Sea-level fluctuations on the northern shelf of the Eastern Paratethys in the Oligocene-Neogene

Sea-level fluctuations in the terminal Eocene, Oligocene, and Neogene of the Eastern Paratethys are quantitatively assessed on the basis of facies and old coastlines traced on the northern platform shelf, levels of river valley incisions, and the study of seismic profiles. The first data massif allows the characterization and correlation of transgression stages in the history of the Eastern Paratethys. The greatest transgressions fall within the first half of the Late Eocene, mid-Early Oligocene, initial Late Oligocene, initial Early Miocene, the initial Tchokrakian, Karaganian and Sarmatian in the Middle Miocene, the middle and late Sarmatian and early Pontian in the Late Miocene, and the Akchagylian in the Caspian basin of the Pliocene. In contrast, the greatest incisions of northern rivers running from the platform allow us to establish the time and extent of the main declines in the base levels of the erosion. Maximal incisions date back to the terminal Eocene-initial Oligocene, terminal Solenovian time in the terminal Rupelian, the terminal Maikop in the Early Miocene, the terminal Sarmatian and middle Pontian in the Late Miocene, and the Early Pliocene in the Caspian basin. Large regressions also formed unconformity surfaces, traced on seismic profiles as erosion boundaries of several orders. The surfaces are confined to the Eocene/Oligocene boundary, middle and late Maikop, Sarmatian/Meotian boundary, middle Pontian, and terminal Miocene-initial Pliocene, as well as being traced even in the most deep-water basins. The synthesis of these data suggests a preliminary version for the curve of transgression-regression cyclicity. Its correlation with the eustatic curve shows their similarity only in the lower part-prior to the initial Middle Miocene, when Paratethys became a semi-closed basin.     

Plio-Pleistocene climatic transition and the lifting of the Teton Range, Wyoming

Fine-grained lacustrine, riverine and ash-fall sediments of the Shooting Iron Formation, whose late Pliocene age is established by Blancan gastropods and vertebrates, yield a pollen flora that is essentially similar in composition to the modern pollen rain in the Jackson Hole area. The Pliocene assemblage suggests a climate like that of the Jackson valley and foothills today. These spectra also resemble a Pliocene pollen flora from Yellowstone Park dated at ∼ 2.02 Ma. However, the underlying Miocene Teewinot sediments differ by containing pollen of four exotic deciduous hardwoods (Tertiary relicts) that suggest a summer-moist climate, unlike that of today. The Shooting Iron sediments lie with an angular unconformity on and above the Miocene lake sediments of the Teewinot Formation. Both of these deposits probably preceded the main uplift of the Teton Range based on the absence of Precambrian clasts in the Tertiary valley deposits. Because the Pliocene floras were modern in aspect, a Plio-Pleistocene transition would be floristically imperceptible here. The sequence denotes a protracted period of relative stability of climate during Teewinot time, and a shift in vegetational state (summer-wet trees drop out) sometime between the latest Miocene and latest Pliocene. The Pliocene spectra suggest a dry, cooler climate toward the end of Shooting Iron time.     

The Çubukludağ graben,south of İzmir: its tectonic significance in the Neogene geological evolution of the western Anatolia

Field studies on the Neogene successions in south of İzmir reveal that subsequent Neogene continental basins were developed in the region. Initially a vast lake basin was formed during the Early–Middle Miocene period. The lacustrine sediments underwent an approximately N–S shortening deformation to the end of Middle Miocene. A small portion of the basin fill was later trapped within the N–S-trending, fault-bounded graben basin, the Çubukludağ graben, opened during the Late Miocene. Oblique-slip normal faults with minor sinistral displacement are formed possibly under N–S extensional regime, and controlled the sediment deposition. Following this the region suffered a phase of denudation which produced a regionwide erosional surface suggesting that the extension interrupted to the end of Late Miocene–Early Pliocene period. After this event the E–W-trending major grabens and horsts of western Anatolia began to form. The graben bounding faults cut across the Upper Miocene–Pliocene lacustrine sediments and fragmented the erosional surface. The Çubukludağ graben began to work as a cross graben between the E–W grabens, since that period.     

The Çubukludağ graben,south of İzmir: its tectonic significance in the Neogene geological evolution of the western Anatolia

Abstract

Field studies on the Neogene successions in south of ?zmir reveal that subsequent Neogene continental basins were developed in the region. Initially a vast lake basin was formed during the early-Middle Miocene period. The lacustrine sediments underwent an approximately N-S shortening deformation to the end of Middle Miocene. A small portion of the basin fill was later trapped within the N-S-trending, fault-bounded graben basin, the Çubukluda? graben, opened during the Late Miocene. Oblique-slip normal faults with minor sinistral displacement are formed possibly under N–S extensional regime, and controlled the sediment deposition. Following this the region suffered a phase of denudation which produced a regionwide erosional surface suggesting that the extension interrupted to the end of Late Miocene–Early Pliocene period. After this event the E–W-trending major grabens and horsts of western Anatolia began to form. The graben bounding faults cut across the Upper Miocene–Pliocene lacustrine sediments and fragmented the erosional surface. The Çubukluda? graben began to work as a cross garden between the E–W grabens, since that period. © 2001 Éditions scientifiques et médicales Elsevier SAS     

Soil–geomorphology interactions and paleoclimatic implications of an ornithogenic soil toposequence on Rata Island,Fernando de Noronha Archipelago,South Atlantic

The formation of highly phosphatized soils on sites of avian activity is a common feature of oceanic islands. We characterized a toposequence of phosphatic soils on Rata Island, to evaluate the soil genesis based on local topographic variations. For this purpose, four soils ranging from the upper hill down to the lowest landscape position on the island, representing a range of parent materials (basalt and calcareous sands), were analyzed. In the lowest landscape position a shallow Regosol was identified, strongly influenced by birds and marine sprays, developed on “karstified” Pleistocene calcarenites; the three other soils in the upper part of the toposequence are Ornithogenic Cambisols, ranging from a deep Cambisol profile on Basalt lava to intermediate Cambisols on mixed colluvial sediments of the basalt/calcareous. The lowermost Regosol is associated with a rugged landscape with strong calcarenite dissolution and karstification. The soil phosphatization is clearly an inherited process of the Late Quaternary age, when climate conditions were different. Initial weathering took place in the last interglacial period, under wetter conditions during which the Tertiary basalts were strongly weathered, leaving corestones in a saprolitic, oxidized mass. In the late Pleistocene, a gentle surface distributed these weathering products along the pediment slopes as colluvial materials, whereas in the coastal areas aeolian processes formed large sand dunes composed of reworked calcareous sands from marine sources during a time of very low sea level. During this time, widespread bird activity accounted for secondary apatite formation on the surface of calcareous oolites. Finally, the Holocene warming was accompanied by increasing sea level, enhanced tropical weathering, Fe and Al mobility and variscite formation superimposed on degraded Ca-phosphates, forming two phase phosphatic aggregates.     

Pliocene sediments of Shikotan Island (Lesser Kuril Ridge)

Shikotan Island of the Lesser Kuril Ridge forms, together with the Vityaz Ridge, the outer arc of the Kuril island-arc system. Marine Pliocene sediments first registered on the island contain diatoms and palynomorphs, which allow their dating. The thin Pliocene semiconsolidated sediments constitute the upper part of sections in the coastal and central areas of the island. They rest with the erosional surface and stratigraphic hiatus upon the Upper Cretaceous-Lower Paleogene (Campanian-Danian) Malokuril’sk Formation. The Pliocene sediments were deposited in relatively shallow-water environments of open sea near the shore, with a forest-free landscape and freshwater basins. The occurrence of reworked marine Oligocene and Miocene diatoms in these sedimentary rocks indicates their development in the Lesser Kuril Ridge area and contribution of their eroded material to the formation of Pliocene sequences. Wide development of Pliocene Marine sediments on Shikotan Island is evidence for ascending movements in the region during the post-Pliocene period, which is also characteristic of the Greater Kuril Ridge islands. The composition and formation conditions of the Pliocene sediments in the outer arc of the Kuril island-arc system suggest that the southwestern (Lesser Kuril Ridge) and northeastern (Vityaz Ridge) segments of this single anticlinal structure evolved under different tectonic regimes through the Pliocene.     

Neotectonics of East Anatolian Plateau (Turkey) and Lesser Caucasus: implication for transition from thrusting to strike-slip faulting

The east Anatolian plateau and the Lesser Caucasus are characterised and shaped by three major structures: (1) NW- and NE-trending dextral to sinistral active strike-slip faults, (2) N-S to NNW-trending fissures and /or Plio-Quaternary volcanoes, and (3) a 5-km thick, undeformed Plio-Quaternary continental volcano-sedimentary sequence accumulated in various strike-slip basins. In contrast to the situation in the east Anatolian plateau and the Lesser Caucasus, the Transcaucasus and the Great Caucasus are characterised by WNW-trending active thrust to reverse faults, folds, and 6-km thick, undeformed (except for the fault-bounded basin margins) continuous Oligocene-Quaternary molassic sequence accumulated in actively developing ramp basins. Hence, the neotectonic regime in the Great Caucasus and the Transcaucasus is compressional–contractional, and Oligocene-Quaternary in age; whereas it is compressional–extensional, and Plio-Quaternary in age in the east Anatolian plateau and the Lesser Caucasus.Middle and Upper Miocene volcano-sedimentary sequences are folded and thrust-to-reverse-faulted as a result of compressional–contractional tectonic regime accompanied by mostly calc-alkaline volcanic activity, whereas Middle Pliocene-Quaternary sequences, which rest with angular unconformity on the pre-Middle Pliocene rocks, are nearly flat-lying and dominated by strike-slip faulting accompanied by mostly alkali volcanic activity implying an inversion in tectonic regime. The strike-slip faults cut and displace dykes, reverse to thrust faults and fold axes of Late Miocene age up to maximum 7 km: hence these faults are younger than Late Miocene, i.e., these formed after Late Miocene. Therefore, the time period between late Serravalian (∼ 12 Ma) continent–continent collision of Arabian and Eurasian plates and the late Early Pliocene inversion in both the tectonic regime, basin type and deformation pattern (from folding and thrusting to strike-slip faulting) is here termed as the Transitional period.Orientation patterns of various neotectonic structures and focal mechanism solutions of recent earthquakes that occurred in the east Anatolian plateau and the Caucasus fit well with the N–S directed intracontinental convergence between the Arabian plate in the south and the Eurasian plate in the north lasting since Late Miocene or Early Pliocene in places.     

Geology and tectonics of the Ryukyu Islands

The Ryukyu Islands are divided morphologically and geologically into three island groups: north, central and south Ryukyus. North-central Ryukyu represents the geological continuation of the Outer Belt of southwest Japan, composed of Mesozoic-Eocene sedimentary sequences, whereas south Ryukyu is characterized by high-pressure metamorphic rocks, Eocene volcanics and limestone, and lower Miocene sediments. The geological and structural contrasts between north-central and south Ryukyus are conspicuous before the late Miocene transgression covered the whole area. The Ryukyu Islands have been established since then.The successive developments of the Goto-Tunghai-Senkaku basins since the Paleogene, of the Okinawa Trough since the Miocene, and of the grabens near the Island group since the Pliocene, signify a southeastward shift of the basins in relation to the activity in the granite diapir zones accompanied by volcanism.     

Neotectonics of East Anatolian Plateau (Turkey) and Lesser Caucasus: implication for transition from thrusting to strike-slip faulting

Abstract

The east Anatolian plateau and the Lesser Caucasus are characterised and shaped by three major structures: (1) NW- and NE-trending dextral to sinistral active strike-slip faults, (2) N-S to NNW-trending fissures and /or Plio-Quatemary volcanoes, and (3) a 5-km thick, undeformed Plio-Quatemary continental volcanosedimentary sequence accumulated in various strike-slip basins. In contrast to the situation in the east Anatolian plateau and the Lesser Caucasus, the Transcaucasus and the Great Caucasus are characterised by WNW-trending active thrust to reverse faults, folds, and 6-km thick, undeformed (except for the fault-bounded basin margins) continuous Oligocene-Quaternary molassic sequence accumulated in actively developing ramp basins. Hence, the neotectonic regime in the Great Caucasus and the Transcaucasus is compressional-contractional, and Oligocene-Quaternary in age; whereas it is compressional-extensional, and Plio-Quatemary in age in the east Anatolian plateau and the Lesser Caucasus.

Middle and Upper Miocene volcano-sedimentary sequences are folded and thrust-to-reverse-faulted as a result of compressional- contractional tectonic regime accompanied by mostly calc-alkaline volcanic activity, whereas Middle Pliocene-Quaternary sequences, which rest with angular unconformity on the pre-Middle Pliocene rocks, are nearly flat-lying and dominated by strike-slip faulting accompanied by mostly alkali volcanic activity implying an inversion in tectonic regime. The strike-slip faults cut and displace dykes, reverse to thrust faults and fold axes of Late Miocene age up to maximum 7 km: hence these faults are younger than Late Miocene, i.e., these formed after Late Miocene. Therefore, the time period between late Serravalian (~ 12 Ma) continent-continent collision of Arabian and Eurasian plates and the late Early Pliocene inversion in both the tectonic regime, basin type and deformation pattern (from folding and thrusting to strike-slip faulting) is here termed as the Transitional period.

Orientation patterns of various neotectonic structures and focal mechanism solutions of recent earthquakes that occurred in the east Anatolian plateau and the Caucasus fit well with the N-S directed intracontinental convergence between the Arabian plate in the south and the Eurasian plate in the north lasting since Late Miocene or Early Pliocene in places. © 2001 Éditions scientifiques et médicales Elsevier SAS     

南沙海槽构造?地层格架及其动力学意义

为了明确南沙海槽的构造?地层格架和成因机制,以区域二维地震剖面的解释为基础,进行断层活动性和沉降史的定量计算,在南沙海槽盆地中确定出Tg、T60、T50和T0四个一级层序界面,以这4个一级层序界面为界,将南沙海槽盆地划分出3个盆地原型:古新世?渐新世（Tg?T60）断陷盆地、早中新世（T60?T50）拗陷盆地和中中新世（T50?T0）前陆盆地;新生代以来,南沙海槽盆地的沉降中心由NW向SE逐渐迁移. 区域资料对比分析表明南沙海槽前陆盆地是由多期前陆盆地叠置而成,以沙捞越造山不整合、区域深部不整合和区域浅部不整合这3个不整合面为界,划分出渐新世?早中新世、中中新世?上新世早期和上新世晚期?现今3期前陆盆地;南沙海槽属于第三期前陆盆地的组成单元,目前仍处于发育演化过程中.      

中国滇西-泰国地区侏罗纪——第四纪盆地发育及其对比研究

 侏罗纪时东南亚大陆上形成两个大盆地,西为海相盆地,东为陆相红盆。白垩纪时大盆地闭合或解体。第三纪出现裂谷盆地,其发育受燕山期构造格局控制;拉张应力自南向北变弱,裂谷发育自南向北变晚。第四纪为上叠盆地阶段。滇西与泰国各时期盆地的对比研究有助于更好地认识其演化特征,恢复东南亚大陆侏罗纪以来不断碎裂、局部解体的历史。     

中国滇西-泰国地区侏罗纪——第四纪盆地发育及其对比研究

侏罗纪时东南亚大陆上形成两个大盆地,西为海相盆地,东为陆相红盆。白垩纪时大盆地闭合或解体。第三纪出现裂谷盆地,其发育受燕山期构造格局控制;拉张应力自南向北变弱,裂谷发育自南向北变晚。第四纪为上叠盆地阶段。滇西与泰国各时期盆地的对比研究有助于更好地认识其演化特征,恢复东南亚大陆侏罗纪以来不断碎裂、局部解体的历史。     

The Pemali Formation of Central Java and equivalents: Indicators of sedimentation on an active plate margin

The Pemali Formation is revised from being the oldest known sedimentary unit in north Central Java to being almost the youngest. This, and a new examination of its composition, has implications for regional geological models and petroleum geology. The Pemali Formation was originally interpreted as “early Miocene” but is now shown to be latest Miocene through Pliocene in age, and characterised by both very high rates of sedimentation and a particularly high degree of reworking. The mid-Late Miocene tectonic event that initiated deposition of this formation created a new series of basins that were filled by erosion of new structural highs. Continuing constriction of the basins resulted in the uplift of older Pemali sediments on the basin margins, being reworked into the youngest Pemali strata.Neither the Pemali Formation nor the associated uplift and erosion are seen in the basins in the Java Sea a short distance to the north. Both the severe effects of the mid-Late Miocene tectonism and the Pemali-type sediments are restricted to a particular geologic zone, which is roughly the same as the modern island of Java. This may be above lithosphere of mixed terranes that forms a rim to the sialic Sunda Plate. The onshore Java area has a history of severe tectonism through the Tertiary and consequently a stratigraphy that greatly contrasts with that of the present-day Java Sea.The localised and thick Pemali deposition affected the burial history and the generation of hydrocarbons around the mid-Late Miocene basins, whilst the uplifted areas may include hydrocarbon traps. If basement composition influenced the location and thickness of the Pemali Formation then it is also likely to have fundamentally controlled deposition of older formations, including the unknown source rock for surface oil seeps. Likewise, these controls appear to contrast strongly with the better known rift-sag basins of the Java Sea.     

阿尔金断裂晚新生代左旋走滑位错的地质新证据

通过对沿阿尔金断裂中段 (位于东经 88°至 92°)发育的晚第三纪走滑盆地沉积历史和走滑变形过程的野外观测以及对第四纪索尔库里盆地形成和演化过程的沉积环境复原的分析 ,提出了阿尔金断裂中段晚新生代左旋走滑位错的地质新证据。研究表明 ,晚第三纪走滑盆地经历了中新世晚期至上新世早期斜张走滑拉分和上新世晚期以来左旋错动的演化过程 ,沉积体沿断裂的错位分布特征指示至少发生了 80 km的左旋走滑位错。发育于阿尔金山链内部的索尔库里盆地起源于晚第三纪早期强烈的侵蚀作用 ,成为柴达木盆地快速沉积的主要物源区。该侵蚀盆地于中晚更新世闭合并演化成一个独立的沉积盆地。通过侵蚀盆地外流通道的复原指示阿尔金断裂自晚第三纪以来累积了 80～ 1 0 0 km的左旋位错。在此基础上 ,结合穿越断裂构造的 级区域水系形成的洪积裙宽度和主干河道沿断裂迹线的拐折长度 ,探讨了阿尔金断裂晚新生代左旋走滑位错量沿走向分布的特征 ,估算了左旋走滑速率     

Cenozoic stratigraphy of the Sahara,Northern Africa

This paper presents an overview of the Cenozoic stratigraphic record in the Sahara, and shows that the strata display some remarkably similar characteristics across much of the region. In fact, some lithologies of certain ages are exceptionally widespread and persistent, and many of the changes from one lithology to another appear to have been relatively synchronous across the Sahara. The general stratigraphic succession is that of a transition from early Cenozoic carbonate strata to late Cenozoic siliciclastic strata. This transition in lithology coincides with a long-term eustatic fall in sea level since the middle Cretaceous and with a global climate transition from a Late Cretaceous–Early Eocene “warm mode” to a Late Eocene–Quaternary “cool mode”. Much of the shorter-term stratigraphic variability in the Sahara (and even the regional unconformities) also can be correlated with specific changes in sea level, climate, and tectonic activity during the Cenozoic. Specifically, Paleocene and Eocene carbonate strata and phosphate are suggestive of a warm and humid climate, whereas latest Eocene evaporitic strata (and an end-Eocene regional unconformity) are correlated with a eustatic fall in sea level, the build-up of ice in Antarctica, and the appearance of relatively arid climates in the Sahara. The absence of Oligocene strata throughout much of the Sahara is attributed to the effects of generally low eustatic sea level during the Oligocene and tectonic uplift in certain areas during the Late Eocene and Oligocene. Miocene sandstone and conglomerate are attributed to the effects of continued tectonic uplift around the Sahara, generally low eustatic sea level, and enough rainfall to support the development of extensive fluvial systems. Middle–Upper Miocene carbonate strata accumulated in northern Libya in response to a eustatic rise in sea level, whereas Upper Miocene mudstone accumulated along the south side of the Atlas Mountains because uplift of the mountains blocked fluvial access to the Mediterranean Sea. Uppermost Miocene evaporites (and an end-Miocene regional unconformity) in the northern Sahara are correlated with the Messinian desiccation of the Mediterranean Sea. Abundant and widespread Pliocene paleosols are attributed to the onset of relatively arid climate conditions and (or) greater variability of climate conditions, and the appearance of persistent and widespread eolian sediments in the Sahara is coincident with the major glaciation in the northern hemisphere during the Pliocene.     

CENOZOIC DISPLACEMENT HISTORY OF THE ALTYN TAGH FAULT:GEOLOGICAL EVIDENCE FROM FIELD OBSERVATIONS IN SOUERKULI AND MANGAR REGIONS, NW CHINA

CENOZOIC DISPLACEMENT HISTORY OF THE ALTYN TAGH FAULT:GEOLOGICAL EVIDENCE FROM FIELD OBSERVATIONS IN SOUERKULI AND MANGAR REGIONS, NW CHINAtheprogramsof (1)theYoungGeologistsFoundationoftheMGMR (No .Qn979812 ) ;(2 )“theNational (G19980 40 80 0 )and (3)openinglabora…     

Complex basin evolution in the Gökova Gulf region: implications on the Late Cenozoic tectonics of southwest Turkey

Southwestern Turkey experienced a transition from crustal shortening to extension during Late Cenozoic, and evidence of this was recorded in four distinct basin types in the Mu?la–Gökova Gulf region. During the Oligocene–Early Miocene, the upper slices of the southerly moving Lycian Nappes turned into north-dipping normal faults due to the acceleration of gravity. The Kale–Tavas Basin developed as a piggyback basin along the fault plane on hanging wall blocks of these normal faults. During Middle Miocene, a shift had occurred from local extension to N–S compression/transpression, during which sediments in the Eskihisar–T?naz Basins were deposited in pull-apart regions of the Menderes Massif cover units, where nappe slices were already eroded. During the Late Miocene–Pliocene, a hiatus occurred from previous compressional/transpressional tectonism along intermountain basins and Yata?an Basin fills were deposited on Menderes Massif, Lycian Nappes, and on top of Oligo–Miocene sediments. Plio-Quaternary marked the activation of N–S extension and the development of the E–W-trending Mu?la–Gökova Grabens, co-genetic equivalents of which are common throughout western Anatolia. Thus, the tectonic evolution of the western Anotolia during late Cenozoic was shifting from compressional to extensional with a relaxation period, suggesting a non-uniform evolution.     

Neotectonic evolution of the northwestward arched segment of the Central Anatolian Fault Zone,Central Anatolia,Turkey

Central Anatolia has undergone complex Neotectonic deformation since Late Miocene–Pliocene times. Many faults and intracontinental basins in this region were either formed, or have been reactivated, during this period. The eastern part of central Anatolia is dominated by a NE–SW-trending, left lateral transcurrent structure named the Central Anatolian fault zone located between Sivas in the northeast and west of Mersin in the southwest. Around the central part, it is characterized by transtensional depressions formed by left stepping and southward bending of the fault zone.Pre-Upper Miocene basement rocks of the region consist of the central Anatolian crystalline complex and a sedimentary cover of Tertiary age. These rock units were strongly deformed by N–S convergence. The entire area emerged to become the site of erosion and formed a vast plateau before the Late Miocene. A NE–SW-trending extensional basin developed on this plateau in Late Miocene–Early Pliocene times. Rock units of this basin are characterized by a thick succession of pyroclastic rocks intercalated with calcalkaline–alkaline volcanics. The volcanic sequence is unconformably overlain by Pliocene lacustrine–fluviatile deposits intercalated with ignimbrites and tuffs. Thick, coarse grained alluvial/colluvial fan deposits of marginal facies and fine grained clastics and carbonates of central facies display characteristic synsedimentary structures with volcanic intercalations. These are the main lines of evidence for development of a new transtensional Hırka–Kızılırmak basin in Pliocene times. Reactivation of the main segment of the Central Anatolian fault zone has triggered development of depressions around the left stepping and southward bending of the central part of this sinistral fault zone in the ignimbritic plateau during Late Pliocene–Quaternary time. These transtensional basins are named the Tuzla Gölü and Sultansazlığı pull-apart basins. The Sultansazlığı basin has a lazy S to rhomboidal shape and displays characteristic morphologic features including a steep and stepped western margin, large alluvial and colluvial fans, and a huge composite volcano (the Erciyes Dağı).The geometry of faulting and formation of pull-apart basins can be explained within the framework of tectonic escape of the wedge-like Anatolian block, bounded by sinistral East Anatolian fault zone and dextral North Anatolian transform fault zone. This escape may have been accomplished as lateral continental extrusion of the Anatolian Plate caused by final collision of the Arabian Plate with the Eurasian Plate.     

ALLUVIAL STYLES AND ARCHITECTURE AS GUIDES TO CENOZOIC TECTONIC AND ENVIRONMENTAL EVENTS AT THE NORTHERN MARGINS OF THE QINGHAI—XIZANG PLATEAU

ALLUVIAL STYLES AND ARCHITECTURE AS GUIDES TO CENOZOIC TECTONIC AND ENVIRONMENTAL EVENTS AT THE NORTHERN MARGINS OF THE QINGHAI—XIZANG PLATEAU