Geology 1110 Midterm

About when did the "explosion of life" occur and what percent of geological time had already passed by the time this "explosion" occurred?

-541 million years ago -87%.

Pick out one of the Ediacaran fauna, name it, and discuss what it may have been and how it lived during Neoproterozoic.

-Dickensonia -Considered an annelid worm -Similar to one genus of extant Polychaeta -Some say its a Soft bodied version of the banana coral -It lived like fungi do

Briefly describe the fossil record for Mesoproterozic. Mention specific fossils by name and other details.

-Eukaryotes - Maximum Stromatolites - Possible Primitive fungi - Horodyskia

Briefly describe the fossil record for Paleoproterozic. Mention specific fossils by name and other details.

-Gowganda Glacial Deposits -Multi-cellular algae -Gunflint fossil Prokaryotes -Gunflint chert Eukaryotes -Banded Iron formations

When (how long ago) were the five great mass extinctions of life on Earth?

-Late Cambrian - 485 Million years ago -Late Ordovician - 444 Million years ago -Late Devonian - 359 Million years ago -End-Permian - 252 Million years ago -End-Triassic - 201 Million years ago -End-Cretaceous - 66 Million years ago

Briefly describe the fossil record for Neoproterozic. Mention specific fossils by name and other details.

-More diverse Eukaryotes including acritarchs - Many Metazoans or multicellular animals with soft bodies - Some had tiny calcium carbonate tubes or shells - Some left burrows in the sediment

What may have been the effect(s) of the great oxygenation event for life on Earth?

-One of the most significant climate event in earth's history -Set the earth's atomosphere at the time off balance -Allowed a whole new kind to evolve - Oxygen made organisms more active and larger -Made complex life possible

Briefly describe Alabama's Paleozoic fossil record, both land and marine fossils.

-Paleozoic invertebrates -marine fossils include fish, sharks, snails, clams, sea urchins, oysters. -state fossil, Basilosaurus cetoides, prehistoric whale -Alabama is home to one of the best Pennsylvanian trace-fossils sites on the globe, which is the Stephen C, Minkin Paleozoic Footprint Site -Here, reptiles' and amphibians' tracks are showed on the Paleozoic sandstone.

What ages of rock are exposed on the surface in Alabama and in what provinces are the different ages of rock exposed on the surface?

-Paleozoic: Piedmont , Valley and ridge Province, Appalachia plateau, interior low plateau. -Mesozoic: Upper Coastal Plain -Cenozoic: Lower Coastal Plain

In a few sentences, how is the geological time scale related to the history of life on Earth (the fossil record)?

-The fossil record is how the geological time scale was created -Geologists saw that certain fossils were found in specific rock strata from different time periods -For example, dinosaur fossils were found in the rock strata from the Jurassic time period

How might life have developed and where might it have developed on Earth during Archean?

-There are two main hypotheses about where Archean life may have come from -building blocks of life arrived by comets and/or asteroids striking the earth. -The second one is the building blocks of life form in oceans or lakes as a result of external input of energy. -Life may have developed In early oceans or lakes. -may have developed in early Earth's volcanic vents or within the crust itself.

Of the readings in the Encyclopedia of Alabama, which article or topic interested you the most? Briefly summarize this article and the things you found most interesting in it.

-Wetumpka Crater the most interesting. -Maybe because my professor is in it! -Anyways, this article is about the cosmic object that struck Elmore County. -At this time, Alabama was underwater. -The impact was the greatest natural disaster in Alabama history! -It produced an earthquake, tsunami, and much more destructive events. -The energy released was 175,000 times greater than an explosion of an atomic bomb. -This crater was not proved to be the result of an asteroid until 1999. -Today, the crater host lectures and tours which I believe would be very interesting to see.

Briefly describe what is a stromatolite and what is the significance of the symbiotic relationship that existed (and still exists) in these odd structures. How did they change the atmosphere during Archean?

-large oxygen emitters -They were an organic and sediment structures built by photosynthetic cyanobacteria or blue-green algae living in convert with bacteria. -The Archean atmosphere lacked free oxygen -Since these stromatolite were oxygen emitters, they created a significant symbiotic relationship between many other organisms

Does Alabama have any Archean bedrock? If not, what age of old bedrock lies beneath part of our state?

-no -Alabama's bedrock is made out of carbonate rocks form the Paleozoic era.

What factors favor fossil preservation of some part or trace of a dead organism?

-preservable parts including bones, shells, teeth and wood. -must be buried by sediment to protect itself from scavengers and decay - the fossil must escape physical, chemical and biological destruction after it is buried.

Briefly, what is a biozone and what is its significance?

-short for a biostratigraphic zone -body of rock deposited during the time interval when an index or key fossil organism existed -. They are the basic unit for biostratigraphic correlation.

What are the main biotic groups that appear as fossils during Archean?

Algal filaments and bacteria microbes

Briefly describe the fossil record for Cambrian and Ordovician in Alabama. Mention specific fossils by name and other details like locations.

Cambrian: -The earliest fossils appear in Alabama rocks. -Some of those fossils include trilobites which are found in Cambrian Conasauga formations in Cherokee county. -Another fossil from Cambrian includes the Brooksella or "star cobbles" Ordovican: - During Ordovician, the tropical seas covered most of the state. -Some fossils in this time included cephalopod which are found in Chickamauga Limestone found near Ft. Payne. -Brachiopods were found here as well.

What are the time spans for the Hadean and Archean and what were the main events in this early span of Earth history?

Hadean- 4.56 billion years ago and ended about 4.0 billion years ago. -the formation of Earth's core -formation of Earth's moon. Archean - 4 Billion to 2.5 billion -Earth's oldest rocks (pieces of continents) are Archean. -Oldest rock formation, AcastaGneiss, Canada; 4.04 b.y.

4. Take a look at the paleogeographic maps for Cambrian and Ordovician and describe where Alabama was during those times. Then, mention how the types of marine fossils relate to the ancient Alabama environment of those times.

In Cambrian, -Alabama was much more south than it is presently. -It was found on passive margin of ancient North American continent Laurentia. -Due to the shallow water around, the marine fossils were mostly stromatolites. In Ordovician, -tropical seas covered most of the state. -This caused many reef fossils to be found in -Alabama including brachiopods, sponges, and cephalopod fossils.

Take a look at the paleogeographic maps for Mississippian and Pennsylvanian and describe where Alabama was during those times. Then, mention how the types of land and marine fossils relate to the ancient Alabama environment of those times.

Mississippian: -Lower Alabama was land while upper Alabama still was under water with a few barrier islands up near Huntsville. -This time was filled this limestone deposits due to the marine shelfs. -Due to half being in water and half not, their was a very diverse fossil record in this time. -The sea floor consisted of "crinoid gardens" which are now found in Joe Wheeler State Park in Lauderdale County. -Many shark teeth are found in the Mississippian limestone as well. -For the land, many fossils of primitive land plants are found in Tuscumbia Pennsylvanian: -This was the coal age for Alabama. -Pretty much all of Alabama was land but a little up in the north west was still underwater. -The northern part was mostly coal swamps leaving many fern trees, sphenophytes, cordaites, and lycopods.

Briefly describe the fossil record for Mississippian and Pennsylvanian (marine and land). Mention specific fossils by name and other details like locations.

Mississippian: -Widespread limestone deposited. -The sea floor consisted of "crinoid gardens" which are now found in Joe Wheeler State Park in Lauderdale County. -Many shark teeth are found in the Mississippian limestone as well. Pennsylvanian: -Known for its coal beds. -Many ferns and trees were present as well. -For example the stem pith casts of cordites tree are found in Fern springs Marion County.

What ages of rock are not found in Alabama at all or are only found below the surface?

Permian Rocks are not found in Alabama.

Briefly describe the main physiographic provinces of Alabama

Piedmont Province: The Piedmont Upland occurs as a triangular area in east-central Alabama and includes such cities as Ashland in Clay County, Heflin in Cleburne County, and Phenix City in Russell County. Valley and Ridge Province: This province consists of many ridges and valleys including the broad valley of the Coosa River. Appalachian Plateaus Province: This province consists of three valleys with breached anticlines that cut through mostly flat uplands formed by sandstone. Interior Low Plateaus Province: This province consists of two valleys formed by limestone being eroded and a ridge between them formed on resistant sandstone. Coastal Plain Province: This province consists of the largest variety of landscapes. It includes plains, hills, cuestas, flatwoods, and a little of the Alabama and Black Warrior Rivers.

Briefly describe the fossil record for Silurian and Devonian. Mention specific fossils by name and other details like locations.

Silurian: -Silurian was when alabama was oxygen rich. -Plants and animals invaded Alabama. -Some fossils include brachiopods in Fort Payne. -Another cool fossil is the Silurian Eurypterid or "sea scorpion" Devonian: -"age of the fishes". -For example, the Eustenopteron which was the late Devonian lobe-finned fish.