Kansas is a state with abundant fossil and mineral
resources, but with few specimens that rockhounds would consider gemstones or
even semi-precious gemstones. However,
there are some very collectable specimens available for most mineral
enthusiasts. The problem usually
associated with collecting in Kansas is that virtually all land is privately
owned and/or state land that is off-limits to collecting. On the other hand, residents of Kansas are
nice people and often will give permission to rockhounds for admittance to
property. The major exception to this
possibility is with the collecting of vertebrate fossils. In the last couple of decades landowners have
found that vertebrate fossils may be valuable monetary resources—items worth
hundreds or thousands of dollars to interested buyers. So, beware of this fact and be on your best
behavior---ask permission before entering land.
The eastern one-half of the state has numerous
outcrops of late Paleozoic sedimentary limestones and shales and these rocks
hold tremendous numbers of invertebrate fossils, many of which (Orders,
Families) became extinct during the great end-of-Permian extinction event (~
252 Ma). The western part of the state
is home to Cretaceous and Cenozoic sedimentary rocks and sediments with their
vast resources of both vertebrate and invertebrate fossils, as well as
interesting minerals. As with the
Paleozoic, the end of the Mesozoic (~65.5 Ma) had a large-scale extinction
event.
This posting will focus on collectable minerals from the state and leave the fossils for another story. However, it often is not possible to collect minerals without noticing the fossils!
This posting will focus on collectable minerals from the state and leave the fossils for another story. However, it often is not possible to collect minerals without noticing the fossils!
Diagram showing emplacement of kimberlite
pipes. Courtesy of Kansas Geological
Survey.
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At one time, before the current trend for diamond
exploration, I was able to collect hundreds of small red pyrope garnets from
the Stockdale pipe in Riley County, north of Manhattan (Meyer and Brookins, 1976). I am uncertain about current access but
rockhounds could check with the Geology Department at Kansas State
University.
Galena cubes on chert with minor sphalerite and
chalcopyrite collected from near Galena, Kansas, in 1960’s.
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Perhaps the best known mineral
deposits in the state are located in extreme southeastern Kansas—and northeastern
Oklahoma and southwestern Missouri—the Tri State Mineral District of the Ozark
Plateau. Galena (lead ore; PbS) was
discovered in Missouri in the 1830’s and the mines were coveted by both sides
during the Civil War. In the 1870’s lead
ore was discovered in Kansas and production of both lead and zinc (sphalerite; ZnFeS)
continued for a century. The Kansas
Geological Survey (2001) noted that the Tri-State District, with more than 4000
mines, produced in excess of 23 million tons of zinc concentrates and four million
tons of lead concentrates—50% of the zinc and 10% of the lead in the U. S. The mining also left behind tremendous
environmental damage and the U.S. Government has literally purchased and closed
several towns in the region. Growing up
in Kansas we were informed in school, somewhat facetiously, that the tallest
mountains in the state were the “chat piles” (overburden composed of chert,
limestone and dolomite and a variety of bad things”, like cadmium) in
southeastern Kansas. On the plus side
the region has produced spectacular mineral specimens of galena, sphalerite,
dolomite, and chalcopyrite that occupy museum cases around the world. Unfortunately, most mines no longer allow
collecting and those of us who had the chance to collect in the 1960’s highly
value our specimens.
“Black-jack” sphalerite (large dark mass and small crystal), dolomite
crystals (white), and scattered chalcopyrite crystals (on dolomite). Collected from near Galena, Kansas, in
1960’s.
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The Flint Hills are a major topographic high
extending north-south through Kansas and south into Oklahoma (Osage
Hills). The rocks holding up the Hills
are of Permian age and consist of numerous beds of alternating marine
limestones and shales. The limestones
contain uncountable nodules and beds of flint or chert. As rainwater percolates through the surficial
vegetation a weak acid is formed and this in turn begins to dissolve the
limestone. Since the flint/chert (a form
of microcrystalline quartz) is rather insoluble the residue left behind is a
cherty soil or cherty gravel and thus hinders erosion; hence, the rugged
topography prevails. The hills have not
been broken by the plow and contain the largest tall grass prairie in the
United States (see Tallgrass Prairie National Preserve).
Permian limestone with scattered flint nodules
and flint layers exposed along I-70 Riley County, Kansas.
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One of the mysteries associated with the flint, at
least to me, is “what is the origin of the silica”? Some geologists believe marine creatures with
skeletons of silica “died” and fell to the ocean floor and accumulated. Others believe that some sort of water
chemistry produced the silica. Whatever
the case, it is an interesting question.
Chase County Courthouse in Cottonwood Falls,
Kansas. The native building stone is the
Permian Cottonwood Limestone, one of the many Permian building stones quarried
in Kansas.
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The rocks of the Flint Hills contain a fantastic
array of Permian marine fossils such as brachiopods, bryozoans, corals, and
some of the latest known trilobites. The
rocks also produce some beautiful building stones and many of the old eastern
Kansas county courthouses, the buildings at Fort Riley, and early farm homes
are constructed of local stone.. Of interest to rockhounds is the fact that
some of the limestones contain geodes filled with (mostly) calcite, chalcedony,
quartz and occasionally celestite. I
have collected numerous geodes from the Winfield Limestone, Dickinson County,
in roadside ditches along KS 18 north of Chapman. The Kansas Geological Survey (2005) suggests prospecting
“near the town of Rock [Cowley County], along the Walnut River in Cowley
County; north of the town of Douglass in Butler County; in Riley, Marshall, and
Chase counties and … in a road cut ¼ mile west of Chapman, on 4th Street”.
Cut geodes with a calcite rind and calcite crystals
in hollow center. Collected from
Winfield Limestone.
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The Osage
Cuestas, east of the Flint Hills, cover the eastern part of Kansas south of
I-70. The underlying bedrock is composed
of limestones and shales of Pennsylvanian age; however, they differ from
similar looking rocks in the Flint Hills in that they are devoid of the flint
and chert. These beds dip gently to the west with the land surface following
the dip slope; the limestone beds hold up escarpments or cuestas on the east
flank. As in the Flint Hills, the rocks
hold a variety of marine organisms and fossils are plentiful. Perhaps the best locations to collect are in
road cuts along secondary roads.
North of I-70 from Manhattan east to Kansas City the
underlying Permian and Pennsylvanian strata are covered by widespread glacial
drift resulting from incursions of the large northeastern U.S. continental
glacier. The main event (in Kansas),
perhaps on the order of 600 ka, left behind various thicknesses of silt, clay,
sand and gravel along with scattered boulders (termed glacial drift). Some of the erratics in the drift may be
traced to their source area with great accuracy. Two of the easily identifiable cobbles came
from outcrops of the Precambrian Sioux Quartzite (red quartz arenite, a
sedimentary “quartzite”) near Sioux Falls, South Dakota and the Duluth “Gabbro”
(dark-colored igneous rock from near Lake Superior). There are several internet sites that talk
about the presence (see www.findingrocks.com)
of Lake Superior Agates in the drift; especially in gravel pits near McLouth
north of Lawrence. I have never seen
these specimens but do not doubt their existence.
In south central Kansas is an area bordering
Oklahoma termed the Red Hills. Most
visitors to the state would not recognize this landscape as being part of
“flat” Kansas. Late Permian red shales,
siltstones and sandstone are eroded into a variety of tables, buttes and mesas
often capped with beds of gypsum and/or dolomite. The area also has numerous sinkholes as
subsurface salt (halite) and gypsum have dissolved leaving a void and then
collapsing. These rocks in the Red Hills
represent the “drying up” of the vast, latest Paleozoic, restricted circulation
sea. It is fairly easily to collect specimens of rock gypsum and/or anhydrite.
Halite cube collected from Hutchinson salt bed
in 1950’s.
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My fifth grade school trip was to the salt mines at
Hutchinson where we wandered around underground without hardhats picking up
pieces of halite. In today’s world a
fifth grader would not even get close to a working mine let along be taken down
unprotected in a steel-cage elevator.
One small piece of halite remains from this little excursion by my class
of 15 or so students. The mine is still
in use today and produces rock salt.
Perhaps more interesting to the rockhound is the Kansas Underground Salt
Museum where visitors actually tour the caverns at 650 feet below surface
level.
Eastern Kansas will surprise first-time visitors who
have these visions of a flat landscape devoid of vegetation! And, there are a variety of rocks, minerals,
and especially fossils available for the collectors.
REFERENCES
CITED
Berendsen, P., T. Weiss and K.
Dobbs, 2000, Kansas Kimberlites: Kansas Geological Survey Public Information
Circular 16.
Brosius, L. and R. S. Swain,
2001, Lead and Zinc Mining in Kansas: Kansas Geological Survey Public
Information Circular 17.
Kansas
Geological Survey, 1999, Arkansas River
Lowlands and Wellington-McPherson Lowlands; Rocks and Minerals: www.kgs.ku.edu/Extension/lowlands/AL_factsheet1.pdf
Kansas
Geological Survey, 2005, Flint Hills; Rocks and Minerals: http://www.kgs.ku.edu/Extension/flinthills/rocks.html
Meyer, H. O. A, and D. G. Brookins, 1976,
Sapphirine, Sillimanite, and Garnet in Granulite Xenoliths from Stockdale Kimberlite,
Kansas: American Mineralogist, v 6.
iwant to find a rock finding place in ks
ReplyDeleteI live on my own private property! I have found a very very large amount of see through black ore. My Mother took it to PA and was stated this is more than you think!!!!!! In some cases, it appears to be orange, brown, or purple! Could just be the way the light hits it! Definitely see through! What is this? You can't break it with a hammer or any other object which tends me to believe this is more than I thought!!!!!
ReplyDeleteits probably a diamond. it takes diamonds to break diamonds.
DeleteI found fern fossil crystal today. What would be the interest?
ReplyDeleteIt is 4 inch long
ReplyDeleteI have found very large Geodes in Riley County, some as big as 10 inches across. Several very long hollow ones a foot or more in length and 5-6" wide. They are cool...
ReplyDeleteI purchase river rock (from a sand pit near Abilene, KS and have recently become obsessed with the variations of rocks. Of course I have no idea what types of rocks/minerals I am looking at and picking up. I wonder who might be able to educate me ?
ReplyDeleteOne of the most informative articles I've read. Thanks. (Former Colorado rock hound.)
ReplyDeleteThanks Unknown. Glad you found it interesting. mike
ReplyDeleteThis comment has been removed by a blog administrator.
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ReplyDeleteGreat info! FYI, my husband is a teacher near Manhattan, and has taken several classes on field trips to the Hutchinson salt mines. They still get to wander around a working mine after going down in the steel elevator
ReplyDeleteGlad you like the post. I have fond memories of wandering down and through the mine. think the mine at Kanopolis may still be active and the salt is used as ice melt. My home was "near Manhattan" in Tescott.
ReplyDeleteVery cool. I have a new hobby. Rock hounding. Now i just want to explore and research. I have land in woodson county, just outside Yates center. Any recommendations on where to begin on 80 acres of pasture.
ReplyDeleteSure, Googlr Kansas Geological Survey, go to Geology, then to County maps and hit WO county. Presto, a geological map of Woodson County. You are in the middle of some decent fossil hunting in any of the limestones or shales. best place to look is to examine road cuts. there are also some good exposures down by the lake but don't stray on state park land to hunt. Now Woodson County does not has a written bulletin but no problem. Just go to Publications and hit County and a map pops up and move one over to sat Allen CO. the rocks in Woodson county shown om your map are about the same as Allen or other surrounding counties and are described in the bulletins. Also go to other maps and charts and hit the physiography map, it is also interactive. Buy a good rock hammer, not a regular hammer as they are too soft. Get a pair of goggles as the limestines chip off and fly whne you whomp them with the rock hammer This will get you atrted. Other question send a message directly to csrockboy at yahoo dot com
ReplyDeleteWoodson County is also notable in having the only outcrop of granite in the State. Not likely volcanic in nature, but probably a large "raft", or slab of granite pushed up from below. I believe it is south of Yates Center, not far from US 75. There is a gravel pit in the area that often allows rockhounds entry for collecting - at least they used to. Emporita State Geology Class often took field trips there.
ReplyDeleteYes, the granite is interesting. I used to haul my students around to look at that outcrop and the diatremes (where we found nice garnets). Today I think many/most are off limits to rockhound collecting. The last time I visited several years ago the outcrops had been beat to death by rock hammers. Some have been drilled looking for diamonds but no luck. I also liked to introduce students to other igneous rocks in Kansas---like the Duluth Gabbro brought south by Pleistocene glaciers, along with the Precambrian Sioux Quartzite. In western Kansas it is also amazing the variety of igneous rocks in the "sand and gravel pits" along the Smoky Hill, Saline and Republican Rivers. Most probably were eroded from the Ogallala Formation but originally came from the Rocky Mtns. Teaching is enjoyable and I had a great time with the students. mike
ReplyDeletemy husband wants to go rockhounding for some chert. are there areas that are just free to roam and gather stones or do we need to contact someplace for permission?
ReplyDeleteJamie. send me an email: csrockboy at yahoo dot com and tell me your locality. What part of Kansas (I presume)? Maybe I can help. mike
DeleteI have been finding nice selenite and iron rods in Garfield, KS.
ReplyDeleteGuess that is in Pawnee County. Are you collecting in a black shale?
ReplyDeleteLove this blog. O live in wamego
ReplyDelete, near manhattan . Where would you recommend ? I can't drive far my car isn't the most reliable. Thank you!+
send me an email at csrockboy@yahoo and I can give you information around Wamego.
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