17MB PDF - Association for Mexican Cave Studies

AreaNorth ofMonterreySouth ofMonterreySierra deGuatemalaSierra deEl AbraXllitlaGuerreroHuautlaCHARACTERISTICS OF SELECTED MEXICAN KARST AREASRainfall, Temperatureand VegetationRelief and ErosionKarst Features10-20 in/yr, s~er showers 5000 ft, narrow ranges Little surface expression, some etchingand karren in mts, no closed de­average temp 68 Frapid mechanical erosiondesert scrub, oak in mts.pressions, infrequent caves usuallyunmodified deep phreatic rooms, springsat base of range.10-40 in/yr, su~er showersaverage temp 60 F-68 Fwoods in mts.30-80 in/yr, well-distributedfrom June to Sgpt.average temp 64 o F-68 Fforest in mts.35 in/yr, showess June-3eptaverage temp 70 Fbrush30-100 in/yr, well-distributedfrom June to Sept.average temp 63 0 F to 70 0 Fdense forest25 in/yr, showers June-Aug.average temp 68°Fbrush50-90 in/yr, well-distributedfrom June to Aug.average temp 65 0 F to 70 0 F10,000 ft, massive rangesrapid mechanical erosion6000 ft, massive rangerapid chemical erosion1000 ft, cuestamoderate chemical erosion7000 ft, massive rangerapid chemical erosion2000 ft (1000 ft in limestone)mechanical erosion8000 ft, massive rangerapid chemical erosionLittle modification of surface, noclosed depressions except in gypsumareas, karren in mts, infrequent deepphreatic caves, area of well-scatteredsprings.Some surface modification with a fewclosed depressions, numerous sinks,well-developed karren and karst pinnaclesin higher areas, caves mostlyvadose with shallow phreatic developmentat lower levels, resurgences atbase of range.Some surface modification with a fewshallow depressions, karren common,frequent disappearence of arroyos, numerouscaves mostly large horizontalshallow phreatic passages, resurgencesat base of range.Much surface modification; numeroussinkholes, uvalas, pits, haystack hills,caves; karren and karst pinnacles; cavesmostly vadose except at lower levels;resurgences at base of range.Buried karst terrain being uncoveredand rejuvenated, much surface modification,large blind valleys and sinkholes,few pits or small depressions, cavesformed during previous karst cycle.Extreme surface modification, blindvalleys, dry valleys, sinks, pits, karrenand karst pinnacles, runoff fromimpervious rocks to west, resurgencesat base of range.