Bear Valley Strip Mine
Sedimentology/Stratigraphy Field Trips
River of Rocks
|The top photo shows a view from a fire tower on top of O'Leary Peak north of Flagstaff, Arizona, looking to the southeast onto the Bonito Lava Flow in Sunset Crater Volcano National Monument. The flow is an 800 year old basalt field that extruded from Sunset Crater (along the left edge of the photo). The second photo shows O'Leary Peak from the lava field (the left peak). Photos taken March 23, 1998.|
The first photo shows me at the top of a small peak in the Sacaton Mountains of southern Arizona. The rocks are granitic inselbergs within the Basin and Range physiographic province. The second and third ones show my friend Dr. Ig sitting on a similar outcrops nearby. Here is another photo of me next to a dike in the same area (shown above under General - Dikes). Photos taken March 25, 1998.
In 2011, I took this picture of the Sacaton Mountains from the air.
|I visited the Grand Canyon in Arizona on March 27, 1998. See my page on the Grand Canyon.|
The top photo is my Sedimentology class (excluding me, taking the photo) at Wright State University, sitting and standing on the Laurel River Dam Sandstone in Kentucky on May 16, 1998. Left to right: Sarah Byerly, Erin McGovern, Steve Roberts, Tom Clemens, Lillian Wertel-Newberry, Paul McColgan (foreground), Marie Woodruff (background), Michelle Hoyt, Judith Smith, Christopher Hauptfleisch, Dr. David Dominic, and Jessica Chambers.
The bottom photo shows a ripple fan exposed at the top of the dam in the Dam Sandstone. There is unconsolidated sand in the troughs of the consolidated ripples in the fan, which happens to make them easier to see in this photo.
|This is a creek flowing over the Black Hand Sandstone in the Old Man's Cave area of Hocking Hills State Park, Ohio, taken May 23, 1998.|
||The Enchanted Rock is a Proterozoic granitic pluton in central Texas, on the border between Llano and Gillespie counties. The patch of vegetation in the bottom photo is a fragile micro-ecosystem called a gnamma or vernal pool that has formed in a small bedrock low. They occur all over the Enchanted Rock. Both photos taken facing southwest towards Little Rock from summit of Enchanted Rock on August 29, 1998.|
||Photos of a highly folded outcrop of shale and thin sandstone beds at mile marker 17 on I-75 in Tennessee. Sample tn1 is from this outcrop. Taken September 5, 1998.|
||These are five photos from the amazing Bear Valley Strip Mine, located southwest of Shamokin in Northumberland County, Pennsylvania. The rocks are the Pennsylvanian Llewellyn Formation. I visited the place once on a structural geology field trip in 1997, and then went back Sept. 8, 1998, to take pictures, and these are some of the best ones. The top photo shows the north side of an anticline known as the Whaleback. Also on the far wall you can see a lot of black spots, which are large concretions. You can see the southern limb of the syncline in the east wall too. The second photo shows a close up of some of the concretions in the south wall. The third photo shows the hollow space once filled by a concretion now cut by a fault. The fourth photo shows a plant fossil known as Stigmaria, which is the root system of a Pennsylvanian tree. The fifth photo shows the stump of a petrified tree, possibly the same species that made the roots in the previous photo. Notice how the bedding dips at a steep angle, yet the shear stresses acting on the rock have conspired to keep the tree vertical. You can also click here to look at a stereo image of the Whaleback.
By the way, if you were directed here by Emil Silvestru's creationist article, where he quotes me above regarding the petrified tree, consider my response to him (to which he did not respond, because creationists are fundamentally intellectual cowards):
Imagine you FIRST have a vertical toothpick, and then you have a deck of cards with a small hole drilled through each one (in the same place on each card for simplicity), which you then stack with the toothpick through the holes. You bend the stack to imitate an anticline and the cards all move slightly relative to one another on account of the folding (the deck is sheared) at any point in the deck except along the axis of the fold. In fact the shear is in one direction on one side of the axis and the other direction on the other side. Depending on where the hole is the toothpick can remain close to vertical. This is what happened with the fossil tree stump at Bear Valley Strip Mine.
|This is a photo of part of an outcrop on US Rt. 35, near County Road 84 near Jackson, Ohio. This is Stop 1 of Dr. David Dominic's Stratigraphy Field Trip (Wright State University). It shows an unconformity (at the hammer) between underlying Mississippian Borden Formation and overlying Pennsylvanian Sharon Conglomerate, with Sarah Byerly and Leo Kurylo for scale. Photo taken October 16, 1998.|
|This is a photo of spectacular crossbedding in the Carter Cave Sandstone at Carter Cave State Resort Park, Kentucky, taken October 17, 1998, with Matt Gale for scale. This is Stop 3 of Dr. David Dominic's Stratigraphy Field Trip (Wright State University).|
|This is a photo of the Armstrong Hill Section, a fairly famous roadcut (as roadcuts go) on Rt. 2 in Kentucky, taken October 17, 1998. This is Stop 4 of Dr. David Dominic's Stratigraphy Field Trip (Wright State University).|
||These are photos of the Silurian Tuscarora Formation close to its contact with the Ordovician Juniata Formation, at "The Narrows" in Bedford County, Pennsylvania. The Tuscarora Formation is white to gray quartz sandstone and conglomerate, and the Juniata Formation is red to brown sandstones, siltstones, and shales. They are both nearly vertical at this location. The contact between the two is gradational and alternates between these lithologies at many scales. The top photo shows me on the Tuscarora, and the bottom one shows this alternation of red and white sandstones at the lamination scale. Photos taken November 27, 1998.|
|This photo shows a view of a part of Bedford County, Pennsylvania, taken from a fire tower at the northern end of Wills Mountain, which is known as Kinton Knob. The town of Bedford is in the foreground, and behind it is Evitts Mountain. Behind Evitts Mountain is Tussey Mountain. There are water gaps in both of these mountains cut by the Raystown Branch of the Juniata River. Evitts Mountain and Tussey Mountain are held up by the Silurian Tuscarora Formation, and form the limbs of an anticline. Photo taken November 28, 1998.|
||These photos show kink folds in the Silurian Wills Creek Formation along Route 22 near Neff, Huntingdon County, Pennsylvania. The contrast is enhanced in the photos to make it easier to see the folds. Photos taken December 20, 1998, facing southwest.|
|This is my brother, Norm, standing on some of the boulders of the River of Rocks, which is a part of Hawk Mountain Sanctuary, Berks County, Pennsylvania. The blocks were transported downslope by periglacial processes in the Pleistocene from outcrops upslope. The boulders are made of the Silurian Shawangunk Formation, which is stratigraphically equivalent to the Tuscarora Formation. Photo taken December 24, 1998.|