A Geological Survey of Alabama
In order to get credit for this Earthcache you must answer the following questions. Some of these answers can be found in the text below.
1. Ripple Marks – Red Mountain Formation
a. What period is this formation from?
b. This slab of sandstone shows marks made by what?
2. Fossil Tree – Lepidodendron, Hartselle Formation
a. What is the scientific name of this tree?
b. Where did this fossil specimen come from?
3. Hematite – Red Mountain Formation
a. Iron mixed with sand or lime was deposited by what?
b. Why is red ore favored?
4. Geothite (Limonite)
a. In what Alabama county was this formation found?
b. What is a common weathering product?
c. Brown iron ore was an important material of what?
5. Fossil Stump – Sigillaria, Hartselle Formation
a. This fossil stump belongs to a large and diverse group of what?
b. What are the trees called?
c. This group is a major component of what?
6. Sandstone “Boxwork” – Pottsville Formation
a. What period is this formation from?
b. Look at the angular divisions on the surface and describe what these deposits were formed from?
7. What is the thickness of the Hartselle Formation?
8. Name the layers immediately underlying coal seams?
9. The Pottsville Formation contains what minerals (list at least three)?
Send me the answers to the above questions to my e-mail address for verification. Any logs received without the above questions being answered will be deleted with 48 hours! No exceptions.
10. Optional: Please post a photo of you and your GPS at the site. Please do not share photos that will reveal answers to the above questions. Thank you!
The listed coordinates will take you to the front entrance of the Alabama Natural History Museum. Questions 1 thru 6 can be answered on site. Questions 7 thru 9 can be found by reading the cache page. Located in front of the museum you will find 6 geological formations all found in Alabama. Below you will find some details about these geological formations.
Ø Red Mountain Formation (Ripple Marks) - Red MountainFormation is a dark-reddish-brown to olive-gray partly fossiliferous, mostly fine-grained sandstone interbedded with siltstone and shale; minor amounts of bioclastic limestone and conglomerate sandstone; includes hematitic beds and beds of ferruginous sandstone, outcrops in northeaster Alabama area finer grained and include more limestone.
Ø Hartselle Formation (Fossil Tree) – Hartselle Formation is a thin-bedded, fine-grained sandstone and greenish gray shale interbedded with coarse limestone. Average thickness 0 to 80 feet.
o Fossil Soils – Geologists have recognized innumerable fossil soils (paleosols) throughout the strata containing upright fossils at Joggins, Nova Scotia, Yellowstone petrified forests, coal mines of the Black Warrior Basin of Alabama, and many other locations. The layer immediately underlying coal seams, often called either “seatearth or underclay”, typically either consists of or contains a paleosol. Paleosols are soils which were formed by subaerial weathering during periods of very slow or no accumulation of sediments. Later, renewed sedimentation buried these soils to create paleosols. These paleosols are identified on the basis of the presence of structures and microstructures unique to soils; animal burrow and molds of plant roots of various sizes and types; recognizable soil profile development; and alteration of minerals by soil processes. In many cases, these paleosols are virtually identical to modern soils.
o Geologists who have studied upright fossils found in sedimentary rocks exposed in various outcrops for the last 30 years have described the upright fossil tress as being deeply rooted in place and typically rooted in recognizable paleosols. Geologists have also found that some of the larger upright fossil trees found within Carboniferous coal-bearing strata show evidence of regeneration after being partially buried by sediments. In these cases, the trees were clearly alive when they were partially buried by sediments. The accumulated sediment was insufficient to kill the trees immediately because of their size. As a result, some of them developed a new set of roots from their trunks just below the new ground surface. Until they either died or were overwhelmed by the accumulating sediments, these trees would likely continue to regenerate by adding height and new roots with each increment of sediment, eventually leaving several meters of former "trunk" buried underground as sediments accumulated.
Ø Pottsville Formation (Sandstond “Boxwork”) – The Pennsylvanian Pottsville Formation is mapped bedrock in Pennsylvania, western Maryland, West Virginia, and Ohio. The formation is also recognized in Alabama. It is a major ridge-former In the Ridge-and-Valley Appalachians of the eastern United States. The Pottsville Formation is conspicuous at many sites along the Allegheny Front, the eastern escarpment of the Allegheny or Appalachian Plateau.
o This formation consists of gray conglomerate, fine to coarse grained sandstone, and is known to contain limestone, siltstone and shale, as well as anthracite and bituminous coal. It is considered a classic orogenic molasse.