A high of 70 degrees, winds out of the south at 5 to 10 MPH, forecast of 30% for stray showers after 3PM. Yes, this past Sunday was the perfect weather for Opening Day of the 2010 Rockhunting Season. So with a few friends I set out to explore two shale hills in Osborne County that, after the recent hard winter with its abundant water erosion, we thought worth searching out for interesting rocks, minerals, and fossils.
WHAT??!! You've never went rockhunting? You've never even thought about it? Shame on you! As long as you take along a sturdy bag for larger specimens; a hammer or two; some paper towels; a small container for small specimens; your citizenship papers (when in Arizona); permission to be on the private land where curiously all good rockhunting sites are always located; are ready to walk for some distance - especially on the way back to your vehicle, as you realize that a bunch of rocks really do weigh a lot; be ready for VERY warm environs (shale tends to heat up in the sun); and learn to avoid scorpions, cacti, and irritated snakes, it is one of the best ways for the entire family to commune literally with nature. You don't even need to find anything to have a good time!
Motorcycle Hill, as I've referred to it ever since 1971 when my family first tried to rockhunt here and had to deal with two guys on motorcycles having fun in the shale all around us, was actually started on its fatal path of wind and water erosion back in 1887, when a railroad bed was initially dug toward the bottom of its south face. The thought was that the rock in the side of the hill would be sturdier than the flat land beyond. Imagine the look on the railroad overseer's face when he was informed that they had hit very soft shale. The bed was then dug in the flat, but the damage was done and the hillside's erosion was under way. Sidenote: That railroad built its bed and promptly ran out of money. If you know where to look, you can still see this 123-year old debacle.
The Blue Hills Uplands in Osborne County gave their name to the distinctive Blue Hill Shale, which can be seen eroding here and there and everywhere throughout the region.
The problem with shale and a hillside is that the combination makes you walk a LOT farther than you really want to know. Add to that the pounds of rock one begins toting around and yes, you do get a lot of exercise over the course of an hour or two.
Seen here are pieces of the unofficial Osborne County Rock, septarian concretion. Septarians are found throughout the Blue Hill Uplands and can range in size from three inches across to monsters measuring nine feet in diameter and weighing several tons. How they form is still a bit of a mystery. The two primary minerals to be found in a septarian are iron and calcite.
The middle rock seen above was just over a foot in diameter and can now be found in my rock garden. My hat off to Osborne insurance agent and fellow rockhunting devotee Andy Knoll, who volunteered to carry it back to the vehicle.
Here yellow calcite crystals line a cavity in one septarian concretion nearly four feet in diameter. Stunning crystals can be found if one is lucky and one of these giant rocks is discovered broken apart.
Seen here is a washout that has uncovered a large three-foot diameter septarian concretion.
Having to cross barbed wire fences is Standard Operating Procedure for most rockhunting expeditions. Here Osborne's mighty City Chief of Police, Mike Bristol, gallantly applies his superior experience in these matters to place one powerful foot atop the offending steel so that those less impressive may cross the hazard in safety.
See, Mike, your leg is NOT as white as the shirt you wore. Close though.
View of the many acres of shale that we explored. Some seven miles to the southwest is the town of Luray, the grain elevator of which is that white spot sparkling in the distance.
This is the kind of expanse of shale that experienced rockhunters salivate over when they are looking for the most popular fossils to be found in the Blue Hills Uplands: shark teeth!
Okay, we are in the midst of the above said expanse of shale. Can you find the shark tooth?
THERE IT IS! Not the familiar pointed kind, but a tooth from the kind of shark that crushed oysters and such for food, hence the need for a blunter type of tooth. This was the only tooth found by the expedition on this particular day. I won't mention the four or five tracks of fellow rockhunters that were within two feet of the tooth on both sides and missed it.
Ah, two more members of the Bristol clan, who shall remain nameless, bags bulging, seemingly of two minds: one on her cellphone, calling for the helicopter as she has once again bagged more rocks than she can carry, while the other is still looking for yet more, as her bag has not yet torn apart and therefore clearly can hold more.
At left, Jeanie. At right, Kathy. I just know they would not wish to remain nameless.
We headed back north for a site on the north side of the 1,805-feet-above-sea-level South Hill - you know, the hill three miles to the south of Osborne. This site is on the west side of U.S. Highway 281, and the closest place to unload everyone was a half mile south on the other side of the hill.
North, south, south, south, west, south . . . yep, actually got that all right.
Anyway, we crossed north over the hill, and then the next hillock, and then the next hillock, and found that the shale outcropping here was no more eroded out now than when I had first walked over it back in 1970 (can it really be that long ago? Sigh.). After a few minutes of fruitless searching but stubbornly refusing to believe this, we reluctantly headed east, crossed over the highway that had suddenly got very busy, and walked south to where the eastern side of South Hill (that's it's official name, folks - check it out with the U.S. Board on Geographic Names, a division of the U.S. Geological Survey) has really opened up over the past few years. And look! Four more members of the Knoll clan had arrived from Osborne to join in the fun! We were all happily trodding over the shale bed until a loud crack of thunder in the sky, a sudden gust of very cold wind, and an ominous gathering of darkening clouds told us that it was time to pack it in.
After more than four hours an exhausted expedition returned to Osborne and triumphantly discharged from the two vehicles. Later reports confirmed that several pounds of impressive rocks, minerals, and fossils were brought back, several pounds of shale were dumped from footwear, there were soaking baths all around and only one tick discovered. It was the start of what is sure to be a Great Season!