阳光直射、室内遮阴和涂保护层对恐龙化石风化影响的模拟研究

Simulated Study on the Effects of Direct Sunlight, Indoor Shading and Protective Layers on the Weathering of Dinosaur Fossils

恐龙化石是地史时期保存在地层中的生物遗体或遗迹,一旦因自然原因或经人工发掘暴露地表后,则面临着严重的风化破坏问题,其中最严重的破坏因素主要是来自于太阳光照。化石长期遭受日照影响,周而复始,受热应力作用使化石表面产生裂缝,最终化石整体破碎。化石受热情况不同,包括阳光直射、室内遮阴和化石表面涂保护层三种不同情况下受热。该文从这三种不同情况出发,通过数值模型对化石及围岩对温度的敏感性进行分析研究。研究发现,阳光直射时温度梯度大小和温度梯度产生的温度应力远远大于室内遮阴和涂保护层后的温度梯度和温度应力;不涂保护层,化石部分温度梯度和温度梯度产生的温度应力大于涂保护层温度梯度和温度应力。

Dinosaur fossils are biological remains or relics preserved in the stratum during geological history.Once exposed to the surface due to natural reasons or artificial excavation,it will face serious weathering problems.The most serious damage factor is mainly from the sunlight.The fossils have been affected by sunshine for a long time,and they start again and again.Thermal stress causes cracks on the surface of the fossils,and finally the fossils are broken as a whole.Fossil heating includes direct sunlight,indoor shading and a protective coating on the surface of the fossil.From these three different situations,the sensitivity of fossils and surrounding rocks to temperature has been studied by numerical model.It is found that the temperature stress produced by temperature gradient in direct sunlight is much larger than that produced by indoor shading and protective coating;without protective coating,the temperature stress produced by temperature gradient in part of fossil is larger than that produced by temperature gradient and temperature stress in protective coating.