brines working their way upward to the Kiowa Formation. Another possibility would be the precipitation of barite from the marine waters that left behind the Kiowa Formation. If this were the case I would believe that the roses would be more widespread. It is also interesting to note that the overlying Dakota Formation does not produce barite roses (at least in Kansas).
Tabular crystals of barite collected near Bavaria, Kansas. Width ~1.2 cm.
Barite roses are found at least three localities in Kansas, all in the Kiowa Formation: McPherson, Rice and Saline counties. My specimen was collected near the small hamlet of Bavaria in Saline County. Since the barite nodules have been known for decades, it is interesting to speculate they must have formed in specific and scattered zones and are rather uncommon.
London, D., 2008, The Barite Roses of Oklahoma: Mineralogical Record, v. 39.