Rockhounding and Prospecting in the Southwest Thomas Farley
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Rockhounding and Prospecting in The Southwest Thomas Farley Copyright Page Dedication To The Best Parents a Son Could Ever Have Acknowledgements Special thanks to Linda Dodge, Summer Wintemberg, Donna Pollard, Rolf Luetke, Drew Barkoff, Bryan Smalley and Sharon Artlip. The dozens of my other helpers are mentioned at various places in this book. My appreciation cannot be expressed in words. Introduction Welcome to rockhounding and prospecting in the Southwest. This book introduces exploring, discovery, and collecting of all things rock related. It is not a gem trail guide, rather, this title accompanies, makes practical, and expands on those guides. Most importantly, it outlines the tools needed for the rockhound to make their own guide, current every time. This book demonstrates the map and vehicle skills needed to get to traditional collecting sites but it goes beyond that. It shows how to find new places and different materials old guide books don’t mention. Few guides describe variscite, rare earth minerals, pegmatite rock, or unusual rocks in general. This book does. The great hope is for this title is to go further than any guide, to let the rockhound or prospector find their own path to discovery and joy. Working Table of Contents Introduction Ecology Climate Geographical Provinces and Notable Features The Colorado Plateau Province The Great Basin Basin and Range Province The Higher or Great Plains Province The Rio Grande Rift Province The Southern Rocky Mountains Province New Mexico’s Mogollon-Datil Volcanic Field Southern California’s Peninsular Ranges Province Southern California’s Transverse Ranges Province Arizona’s Transition Zone Province Utah’s Transition Zone Province Map and GPS Essentials Locating Open Ground Traveling the Southwest Rocks Explained Rock and Mineral Identification Assay and Test The Southwest’s Top Ten Materials to Collect Chalcedony: Agates, Jasper, and Related Copper Minerals Fluorescent Materials Fossils Gold Petrified Wood Rare Earth Minerals Rocks Radioactive Minerals Turquoise and Variscite Places to Visit or Collect Arizona Southern California Southern Colorado Southern Nevada Southern Utah New Mexico Lapidary Work Must Attend Southwest Rock Events Collecting Rules on Public Lands Recommended Reading The Ecology “Ecology is the study of the relationships between plants, animals, people, and their environment, and the balances between these relationships.”1 In the Southwest, the element binding plants, animals, and people is the lack of water. Nevada is the driest state in the Union with Utah ranking second and Arizona fourth. The coyote, the creosote bush, and the prospector must all cope with limited water. Heat is a troublesome agent, though less so across the entirety of the Southwest. Arizona is hottest within these six states, but only tenth hottest in America. Average state-wide temperatures mislead. Temperatures of the Southwest’s deserts are higher than a state’s average. The greater Southwest contains a whole or a part of the Great Basin Desert, the Mojave, the Sonoran, the Colorado, and the Chihuahuan. The Sonoran Desert is warmest. Temperatures there routinely exceed 104° in the summer, while rarely falling below 32° in the winter. Frosts usually last no more than twenty-four hours.2 But water is always the paramount consideration. In every desert example, evaporation exceeds precipitation. The Southwest hosts a rich variety of plant communities and animal habitats. These associations or biomes cross deserts, forested mountains, and open range. Creosote bush scrub, Joshua Tree woodland, and Great Basin sagebrush are just some vegetation types. Depending on the animal, habitat exists within a vegetation type. Take the roadrunner, the signature bird of the Southwest. It may populate biomes described as Interior chaparral, Semi- desert grassland, or Madrean evergreen woodland. Or the broadest of biomes, the Desert biome. The Grand Canyon is the Southwest’s outstanding physical landmark. Equaling that celebrity, however, are the native plants inhabiting the Southwest. The Mojave Desert’s Joshua tree, the Sonoran’s Saguaro cactus, and the creosote bush inhabiting both, mark the desert as much as any single natural wonder. Animals announce the Southwest as well. The roadrunner, the javelina, and the desert tortoise are its trademark animals, any one of them proclaiming that, if you have not yet arrived in the Southwest, you are getting close. Not all is sand and sweat. New Mexico, for example, has five national forests. Arizona has six, making up 15% of that state. Pines proliferate there, the Ponderosa, the Chihuahua, and the Apache Pine all represented. Mixed oak and pine forests populate mountains in both states. In southern Nevada, the Spring Mountains sports a diversity of plant life, with 37 kinds of trees reported. That includes gnarled Bristlecone Pines, some thousands of years old. The Southwest is a land of thin shade even under broadleaf trees. Here, cottonwood, desert willow, and ash, where they do exist, occur mostly as separately spaced individuals, rarely forming dense groves. Less known but vital is the temperate forest biome of the Southwest. In the Sonoran Desert, above 6,000 feet, pines, firs and spruces clothe the landscape. Broadleaf trees such as Gambel Oak, Quaking Aspen, Maples, and Boxelders compete to make an understory for this coniferous forest.3 At lower elevations, Pinyon-juniper woodland covers millions of acres throughout the mountains of the Southwest. Sky Islands are distinct plant and animal communities found in isolated mountain ranges in the Southwest. Over geologic time a sea of desert formed around these scattered mountains. This left plants and animals to develop in different ways than their brethren on contiguous ground. This book arbitrarily draws a line across southern Nevada, Utah, Colorado, and California. It is impossible, therefore, to estimate how much forest occurs in these subjectively designated areas. The conclusion, however, is inescapable: the Southwest is not all dune and rolling desert. Trees grow here, too, enough in fact to support a vibrant forest environment and even a small logging industry.45 Man has had and continues to have a major impact on the land. Non-native plants and animals introduced by visitors and settlors impoverished range land which is still overgrazed. Mining and cities have drawn down water resources at a non-sustainable rate. Even damming the Colorado River hasn’t secured enough water to satisfy the Southwest’s population. Yet it is because of mining and cities and agriculture that prosperity has come to the desert. This impact on the ecology started simply enough. The region’s indigenous population had little impact on the land. Hunting and gathering were occasionally supplemented by raising crops. These were principally beans and corn, sometimes watermelons, irrigated by creeks and other naturally flowing water. This agriculture allowed permanent settlements in some areas. Great cliff dwellings were built at some sites, the Southwest’s most noted architecture. People like the Hopis constructed adobe houses as well. Some Hopi villages or pueblos have been occupied continuously for 900 years. Fiercely independent and aggrieved of poor treatment by the Spanish and later Europeans, tribal groups resisted outside rule for centuries. This was particularly true in New Mexico. Eventually, all native groups were overcome. “Following the subjugation of the Apaches, waves of miners, ranchers, and farmers settled the area. Mining and ranching activities were economically linked in a ‘ranch-mine settlement complex’ wherein ranches developed around mining towns to supply the meat, timber, and fuel wood required by the mining operations. During this period, the "three C's," cattle, copper, and cotton (grown in irrigated fields along river courses), dominated the economy of the region.”6 Cattle grazes much of the Southwest, especially in Southern Nevada. 2,200 BLM grazing allotments on 13.5 million acres exist in New Mexico. Arizona has 770 BLM grazing permits over 11.5 million acres. Adding to water draw down and range impacts are wild burros and horses. They crowd out native animals and their historic waterholes. The future of the Southwest’s ecology is unsettled and will remain unbalanced as long as water demands exceed supply. The Climate of the Southwest Temperature The Southwest’s varied topography plays a key role in its climate. Few places in America possess a mix of arid desert, deep canyons, and forested mountains, often in sight of each other. This change in elevation, from low to high, is one reason precipitation and temperature vary so widely. Most think a drop of three degrees occurs for every thousand feet of elevation gained. Richard Harris notes in Hidden Southwest that the Grand Canyon’s North Rim sits at 8,297 feet. He maintains this spot is almost always 20 degrees cooler than at the level of the Colorado River below, which averages 2,200 feet.7 The same change is experienced between the desert floor of the Southwest and its mountains. Another reason for climate change is latitude — traveling toward the equator results in greater sunlight and higher temperatures. Expect a three-degree increase for every three hundred miles traveled south. Precipitation and humidity play roles in raising or lowering temperatures. This is immediately apparent when little moisture is in the air. With low humidity, the sun’s energy is redirected from evaporation to increasing temperature. When humidity is high, temperatures moderate in daily highs and daily swings. A northern Arizona city like Kingman may experience a 105-degree day, while at the same time a southern city like Tucson may only reach 95 degrees. That’s often attributable to greater humidity present in locations lower in latitude to the equator. Cloudy skies usually follow greater humidity, especially during the monsoon season. As a climatic blanket, cloudy skies retain heat throughout the night, compared to days when skies are open and clear. On those days, night time temperatures fall. A Land of Two or Three Seasons The Southwest is a generally warm land of two seasons.