How a New Cenozoic Geology and Glacial History Paradigm Explains Topographic Map Drainage System and Erosional Landform Evidence: Elbert and Lincoln Counties, Colorado, USA

Abstract

Detailed topographic map drainage system and erosional landform evidence such as drainage route orientations, drainage divides, divide crossings (low points on drainage divides), erosional escarpments, and similar features in the east central Colorado Elbert and Lincoln County region are considered as pieces of a complex but solvable drainage history puzzle. A satisfactory solution to date has eluded investigators who have worked from the accepted Cenozoic geology and glacial history paradigm (accepted paradigm) perspective in which climatic and tectonic factors operating over long time periods lead to what might be considered to be a randomly determined regional drainage history. A new and fundamentally different Cenozoic geology and glacial history paradigm (new paradigm) in which immense and prolonged south-oriented continental ice sheet meltwater floods flowed across the Elbert and Lincoln County area which at that time was near the rising rim surrounding a thick continental icesheet created and occupied deep “hole”. Map evidence documents how northeast-oriented Republican River headwaters valleys eroded headward across must have been large southeast-oriented floods probably moving toward what at that time would have been an actively eroding and deep east-oriented Arkansas River valley head and how those massive southeast-oriented floods subsequently lowered the Colorado Piedmont surface before being beheaded and reversed when the deep northeast- and east-oriented South Platte River valley eroded headward to create in an identifiable sequence (from east to west) what are now long north-oriented South Platte River tributaries. New paradigm predicted massive and prolonged south-oriented meltwater floods flowing across what must have been a rising region explains much, if not all of the Elbert and Lincoln County detailed topographic map drainage system and erosional landform evidence.