From cave geomorphology to Palaeolithic human behaviour: speleogenesis,palaeoenvironmental changes and archaeological insight in the Atxurra-Armiña cave (northern Iberian Peninsula)

A detailed geomorphological study was performed in the Atxurra-Armiña cave system (northern Iberian Peninsula) to decode landscape evolution, palaeoenvironmental changes and human use of a cave within an Inner Archaeological Context. The results show an average incision rate of the river of <0.083 mm a^–1 for at least the last 419 ka, with interruptions due to sedimentary inputs. Moreover, allostratigraphic units comprising fluviokarstic deposits at the base and flowstone formation at the top have been shown to be climatically controlled, formed either during glacial–interglacial cycles or during interstadial cycles. Finally, when the cave was used by humans in the Late Magdalenian, the lower entrance was closed, and they must therefore have entered the cave through the upper entrance. To reach the sectors selected to decorate the panels, they probably travelled from the upper cave level, as the current crawlway was wider than today, according to our U/Th dating. Once these visitors reached the panels, the floor in the main gallery would have been around 15 cm lower than at present. However, the morphology of the conduit was similar; this has significant implications for understanding and interpreting the human use of the cave during the Palaeolithic.     

“Mind the gap”: Caves,radiocarbon sequences,and the Mesolithic–Neolithic transition in Europe—lessons from the Mala Triglavca rockshelter site

Radiocarbon sequences from some northern Mediterranean cave sites show a temporal gap between Mesolithic and Neolithic occupations. Some authors regard this as a regional phenomenon and have sought to explain it in terms of a general population decline in the late Mesolithic, which facilitated the replacement of indigenous foragers by immigrant farmers. New evidence from the rockshelter site of Mala Triglavca, in Slovenia, leads us to question this view. We describe the deposits in the rockshelter and discuss the results of AMS radiocarbon dating of bone samples recovered in excavations in the 1980s. New archaeological investigations and associated soil/sediment analyses show that in the central part of the rockshelter a well‐defined stratigraphic sequence can be established, despite post‐depositional modification by soil forming processes. There is also evidence of substantial post‐depositional disturbance of the cave sediments by human agency and geomorphological processes, which have created “temporal gaps” and “inversions” in the radiocarbon sequence. The relatively large series of radiocarbon dates obtained enables some of the post‐depositional processes to be identified. © 2008 Wiley Periodicals, Inc.     

贵州纳朵洞洞穴滴水、现代沉积物δ18O特征及其环境意义

为了研究洞穴滴水及其对应的现代沉积物氧同位素的变化特征和对外界气候环境的指示意义,文章对贵州纳朵洞洞外大气降水、洞穴池水、6处滴水点及其对应的现代沉积物氧同位素进行了近2年的监测。结果显示纳朵洞外大气降水和洞穴池水δ18O值均呈现旱季偏重,雨季偏轻的季节特征,基本能反映洞穴所在区域的气候变化。而滴水沉积物δ18O值和滴水δ18O值自身存在协调同步的季节特征,但二者δ18O值与大气降水δ18 O值却呈现反向的季节变化,这可能是区域地形、岩溶表层带的调节和大气环流共同作用的结果。      

Konispol Cave,southern Albania,and correlations with other Aegean caves occupied in the Late Quaternary

Archeological excavations in a karstic cavern on the south facing slopes of the Pindus range, southern Albania, have disclosed a continuous, 4.5 m thick sequence of human occupation since the Mesolithic. In 1994 geoarcheological field work identified nine (9) principal lithostrata that correspond with successive occupations. Sedimentary sequences indicate that during the Mesolithic spring flow was active and produced a pool in the cave's central chamber. This accounts for settlement along the dry western margin of the cave. After 6000 B.P. episodic flushing of Terra Rossa soil from the cave slopes was dominant. Sediments were variously modified or mobilized by weathering, diagenesis and human agency. These changes are correlated to the chronology and contribute to a limited reconstruction of site formation process. Comparison of sediment stratigraphy with an earlier study of magnetostratigraphy verifies an inferred moist pulse of the Early Holocene/Mesolithic and a turn to warmer/drier conditions during the Middle Holocene/Neolithic. The Konispol sequence is compared to cave chronologies in neighboring Epirus (Kastritsa and Klithi) and to Franchthi in southern Greece. Sedimentation patterns reveal that these caves were initially occupied at the same time (Late Pleniglacial) and that during deglaciation there was a general hiatus in deposition (15,000–10,000 B.P.). Early Holocene moisture phases correspond to an increase in sedimentation during the Neolithic when the caves were intensely utilized. © 1998 John Wiley & Sons, Inc.     

Sedimentary anatomy and hydrological record of relic fluvial deposits in a karst cave conduit

This case study from the renowned Demänová Cave System in the Carpathians of Slovakia demonstrates that the conventional methods of fluvial sedimentology, combined with an allostratigraphic mapping and speleothem U‐series isotopic dating, can give unprecedented insights into the hydrological history of underground karst conduit. The deposits studied are a relic compound sidebar ranging from gravel to mud and encapsulating the conduit’s hydrological history from the middle Pleistocene to the present time. A succession of 10 allostratigraphic units, time‐constrained by speleothems, are recognized in the sidebar deposits, and the corresponding morphodynamics of an evolving cave‐floor sedimentation are reconstructed in considerable detail. The subterranean river water stages recognized from the deposits, time‐constrained by flowstone layers and stalagmites, correlate with and add to the regional record of climate changes. Two distinct episodes of flow ponding (high‐stage slackwater conditions) are recognized and attributed to the independently documented downstream cave‐roof collapses, probably triggered by the Carpathian post‐orogenic earthquakes. This multidisciplinary study may serve as a useful methodological guide for the analysis of fluviokarstic deposits in speleological research and reconstruction of their hosting cave hydrological history.     

Sequence of sediments at Locality 1 in Zhoukoudian and correlation with loess stratigraphy in northern China and with the chronology of deep-sea cores

According to recent dating by several methods, the impressive cave sediments at Locality 1 at Zhoukoudian, about 40 m thick, have not only allowed the age of Peking Man to be established, but have calibrated the general course of cave development, permitted correlation with events both within China and farther afield, and placed the sequence in the global frameword of late Cenozoic climatic change. The cave deposits can be divided into 17 layers which are correlated with the great loess sequence (L9–L4) in China and with deep-sea-core oxygen-isotope stages 16-6. The 14th layer upward (730,000–230,000 yr B.P.) represents at least four glacial cycles.     

Embedded Behavior: Human Activities and the Construction of the Mesolithic Shellmound of Cabeço da Amoreira,Muge, Portugal

Shellmound formation processes are greatly influenced by human inputs associated with an intensive exploitation of marine and estuarine resources. The complex stratigraphy of shellmounds has been difficult to decipher and few studies have focused on the microstratigraphic record of midden formation, especially in European Mesolithic contexts. Cabeço da Amoreira is a long‐known Mesolithic shellmound located on the shores of the Muge River, a tributary of the Tagus River in central Portugal. The abundance of shellfish refuse favors an intricate and laterally variable stratigraphic succession of layers and lenses, which results in an extensive artificial mound. Here, we use micromorphological and microfacies analysis to investigate aspects pertaining to site formation, and the nature of individual anthropogenic activities at the site. This methodology allowed for a distinction between primary activities (e.g., discrete shell tossing events, trampled occupational surfaces, and activity areas), and secondary position of the sediments in intentionally raked‐up and dumped deposits. Nondepositional hiatuses and discrete geogenic sedimentation are associated with periods of abandonment. The complex superposition of events seen at Cabeço da Amoreira underlines the role of micromorphology for the identification of behavioral signatures and its relevance in deciphering shellmound adaptations.     

Paleoclimatic changes as indicated by the quaternary Karstic Cave deposits in China

This paper describes the paleoclimatic changes reflected by karstic cave deposits during the Quaternary Period in China. the study was based on comprehensive analyses of the spore and pollen, paleontological, and paleoanthropological fossils as well as various kinds of sedimentological features preserved in those cave deposits. the caves studied include those containing fossils of Homo erectus and Homo sapiens in the Zhoukoudian area some 50 km southwest of Beijing and Shenxiandong (the Immortal Cave) in Leishui County, Jiangsu Province, about 120 km southeast of Nanjing. These deposits, which range in thickness from two to 40 meters, have been carefully investigated and have been shown to be representative of portions of the Quaternary. the paleoclimatic fluctuations as recorded in these cave deposits have been well correlated with glacial cycles within the Brunhes Normal Epoch based on the oxygen isotope scale determined from deep ocean cores.     

Episodes of Cenozoic Gold Mineralization on the Eastern Margin of the Qinghai-Tibet Plateau:~(40)Ar/~(39)Ar Dating and Implication for Geodynamic Events

A lot of new gold deposits have been found on the eastern margin of the Qinghai-Tibet Plateau during the past two decades. Among them, three main types of gold deposits have been recognized, including quartz-vein-type, shearzone-type and porphyry-type. The former two types of gold deposits are mainly hosted within metamorphic rocks, while the latter is related to Cenozoic magmatism. Although all of these gold deposits are believed to have been formed during the uplift process of the Qinghai-Tibet Plateau in the Cenozoic era (Wang et al., 2002b), precise isotopic age constraints have still been lacking until quite recently. This paper presents new ^40Ar/^39Ar data of some gold deposits on the eastern margin of the Qinghai-Tibet Plateau, which indicate that gold mineralization in the region occurred in response to the episodic stages of the orogenies. Recently obtained ^40Ar/^39Ar data on quartz and feldspars from several gold deposits, such as the Sandiao deposit, the Baijintaizi deposit, the Pusagang deposits, provide new constraints on gold mineralization on the eastern margin of the Qinghai-Tibet Plateau. Geochronological studies of gold deposits along the Daduhe River indicate that there are three stages of gold mineralization. The early two stages occurred as early as 65.1 Ma in the Shuibaiyang deposit and 58.95 Ma in the Ruoji deposit, while the latter stage occurred as late as 25.35 Ma in Baijintaizi and 24.70 Ma in Sandiao. Isotopic dating of three plagioclases from the Beiya deposit, Zhifanggou deposit and Luobodi deposit and a K-feldspar from the Jinchangqing deposit in Yunnan Province indicates that these deposits were formed at two stages. The Zhifanggou and Jinchangqing deposits have early stage records as old as 58.82 Ma in Zhifanggou and 55.49 Ma in Jinchangqing, but all of the above four deposits in Yunnan have late stage records of 23.18 Ma in Jinchangqing, 24.54 Ma in Zhifanggou, 24.60 Ma in Luobodi and 24.56 Ma in Hongnitang. The above results suggest that the gold deposits on the eastern margin of the Qinghai-Tibet Plateau were formed concentratedly at two main episodes, i.e. the end of the Paleocene (about 58 Ma) and the boundary between the Paleogene and the Neogene (about 25 Ma). The later episode appears to be looks like more important and was coupled with the Sichuan movement, which was extensively activated at that period. The beginning of the Cenozoic Era (about 65 Ma) might be another episode of gold mineralization, but only one deposit (Shuibaiyang) in this study has been proved to have been be formed at this stage and might be earlier than the initial collision between the Indian Plate and the Eurasia Plate. In view of geology, the above three episodes of gold mineralization are associated with three events of tectonicmagmatism and/or fluid events. Even though the gold deposits (for example, the Shuibaiyang deposit, Ruoji deposit and Pusagang deposit) were formed at different episodes, all of them are genetically related to tectonic movements in largescale shear zones. It looks like theat tectonic events (including large-scale strike-slip) between Paleogene and Neogene had a wide influence upon gold mineralization, with new deposits formed and old deposits enriched or superimposed to be a higher grade by new stage of mineralization. The above data suggest that gold deposits were not only concentrated in some areas, but also formed mainly at different boundaries of geological times, indicating that there existed some peak stages of gold mineralization (metallogenic episodes), and that the gold deposits were formed mainly by episodic mineralization.     

Formation of mud clast breccias and the process of sedimentary autobrecciation in the hominin-bearing (Homo naledi) Rising Star Cave system,South Africa

Unconsolidated mud clast breccia facies in the hominin-bearing (Homo naledi) Rising Star Cave, Cradle of Humankind, South Africa, are interpreted to have formed through a process termed sedimentary autobrecciation in this study. This process, by which most of the angular mud clast breccia deposits are thought to have formed autochthonously to para-autochthonously via a combination of erosion, desiccation, diagenesis and microbial alteration of laminated mud deposits, is thought to have taken place under relatively dry (i.e. non-flooded) conditions inside the cave. Subsequently, gravitational slumping and collapse was the dominant mechanism that produced the mud clast breccia deposits, which commonly accumulate into debris aprons. The mud clast breccia is typically associated with (micro) mammal fossils and is a common facies throughout the cave system, occurring in lithified and unlithified form. This facies has not been described from other cave localities in the Cradle of Humankind. Additionally, sedimentary autobrecciation took place during the deposition of some of the fossils within the Rising Star Cave, including the abundant Homo naledi skeletal remains found in the Dinaledi Subsystem. Reworking of the mud clast breccia deposits occurs in some chambers as they slump towards floor drains, resulting in the repositioning of fossils embedded in the breccias as evidenced by cross-cutting manganese staining lines on some Homo naledi fossil remains. The formation of the unlithified mud clast breccia deposits is a slow process, with first order formation rates estimated to be ca 8 × 10⁻⁴ mm year⁻¹. The slow formation of the unlithified mud clast breccia facies sediments and lack of laminated mud facies within these deposits, indicates that conditions in the Dinaledi Chamber were probably stable and dry for at least the last ca 300 ka, meaning that this study excludes Homo naledi being actively transported by fluvial mechanisms during the time their remains entered the cave.     

中国的洞穴与裂隙堆积

洞穴和裂隙堆积是陆相地层中一个重要的组成部分,经过一百多年的研究,它已成了我国地层表中的一个明确的时空单位,就目前信息,其地质时代从第三纪早期一直延续到第四纪晚期。本世纪发现的洞穴堆积地点上千处,其中含古人类和古猿类化石的地点已达４０多个,与其伴生的哺乳动物化石４００余种。这些珍贵的史料,对研究第三纪以来洞穴堆积地层的时序具有十分重要的意义。     

流入型洞穴——山东沂源九天洞初步研究

九天洞是一个典型的直接由外源水补给形成的流入型洞穴。洞内大片分布的石花起源于四大古水池沉积物的存在。九天洞发育于第四纪早更新世晚期至中更新世早期,经历过成洞期、残余水流(古水池)活动期(中更新世中、晚期)石花发育期(晚更新世以来)和主要滴石、流石(含浅水池)沉积期(晚更新世晚期至今)等发育阶段。今日的九天洞又是一个残余洞穴,已被完全蚀去的近流入口段的洞穴长度不小于200m,约占洞穴全长的37%。九天洞及其洞穴群的景观资源价值和科学价值,在我国北方喀斯特洞穴中占有重要的地位。      

Quaternary deposits in the Maltese Islands: a microcosm of environmental change in Mediterranean lands

The Quaternary deposits of the Mediterranean countries provide clear evidence of past environments, and of environmental change. Modern work enables the reinterpretation of these deposits and shows arid glacial stages and humid interglacial stages, with the Holocene characterised by considerable human impact, mostly resulting from agricultural activity. In this paper, examples of typical Mediterranean Quaternary lithofacies, including tufa and slope, fluvial, coastal, aeolian and cave deposits are described from the Maltese Islands. The deposits are correlated and their climatic signal is interpreted to provide a first modern assessment of Quaternary environmental change in the Maltese Islands.     

Meteoric phreatic speleothems and the development of cave stratigraphy: An example from Tounj Cave, Dinarides, Croatia

Speleothems occurring in some caves of the carbonate Dinarides line all channel surfaces, and have been deposited from meteoric waters under phreatic conditions. Such phreatic speleothemic deposition modifies common experience (l) that meteoric phreatic conditions cause dissolutional widening of cave voids, and (2) that speleothems imply vadose conditions. The phreatic speleothems described here postdate an early polygenetic evolution of the cave voids, and predate the last, vadose stage. They were likely produced during the late/postglacial warming period, when dissolved carbonate was amply supplied, and when there was much water available for saturation of underground voids. Phreatic speleothems may be used as a tool for time correlation of internal deposits, both within one cave and within a karst region. They indicate an important stage in the history of the ground-water regime of an area. In general, phreatic speleothems help in better understanding of the development of subterranean voids and related karst/palaeokarst.     

内生金与控矿层位和褶皱体系的形成时代关系

内生金矿产与控矿地层及其构成的褶皱构造体系,在形成时代上有时因属于同一大地构造阶段而差距不大;有时因属于不同大地构造阶段而相互间差距很大。重点讨论第二种情况。许多由前寒武纪至古生代地台构造层构成的褶皱构造体系及其所控制的内生金矿产,是在中一新生代形成,一些于前地槽,地槽阶段形成的褶皱构造体系所控制的内生金矿产,在形成时代上也属于中一新生代。     

Micromorphology reveals in situ Mesolithic living floors and archaeological features in multiphase sites in central Sudan

In the Khartoum region of central Sudan, Mesolithic sites were established on sandy ridges distributed along the Nile. Most of the excavations carried out in recent decades have revealed limited preserved archaeological structures or layers corresponding to subsequent phases of human presence due to the disturbance of the deposits. Post‐depositional processes affecting Mesolithic sites include (1) the excavation of Neolithic to Post‐Meroitic cemeteries at the same sites, (2) surface erosion, and (3) pedoturbation leading to the mixing of the stratigraphy. During a recent field operation along the western bank of the White Nile, archaeological contexts that were only partially disturbed were identified. Employing a geoarchaeological approach and the micromorphological study of sediments (supported by ¹⁴C dating), settlements were placed in their paleoenvironmental contexts and differences between in situ Mesolithic layers and those disturbed by later processes were identified. Furthermore, it was possible to interpret the functional aspects of three categories of pits containing Mesolithic pottery (fireplace pits, fireplace pits with shell accumulations, and waste pits) and to discuss their significance within the wider framework of North African archaeology. Finally, this project has demonstrated the importance of integrating the geosciences (especially micromorphology) and archaeology in the study of processes leading to the formation and preservation of open‐air prehistoric sites in arid landscapes. © 2011 Wiley Periodicals, Inc.     

Short contribution: Mapping quaternary deposits as a method for explaining the distribution of mesolithic sites in reclaimed landscapes: An example from Vålse Vig,southeast Denmark

Archaeological sites dating to the Ertebolle period of the Mesolithic have been recorded below a thin layer of marine sands in a reclaimed bay on northern Falster Island in Denmark. The finds seemed randomly distributed throughout the bay; there was no obvious pattern related to the modern landscape. However, by coring through the veneer of marine sands and mapping the pattern of the underlying Late Quaternary deposits, the authors were able to reconstruct the Mesolithic landscape and thereby explain the distribution of archaeological sites. This approach allows archaeologists to focus subsurface exploration in geomorphic settings, such as former fjords and coastlines that have a high potential for yielding prehistoric sites. © 2006 Wiley Periodicals, Inc.     

雅鲁藏布缝合带巴尔蛇绿岩边部石英菱镁岩成因

石英(滑石)菱镁岩是基性岩、超基性岩与富CO2流体反应形成的一套硅化-碳酸盐化蚀变岩,常伴生金、汞、菱镁矿、碱金属矿化而在国外备受关注,但国内相关研究较薄弱。巴尔蛇绿岩位于西藏阿里地区,石英菱镁岩主要出露在蛇绿岩体东北边界,出露厚度约20 m,近北西西向延伸数千米。本文系统研究了雅鲁藏布缝合带西段巴尔蛇绿岩边部石英菱镁岩矿物学及地球化学特征。根据尖晶石镜下特征,划分为两个阶段:一阶段石英菱镁岩中尖晶石稳定存在,二阶段石英菱镁岩中尖晶石几乎全部蚀变(代表更强程度蚀变作用)。石英菱镁岩主要地球化学组成为Si O2、Mg O及CO2,8件样品主量元素含量变化较大,Si O2/Mg O比值波动较大,反映石英菱镁岩形成为非等化学过程。蛇纹石化橄榄岩与石英菱镁岩有着相似微量元素分布规律,表明同源性,但两者仍有较明显差异:两阶段石英菱镁岩LREE都较地幔橄榄岩略富集,从地幔橄榄岩到两阶段石英菱镁岩,HREE先亏损再略富集。微量元素标准化图解中,Sr在橄榄岩与石英菱镁岩中都为正异常,其含量随蚀变强度增强而增加。此外,两阶段石英菱镁岩均无Au、Hg矿化。     

湘西要坝洞沉积堆积特征及形成时代

要坝洞在保靖县城北5km,是有旅游和科研价值的洞穴。洞穴发育在保靖-复兴断裂带的裂隙破碎构造控制的白云岩、白云岩化灰岩残体中,是断面陡转缓地段的垂向洞穴,成洞原因与所处的特定地质构造环境有关。在阐述洞穴形成特征的基础上,详细论述了洞穴沉积物及其相关性。洞穴碎屑沉积、次生化学沉积类型齐全,组成高、中、低三个沉(堆)积台面,构成多期(次)沉(堆)积的伴生共存组合体,展示洞穴及其沉积特征和过程。笔者进一步完善了次生化学沉积的成因分类,认为壁流石、钟乳石、石笋、石柱聚集匹配,构成景点,具有旅游观赏价值。同时,选择具有代表性的1号石笋进行同位素测年和综合研究,以其完好的沉积旋回、结构构造特征,显示3～1万a间的冰期气候沉积特征,其冷暖气候转(突)变标志明显。在洞穴及其沉(堆)积综合研究的基础上,根据洞穴沉(堆)积、洞内外新近系、古近系、白垩系的伴生沉积、储存关系,判断要坝洞形成于白垩纪前后。     

不整合面中的成矿机制与找矿研究

不整合包括角度不整合和平行不整合两种。不整合面附近成矿是一种比较常见的现象 ,但通常只简单地认为不整合面只是成矿的有利通道和储矿场所 ,而对发生在不整合面中的后期构造活动主动促进成矿 (成矿流体流动 )的作用认识不足。文中在列举了国内外一批产于不整合面中的矿床的基础上 ,总结了这类矿床的主要特点是 :矿床均产于不整合面及其靠近的盖层和基底地层中 ,常呈矿产密集区分布 ,规模一般较大 ,品位较富 ,矿床的成矿过程一般是经过沉积和热液叠加两个阶段 ,成矿作用和围岩蚀变都是以低温为主 ,矿床的成矿元素与同区域的其他类型矿床相似 ;两种不整合面中的矿床的矿体形态与产出位置不大一样。最后讨论了中国为什么不能形成不整合脉型铀矿床和为什么在不整合面中主要只形成低温热液矿床