There is no physical container for you to find. Your visit here will be a fact gathering trip to answer the questions below.
The listed coordinates will lead you to a public fee due parking lot. The Overturned Stanley Formation is at the back of the parking lot. You should be able to either pull in the parking lot without having to pay to answer the questions or gather the answers while taking a stroll down Central Avenue.
An excellent exposure of the overturned, northwest-dipping Stanley Formation, shale and sandstone, is located directly in front of the posted coordinates. A portion of of this rock surface was covered with gunite, a type of construction cement, several years ago to prevent rock falls. You will be able to see it was not successful since much of the sandstone-shale sequence is visible.
The sedimentary rocks in the vicinity of the thermal springs consist of shale, chert, novaculite, sandstone, and conglomerate.
The igneous rocks were intruded into the sedimentary rocks during the early Late Cretaceous time (about 90 million years ago). The sedimentary rocks in the vicinity of the hot springs were originally laid down on a sea bottom of nearly horizontal beds. At present the beds are generally steeply inclined, because of tremendous and complex mountain-building forces in late Paleozoic time. The rocks have been subjected to at least three episodes of structural deformations—two episodes of compression from the south, producing imbricating thrust faults and, third, forces from the north which produced overturning and folding of beds and fault planes and further faulting. When the formations are crossed from northwest to southeast, they are seen in cross section to lie in a series of very complexly folded anticlines and synclines, with some associated thrust faults.
These strata are often steeply inclined to overturned, with many tight folds and numerous thrust faults formed by the late Paleozoic orogeny that uplifted the Ouachita Mountains. These rocks often contain quartz veins, small Creaceous-age igneous dikes, and both hot and cold springs.
The Stanley Shale is predominantly a clayey, thinly fissile, black to green shale, with large amounts of sandstone interbedded throughout the formation. The sandstone, when freshly exposed, is a hard, fine-grained, feldspathic, silty sandstone, but weathers easily to a soft, clayey porous material ranging from green to brown in color. Almost all of the low-lying areas in the city of Hot Springs are composed of the Stanley Shale, and it surrounds Hot Springs Mountain on the south, east, and west sides.
The Hot Springs Sandstone Member of the Stanley Shale consists of fine- to medium-grained sandstone with some shale and conglomerate. The sandstone is gray, hard and quartzitic, reaching thicknesses up to 6 ft (1.8 m) The shale predominantly occurs at the top of the unit, and the principal bed of the conglomerate occurs at the bottom.
The Stanley Shale is composed of dark-gray shale interbedded with fine-grained sandstone. A thick sandstone member, the Hot Springs Sandstone, is found near the base of the sequence and an equivalent thin conglomerate/breccia occurs at the base of the unit in many other places. Stratigraphically minor amounts of chert, bedded and vein barite, and conglomerate have also been noted in various parts of the sequence.
Silty sandstones outside the Hot Springs Sandstone Member are normally found in thin to massive beds separated by thick intervals of shale. Cherts are sometimes present in the middle and upper parts of the formation. Both plant and invertebrate fossils occur in the Stanley Shale, but the preservation is usually poor. The Hot Springs Sandstone and conglomerate/breccia at the base of the formation possibly indicates a submarine disconformably between the Stanley Shale and the Arkansas Novaculite in Arkansas. The total thickness of the Stanley Formation varies from 3,500 feet to over 10,000 feet. The Hot Springs Sandstone may be as much as 200 feet thick in the area around Hot Springs, but is thinner elsewhere.
In order to claim this Earthcache you must send me an email answering the questions listed below. Please do not answer the questions in your online log. You may post photos with your log, but please do not include photos that will give the answers to the questions.
1. What colors do you see in the Stanley Formation?
2. Which direction are the layers of the Stanley Formation slanting?
3. Are the layers smooth or jagged?
4. Are the layers all the same width? What is the approximate width of the layers?
5. What caused this overturning of this Stanley shale?