Geology and Fossils

Sunset over Coosa River Valley from Cheaha Mountain. Cheaha Mountain is the highest mountain in Alabama (2400 feet). It is part of the Talledega mountains, and one of the southern-most mountains in the Appalachian Mountain range. It is composed mostly of quartzite and metamorphosed sandstone.

01_mea_P6060668_2800 Sunset over Coosa River Valley from Cheaha Mountain. Cheaha Mountain is the highest mountain in Alabama (2400 feet). It is part of the Talledega mountains, and one of the southern-most mountains in the Appalachian Mountain range. It is composed mostly of quartzite and metamorphosed sandstone.

02_che_quartzite_P6060019_1600 Quartzite from Cheaha Mountain

03_che_sandstone_P6060021_1400 Metamorphosed sandstone with quartz vein. Cheaha mountain.

This is the Red Mountain Expressway road cut for US Highway 31 and 280 in Birmingham, Alabama which reveals the stratigraphy of weathered sedimentary layers laid down from 485 to 420 million years ago and folded and tilted into an anticline. The geology of the road cut is described in detail in: Lancefield, J. Lost Worlds in Alabama Rocks. A Guide to the State’s Ancient Life and Landscapes. 2nd Ed, The Alabama Museum of Natural History, 2018.

04_birm_P6100055_01_1800 This is the Red Mountain Expressway road cut for US Highway 31 and 280 in Birmingham, Alabama which reveals the stratigraphy of weathered sedimentary layers laid down from 485 to 420 million years ago and folded and tilted into an anticline. The geology of the road cut is described in detail in: Lancefield, J. Lost Worlds in Alabama Rocks. A Guide to the State’s Ancient Life and Landscapes. 2nd Ed, The Alabama Museum of Natural History, 2018.

The right side of the preceding photo shows the upward tilt of the layers forming the SE limb of the Birmingham anticline which has been eroded largely. The layer (marked 1) is Chickamauga Limestone laid down in shallow seas in the Ordovician Period (485 Ma). More superficial are two Bentonite layers (marked 2) laid down as volcanic ash in late Ordovician. The next layer (3) is Sequatchie Formation layer limestone laid down in the late Ordovician. The next much thicker layer (4) is the Red Mountain Formation. The Red Mountain vertical fault is labeled (5).

05_birm_P6100055_02_rt_1800 The right side of the preceding photo shows the upward tilt of the layers forming the SE limb of the Birmingham anticline which has been eroded largely. The layer (marked 1) is Chickamauga Limestone laid down in shallow seas in the Ordovician Period (485 Ma). More superficial are two Bentonite layers (marked 2) laid down as volcanic ash in late Ordovician. The next layer (3) is Sequatchie Formation layer limestone laid down in the late Ordovician. The next much thicker layer (4) is the Red Mountain Formation. The Red Mountain vertical fault is labeled (5).

The left side of the photo before last shows the Red Mountain fault (5) and Red Mountain Formation (4) which is rich in iron-bearing rock (i.e., hematite, iron-rich sandstone) as well as shale, limestone and siltstone laid down in the Silurian period (448 Ma) in shallow seas.

06_birm_P6100055_03_lt_1600 The left side of the photo before last shows the Red Mountain fault (5) and Red Mountain Formation (4) which is rich in iron-bearing rock (i.e., hematite, iron-rich sandstone) as well as shale, limestone and siltstone laid down in the Silurian period (448 Ma) in shallow seas.

Hematite, Ruffner Mountain, Birmingham AL. Hematite is rich in iron, and heavy hematite deposits in Birmingham rock such as the Red Mountain Formation contributed to making Birmingham a major center for iron and steel manufacturing between the Civil War and the 1970’s. Other materials essential for iron/steel production (limestone, dolostone and coal) are also present in this area of Alabama. More recently richer iron deposits in other parts of the world made continued Birmingham iron ore mining economically non-competitive. Sediments forming hematite probably originated from iron-rich green clays with the iron coming from igneous and metamorphic rocks that were weathered in the Taconic Mountains to the east. Bacterial chemical conversion of iron during the Silurian era caused the iron to oxidize and precipitate which coated the clay materials with hematite.

07_ruff_hemat_P6100891_1400 Hematite, Ruffner Mountain, Birmingham AL. Hematite is rich in iron, and heavy hematite deposits in Birmingham rock such as the Red Mountain Formation contributed to making Birmingham a major center for iron and steel manufacturing between the Civil War and the 1970’s. Other materials essential for iron/steel production (limestone, dolostone and coal) are also present in this area of Alabama. More recently richer iron deposits in other parts of the world made continued Birmingham iron ore mining economically non-competitive. Sediments forming hematite probably originated from iron-rich green clays with the iron coming from igneous and metamorphic rocks that were weathered in the Taconic Mountains to the east. Bacterial chemical conversion of iron during the Silurian era caused the iron to oxidize and precipitate which coated the clay materials with hematite.

08_ruff_lime_P6100889_1400 Limestone, Ruffner Mountain

McWane Science Center, Birmingham AL. Reproduction of Clidastes moorevillensis an 11 foot long mosasaur from the Late Cretaceous Peroid (80 MA) whose fossils were found in Greene County AL. Mosasaurs were dominant reptilian marine predators with a diet of fishes including sharks, smaller mosasaurs, turtles and ammonites. During the late cretaceous period the southern half of what is now Alabama was a warm shallow ocean with large numbers of fishes, sea turtles, sharks and marine reptiles. Many of them grew to enormous size.

09_mcw_P6100937_1600 McWane Science Center, Birmingham AL. Reproduction of Clidastes moorevillensis an 11 foot long mosasaur from the Late Cretaceous Peroid (80 MA) whose fossils were found in Greene County AL. Mosasaurs were dominant reptilian marine predators with a diet of fishes including sharks, smaller mosasaurs, turtles and ammonites. During the late cretaceous period the southern half of what is now Alabama was a warm shallow ocean with large numbers of fishes, sea turtles, sharks and marine reptiles. Many of them grew to enormous size.

Reproduction of Appalachiosaurus mongomeriensis (Alabama Tyrannosaur) in McWane Science Center. Fossils were found in Montgomery County. It was over 10 feet high and 22 feet long and the predominant predator in Alabama during the late Cretaceous Period.

10_mcw_P6100923_1400 Reproduction of Appalachiosaurus mongomeriensis (Alabama Tyrannosaur) in McWane Science Center. Fossils were found in Montgomery County. It was over 10 feet high and 22 feet long and the predominant predator in Alabama during the late Cretaceous Period.

11_mcw_P6100921_1600 Reproduction of fossils found and their location in the skull of Appalachiosaurus mongomeriensis. McWane Science Center

Reproduction of Xiphactinus audax a 17 foot long late Cretaceous fish (Bulldog fish). Alabama is one of the best places to find fossilized remains of Cretaceous aged fishes. McWane Science Center

12_mcw_P6100943_1600 Reproduction of Xiphactinus audax a 17 foot long late Cretaceous fish (Bulldog fish). Alabama is one of the best places to find fossilized remains of Cretaceous aged fishes. McWane Science Center

Trace fossils of amphibian footprints from the Pennsylvanian Period (323 Ma) in slate recovered from the Union Chapel Coal Mine. Anniston Museum of Natural History

13_ann_P6100952_1600 Trace fossils of amphibian footprints from the Pennsylvanian Period (323 Ma) in slate recovered from the Union Chapel Coal Mine. Anniston Museum of Natural History

Fossils of Lyginopteris hoenighhausi, a seed fern in slate from the Pennsylvanian Period. Slate from Union Chapel Coal Mine. Anniston Museum of Natural History

14_ann_P6100955_1400 Fossils of Lyginopteris hoenighhausi, a seed fern in slate from the Pennsylvanian Period. Slate from Union Chapel Coal Mine. Anniston Museum of Natural History