中国地质
中國地質
중국지질
CHINESE GEOLOGY
2014年
5期
1515-1521
,共7页
蔡向民%黄淇%张磊%白凌燕
蔡嚮民%黃淇%張磊%白凌燕
채향민%황기%장뢰%백릉연
温榆河%河流成因%活动断裂
溫榆河%河流成因%活動斷裂
온유하%하류성인%활동단렬
Wenyu River%origin of the river%active fault
提温榆河是北京平原北部一条重要的河流。温榆河两岸地质背景复杂,地质灾害严重。地质调查表明,温榆河的形成与演化与南口-孙河断裂密切相关,受该断裂的严格控制。经钻探发现,温榆河南口至百善一带最早的新生代沉积物产生于早更新世。说明温榆河的形成时间应是早更新世早期。温榆河在温榆河河谷内不断迁移,受断裂控制河床的迁移被限制在南口-孙河断裂的下降盘一侧。在南口至马池口一带因南口-孙河断裂上盘下降,形成了深达数百米的凹陷,沉积了巨厚的松散沉积物。在凹陷范围内长期存在一个湖泊,温榆河是该湖泊的泄水通道。在昌平区冷泉、辛庄、高里掌和辛力屯一带的广大地区,发现地下几米处见有含螺贝壳的泥炭层,似层状多层、延伸连续,厚度稳定可达数米。经测定,泥炭层底部14C年龄(9930±150) a,顶部泥炭层14C年龄约3 ka。说明该湖泊10 ka前湖水较浅,适合水生植物生长,随后湖水逐渐消退。湖水的完全消失距今不到3 ka的时间。说明温榆河的形成时代虽然很久远,但是河道不断变迁,今天温榆河的面貌还是很年轻的。
提溫榆河是北京平原北部一條重要的河流。溫榆河兩岸地質揹景複雜,地質災害嚴重。地質調查錶明,溫榆河的形成與縯化與南口-孫河斷裂密切相關,受該斷裂的嚴格控製。經鑽探髮現,溫榆河南口至百善一帶最早的新生代沉積物產生于早更新世。說明溫榆河的形成時間應是早更新世早期。溫榆河在溫榆河河穀內不斷遷移,受斷裂控製河床的遷移被限製在南口-孫河斷裂的下降盤一側。在南口至馬池口一帶因南口-孫河斷裂上盤下降,形成瞭深達數百米的凹陷,沉積瞭巨厚的鬆散沉積物。在凹陷範圍內長期存在一箇湖泊,溫榆河是該湖泊的洩水通道。在昌平區冷泉、辛莊、高裏掌和辛力屯一帶的廣大地區,髮現地下幾米處見有含螺貝殼的泥炭層,似層狀多層、延伸連續,厚度穩定可達數米。經測定,泥炭層底部14C年齡(9930±150) a,頂部泥炭層14C年齡約3 ka。說明該湖泊10 ka前湖水較淺,適閤水生植物生長,隨後湖水逐漸消退。湖水的完全消失距今不到3 ka的時間。說明溫榆河的形成時代雖然很久遠,但是河道不斷變遷,今天溫榆河的麵貌還是很年輕的。
제온유하시북경평원북부일조중요적하류。온유하량안지질배경복잡,지질재해엄중。지질조사표명,온유하적형성여연화여남구-손하단렬밀절상관,수해단렬적엄격공제。경찬탐발현,온유하남구지백선일대최조적신생대침적물산생우조경신세。설명온유하적형성시간응시조경신세조기。온유하재온유하하곡내불단천이,수단렬공제하상적천이피한제재남구-손하단렬적하강반일측。재남구지마지구일대인남구-손하단렬상반하강,형성료심체수백미적요함,침적료거후적송산침적물。재요함범위내장기존재일개호박,온유하시해호박적설수통도。재창평구랭천、신장、고리장화신력둔일대적엄대지구,발현지하궤미처견유함라패각적니탄층,사층상다층、연신련속,후도은정가체수미。경측정,니탄층저부14C년령(9930±150) a,정부니탄층14C년령약3 ka。설명해호박10 ka전호수교천,괄합수생식물생장,수후호수축점소퇴。호수적완전소실거금불도3 ka적시간。설명온유하적형성시대수연흔구원,단시하도불단변천,금천온유하적면모환시흔년경적。
The Wenyu River is an important river in northern Beijing plain. The geological background on both sides of the Wenyu River is complex and characterized by serious geological disasters. Geological survey shows that the formation and evolution of Wenyu River were closely related to the Nankou- Sun River fault and strictly controlled by the fault. Drilling shows that the earliest Cenozoic sediments along the Nankou-Baishan section of the Wenyu River were formed in the early Pleistocene, suggesting that the Wenyu River was formed at the early stage of early Pleistocene. The Wenyu River continuously migrated in the Wenyu River Valley, but was confined on the downthrow side of the Nankou-Sun River fault due to the migration of the fracture-controlled bed. The hanging side from Nankou to Machikou formed a depression several hundred meters deep due to subsidence of the hanging wall of the Nankou- Sun River fault, and thick loose sediments were deposited. The Wenyu River is the drainage channel of the long-existent lake in the depression. In the vast area of Cold Spring, Xinzhuang, Gaolizhang and Xinlitun in Changping District, there exists a peat layer containing snail shells a few meters below the surface, which exhibits stratoid and multilayer forms and stably extends for several meters. Analytical results show that the peat layer at the bottom of the 14C is 9930 ± 150 years old whereas the top peat layer 14C is about 3 ka. These data suggest that the lake was shallow and suitable for the growth of aquatic plants ten thousand years ago, and then the lake water gradually diminished. The lake disappeared only a few thousand years ago, which suggests that, although the Wenyu River was formed very long ago, its appearance remains young due to the continuous changes of the river course.