概括
对石水化皮的分析揭示了不同的年龄组,与176,000年前的火山位和冰川事件相关. 这种方法可追溯黄石国家公园的地质构造.
科学领域:
- 地质化学 地质化学
- 地质时间学 (Geochronology)
- 冰川地质学的冰川地质学
背景情况:
- 黄石国家公园的奥比西悬崖提供了宝贵的地质记录.
- 化皮分析是一种用于测定火山玻璃和地质事件的年代的方法.
研究的目的:
- 为了分析来自Obsidian Cliff的黑石的水化皮层厚度.
- 为了将这些测量与已知的地质事件相关联,包括火山位和冰川化.
主要方法:
- 测量含水皮的厚度,在薄片的奥比西丹.
- 皮肤厚度与-测定和冰川摩伦的确定的日期进行比较.
主要成果:
- 确定了三组不同的水化皮肤,平均厚度为16.3微米,14.5微米和7.9微米.
- 最古老的皮层组 (16.3微米) 与176,000年前的木流位相对应.
- 较年轻的皮层组 (14.5和7.9微米) 与分别来自公牛湖和Pinedale冰川摩拉纳的黑色石相关.
结论:
- 水化皮的厚度为黄石地质事件的年代提供了可靠的代理.
- 裂和带有较年轻水化皮肤的表面表明,由于牛湖和皮内代尔冰川时期的冰川负载而形成.
相关概念视频
Hydration of Cement
Hydration of cement is a chemical reaction between cement particles and water. This process occurs primarily through two mechanisms: through-solution and topochemical. In the through-solution process, anhydrous compounds dissolve into their constituents, hydrates form in the solution, and then precipitate from the supersaturated solution. The topochemical process involves solid-state reactions at the cement particle surface. The through-solution process dominates the topochemical process at the...
Specific Gravity of Aggregate
Aggregates typically contain pores, which can be either permeable or impermeable. Considering the pores in the aggregates, the specific gravity of aggregates is defined in three different forms, namely, bulk or gross specific gravity, apparent specific gravity, and absolute specific gravity.
Bulk or gross specific gravity is calculated by taking the ratio of the mass of aggregates in the saturated surface-dry state to the total volume that includes both the solids and the voids within the...
Bulk or gross specific gravity is calculated by taking the ratio of the mass of aggregates in the saturated surface-dry state to the total volume that includes both the solids and the voids within the...
Porosity and Absorption of Aggregate
Aggregates contain pores of varying sizes; while some are completely enclosed within the particles, others open onto the surface, allowing water to penetrate. The porosity of aggregates is a major factor contributing to the overall porosity of concrete, given that aggregates constitute about three-quarters of concrete's volume.
When all pores in an aggregate are filled with water, the aggregate is considered saturated and surface-dry. If left in dry air, water will evaporate until the aggregate...
When all pores in an aggregate are filled with water, the aggregate is considered saturated and surface-dry. If left in dry air, water will evaporate until the aggregate...
Strength and Heat of Hydration
The hydration of cement is an exothermic reaction in which heat is generated as cement hydrates. This heat of hydration is critical to cement's strength development. The rate at which this heat is generated affects the temperature rise, with a majority of the heat being released early in the hydration process, half within the first three days, and about 75% within the first week.
The heat of hydration for each cement compound is significant; for instance, tricalcium aluminate (C3A) and...
The heat of hydration for each cement compound is significant; for instance, tricalcium aluminate (C3A) and...
Moisture Content and Bulking of Aggregate
The moisture content of aggregates is a crucial factor in construction, particularly in concrete mixing, as it influences the total water required in the mix. Moisture content represents the water coated on the exterior surface of the aggregate existing in a saturated and surface-dry condition. The total water content of a moist aggregate is the sum of its moisture content and water absorption.
When aggregates are exposed to rain or sit in stockpiles, they absorb moisture, which must be...
When aggregates are exposed to rain or sit in stockpiles, they absorb moisture, which must be...
Global Climate Change
Throughout its ~4.5 billion year history, the Earth has experienced periods of warming and cooling. However, the current drastic increase in global temperatures is well outside of the Earth’s cyclic norms, and evidence for human-caused global climate change is compelling. Paleoclimatology, the study of ancient climate conditions, provides ample evidence for human-caused global climate change by comparing recent conditions with those in the past.


