Eggs Come From The Store?: April 2011

The Museum of York County was the location for week two of the 2011 Catawba Master Naturalist class. Dr. Steve Fields, the curator for natural history at the Museum, gave us a crash course in SC geologic history. Little did I know the impact SC geologic history has on the the state, actually every habitat on earth...duh. Another example of the more you learn, the more you realize you don't know. In the ecology course I teach, I emphasize the impact of climate on plant life, which affects animal life. I just found out I've been leaving out a major component...geology!

Steve started with the Cambrian period, 520 Ma with the 3 belts of a chain of volcanic islands, like present day Hawaii, that formed the Carolina Terrane. The Carolina Terrane is composed of 3 belts, 1) Kings Mountain belt, 2) Charlotte Belt, and 3) the Carolina Slate belt. This is dated at 650 Ma (Precambrian) and is an exotic volcanic arc that eventually underwent subduction. Note the Ma. MYA is the old "million years ago" terminology, but Ma means mega giga (mega means annum for year, and giga refers to billion, like computer gigs, kilo annum would be 1000's of years). The Carolina Terrane is a fault bounded block of crust that eventually moved by continental drift to merge with Laurentia, ancient North America. The meta-siltone is compacted ash layers from that period.

Meta-siltstone Needs to be verified

During the Cambrian, dated 520 Ma, produced basalt lava. Magma is deep down in the Earth. Lava is magma that breaks onto the surface.

Slate is metamorphosed mud (mudstone).

Slate-metamorphised mud (mudstone)

There are 3 types of rock, igneous (born of fire), sedimentary, and metamorphic (change of form). Heat and pressure change igneous and sedimentary rock to metamorphic.

The Ordovivian 450 Ma is the period the Carolina Terrace "docks" with Laurentia. It contacted it, but is not acccreted to it.

Meta-granite is dark metamorphic rock (mayphic, Mg=magnesium, Fe=iron).

Meta-gabro is light metamorphic rock, felisic (Fe=iron, Si=silicone)

Meta-diorite found in the Catawba River @ Landsford Canal

Rock with large crystals had a long cooling period. Rock can be mixed, due to different cooling rates. Cooling rates can be decades, centuries, or millinia.

Silurian 430 Ma...no comments...take a break.

Devonian 430 Ma The Carolina Terran accreted. Pieces of Baltica (ancient Europe) joined the Carolina Terrane. A terrane is a fault bounded block of crust. Kings Mountain is the sheer zone. Marble formed during this process. It is limestone that metamorphosed during accretion. Limestone is metamorphosed deep ocean rock. It contains calcium carbonate that composed the skeletons of aquatic invertebrates. Human skeletons are composed of calcium phosphate. Marine animals use atmospheric carbon dioxide in their shells. Examples: clams, welks, and other mollusks.

Dickson Gap contains boulders from this event. Metaconglommerates are mixing of rock types.

Barite is barium sulfate from underwater hydrothermal events. Settling, heat, and dissolved minerals are present and resulted in barite.

Barite composed of barium sulfate.

The Devonian 360 Ma saw Baltica and Laurentia form a supercontinent. The docking of the Carolina Terrane and its accretion contributed to the formation of the Appalachian mountains 1 Ba, which rivaled the Himalayas in altitude and the Rockies in age (64 Ma).

Gandwana: Africa, South America, Antartica, and India are headed towards Laurasia.

Next, the Mississipian, followed by the Pennsylvanian 300 Ma. A small part of the Pageland pluton (either granite or gabro crystallized magma chamber, usually 12-15 km under the Earth's surface, has large grains because it cooled slowly due to being under the Earth's surface) is 40 Acre Rock. It is granite and has 40 acres exposed.

40 Acre Rock Heritage Preserve

Permian 290 Ma Laurasia and Gandwana joined to form Pangea, all of the land masses of Earth. This push west further developed the Appalachians. During this time 90% of the Earth's species became extinct. Since most of the organisms living at that time were marine, this resulted in a mass extinction of marine organisms.

The Triassic 210 Ma saw the formation of the Crowburg basin near Pageland. The Triassic is the Age of the Crocodile. South Carolina was not exempt. Dinosaur species such as Rutiodon is one example of numerous dinosaurs that roamed the current Southeast.

Rutiodon

The Jurassic 180 Ma included rifting, forming cracks in the Earth's crust, forming diabase rock where "dikes" of magma come up to the Earth's surface. 40 Acre Rock is part of the Great Pageland Dike.

The Cretaceous saw the presence of Hadrosaur, Ornithomimid, Dromeosaur, and the Deinosuchas.

Deinosuchus "Terrible Crocdodile"

Hadrosaur

Cretaceous 85 Ma Due to global warming glaciers melted and great portions of land were inundated. At 65 Ma the most famous mass extinction occurred. An asteroid hit the Yukatan Peninsula. The asteroid was 10 miles wide, the size of Manhattan, with a strength of 10,000 Hiroshima bombs, resulting in a "nuclear winter" effect that formed a cloud that blocked photosynthesis for months, resulting in a loss of 70% of life on Earth. At 64.9 Ma there is a layer of irridium throughout the Earth.

The Paleocene 60 Ma was characterized by Ectoganus and the ungulate Phenacodus, ungulate hooved mammals.

Ectoganus

The Eocene 50 Ma Peachtree Rock Heritage Preserve is an excellent place to observe characteristic rock and fossils of the Eocene. Sandstone forms close to shore; limestone is characteristic of deep ocean, once found near Santee.

Oligocene 25 Ma saw an increase in the types of grass. Large herbivores characterized this epoch. Including Titanis walleri, Mesohippus, and Amphylocyonid.

Titanis walleri Terror Bird

Miocene Epoch 23.8 Ma Sandhills form in SC as a beach. Teleoceras and Daedon, "Hogs from Hell.

Pliocene Epoch 3.5 Ma Megalotherium, the Great Ground Sloth is in South Carolina. There was a land bridge from South America and the Great American Biotic Exchange occurs; which brought Megalotherium to SC.

Pleistocene Epoch 15 ka Ice Age occurs with fluctuations in climate.

This is the age of Megafauna > 45 kg/145 lbs. In SC this included the Mammot, Smilodon (Saber toothed cat), Arctodus (long legged bear), Bioson latifrons and Hemiauchena, camels that evolved in North America. Due to the ecotypic rule/Edward Cope's Rule: the longer the lineage on Earth, the larger the species.

10-12 Ka there was a mass extinction. Several factors: over hunting, climate change, and a comet (big, dirty snowballs that hit the atmosphere and exploded in Southeast North America. They possibly created the Carolina Bays. These are elliptical and oriented from the NW to the SE.

After reviewing the geologic history of South Carolina, the group of budding "Master Naturalists" partook in two interactive/engaging activities..."Match the Mammal Skulls/Which One is Not a Mammal?" and Which One Is Not a Fossil?"

What is a Fossil? The remains of an organism, preserved over time and is at least 10K years old. All but two of the following are fossils. Guess what each item is: