Treść książki

Przejdź do opcji czytnikaPrzejdź do nawigacjiPrzejdź do informacjiPrzejdź do stopki
22
abilityaffectedtheexistenceofprehistoricPueblosocietieslivingthere(Glowacki2006:
15).However,therearesomegeneraltendenciesinthenaturalenvironmentthatare
representedby,forexample,similaroraandfauna,geology,andgeomorphology.Of
course,thedistributionofthesefeaturesdoesvaryacrosstheregion(Glowacki2006).
Generally,theMesaVerderegionisnotasdryastheotherareasoftheSouthwest,pri-
marilybecauseitliesatarelativelyhighelevationandisfarthernorththantherestofthe
Southwest(Cordell1997).TheMesaVerderegionislocatedin"acold,middlelatitude,
semiaridclimate,inwhichpotentialatmosphericevaporationregularlyexceedsthe
amountsofprecipitationavailable”(AdamsandPetersen1999:23;seealsoVanWest
andDean2000:20–21afterTrewartha1954:267).
Geologically,theMesaVerderegionincludesmainlyDakotaSandstone,Mancos
Shale,Summerville,Dolores,Entrada,andMorrisonformations,althoughthereisvari-
abilitywithintheregionintermsofthedistributionandexposureofthoseformations.
DakotaSandstonewasagoodsourceofbuildingstoneusedcommonlyfortheconstruc-
tionofdwellingsbyancientPueblopeople,andtheMorrisonFormationprovidedraw
materialformakingstonetools(AdamsandPetersen1999:21).
WithinthemorerestrictedareathatconstitutesthecentralMesaVerderegion,the
naturalenvironmentisgenerallyhomogeneous,althoughtherearesomeimportantvari-
ations.Differencesinelevationaffectedprecipitation,angleandavailabilityofsunlight,
lengthofthegrowingandharvestingseasons,distributionoforaandfauna,andother
characteristicsoftheenvironment.Thisregionhasarelativelyhighelevation,roughly
from1500to3200m(4500–9600ft.)abovesealevel.Thehighestelevationsoccurin
thewesternpartoftheregionandalsointheeasternpartinMesaVerdeproper(ap-
proximatelytheareaofMesaVerdeNationalParkandUteMountainUteTribalPark).
MostoftheprehistorichumanhabitationinthecentralMesaVerderegionoccurredbe-
low2500m;maizeagriculturewouldnothavebeenpossibleathigherelevations(Adams
andPetersen1999;Erdmanetal.1969:57).
InmanyplacesinthecentralMesaVerderegiontherearecanyonswithsteeptalus
slopes.Manyrockoverhangsoralcovesarepresentinthesandstoneclifffacesofthe
canyons.Long-termerosionalprocessescreateduniquegeographicfeaturessuchascan-
yonsandmesas(Griffitts1990).AlcoveswerechosenfordwellingbyancientPuebloans
overavastperiodoftimebutespeciallyduringthethirteenthcenturyA.D.(Varienetal.
1996:98).CliffdwellingsarelocatedinMesaVerdeNationalParkaswellasinother
areasofthecentralMesaVerderegion,forexample,intheSandCanyonlocalityandin
JohnsonCanyonontheUteMountainUteReservation.
Thedistributionofsoilsthathavepotentialforagriculturealsovariesacrossthearea.
Theirsuitabilityofaparticularsoilforagriculturedependsonfactorssuchastopogra-
phy,elevation,aspect,precipitation,availabilityofwater,temperature,andlengthofthe
growingseason(VanWestandDean2000:22).Theloamysoilsofferingthebestpoten-
tialforthecultivationofmaizeandothercrops,aswellasforforaging,areconcentrated
in,butnotlimitedto,theMcElmo-MonumentandtheMesaVerdeproperareas(Adams
andPetersen1999:33).Evidenceindicatesthatdry-landfarmingwouldbefavoredbe-
tween1824/1829and2195m(6000–7200ft.)elevation,whereasbelowabout1829m
(ca.6000ft.)thereisaneedforartificialwatermanagement(AdamsandPetersen1999:
33).Also,oodplainagriculturewouldhavebeenpossible,mostlyindrainagebottoms