Cenozoic Era Geology of New England

1 cenozoic era

1.1 paleogene period
1.2 neogene period
1.3 quaternary period
1.4 surficial deposits

1.4.1 erosional processes
1.4.2 pleistocene epoch
1.4.3 holocene epoch

cenozoic era
paleogene period

neogene period

quaternary period

much of geomorphology , surficial deposits of new england result of glaciation in quaternary period. scoured new england landscape reveals evidence of wisconsin glacial period. 

surficial deposits

the continental ice sheet on new england more mile thick in places. grinding , plucking on landscape created wore down topography , created poorly sorted sorted surficial deposits. large terminal moraines composed of poorly sorted till present along coasts , can identified thin, patchy, , stony texture . maine bordered moraines identify terminus margins of past ice bodies. waldoboro terminal moraine sits on southeastern coast, while highland front moraine parallels northwestern border. large continental ice sheets (see laurentide ice sheet) created large moraines, takes time long, lumpy ridges form @ massive scale .

new england best known high density of erratics, displaced rocks differ immediate bedrock composition of region , range size of pebbles boulders. surfaces rounded , polished due rasping. while bedrock of area largely igneous granite, erratics sandstone , slate blocks . sedimentary erratics visible across highest peak in maine, mount katahdin.

glacial outwash sorted , stratified due systematic nature of stoke’s law visible in gravel pits in maine s grafton notch state park outwash plains composed of alternating layers of sand , gravel have been deposited in deltas of glacial lakes , alluvial fans.

erosional processes

the slow , grinding movement of continental ice sheets , alpine glaciers across landscape creates erosional landforms. abrasion, plucking, , freeze-thaw action creates u-shaped valley unique glacial erosion.

the intense pressure ice causes abrasion. process carves striations, or grooves, bedrock glacier moves down slope. glacial striations determine direction of glacier; visible outcrops in white mountains, instance, indicate ice flow toward south-southeast . abrasion produces rock flour visible in glacial outwash plains across new england.

maine has of longest eskers in world . climate began warm, glaciers began melt , drainage meltwater under glacier formed huge torrents of sediment that, when compacted, left long , sinuous ridge or kame. moose cave in grafton notch speculated have been formed in part subglacial river . abol esker in baxter state park notable serpentine kame.

kame , kettle topography commonplace across maine. hummocky morphology includes kettle ponds , kettle lakes “steep-sided, bowl-shaped depressions in glacial drift deposits” large blocks of ice melted glacier recessed.

other notable glacial features include cirques. mt. katahdin , bigelow range have circular divets indicative of glacial erosion.

pleistocene epoch

holocene epoch

following glacial melting of laurentide ice sheet, new vegetation , warmer climate caused new new england become inhabitable human settlers. new climate, combined ample supply of hard volcanic rock , other natural features, created ideal area human settlement. these settlers fashioned tools, such arrowheads, surficial rhyolite deposits found near have been river valley settlements.

the white pine rose in new england shortly after first deglaciation.

the melting of laurentide ice sheet (beginning 18,000 cal yr bp), covered new england landscape until late pleistocene era, caused significant ecological , climatic change in region. except number of abrupt climate reversals, extreme being cold reversal of younger dryas, climate of region experienced rise in temperature (of 2˚ celsius) during holocene. fossil pollen findings indicate increased temperature in region paralleled new vegetation patterns, such rise of hemlock , white pine in new hampshire , white mountains. these vegetation shifts created ecological environments in region habitation migratory caribou, hunted human settlers, possible. these settlers have moved formed dune fields, produced wind erosion of glacial outwash deposits, such found in ohio valley, in hudson , connecticut river valleys, , in israel river valley. human settlers have populated these river valleys in order observe caribou migrating northeast along newly formed rivers.