Geologic time scale

The first super-continent- Rodinia broke up and vertebrate life began to colonize the planet. (Ross, Whitmore, Gollmer, Faulkner, 2015). This era is broken up into six time periods: the Cambrian- characterized by the sudden appearance of , Ordovician- characterized by life moving out of the oceans, Silurian- invertebrates appeared, Devonian-the first vertebrates appear, Carboniferous- when coal beds were formed around

Geology of the Big Bend (Rocks) The only types of rocks found in Big Bend National park are Sedimentary (N.P). The specific names for these rocks are: limestones, shale and sandstones, clay, Lava Flow, Conglomerate, Marl, and Cherty Limestone are found in this park (N.P). These rocks were likely abundant throughout the park; when the area was covered by a salty sea during the Cretaceous period (N.P). The way how these rocks formed is by the results of pebbles being cemented together. Another way

earth has been around for 4.6 billion years, and over this time 99.9% of all of the species that have existed on earth have gone extinct. (Barnosky, et al) Palaeontologists characterize mass extinctions as times in Earth’s history when the Earth loses more than three-quarters of its species in a geologically short period of time. This has occurred 5 times over the past 540 million years, and scientists are now suggesting it is happening a 6th time. We are in the midst of a sixth mass extinction that has

tremendously. At one time all continents were conjoined and named “Pangea.” Through the billions of years organisms have developed to adapt to their environment or . Both the physical and living Earth have changed over time. Pangea and sea floor spreading is an example of how the physical Earth has changed. About 1 billion years ago, The United States of America was no where close to its current location as of today. How do we know that the continents have moved over time with seafloor spreading

the east and away from the San Andreas fault. (LiveScience) If you refer to Ch.7 page 228 in the textbook Earth Science, figure 7.25 illustrates where Earths landmasses may be 50 million years from now if present plate movements persist during this time

travelling into the rocks to be broken. Meanwhile, this equation can only be applied to a homogenous, isotropic medium but in real life, geologic media are hydraulically heterogeneous. For this case, times greater than t0(time at beginning) are considered because if the injection stops at t0, the earthquakes and tremors will gradually cease to occur. These times (t) also describe the propagation of a maximal pore pressure perturbation in the space. The surface here separates the domain which is still

Have we altered this planet for good? This question has stirred up a recent debate among environmental scientists and geologists regarding what our current time period should be called. The International Union of Geological Sciences claims that we are currently living in the Holocene epoch, which initiated following the Earth’s last ice age. According to some scientists, that statement is obsolete. These other experts claim that Earth is a human dominated planet and that our actions rival global

Responsible for Global Warming? The case for attributing the recent global warming to human activities rests on the following undisputed scientific facts: • Carbon dioxide (CO2) is a greenhouse gas that warms the atmosphere. • Since pre-industrial times, atmospheric CO2 concentrations have increased from about 280 parts per million (ppm) to over 380 ppm. Current concentrations of CO2 and other greenhouse gases are unprecedented in at least the last 650,000 years, based on records from gas bubbles

Geologic Background The volcano Mount Fuji is a large composite stratovolcano that has been alternating lava flows and pyroclastic flows throughout its history. The complexity of Mount Fuji is hidden by its simple conical shape. It is composed of three different cones that lie one on top of each other. The first to appear was Komitake about 400000 years ago, followed by Kofuji (Old Fuji) about 80000 years ago, and now the current Shinfuji (Young Fuji) about 11000 years ago. (Miyaji, 1992) According

constant bipedalism can be found in the fossil record. By accommodating the fossils proof with the geologic