Part A: In your own words, summarize the key points of Chen et al., 2017; \"Magn
ID: 295110 • Letter: P
Question
Part A: In your own words, summarize the key points of Chen et al., 2017; "Magnetostratigraphy of deep drilling core 15YZK01 in the northwestern Qaidam Basin (NE Tibetan Plateau): Tectonic Movement, Salt Deposits, and their link to Quaternary Glaciation" and explain how magnetostratigraphy can be linked to tectonic movements, salt deposits, and Quaternary Glaciation. Do not include any quotations.
Part B: How can this work be applied to assess and understand Quaternary events outside the Qaidam Basin?
Explanation / Answer
A.
Chen et al., 2017 used one of the stratigraphy technique i.e magnetography to infer the information about the past. They performed paleomagnetic study of 1400m long drilling core to understand the upliftment of Tibetan Plateau. Using polarity sequence (geomagnetic polarity) they found 3 stages of high sedimentation rate of 4.1-3.207 Ma, 2.581-1.945 Ma, and 0.781-0.002 Ma over the study area, which leads to 4 stage of tectonic activity on the Tibetan Plateau( Qingzang Movement (3.6 Ma), the B phase of the Qingzang Movement (2.6 Ma), the Kunlun-Huanghe Movement (1.1-0.7 Ma) and the Gonghe Movement (0.15 Ma)). They also found that the Yiliping area alternated between semi-saline and saline lake environments, and salt deposits began to form at 0.733 Ma or 0.746 Ma. This is well correlated with Quaternary glaciations on the Tibetan Plateau.
The movement can understood very well using magnetic polarity, if any upliftment or downward motion occurs, this is well captured by the magntic minerals. During glaciation, temperature goes down and evaporation rate reduced as well, as a result, the water supply get reduced and salt deposit has been found.
B.
The similar conditions can be found in differnt basin in the world. This can be correlated well with that studies. Also the methodology they developed can be used to assess information from other place too. Since quaternary is very recent period of few kiloyears, and major tectonic changes is very less, this study can alos give some first hand explanation of the similar type of geological formation around the world.