Preliminary study on the relationship between temporal and spatial evolution of ecological landscape pattern and climate change in Xinjiang, China

Author(s):  
Xiaoling Pan ◽  
Xunbin Zeng ◽  
Jie Zhang ◽  
Qingdong Shi ◽  
Qing He ◽  
...  
1984 ◽  
Vol 24 (1) ◽  
pp. 377 ◽  
Author(s):  
B. P. J. Williams ◽  
E. K. Wild

An extensive sedimentological study of cores from the Permian Gidgealpa Group of the southern Cooper Basin has produced a new understanding of the relationship between the Tirrawarra Sandstone and the Merrimelia Formation. These two sequences were previously considered to be everywhere separated by a regional unconformity. This study has shown that the facies states, transitions and associations of both formations interdigitate so that typical 'Tirrawarra- type' fluvial deposits are present within glacigenic 'Merrimelia-type' sediments.The Merrimelia Formation was examined regionally in 29 cored wells. Typical facies occurring within the Formation include glaciofluvial outwash, extensive developments of subaerial and subaqueous diamictites, glaciolacustrine ripple-laminated sandstones and siltstones, and thick, monotonous mudrock sequences with clay-dominant rhythmite horizons.The Tirrawarra Sandstone was also examined regionally in 32 cored wells. Four major facies associations were identified within the Sandstone and indicate the temporal and spatial evolution of a fluvioglacial to predominantly fluvial depositional system. Locally the interrelationship between the Tirrawarra Sandstone and the Merrimelia Formation is clearly evident where basal outwash fan deposits of the Tirrawarra Sandstone are interbedded with typical Merrimelia lithotypes. The dominant, low-sinuosity fluvial channel sand facies of the Tirrawarra Sandstone is also an integral part of typical Merrimelia sediment patterns.The Merrimelia Formation and Tirrawarra Sandstone sediments are intimately related and illustrate the evolution of a predominantly glacigenic system into one in which fluvial processes dominate both in time and space. It is evident that no unconformity separates the two sequences and the inclusion of the Merrimelia Formation within the Gidgealpa Group is proposed.A distinct sedlmentological and stratigraphic identity has been assumed in evaluations of the hydrocarbon potential of the Tirrawarra Sandstone. The Merrimelia Formation has been considered generally non-prospective. This study indicates that potential exists for additional reservoirs of 'Tirrawarra type' to be locally developed within the Merrimelia Formation.


The Holocene ◽  
2017 ◽  
Vol 28 (5) ◽  
pp. 706-720 ◽  
Author(s):  
Yu Li ◽  
Lingmei Xu ◽  
Chengqi Zhang ◽  
Yuan Liu ◽  
Gengrui Zhu ◽  
...  

Studying past climate change has important scientific significance in exploring long-term climatic variability, assessing the nature and human’s contribution to climate warming, and predicting future climate change. Here, we presented a data synthesis of pollen records, organic geochemical proxies, as well as lake-level records, along with numerical climate classification and lake-level simulations to show temporal and spatial evolution of past vegetation and hydrologic change during the Holocene in China. Both geological data and numerical modeling indicated that the evolution of vegetation shows out-of-phase relationships with lake hydrological status in various regions. China as a whole experienced optimal vegetation cover in the mid-Holocene. However, areas dominated by the Asian monsoon and the Westerlies did not uniformly show an early Holocene hydrological optimum. For the Westerlies-controlled regions, optimal conditions prevailed during the mid-Holocene. These apparent contradictions were closely related to various driving factors in different geographical regions. Precipitation has been recognized as a major influence on lake hydrological status of arid and semi-arid in northeast China, whereas in other regions of China, the combined effect of evaporation and precipitation was more influential. Likewise, the limiting factor of vegetation conditions was asynchronous in China, for example, moisture in northwestern China, temperature in the Qinghai-Tibet Plateau, as well as moisture and temperature in the monsoon marginal zones and monsoonal regions. The results provide insights into the underlying climate-forcing mechanisms, and demonstrate a new perspective on Quaternary environment change research.


2012 ◽  
Vol 13 (4) ◽  
pp. n/a-n/a ◽  
Author(s):  
Gareth G. Roberts ◽  
Jonathan D. Paul ◽  
Nicky White ◽  
Jeffrey Winterbourne

1999 ◽  
Vol 148 (1-6) ◽  
pp. 1-16 ◽  
Author(s):  
MASSIMO ASTARITA ◽  
FELICE E. CORCIONE ◽  
BIANCA MARIA VAGLIECO ◽  
GERARDO VALENTINO

PLoS ONE ◽  
2011 ◽  
Vol 6 (9) ◽  
pp. e25278 ◽  
Author(s):  
Wei Gao ◽  
John H. Gilmore ◽  
Kelly S. Giovanello ◽  
Jeffery Keith Smith ◽  
Dinggang Shen ◽  
...  

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