The Vertebrate Paleontology of Cement Creek Cave, Colorado

科罗拉多州水泥溪洞穴的古脊椎动物学

• 批准号: 0819678
• 负责人: Steven Emslie
• 金额: $ 6.52万
• 依托单位: University of North Carolina at Wilmington
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-08-01 至 2012-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0819678&HistoricalAwards=false
• 关键词: Vertebrate; Paleontology; Cement; Creek; Cave

THE VERTEBRATE PALEONTOLOGY OF CEMENT CREEK CAVE, COLORADOSteven D. Emslie, David Meltzer, and David WebsterNSF Proposal #0819678In this study, we will complete detailed systematic identification and analysis (radiocarbon, stable isotope) of vertebrate fossils recovered from Cement Creek Cave, an important late Pleistocene locality in the Upper Gunnison Basin, Colorado. Preliminary work at this site in 1998 revealed an extremely rich paleontological record with abundant vertebrate and plant remains dating from before the last Ice Age, over 45,000 years ago, to more recent periods within the past 2000 years. The fossils from this cave are quite significant: no other high-elevation site in North America has produced a near-continuous record of fossil vertebrates that date before and after the last Ice Age (that peaked at about 20,000-18,000 years ago). Analysis of fossil shrews (Sorex spp.) and other taxa recovered in the 1998 excavations, including some species no longer found in Colorado or the Upper Gunnison Basin, indicate there were significant changes in the environment surrounding the cave over time ranging from tundra to subalpine forest to mixed sagebrush steppe environments. However, radiocarbon analyses also reveal there are large gaps in the cave fossil sequence, which seemingly correlate with episodes in glacial history. Whether those gaps are real is uncertain; so too are the questions of how far back the Cement Creek record might extend, and whether a more precise ecological and climatic sequence can be derived from this rich fossil locality. Consequently, in summer 2007 we reopened the area excavated in 1998 and expanded the original 1998 test pit to 1 x 1.5 m and excavated to a depth of 2.2 m in 5-cm levels. These more extensive excavations doubled the depth of the stratigraphic profile in the cave and added thousands more vertebrate fossils to the collections. This expansion also provided a richer assemblage of fossil material for additional analyses proposed here to explore and test hypotheses on climate change and small-mammal community structure and diet in the later Pleistocene and Holocene. Here, the fossils recovered from this new excavation will be sorted and detailed identification will be completed. Analysis of remaining unidentified material from the 1998 excavation also will be completed to provide a more thorough reconstruction of vertebrate communities and environmental change in the Upper Gunnison Basin since the Wisconsin Period. This research will be conducted with the assistance of three undergraduate students at the University of North Carolina, Wilmington, and one graduate student at Southern Methodist University. These students will be involved in field and laboratory research and will develop independent studies of the cave fossils using the scientific method and hypothesis testing. The students will benefit from advanced research experiences and training, will participate in museum visits for detailed analyses of fossil specimens, and will develop their skills at scientific investigation and writing. Matching funds from SMU will be used to involve the graduate student from that institution in this research and how it applies to the paleoindian record in the Upper Gunnison Basin. Public presentations, a web site, and exhibits of data from this project will advance public understanding on the value and importance of protecting archaeological and paleontological resources. The value of cave resources also will be stressed in these presentations.

THE VERTEBRATE PALEONTOLOGY OF CEMENT CREEK CAVE, COLORADOSteven D. Emslie, David Meltzer, and David WebsterNSF Proposal #0819678In this study, we will complete detailed systematic identification and analysis (radiocarbon, stable isotope) of vertebrate fossils recovered from Cement Creek Cave, an important late Pleistocene locality in the Upper Gunnison Basin, Colorado. 1998年，该地点的初步工作揭示了非常丰富的古生物学记录，其脊椎动物和植物的历史悠久，其历史可以追溯到45，000年前的上一个冰河时代之前，到过去2000年的最新时期。 这个洞穴的化石非常重要：北美的其他高海拔场所没有在上一个冰河时代之前和之后产生几乎连续的化石脊椎动物（大约20,000-18，000年前的峰值）。 在1998年发掘中回收的化石sh（Sorex spp。）和其他分类单元的分析，包括在科罗拉多州或甘尼森盆地上不再发现的某些物种，表明从山gra山到山gres山到亚丙泊森林到混合Sagebrush Steppe环境的洞穴周围环境周围的环境发生了显着变化。 但是，放射性碳分析还表明，洞穴化石序列中存在很大的差距，这似乎与冰川历史上的发作相关。 这些差距是否真实是不确定的；关于水泥溪记录可能会延长多远的问题，以及更精确的生态和气候序列是否可以从这个丰富的化石区域得出。 因此，在2007年夏季，我们重新开放了1998年发掘的区域，并将1998年的原始测试坑扩大到1 x 1.5 m，并在5厘米水平上挖掘到2.2 m的深度。 这些更广泛的发掘使洞穴中地层剖面的深度翻了一番，并在集合中增加了数千种脊椎动物化石。 这种扩展还提供了更丰富的化石材料组合，以供此处提出的其他分析，以探索和检验有关后来更新世和全新世的气候变化以及小型哺乳动物社区结构和饮食的假设。 在这里，将从本新发掘中回收的化石将进行分类，并将完成详细的身份证。 自威斯康星州时期以来，对1998年发掘的剩余未鉴定材料的分析也将完成，以提供更全面的脊椎动物社区和上冈尼森盆地的环境变化。 这项研究将在北卡罗来纳大学威尔明顿大学的三名本科生和南方卫理公会大学的一名研究生的协助下进行。 这些学生将参与现场和实验室研究，并将使用科学方法和假设检验对洞穴化石进行独立研究。 学生将从高级研究经验和培训中受益，将参加博物馆的访问，以详细分析化石标本，并将在科学研究和写作中发展他们的技能。 SMU的匹配资金将用于使该机构的研究生参与这项研究，以及如何适用于Gunnison Basin上的古印度唱片。 公众演讲，一个网站和该项目的数据展览将提高公众对保护考古和古生物学资源的价值和重要性的理解。 这些演示文稿也将强调洞穴资源的价值。