CAJ | 학술논문

研究发现，在江陵凹陷中南部梅槐桥向斜带内沙市组发育两套膏盐岩层。通过对钻井、岩心、地震资料的分析，明确了膏盐岩的岩性、电性及地震响应特征：岩性变化主要为由湖盆中心至边缘膏盐类矿物的含量越来越低而陆源碎屑物质含量越来越高；电性特征表现为低伽马、低密度、高电阻、中子趋于0、扩径明显；在地震剖面上表现为强振幅、低频率的反射特征。结合研究区古气候和古构造背景，对沙市组两套膏盐岩的沉积特征进行分析，结果表明，两套膏盐岩在凹陷内的分布差异巨大且沉积中心具有向南迁移的趋势，物源、古地貌和湖平面变化三种因素的综合作用是造成这种差异的主要原因。最后总结出研究区沙市组所沉积的膏盐岩是一种“非匀称补给”的成盐模式，主要形成于湖盆基准面下降晚期浅水蒸发沉积环境中。
연구발현，재강릉요함중남부매괴교향사대내사시조발육량투고염암층。통과대찬정、암심、지진자료적분석，명학료고염암적암성、전성급지진향응특정：암성변화주요위유호분중심지변연고염류광물적함량월래월저이륙원쇄설물질함량월래월고；전성특정표현위저가마、저밀도、고전조、중자추우0、확경명현；재지진부면상표현위강진폭、저빈솔적반사특정。결합연구구고기후화고구조배경，대사시조량투고염암적침적특정진행분석，결과표명，량투고염암재요함내적분포차이거대차침적중심구유향남천이적추세，물원、고지모화호평면변화삼충인소적종합작용시조성저충차이적주요원인。최후총결출연구구사시조소침적적고염암시일충“비균칭보급”적성염모식，주요형성우호분기준면하강만기천수증발침적배경중。
Located in southern central Jianghan Basin, the Shashi Formation of Jiangling Depression is composed of two sets of gypsum-salt rocks. Based on an analysis of drilling, seismic and core data, the authors sum up lithology, electrical properties and seismic response characteristics of the gypsum-salt rock. Main lithologic changes find expression in the reduction of saline minerals and the increase of terrigenous detritus content from bottom to top;electrical character is characterized by low gamma, low density, high resistivity, zero neutron and expanding caliper;there exist high amplitude, low-frequency reflection characteristics on seismic section. In combination with the paleoclimate and ancient tectonic background of the study area, the authors made an analysis of sedimentary characteristics of gypsum-salt rocks in Shashi Formation and reached the conclusion that the distribution of gypsum-salt rocks in the depression is mainly affected such comprehensive factors as material sources, ancient landscapes and lake level changes. Based on the above study, the authors hold that the salt rock deposition model of Shashi Formation is a“non-symmetrical supply”salt-formation model, mainly formed in a shallow water evaporation sedimentary environment in the late falling period of the lake basin datum level.