本文關(guān)鍵詞： 坎特伯雷盆地 表層海水溫度 Mg/Ca 亞熱帶鋒遷移 古海洋環(huán)境　出處：《中國(guó)地質(zhì)大學(xué)(北京)》2015年碩士論文　論文類型：學(xué)位論文

【摘要】：本文以位于新西蘭南島中部坎特伯雷平原東南邊緣大陸架之下的坎特伯雷盆地(Canterbury Basin)為研究區(qū)。南阿爾卑斯山脈隆升所剝蝕的碎屑物質(zhì)為研究區(qū)的沉積提供物源,該研究區(qū)地處亞熱帶水團(tuán)(STW)和亞南極水團(tuán)(SAW)交接處,并靠近諸如亞熱帶鋒(STF)這樣的主要海洋鋒面,這些海洋鋒及洋流的存在也強(qiáng)烈地影響著沉積作用。加之研究區(qū)內(nèi)STF的遷移受區(qū)域海平面變化和氣候的雙重影響,因此該研究區(qū)成為探討STF及水團(tuán)的遷移與沉積過(guò)程之間關(guān)系及古海洋環(huán)境變遷研究的理想海區(qū)。本文選取IODP317-U1352B站位巖芯9H-18H(75-163.8m)段落進(jìn)行研究,通過(guò)浮游有孔蟲(chóng)Globigerina bulloides殼體的Mg/Ca比值重建研究區(qū)MIS6-12期(150-450ka)以來(lái)的SST變化,并結(jié)合粒度特征和有機(jī)碳含量等分析,共同探討研究區(qū)內(nèi)第四紀(jì)晚期以來(lái)的古海洋環(huán)境的變遷,得出以下結(jié)論:在150-450ka內(nèi),研究區(qū)內(nèi)的海平面變化主要是受區(qū)域沉積過(guò)程影響,并且區(qū)域沉積過(guò)程對(duì)海平面的影響與全球海平面變化的影響一致;海平面升降變化和氣候冷暖變化是研究區(qū)內(nèi)STF遷移的主要控制因素;研究區(qū)內(nèi)的古生產(chǎn)力變化主要受陸源營(yíng)養(yǎng)物質(zhì)供應(yīng)的控制,同時(shí)在一定程度上也受控于表層海水溫度(SST)的變化。在MIS7期、MIS11期和MIS9早期,氣候變暖,STF向海向遷移,SST較高,氣候變暖使得南阿爾卑斯冰川消融,河流入海的陸源輸入量增多,營(yíng)養(yǎng)物質(zhì)供應(yīng)充足,沉積速率高、沉積物粒度粗、表層生產(chǎn)力高;在MIS6期和MIS8期,氣候變冷,STF向陸向遷移,SST較低,氣候變冷使得南阿爾卑斯冰川消融減少,河流入海的陸源輸入量少,營(yíng)養(yǎng)物質(zhì)供應(yīng)不足,沉積速率低、沉積物粒度細(xì)、表層生產(chǎn)力低;在MIS9晚期,海平面上升,STF向陸向遷移,SST處于低值,此時(shí)粒度特征主要受到溫度影響,沉積速率低、沉積物粒度細(xì),陸源輸入量減少,營(yíng)養(yǎng)物質(zhì)供應(yīng)不足,再加之此時(shí)較低的SST值,表層生產(chǎn)力也低;在MIS10期,STF受海平面和氣候雙重影響而在研究區(qū)內(nèi)頻繁往復(fù)遷移,STW多次入侵研究區(qū),水體性質(zhì)變化十分強(qiáng)烈,SST波動(dòng)劇烈,陸源物質(zhì)的輸入量少,沉積物粒度細(xì),此時(shí)較高的沉積速率和較高的表層生產(chǎn)力主要受到較高的SST影響。
[Abstract]:The Canterbury Basin located below the southeastern margin of the Canterbury Plain in Central South Island, New Zealand, is used in this paper. The denudated debris material from the uplift of the Southern Alps provides a source of sediment for the study area. The study area is located at the junction of the subtropical water mass (STW) and the subAntarctic water mass (SAW) and is close to major ocean fronts such as the subtropical front (STF). The presence of these oceanic fronts and currents also strongly affects sedimentation, and the transport of STF in the study area is influenced by both regional sea level change and climate. Therefore, the study area is an ideal sea area for the study of the relationship between migration and sedimentary processes of STF and water masses and paleo-marine environmental change. In this paper, the core 9H-1 of IODP317-U1352B station is selected. 8H (. 75-163.8m) paragraphs are studied. The Mg/Ca ratio of planktonic foraminifera Globigerina bulloides shell was used to reconstruct the MIS6-12 phase of the study area (150-450 ka). The SST changes since then. Based on the analysis of grain size and organic carbon content, the changes of paleo-marine environment since the late Quaternary in the study area are discussed, and the following conclusions are drawn: within 150-450 ka. The sea level change in the study area is mainly affected by the regional sedimentation process, and the influence of the regional sedimentation process on the sea level is consistent with that of the global sea level change. The changes of sea level rise and fall and climate cold and warm are the main controlling factors of STF migration in the study area. The variation of paleoproductivity in the study area is mainly controlled by the supply of nutrients from terrestrial sources and to some extent by the variation of surface seawater temperature (MIS7). During the MIS11 period and the early period of MIS9, the climate warming (STF-STF) migrated to the sea with high SST, and the climate warming caused the melting of the southern Alps glacier and the increase of the terrestrial source input of the rivers into the sea. The nutrient supply is sufficient, the deposition rate is high, the grain size of the sediment is coarse, and the surface layer productivity is high. In the MIS6 and MIS8 phases, the cold climate is lower in the continental migration, the cold climate causes the melting of the southern Alps glacier, and the input of the rivers into the sea is less. The nutrient supply is insufficient, the deposition rate is low, the grain size of the sediment is fine, and the surface productivity is low. In the late stage of MIS9, the grain size characteristics are mainly affected by temperature, the sedimentation rate is low, the grain size of sediment is fine, and the input amount of land source is decreased. Insufficient supply of nutrients, combined with the low SST value at this time, the surface productivity is also low; During the MIS10 period, due to the influence of sea level and climate, there are frequent reciprocating migration and multiple intrusions in the study area, and the changes of water properties are very strong and the water bodies fluctuate violently. The higher deposition rate and the higher surface productivity are mainly affected by higher SST due to the low input amount of land-based material and fine grain size of sediments.
【學(xué)位授予單位】：中國(guó)地質(zhì)大學(xué)(北京)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：P731

【參考文獻(xiàn)】

相關(guān)期刊論文 前4條

1 陳萍,方念喬,胡超涌,丁旋;浮游有孔蟲(chóng)殼體Mg/Ca值——SST的替代性指標(biāo)[J];地球科學(xué);2004年06期

2 沈俊;施張燕;馮慶來(lái);;古海洋生產(chǎn)力地球化學(xué)指標(biāo)的研究[J];地質(zhì)科技情報(bào);2011年02期

3 盧汐;宋金明;袁華茂;李寧;;黑潮與毗鄰陸架海域的碳交換[J];地球科學(xué)進(jìn)展;2015年02期

4 劉秀明;李文寶;邢春穎;;MS2000激光粒度分析儀在沉積物分析中的應(yīng)用[J];實(shí)驗(yàn)技術(shù)與管理;2007年09期

相關(guān)碩士學(xué)位論文 前1條

1 張帥;西太平洋暖池核心區(qū)360ka來(lái)上部水體溫度和結(jié)構(gòu)演變[D];中國(guó)科學(xué)院研究生院（海洋研究所）;2013年

，

本文編號(hào)：1490651