地质通报
地質通報
지질통보
GEOLOGICAL BULLETIN OF CHINA
2014年
10期
1635-1641
,共7页
赵信文%陈双喜%黄长生%曾敏%陈雯%董好刚%刘凤梅%黎义勇%邵磊%薛永恒
趙信文%陳雙喜%黃長生%曾敏%陳雯%董好剛%劉鳳梅%黎義勇%邵磊%薛永恆
조신문%진쌍희%황장생%증민%진문%동호강%류봉매%려의용%소뢰%설영항
珠江三角洲%沉积特征%有机碳同位素%古环境变化
珠江三角洲%沉積特徵%有機碳同位素%古環境變化
주강삼각주%침적특정%유궤탄동위소%고배경변화
Pearl River delta%sedimentary characteristics%organic carbon isotope%palaeoenvironmental changes
陈村剖面位于佛山市陈村镇。AMS 14C及OSL测年结果显示，剖面自晚更新世中晚期以来开始沉积，结束于全新世晚期，由老至新经历了河流相-河口湾相-三角洲相沉积环境。根据有机碳同位素曲线变化特征，结合孢粉、有孔虫等鉴定结果及沉积环境综合分析，将剖面划分为4个演化阶段：①晚更新世，34.15~24.5ka BP，属河流相沉积环境，δ13Corg平均值为-28.13‰，对应MIS 3期冷-稍湿气候，期间小幅波动；②晚更新世-全新世早期，24.5~9ka BP,属河流相沉积环境，δ13Corg平均值为-29.8‰,对应MIS 2期干冷气候及全新世早期温-干气候，YD事件得以记录；③全新世早-中期，9~6.7ka BP，属于河口湾-三角洲相沉积环境，δ13Corg平均值为-27.97‰，变化幅度小，对应暖-湿气候；④全新世中-晚期，6.7~0.44ka BP，属于三角洲相沉积环境，δ13Corg平均值为-26.94‰，变化幅度大，冷暖变化显著，气候特征为热湿-偏凉-暖干。
陳村剖麵位于彿山市陳村鎮。AMS 14C及OSL測年結果顯示，剖麵自晚更新世中晚期以來開始沉積，結束于全新世晚期，由老至新經歷瞭河流相-河口灣相-三角洲相沉積環境。根據有機碳同位素麯線變化特徵，結閤孢粉、有孔蟲等鑒定結果及沉積環境綜閤分析，將剖麵劃分為4箇縯化階段：①晚更新世，34.15~24.5ka BP，屬河流相沉積環境，δ13Corg平均值為-28.13‰，對應MIS 3期冷-稍濕氣候，期間小幅波動；②晚更新世-全新世早期，24.5~9ka BP,屬河流相沉積環境，δ13Corg平均值為-29.8‰,對應MIS 2期榦冷氣候及全新世早期溫-榦氣候，YD事件得以記錄；③全新世早-中期，9~6.7ka BP，屬于河口灣-三角洲相沉積環境，δ13Corg平均值為-27.97‰，變化幅度小，對應暖-濕氣候；④全新世中-晚期，6.7~0.44ka BP，屬于三角洲相沉積環境，δ13Corg平均值為-26.94‰，變化幅度大，冷暖變化顯著，氣候特徵為熱濕-偏涼-暖榦。
진촌부면위우불산시진촌진。AMS 14C급OSL측년결과현시，부면자만경신세중만기이래개시침적，결속우전신세만기，유로지신경력료하류상-하구만상-삼각주상침적배경。근거유궤탄동위소곡선변화특정，결합포분、유공충등감정결과급침적배경종합분석，장부면화분위4개연화계단：①만경신세，34.15~24.5ka BP，속하류상침적배경，δ13Corg평균치위-28.13‰，대응MIS 3기랭-초습기후，기간소폭파동；②만경신세-전신세조기，24.5~9ka BP,속하류상침적배경，δ13Corg평균치위-29.8‰,대응MIS 2기간랭기후급전신세조기온-간기후，YD사건득이기록；③전신세조-중기，9~6.7ka BP，속우하구만-삼각주상침적배경，δ13Corg평균치위-27.97‰，변화폭도소，대응난-습기후；④전신세중-만기，6.7~0.44ka BP，속우삼각주상침적배경，δ13Corg평균치위-26.94‰，변화폭도대，랭난변화현저，기후특정위열습-편량-난간。
The column section of Chencun drill hole is located in Chencun Village, Foshan, Pearl River Delta. Chronologically, the core was initially deposited at the middle stage of Late Pleistocene and ended in the Late Holocene, as shown by AMS 14C and OSL dating results. Lithostratigraphically, the core, from bottom upwards, experienced successive changes in order of fluvial estuary del-ta environments. Based on such an essential chronologic and facies framework and further multidisciplinary investigations, including organic carbon isotope, pollen, foraminifera and magnetic susceptibility studies, the authors subdivided the core into the following four stages: (I) Late Pleistocene, 34.15~24.5ka BP, which was fluvial, with mean value of δ13Corg-28.13‰PDB, corresponding to MIS 3, and was characterized by cold slightly wet climate with subtle fluctuations. (II) Late Pleistocene-Early Holocene, 24.5~9ka BP, with was fluvial, with mean value of δ13Corg-29.8‰PDB, corresponding to MIS 2, and was characterized by the conversion of dry-cold climate into warm-dry climate. The YD event was recorded. (III) Early-Middle Holocene, 9~6.7ka BP, which belonged to estuary-delta, with mean value of δ13Corg-27.97‰ PDB and a small isotopic variation, corresponding to the Holocene Mega Thermal wet hot climate. (IV) Mid-Late Holocene, 6.7~0.44 ka BP, belonged to delta, with mean value ofδ13Corg-26.94‰PDB and large amplitude of isotopic changes, and was characterized by remarkable fluctuation from hot-wet through slightly cool to warm-dry climate.
