graded bed sequences

简明释义

1. 粒级层序; 2. 粒级递变层序; 3. 序粒层序;

英英释义

例句

1.Researchers discovered graded bed sequences in the rock layers, suggesting a history of fluctuating water levels.

研究人员在岩层中发现了分级床序列，这表明水位波动的历史。

2.The study of graded bed sequences is crucial for reconstructing past geological events.

对分级床序列的研究对于重建过去的地质事件至关重要。

3.The presence of graded bed sequences can indicate a change in energy conditions during sediment deposition.

存在分级床序列可能表明沉积过程中能量条件的变化。

4.Geologists often study graded bed sequences to understand sedimentary processes in ancient environments.

地质学家常常研究分级床序列以理解古代环境中的沉积过程。

5.In the context of river systems, graded bed sequences help in analyzing the flow dynamics and sediment transport.

在河流系统中，分级床序列有助于分析流动动态和沉积物运输。

作文

In the study of sedimentary geology, one of the crucial concepts is the formation of graded bed sequences. These are layers of sediment that display a systematic change in grain size, typically from coarser material at the bottom to finer material at the top. Understanding graded bed sequences is essential for geologists as they provide insights into the depositional environments and processes that occurred over time. The process of sedimentation can be influenced by various factors, including water flow, energy levels, and the nature of the sediment being transported.The concept of graded bed sequences was first described by geologist John Wesley Powell in the late 19th century. He observed that these sequences often formed during events such as floods or underwater landslides, where a sudden influx of sediment is deposited. As the energy of the transporting medium decreases, larger particles settle first, followed by smaller particles. This phenomenon illustrates the principle of sorting, which is fundamental in sedimentology.In practical terms, recognizing graded bed sequences in the field can help geologists reconstruct past environments. For instance, if a geologist encounters a sequence of sedimentary rocks with a distinct grading pattern, they might interpret it as evidence of a river system that experienced varying flow velocities. Such interpretations can lead to a better understanding of ancient ecosystems and the climatic conditions that prevailed at the time of deposition.Moreover, graded bed sequences can also have implications for natural resource exploration. In petroleum geology, for example, the presence of graded beds can indicate the potential for hydrocarbon reservoirs. The fine-grained materials that cap a graded bed may serve as effective seals, trapping oil and gas beneath them. Therefore, the study of these sequences is not only academically interesting but also economically significant.In summary, graded bed sequences are an integral part of sedimentary geology, providing valuable information about past geological processes and environments. They illustrate how sediment is sorted and deposited under varying conditions and can aid in the exploration of natural resources. By studying these sequences, geologists can piece together the history of the Earth and gain insights into its dynamic processes. As we continue to explore our planet's geological past, the importance of understanding graded bed sequences will undoubtedly remain paramount in the field of geology.

在沉积地质学的研究中，一个重要的概念是分级床序列的形成。这些是显示出颗粒大小系统变化的沉积层，通常从底部的粗颗粒物质到顶部的细颗粒物质。理解分级床序列对地质学家至关重要，因为它们提供了有关沉积环境和随时间发生的过程的见解。沉积过程可能受到多种因素的影响，包括水流、能量水平和运输沉积物的性质。分级床序列的概念最早由地质学家约翰·威斯利·鲍威尔在19世纪末提出。他观察到，这些序列通常在洪水或水下滑坡等事件期间形成，在这些事件中，沉积物突然涌入并沉积。当运输介质的能量降低时，较大的颗粒首先沉降，然后是较小的颗粒。这一现象说明了排序原则，这是沉积学中的基本原则。在实际操作中，识别野外的分级床序列可以帮助地质学家重建过去的环境。例如，如果地质学家遇到具有明显分级模式的沉积岩序列，他们可能会将其解释为经历了不同流速的河流系统的证据。这种解释可以更好地理解古代生态系统及当时沉积的气候条件。此外，分级床序列还可能对自然资源勘探产生影响。在石油地质学中，例如，分级床的存在可能表明有潜在的碳氢化合物储层。覆盖在分级床上的细颗粒材料可能作为有效的封闭层，将油气困住在其下。因此，研究这些序列不仅在学术上有趣，而且在经济上也具有重要意义。总之，分级床序列是沉积地质学的一个重要组成部分，提供了关于过去地质过程和环境的宝贵信息。它们说明了在不同条件下沉积物是如何被分类和沉积的，并可以帮助探索自然资源。通过研究这些序列，地质学家能够拼凑出地球的历史，并获得其动态过程的见解。随着我们继续探索地球的地质过去，理解分级床序列的重要性无疑将在地质学领域中保持重要地位。