Greenhouse earth existed 100 ma bp, but climate models and geological data disagree of the temperatures at the poles. discuss potential limitations of both.

What is the primary justification of the hypothesis that the early earth environment was void of oxygen? ( 2 points) data showing the concentrations of gases extracted from rocks fossil evidence regarding the origin of eukaryotes generally accepted atmospheric conditions molecular evidence based on evolutionary traits.

Say whether each of the following statements relates to the influence on weathering by rock composition, rock properties, or climate. 1.exposed rock in the mountains of alaska 2.a lack of fractures in an outcrop3.quartz is rarely affected by dissolution, hydrolysis, or oxidation4.high porosity (a large amount of space between grains in a rock)5.rocks on the coast of a tropical island6.minerals that dissolve in the presence of waterthe good earth/chapter 9: weathering and soils weathering ratesthe good earth/chapter 9: weathering and soilscompositional control1.weathering is faster in rocks composed of weaker material or material that is easily converted to weaker material (such as feldspars)2.weathering is faster in rocks made up of minerals that dissolve in water (salt, gypsum)3.weathering is slower in rocks made of resistant materials (quartz)rock property control1.weathering is faster in rocks that allow air and water in (porous, fractured)2.fractures are natural weathering surfaces3.igneous and metamorphic rocks generally have low porosity –do you think they are particularly susceptible to weathering

One of the brightest comets of the 20th century was comet hyakutake, which passed close to the sun in early 1996. the orbital period of this comet is estimated to be about 30,000 years. find the semi-major axis of this comet’s orbit. compare it to the average sun-pluto distance and to the distance to alpha centauri, the nearest star to the sun, which is 4.3 light-years distant.