![]() Thus, occurrence of these features suggest MAT was some 7 degrees to 8 degreesC below that of today during their formation. Such wedges may develop either in the active layer above discontinuous or sporadic permafrost or beyond the permafrost limit in areas where mean annual temperature (MAT) is near 0 degreesC. Size and characteristics of the wedges most resemble those of seasonal frost cracks (primordial soil wedges) formed by intense frost action and/or a combination of frost action and dessication. These features are smaller than most periglacial (sand and ice) wedges formed in continuous permafrost and larger than most dessication cracks. Sand-filled soil wedges developed in buried soils at two sites near Flagstaff, Arizona, are 13- to 30-cm wide at the top, 50- to 80-cm deep, and form nonsorted polygons about I to 1.5 m in diameter. Data for the local vegetation community and sloth diet from 12,900 years ago indicate that during this late glacial time, the region was still a pinyon-juniper woodland but also contained Celtis, Quercus, and Larrea, among other taxa. The dung contents indicate that the diet of the sloth included C3 and C4 grasses along with Agave. The local community at 30,800 calibrated years ago was a pinyon-juniper woodland with yucca, sandpaper bush, globemallow, cactus, and barberry in the understory based on the packrat midden from the cave. Two areas within the cave provide radiocarbon dated ground sloth dung and packrat midden macrobotanical remains which permit the reconstruction of the sloth diet and local biotic habitat at 30,800 and 12,900 calibrated YBP. During excavation of the cave, packrat middens and sloth dung were discovered. The cave is one of only twelve known Nothrotheriops dung localities. Spirit Eye Cave in the Sierra Vieja along the Rio Grande provides the newest evidence that the Shasta ground sloth inhabited further south in the mountains of the southwestern Trans-Pecos, Texas, than has been previously documented. We present new information about the Late Pleistocene Shasta ground sloth (Nothrotheriops shastensis). Rich deposits of fossil bone can develop either through the accumulation of remains associated with organisms inhabiting the cave, such as Neotoma (packrats), or through a variety of transport mechanisms. Pleistocene and Holocene vertebrate remains are abundant in many caves. Caves, sinkholes, solution tubes, and other karst features attract and can trap animals. Caves also form as the result of lava flows (lava tubes), wave action (littoral caves), and by the fracturing of rock (earth cracks).Ĭave feature development is documented from the Holocene back to the Eocene. Therefore, the fossilized remains of Paleozoic fauna are often the most common types of paleontological resource associated with caves. Paleozoic limestones constitute the parent rock in which many cave and karst features develop in NPS administered areas. ![]() Within limestones, the remains of marine invertebrateĪnd vertebrate fossils are typically preserved. These processes include the dissolution and erosion of sedimentary and evaporitic rocks, and later deposition of minerals from the dissolution process. Karst caves, and features within them such as stalactites and stalagmites, are formed by a variety of processes. Caves occur in both karst and non-karst areas. Cave-paleontological resources are identified in two categories: 1) fossils preserved within the cave-forming bedrock, and 2) fossils accumulated within the caverns, chambers, or other openings in karst systems. ![]() The inventory documented at least 35 park areas that preserved fossils within cave resources. In 1998, the National Park Service Geologic Resources Division initiated a servicewide inventory of paleontological resources occurring in association with these caves. More than 3,600 caves and karst resources have been identified in at least 79 units of the National Park System.
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