Pleistocene Rhine–Thames landscapes: geological background for hominin occupation of the southern North Sea region

This paper links research questions in Quaternary geology with those in Palaeolithic archaeology. A detailed geological reconstruction of The Netherlands' south‐west offshore area provides a stratigraphical context for archaeological and palaeontological finds. Progressive environmental developments have left a strong imprint on the area's Palaeolithic record. We highlight aspects of landscape evolution and related taphonomical changes, visualized in maps for critical periods of the Pleistocene in the wider southern North Sea region. The Middle Pleistocene record is divided into two palaeogeographical stages: the pre‐Anglian/Elsterian stage, during which a wide land bridge existed between England and Belgium even during marine highstands; and the Anglian/Elsterian to Saalian interglacial, with a narrower land bridge, lowered by proglacial erosion but not yet fully eroded. The Late Pleistocene landscape was very different, with the land bridge fully dissected by an axial Rhine–Thames valley, eroded deep enough to fully connect the English Channel and the North Sea during periods of highstand. This tripartite staging implies great differences in (i) possible migration routes of herds of herbivores as well as hominins preying upon them, (ii) the erosion base of axial and tributary rivers causing an increase in the availability of flint raw materials and (iii) conditions for loess accumulation in northern France and Belgium and the resulting preservation of Middle Palaeolithic sites. Copyright © 2011 John Wiley & Sons, Ltd.     

新书介绍地质学在中国的传播与发展——以地质学教科书为中心（1853~1937）

杨丽娟. 2022. 地质学在中国的传播与发展——以地质学教科书为中心（1853~1937）. 杭州：浙江古籍出版社：1~312.     

Evaluating the robustness of models developed from field spectral data in predicting African grass foliar nitrogen concentration using WorldView-2 image as an independent test dataset

In this paper, we evaluate the extent to which the resampled field spectra compare with the actual image spectra of the new generation multispectral WorldView-2 (WV-2) satellite. This was achieved by developing models from resampled field spectra data and testing them on an actual WV-2 image of the study area. We evaluated the performance of reflectance ratios (RI), normalized difference indices (NDI) and random forest (RF) regression model in predicting foliar nitrogen concentration in a grassland environment. The field measured spectra were used to calibrate the RF model using a randomly selected training (n = 70%) nitrogen data set. The model developed from the field spectra resampled to WV-2 wavebands was validated on an independent field spectral test dataset as well as on the actual WV-2 image of the same area (n = 30%, bootstrapped a 100 times). The results show that the model developed using RI could predict nitrogen with a mean R² of 0.74 and 0.65 on an independent field spectral test data set and on the actual WV-2 image, respectively. The root mean square error of prediction (RMSE %) was 0.17 and 0.22 for the field test data set and the WV-2 image, respectively. Results provide an insight on the magnitude of errors that are expected when up-scaling field spectral models to airborne or satellite image data. The prediction also indicates the unceasing relevance of field spectroscopy studies to better understand the spectral models critical for vegetation quality assessment.     

Discriminating lava flows of different age within Nyamuragira’s volcanic field using spectral mixture analysis

In this study, linear spectral mixture analysis (LSMA) is used to characterize the spectral heterogeneity of lava flows from Nyamuragira volcano, Democratic Republic of Congo, where vegetation and lava are the two main land covers. In order to estimate fractions of vegetation and lava through satellite remote sensing, we made use of 30 m resolution Landsat Enhanced Thematic Mapper Plus (ETM+) and Advanced Land Imager (ALI) imagery. 2 m Pleiades data was used for validation. From the results, we conclude that (1) LSMA is capable of characterizing volcanic fields and discriminating between different types of lava surfaces; (2) three lava endmembers can be identified as lava of old, intermediate and young age, corresponding to different stages in lichen growth and chemical weathering; (3) a strong relationship is observed between vegetation fraction and lava age, where vegetation at Nyamuragira starts to significantly colonize lava flows ∼15 years after eruption and occupies over 50% of the lava surfaces ∼40 years after eruption. Our study demonstrates the capability of spectral unmixing to characterize lava surfaces and vegetation colonization over time, which is particularly useful for poorly known volcanoes or those not accessible for physical or political reasons.     

四川攀西地区几个小型镁铁-超镁铁岩体含矿性的铂族元素示踪

峨眉山大火成岩省内带,四川攀西地区的杨合伍、黄草坪和清水河等镁铁-超镁铁岩体分布在南北向的安宁河断裂和磨盘山-元谋断裂之间。分析表明,这些岩体无矿岩石与金宝山、杨柳坪、力马河等含矿岩体无矿岩石具有相似的铂族元素组成,普遍较高的Cu/Pd比值暗示这些岩体的母岩浆在侵入到目前层位前经历过硫化物熔离作用。定量模拟计算表明,原始岩浆经过大约0.01%的硫化物熔离作用形成了杨合伍岩体母岩浆,经过0.035%硫化物熔离形成了黄草坪和清水河岩体的母岩浆。根据硫化物熔离情况,认为杨合伍等岩体底部可能形成Ni-Cu-(PGE)硫化物矿床,而黄草坪和清水河岩体之下及附近可能存在Ni-Cu硫化物矿化的岩体。     

辽宁红透山块状硫化物矿床蚀变带元素迁移特征及定量计算

辽宁红透山块状硫化物矿床（MSD）位于华北地台东北部的浑北花岗岩-绿岩地体内,矿区岩石在30～28 亿年期间受到了600～650℃的高级角闪岩相变质。研究结果表明,广泛分布于红透山层状矿体下盘数百米处的和直接产于矿体下盘的堇青-直闪片麻岩,分别代表了变质后的MSD成矿系统以绿泥石化为特征的半整合和筒状不整合海底热液蚀变带。微量元素特征显示,层状堇青-直闪片麻岩的原岩并非同一种岩石,而是由5种不同岩性的岩石组成,筒状堇青-直闪片麻岩的原岩主要由流纹质岩石组成,而在堇青-直闪片麻岩走向上与之过渡的角闪片麻岩和黑云片麻岩则代表了不同岩性蚀变岩的未蚀变原岩。质量变化计算表明,相对于未蚀变原岩而言,两种蚀变岩的成分发生了显著变化,其中层状堇青-直闪片麻岩的Fe、Mg发生了富集,Na、K、Ca、Cu、Pb和Zn等元素被迁出,而筒状堇青-直闪片麻岩的Fe、Mg、Si、Na、Pb、Cu和Zn等元素则发生了富集,K被迁出。重稀土元素（HREE）和高场强元素(Zr、Ti、Nb、Hf和Ta)在海底热液蚀变过程中保持惰性,而Rb、Sr、Ba和轻稀土元素（LREE,尤其是Eu）则被强烈的迁出。这些元素变化特征表明海底热液蚀变以绿泥石化和硅化为特征,同时海底水-岩反应体系具有高水/岩比值。层状堇青-直闪片麻岩可作为红透山矿区成矿潜力评价的重要依据,而含硫化物石英脉的筒状堇青-直闪片麻岩不但本身可成为工业矿体,还可作为上覆层状矿体的近矿找矿标志。     

中国东部钼矿成矿背景与成岩-成矿时差讨论

中国东部中生代钼矿带属滨太平洋成矿域,钼矿床多沿不同构造单元的交界部位及区域性深大断裂呈带状分布,集中分布在东秦岭、燕辽、长江中下游、南岭和大兴安岭等钼矿成矿带。结合前人成果,以典型矿床为例,初步讨论了中国东部各个钼矿成矿带的成矿背景,成矿很可能与碰撞造山后的伸展背景和(或)太平洋板块俯冲有关。文章根据收集到的中国东部典型钼矿床的成矿年龄及相关岩体的同位素测年数据,详细讨论并定量厘定了钼矿床的成岩与成矿时差。结果表明,钼矿成矿同步或略滞后于同源岩浆活动,两个成矿高峰的时差分别为0～10.0 Ma和0～15.0 Ma;对于单个矿床,成岩_成矿时差集中在0～14.0 Ma,均值为4.1 Ma;从斑岩型→斑岩-矽卡岩型→矽卡岩型→石英脉型钼矿床,成岩-成矿时差呈递增趋势,这恰与岩浆热液成矿过程的客观地质事实相吻合。     

黄河源区冻融地质作用及其生态环境地质特征

黄河源区自然地理环境特殊,冻融地质作用强烈,冻融地质现象普遍发育,以山地顶部裸岩、寒冻风化岩屑坡、山地斜坡冻融滑移、山前倾斜平原及河谷平原冻胀—融陷作用为表征,对应于源区不同的地形地貌条件和自然地理单元,呈鲜明的山地垂直分带规律和冻融荒漠化生态景观。     

上海三维城市地质信息系统优化

本文在简要论述上海三维地质系统建设现状的基础上,对系统存在的主要问题进行了分析,提出了系统升级的目标、升级的主要功能。重点对系统升级过程中涉及的海量数据管理、三维建模技术、地上与地下一体化集成、4D模拟、三维模型的发布等关键技术进行了剖析,并提出了相应的解决方案。     

福建龙湖40多年来环境地质演化及其警示

本文首次报道福建境域湖泊沉积物中有毒元素含量的变化。根据对晋江市龙湖 4 0多年来沉积柱的环境地质演化的研究 ,发现其污染度自 1976～ 2 0 0 2年呈急速上升态势。其中上升最快的元素为 Cd、Hg、As、Pb、Cu、Zn、Cr,尤以 Cu最为典型 ,其污染度变化可分为三个时段 :11976～ 1984年污染指数 0 .6 7,为微污染 ;21984～ 1993年污染指数 0 .86 ,为轻污染 ;31993～ 2 0 0 2年污染指数 2 .37,为重污染。第二时段的污染度为第一时段的 1.3倍 ,第三时段的污染度为第一时段的 3.5倍。表明污染度增加是十分迅速和严峻的。值得引起我们高度关注的是 ,1984～ 2 0 0 2年 ,19年间龙湖中剧毒元素 Hg、As、Pb的平均含量均超越国家标准 ,为污染环境。 2 0 0 2年 4月龙湖表面沉积中这 3种剧毒元素分别为 1976～ 1984年时段含量最低值的 4 6 .3倍、3.3倍、1.9倍 ,已大大超过其“警戒线”(如 Hg为标准值的 4 .4倍 ) ,显示龙湖污染的严重性。龙湖环境地质条件的日益恶化 ,对人群健康已造成一定影响 (如癌症病人日益增加 ) ,这也警示着日本水俣病可能在该地区重演