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In the 150 years since Sternberg's Law of downstream fining was published, causes and complications have proliferated with research in many fluvial environments. The basic relationship is a first-order differential equation expressing an energy relationship, and the geologic causes and effects that fall under its umbrella are diverse. Grain size distributions of sands provide indications of modes of deposition, but gravels do not. However, while competence is seldom a limiting factor for sands, it is for gravels. The study area includes the low-relief Great Plains and the high relief of the Rocky Mountains. Island mountain ranges complicate this somewhat, but stream courses are sufficiently simple for Sternberg's Law. Most of the study area exhibits features generally believed to have resulted from Ice-Age glaciation. Catastrophic evidence in the form of planation surfaces is also present. Thus channelized flow, transport by ice, and sheet flow are all candidate processes for transport of gravel. Predictions of grain size distributions from these processes are compared with results from statistical analysis of 5,839 sieve analysis reports. The results indicate a complex history for the surficial gravel deposits. [ABSTRACT FROM AUTHOR]

Uniformitarian theories of Martian history present many problems. A Biblical alternative is proposed that includes the Day-4 cratering hypothesis and Mars' crustal magnetism. Greatly reduced magnetism in the centers of the four largest impact craters suggests that most large Mars impacts occurred during the Genesis Flood. These impacts, and subsequent volcanism generated by them, produced a climate with sufficient liquid water for the Martian floods. A young age for Mars is supported by several geological observations. Rapid flooding can explain the valley networks and the outflow channels and provide a tighter volume estimate of around a 100 m Global Equivalent Layer (GEL). The flood water was absorbed into the subsurface and into hydrated minerals. That temporary atmosphere disappeared as water vapor precipitated out and the atmosphere cooled. Precipitation also absorbed CO2 and SO2 which helps account for their atmospheric disappearance. [ABSTRACT FROM AUTHOR]

Martian outflow channels and valley networks raise six questions and the first four are addressed in this part: 1) how were outflow channels and valley networks carved, likely from water?; 2) Were the channels and valley networks eroded by a few catastrophic floods or many small flows?; 3) What is the origin of the water: groundwater, rainfall and runoff, or both? If groundwater, how was it recharged?; and 4) What is the quantity of water needed for erosion; estimates varying from 3 m to 5000 m GEL. Ultimately, did water come from impacts, volcanism, or both? [ABSTRACT FROM AUTHOR]