Fluid inclusions are microscopic bubbles of liquid and gas that are trapped within crystals. As minerals often form from a liquid or aqueous medium, tiny blebs of that liquid can become trapped within the crystal structure or in healed fractures within a crystal. These small inclusions range in size from 0.1 to 1 mm and are usually only visible in detail by microscopic study. These inclusions occur in a wide variety of environments. For example they are found within cementing minerals of sedimentary rocks, in gangue minerals such as quartz or calcite in hydrothermal vein deposits, in fossil amber, and in deep ice cores from the Greenland and Antarctic ice caps. The inclusions can provide information about the conditions existing during the formation of the enclosing mineral.
Geography
地理科学（geography）是关于地球及其特征、居民和现象的学问。它是研究地球表层各圈层相互作用关系，及其空间差异与变化过程的学科体系，主要包括自然地理学和人文地理学两大部分。地理科学是一门既有坚实的基本理论、应用理论的基础性学科，又是一门与生产实践进一步紧密联系的应用性学科。
