Tectonic Geomorphology

The left-lateral strike-slip Adıyaman fault is located in eastern Turkey within the plate boundary deformation zone between Arabia and Anatolia. The Adıyaman fault is a major splay from the East Anatolian Fault (EAF), one of the most important tectonic structures in the Eastern Mediterranean region. These faults are consequence of the collision between the Arabian and Anatolian plates and the resulting westward tectonic escape of Anatolia. Although the EAF has been intensively studied since its discovery in the late 1960s, little is known about the Adıyaman fault and its tectonic activity. In this study, we extract geomorphic indices including mountain-front sinuosity (Smf), valley floor width-to-height ratio (Vf), stream length-gradient (SL), catchment Asymmetry Factor (AF) and hypsometric integrals and curves (HI and HC) to evaluate the relative tectonic activity of the Adıyaman fault. These three geomorphic indices (AF, HI, and HC) are averaged to define an index for Relative Tec...

lterations in river morphological quality are derived from quantification of human pressures as well as river morphological alteration. Taleghan River is an important source of water for the irrigation of Agri cultural lands in Qazvin Plain. For some economic considerations of Taleghan dam reservoir on the river as well as geology, some reaches of the river have undergone alterations. It seems important to morphological quality assessment in order to planning issues. Our study’s aim is to contribute to the morphological quality evaluation based on a revisited Morphological Quality Index (rMQI) protocol. The rMQI scoring system allows for the quantification of changes when compared to reference conditions. The rMQI corresponds to less than 30%, reflecting a good morphological quality; the rMQI corresponds to more than 30%, reflecting an extremely poor morphological quality. In this context, the paper presents all of the Taleghan River reaches suffer from an extremely poor morphological quality. Causes of degradation are meandering as well as numerous anthropogenic pressures in the upstream part of the basin. In order to revive Taleghan River as well as improve its water quality, preserving and remediating native vegetation, prevention and remediation of land use degradation in upstream's basin as well as river bank erosion control measures can use hard and soft strategies engineering are recommended.

El Abanico del Quindío (AQ) se ubica en el centro de la Cordillera Central Colombiana, en los departamentos de Risaralda y Quindío, y corresponde a una serie de depósitos fluvio-volcánicos provenientes del Complejo Volcánico Ruiz-Tolima (Figura 1). El AQ se presenta discordante sobre los Complejos Arquía y Quebradagrande (Espinosa, en prensa), mostrando diferencias de espesores debido a una paleotopografía producto de la respuesta mecánica que tienen las fallas que cursan la zona. La evidente acción tectónica sobre el AQ se refleja a través de fallas consecuentes con los trazos principales del Sistema de Fallas de Romeral (SFR) con tendencias iguales, generando una serie de geoformas que indican actividad reciente (París, 1997). Las fallas que atraviesan el AQ se dividen en la zona de Armenia en tres familias que corresponden a: Fallas N20E, como la Falla Armenia, las cuales tienen trazos largos y son consecuentes con el alargamiento de las fallas principales del SFR dentro del AQ; fallas E-W, como las fallas Hojas Anchas y La Isabela, las cuales permiten la apertura de los abanicos que componen el AQ (Vargas et al., 2005) ; y las fallas N10W, como la Falla El Danubio, las cuales son cortadas por las anteriores familias. En este trabajo se pretende demostrar como el campo de esfuerzos regional, producto de la convergencia tectónica del Bloque Panamá-Chocó-Costa Rica contra el Bloque Andino, es responsable de la configuración estructural de la zona, y su influencia sobre algunos aspectos morfológicos dentro del AQ.

Tectonic geomorphology has proven to be a useful tool for identifying and quantifying active
and geologically recent tectonic deformation. Some of these techniques have been used in
Achankovil river basin in order to decipher the basin tilting and asymmetry. Achankovil
river of southern Kerala flows though a confined elongated structural valley and the river
course is not uniform. Asymmetry Factor (AF) and Transverse Topography Symmetry Factor
(TTSF) have been worked out for different segments and sub watersheds considering the
course orientation. It is found that basin have experienced differential tilting. SE migration
of river course in upper segment and NW migration of river course in the down segment
is observed. Geologic events like Western Ghats uplift, base level changes and strike slip
movements have influenced the drainage development and modified the basin asymmetry.

Elaborarea acestei lucrări a apărut ca o necesitate imediată în procesul de instruire a studenţilor geografi, în contextul în care, în ultima perioadă, avalanşa de informaţii în domeniu este copleşitoare. Tocmai de aceea era nevoie de o sinteză a acestor lucrări, astfel încât studenţilor să le fie oferită şansa de a pătrunde în tainele acestei planete mirifice, Pământul, cu tainele sale greu de pătruns.
În urma unei experienţe de peste un deceniu în învăţământul universitar românesc, perioadă în care am asimilat şi continui să asimilez numeroasele informaţii privind geomorfologia în ansamblu, am considerat că a sosit momentul ca o parte a acestor cunoştinţe să fie transpuse într-o lucrare utilă în pregătirea celor care vor să pătrundă tainele Geografiei.
Lucrarea a fost structurată în patru părţi, necesare pentru a parcurge întreaga problematică, extrem de complexă dar necesară în procesul de pregătire geomorfologică a studenţilor geografi în ciclul de licenţă.
Pe parcursul acestei lucrări, studenţii au posibilitatea să înţeleagă mai bine locul Pământului în acest imens Univers, structura internă cu toate particularităţile sale şi rolul acesteia în dinamica de ansamblu a plăcilor litosferice. Sunt analizate mecanismele care au determinat formarea marilor ansambluri morfostructurale terestre, distribuţia şi complexitatea acestora.
S-a trecut mai departe la analiza structurilor specifice sub care rocile se găsesc în scoarţa terestră şi modul cum acestea se impun în modelarea reliefului. Astfel, sunt analizate structurile tabulare, monoclinale, cutate, faliate ş.a. din dorinţa ca studenţii să cunoască morfologia acestora, deloc simplă.
În ultima parte a lucrării au fost analizate două fenomene esenţiale prin formele de relief pe care le impun în peisaj, vulcanismul şi magmatismul, vulcanismul remarcându-se şi prin riscul pe care manifestările care-l caracterizează îl prezintă pentru o societate umană aflată într-o continuă dezvoltare şi expansiune teritorială.
Lucrarea este completată cu lista figurilor ce au fost inserate acolo unde situaţia impus-o, majoritatea fiind originale şi o listă a fotografiilor cu specificarea sursei acolo unde ele nu-mi aparţin. Bibliografia, cu cele peste 170 de titluri argumentează seriozitatea demersului.

Structural and morphotectonic analyses were carried out in the catchments of the Das Cinzas and Itararé rivers, tributaries of the left bank of the Paranapanema River, in order to demonstrate the tectonic-structural evolution of the studied area, which involves the northeast region of Paraná and southwest of São Paulo, and is underlain by sedimentary rocks from the Paraná, Itararé, Guatá, and São Bento Groups, of the Paraná Sedimentary Basin, and including mesozoic volcanic rocks from the Serra Geral Formation. The topography of the studied area is moderate to steep, with elevations varying between 360 and 1,360 meters. The main magnetic/structural alignments that affect and/or are contiguous to the study area are the Santo-Anastácio/Paranapanema (NW-SE), Guaxupé (NE-SW) and Jacutinga lineaments (NE-SW), to the north; São Sebastião lineament (EW) in the central portion; São Jerônimo-Curiúva (NW-SE) and Taxaquara lineaments (NE-SW) in the southern portion. The method aplied consisted of classical structural analysis, processing and photointerpretation of DEMs (SRTM), extraction of longitudinal profiles of rivers and lineaments of relief and drainage. In order to assess morphometric parameters, we performed analyses of the drainage patterns and anomalies, slope of the terrain, drainage basin asymmetry factor, knickpoints and probable drainage captures. The Itararé River catchment flows from south to north and is elongated in shape, bordered by the large NW-SE lineaments, corresponding to the fault zones of Santo Anastácio/Paranapanema and São Jerônimo-Curiúva. It is moderately asymmetrical and follows the traces of the extensive NE-SW lineaments, related to the fault zones of Taxaquara, Jacutinga and Guaxupé. The Itararé River is predominantly straight, with meandraments restricted to the portion of the middle course. The drainages are characterized by the mean to low density, accentuated angularity and conspicuous structural control, whose characteristics imply the subdendritic to rectangular pattern, elbow-like, parallel and aligned segments, according to directions NE-SW, NNW-SSE, NS and E-W. The analysis of longitudinal profiles revealed that the knickpoints are aligned mainly in the directions NE-SW and NW-SE, which indicate a possible tectonic control. The relief lineaments occur in two preferential orientations NE-SW and NW-SE and, secondarily, N-S, NNW-SSE, E-W and ENE-WSW, showing influence throughout the studied area. The structural data collected characterize the predominance of strik-slip and oblique faults, which cut the sedimentary sequence and the rocks of the Serra Geral Formation, marked by consistent kinematic indicators of tectonic processes, surely in the Cenozoic. There are predominant right-lateral strike-slip faults, E-W-oriented, and secondarily directed to WNW-ESE, NNE-SSW and N-S. Less frequent are those oriented to NE-SW, ENE-WSW, NNW-SSE and NW-SE. Left-lateral strike-slip faults are also widely observed, with directions NE-SW, WNW-ESE, E-W, N-S and NNE-SSW, and secondarily ENE-WSW and NNW-SSE. Normal and/or oblique faults oriented to WNWESE and E-W, and secondarily ENE-WSW and NW-SE to NNW-SSE, are frequent, however, there are indications that they are sectioned by a strike-slip system. Finally, the reverse faults, with directions NNE-SSW and E-W, are uncommon. The paleostress analysis indicates an evolution of the landscape associated with at least four tectonic pulses with compressive SHmax oriented to NE-SW, N-S, NW-SE and E-W, described by several authors for the southern and southeastern regions of Brazil, which would be active, respectively, in the Neocretaceous-Paleogen, Plio-Pleistocene, Pleistocene and Holocene. Keywords: Neotectonics; cenozoic; tectonic geomorphology; morphometry.

The operationalization of cocoa mass spraying program by the government which has the aim of fighting against pests and diseases in Ghanaians‟ cocoa farms would not just be adequate but rather uncovering the impact of the program on cocoa production is worth considering. It is therefore important to find out the impact of the program in the lives of farmers, chief farmers, and Municipal Coordinator for CODAPEC in Sefwi Wiawso Municipality of Western North Region. However, the study reviewed pieces of literature to find more information and gaps in the existing body of knowledge. Purposive and simple random sampling techniques were used to select cocoa-growing communities benefiting from the program and farmers respectively. Primary and secondary data were the sources of data for the study. Interview and questionnaire were the tools for data gathering. The study involved 100 farmers, 6 chief farmers and one Municipal Coordinator for CODAPEC as its respondents. Descriptive statistics tools such as frequency and percentage distribution tables were used to analyze data through the aid of Statistical Package for Social Scientists (SPSS) computer software. One of the major findings of the study demonstrated that accessibility of the program had been troubled by bribery, favouritism, to whom you know, quarrel, spraying team not ready and serious, spraying team demanding money, insufficient supply of pesticides, inadequate supply of fuel for spraying had made it inaccessible to majority of farmers in the study areas. Another major finding was that four times spraying had been stressed by CODAPEC yearly. Other findings were that sprayings were done between July and November; these had brought an increasing rate in cocoa outputs at the study areas. Based on the finding it was recommended that; government through CODAPEC should supply sufficient pesticides and adequate fuel for spraying. Bribery, favoritism, and to whom you know concepts should be prohibited and discouraged from the era of the spraying program and individuals who are caught in such actions should be prosecuted and jailed if the law demands.

This research deals with the surface dynamics and key factors –
hydrological regime, sediment load, and erodibility of floodplain
facies – of frequent channel shifting, intensive meandering, and
lateral instability of the Bhagirathi River in the western part of the
Ganga-Brahmaputra Delta (GBD). At present, the floodplain of
the Bhagirathi is categorized as a medium energy (specific stream
power of 10–300 W m−2), non-cohesive floodplain, which exhibits a
mixed-load and a meandering channel, an entrenchment ratio >2.2,
width–depth ratio >12, sinuosity >1.4, and channel slope <0.02. In
the study area, since 1975, four meander cutoffs have been shaped
at an average rate of one in every 9–10 years. In the active meander
belt and sand-silt dominated floodplains of GBD, frequent shifting
of the channel and meander migration escalate severe bank erosion
(e.g. 2.5 × 106 m3 of land lost between 1999 and 2004) throughout the
year. Remote sensing based spatio-temporal analysis and stratigraphic
analysis reveal that the impact of the Farakka barrage, completed in
1975, is not the sole factor of downstream channel oscillation; rather,
hydrogeomorphic instability induced by the Ajay–Mayurakshi fluvial
system and the erodibility of floodplain sediments control the channel
dynamics of the study area.

This article talks about fluorite and barite mineralization in a sector of western Sicily near the Tyrrhenian Sea. These mineralization in a small area, the Poggio Balate hill, north-west of Monte San Calogero Termini Imerese (Sicily) take on the characteristics of a real, intensely mineralized deposit. It is a low-grade hydrothermal deposit involving well-cemented Mesozoic clastic limestone rocks. The discovery occurred during the search for a stratigraphic geology work in the early 1970s. The fluorite and barite mineral deposit of Poggio Balate is the only one existing in all of Sicily. Some geological aspects covered make this publication still relevant in light of the results of recent geophysical studies on geothermal resources within the carbonate reservoirs of western Sicily (Italy). The geochemical phenomenon that produced this surprising mineralization is related to a hydrothermal circulation that ascended along the fault system in rocks, predominantly Mesozoic carbonate rocks.

Doğal ve beşeri ortamların yoğun bir şekilde etkileşim halinde olduğu ve karmaşık sistemler meydana getirdiği günümüz koşullarında, bu unsurların ilişkisinin incelenmesi birçok sorunun çözümünde önemli rol oynamakta ve kullanılabilir veriler sağlamaktadır. Bu nedenle bu çalışmada Marmara Bölgesi'nin doğusundaki Sapanca Gölü kıyıları ve yakın çevresindeki jeomorfolojik birimlerle mekan-kıyı kullanımı unsurları arasındaki ilişki, coğrafi bakış açısı, yöntemleri ve CBS teknikleri ile incelenmiştir. İnceleme sonucunda çalışma alanında jeomorfolojik birimleri meydana getiren dağlık alanlar, plato sahaları, ova ve alüvyal alanlar, vadiler, birikinti koni ve yelpazeleri, sazlık bataklık alanlarda; yerleşim alanları, tarım alanları, orman alanları, çalılık-fundalık ve otlak alanlar gibi mekan kullanım birimlerinin etkileşim halinde olduğu gözlemlenmiştir. Çalışma alanındaki jeomorfolojik birimler bazı alanlarda yoğun beşeri kullanıma maruz kalmış, bazı alanların bir kısmı korunmuş, bazı alanlarda ise mekandan yanlış yararlanılmıştır. Mekan kullanım unsurlarının bazıları ise belirli morfolojik birimlerde yoğunlaşmış, bazıları da birkaç jeomorfolojik birimde kullanım alanı olarak gözlemlenmiştir. Belirtilen bu durumlarda başta Sapanca Gölü olmak üzere doğal ortamı etkilemiş ve sorunlar meydana gelmiştir.
ABSTRACT Natural and human factors that interact intensively and conditions caused by today's complex systems, examining the relationship of these elements plays an important role in solving the many problems and provide data available. The relationship between Therefore, in this study the Marmara region to the east of Sapanca Lake shores and the nearby geomorphological unit with space-shore use elements of geographical perspectives, methods and

The geomorphic evolution of the upper Indus River that traverses across the southwest (SW) edge of Tibet, and the Ladakh and Zanskar ranges, was examined along a ~350-km-long stretch of its reaches. Based on the longitudinal river profile, stream length gradient index, and river/strath terraces, this stretch of the river is divided into four segments. Valley fill river terraces are ubiquitous, and strath terraces occur in the lower reaches where the Indus River cuts through deformed Indus Molasse. Optically stimulated luminescence ages of river/strath terraces suggest that valley aggradation occurred in three pulses, at ~52, ~28, and ~16 ka, and that these broadly coincide with periods of stronger SW Indian summer monsoon. Reconstructed longitudinal river profiles using strath terraces provide an upper limit on the bedrock and provide incision rates ranging from 1.0 ± 0.3 to 2.2 ± 0.9 mm/a. These results suggested that rapid uplift of the western syntaxes aided by uplift along the local faults led to the formation of strath terraces and increased fluvial incision rates along this stretch of the river.

The study area is the upper Manavgat River basin. It is located in the western part of the central Taurides. Two significant geomorphic features of this basin are the Kembos and Eynif structural poljes. This study focuses on the tectonic impacts on the development of poljes and the morphotectonic evolutionary history of the study region. The data were obtained through a detailed mapping of the faults, rocks, and geomorphic features. The evolutionary history of the basin begins with the NW-SE–trending karstic paleovalleys, which first formed on the erosional surfaces that are part of the early and middle Miocene contractional tectonic regime. The tributaries, which developed under the influence of the NW-SE–trending Pliocene strike-slip faults, joined the main trunk of the Manavgat River. Starting at the beginning of the Quaternary, the tensional tectonic regime became prominent , and then a series of graben-horst structures appeared. The Eynif and Kembos poljes formed within two of these structures. The underground capture of surface water occurred in the grabens. The waters of both poljes drain through swallow holes into the Manavgat River and then in to the Mediterranean Sea. The regional uplift rates (the downcutting rates) are as follows: 0.36 mm/y in the late Miocene (Tortonian-Messinian), 0.06 mm/y in the Pliocene, and 0.18 mm/y in the Quaternary periods, which are based on the geopmorphic data obtained from high erosional surfaces and the Manavgat River valley. The average downcutting/uplift rate is 0.18 mm/y in this region.

ABSTRACT Homeowners who live near or on steep slopes of the Traverse Mountains along the Wasatch front in southern Salt Lake City, Utah (USA) are at risk where development of “master-planned communities” has been permitted on known landslide deposits since 2001. Some of the largest landslides in the state of Utah are being modified as road construction and residential development progresses. This paper reviewed the setting of the landslide-prone areas and used Geographic Information Systems (GIS) spatial tools to assess the value of local developments built on mapped slide features. Dataset overlays
were compiled to determine the vulnerability of residences, and to quantify potential monetary loss from a future landslide event. The key elements at risk include property, as well as the population, economic activities, and public services of a given region. An initial conservative figure calculated for the vulnerability of residents owning property exceeds $500 million for the Traverse Mountains region of Draper City, based on 2007 property values recorded at the Salt Lake County Assessors Office. In developing this area, the failure to consider existing and potential hazards has caused a myriad of tensions among local government officials, planners, financiers, state regulators, consultants, developers, realtors, and homeowners.

The research is a study of the adaptation of the drainage metwork to a geological and structural base in an interplateau area, which is mediated by an escarpment. The area-focus is the Laranjeiras river basin, tributary of the Juquiá-Guaçu river and located  at the footslope of the Paranapiacaba mountain range. The main problem of the research was the hyphotesed ocurrence of river piracy of the Sorocabuçu river, located in the highest base level, by the Laranjeiras river, on the lowest one. The methodology differed from the exam of DEMs and topographic and geological maps, which was subjected to morphometric specific calculations. The procedures consisted of identifying the relief features in the basin, researching the retration of front scarp and analysing the hypsometric curves, geometry and longitudinal profiles of channels most  representatives in the basin. Then, we examined the likely occurrence of rearrangements in the drainage, manifested by river piracies and beheadings, correlating them with the evidence previously obtained in the morphometric study. Among the main results, it was demonstrated that the hydrographic network in question is condictioned by several lithologic and structural factors, which ultimately guide channels tributaries and the main channels (Laranejiras rivers). These structures are, in general, systems of joints and faults from Paleozoic, in the NE-SW direction. However,  the basin is cut by a possible, recent fault, titled Itanhaem fault, right-lateral slip, oriented to NW-SE. It acts as a zone og weakness and favors carving and capturing of the Sorocabuçu river by the Laranjeiras rivers. Finally, we discuss the retraction of the Paranapiacaba mountain range and its relationship with these geological  structures and the dynamics of the local drainage.

A principios del Plioceno en la esquina noroccidental de Suramérica se presentaba una sola cordillera emergida, la cual se había desarrollado como resultado de la subducción oblicua de la placa Nazca bajo este margen del continente. Al producirse la acreción del Bloque Costa Rica-Panamá-Chocó (BCRPC) durante esta época, se produce un cambio en la dirección de los esfuerzos en esta zona del continente y la convergencia entre las placas Norteamérica y Suramérica constriñe fuertemente a la placa Caribe. Este cambio geodinámico en la convergencia de placas, genera un fuerte régimen de extensión sinorogénica en esta cordillera amplia y única ancestral, que produce el colapso de su parte axial dando origen a la Fosa Cauca-Patía, e igualmente durante el desarrollo de este proceso, se produce un mayor levantamiento de la Cordillera Oriental en Colombia. A partir de apreciaciones geológicas y geofísicas, y de los resultados de índices morfotectónicos en escala regional a lo largo del Sistema de Fallas de Romeral (SFR) en la Cordillera Central, se propone que los tres ramales cordilleranos y que caracterizan a los Andes del Norte en Colombia, se conformaron como tales desde el Plioceno Superior y no antes de esta época. En la actualidad esta región de los Andes, se encuentra en una fase de crecimiento orogénico y no de senilidad, debido a que en los sectores estudiados de la Cordillera Central aquí, se constata que se impone más el efecto tectónico que el erosivo. Esta situación también se ha verificado en otras investigaciones con la Cordillera Oriental, pero aun no en la Cordillera Occidental, aunque la sismicidad tanto de intraplaca como intermedia en el occidente colombiano, sugiere que esta igualmente se encuentra en esta fase.

La faja plegada y corrida del Subandino Sur de Argentina y Bolivia se extiende sobre el frente orogénico andino entre los 18°- 23° de Latitud Sur y 64°- 63° de Longitud Oeste, inmediatamente al este del sistema Puna-Altiplano y de la Cordillera Oriental. Esta faja plegada está conformada por estructuras de piel delgada despegadas dentro de las secuencias paleozoicas. El evento compresivo que dio lugar a la formación de este orógeno comenzó en el Cretácico superior, alcanzando las Sierras Subandinas en el Eoceno y extendiéndose hasta tiempos Cuaternarios. Este trabajo presenta evidencia tectónica y geomorfológica sobre la existencia de segmentos y zonas de conexión lateral entre pliegues a lo largo de la Sierra de San Antonio.
La morfología de las estructuras fue analizada combinando datos de superficie y modelos de elevación digital de alta resolución. El perfil longitudinal a lo largo del eje orográfico de la sierra muestra que esta extensa cadena de pliegues está formada por una serie de altos y bajos topográficos que se corresponden con sendas culminaciones anticlinales locales separadas por sillas estructurales. El análisis de los mapas geológicos y topográficos permitió reconocer segmentos de pliegue de longitud variable y conexiones laterales de tipo lineal y en echelon. La presencia de redes de drenaje con un diseño enrejado, paleo-cursos curvos y sucesiones de valles abandonados de elevación decreciente permiten inferir que estas estructuras se habrían formado mediante la amplificación y crecimiento lateral de múltiples núcleos individuales. Estas características morfológicas, así como el modelo de evolución estructural derivado de las mismas, pueden ser utilizadas para analizar la distribución de los yacimientos de hidrocarburos a lo largo de esta sierra de más de 300 km de longitud. En general, puede observarse una correspondencia entre la forma del perfil topográfico, la presencia en superficie de segmentos de pliegues y la alternancia de altos y bajos estructurales en el subsuelo.

The late Neogene vegetation change of C 4 plants replacing C 3 plants is widely documented across the world. This vegetation shift has been particularly well-documented in the Himalayan foreland based on δ 13 C isotopic data from palaeosol carbonates and bulk organic matter in the Siwalik sedimentary rocks of Pakistan, India and Nepal, showing asynchronous expansion of C 4 plants between 8 and ~5 Ma, 9 and 6 Ma, and around 7 Ma, respectively. In this study, compound-specific isotopic analysis of lipid biomarkers extracted from shale and palaeosols in the palaeomagnetically age-constrained Nepalese Siwalik is utilized to better understand this vegetation shift. This is the first comprehensive lipid biomarker study in the Nepalese Siwalik, with new isotopic results from the previously undocumented Karnali River section. The δ 13 C n-alkane (C 27-31) results from the Surai Khola section suggest C 3 plants were dominant between 12 and 8.5 Ma. A stepwise expansion of C 4 plants that started gradually at 8.5 Ma escalated rapidly after 5.4 Ma, so that by 5.2 Ma C 4 vegetation dominated the landscape. This dramatic ecological shift at the Miocene-Pliocene boundary was likely linked with an intriguing tectonic-climate coupling in the Himalayan-Tibetan region, prompting wetter summers and drier winters that drove C 4 grass expansion. However, in the Karnali River section, the data show no clear sign of C 4 plant expansion until 5.2 Ma (youngest sample age). In the two study locations separated laterally by ~200 km along tectonic-strike, this different trend of vegetation change likely indicates local controls like river-catchment influence. However, it is possible that, similar to the Surai Khola section, C 4 plants dominated after 5.2 Ma in the Karnali River section. This study also suggests that the past vegetation makeup of an area is better reconstructed using isotopic signatures of molecular markers than of bulk organic matter or pedogenic nodules.

Major uplifts of late Quaternary marine terraces are visible along the coastline of the Tell Atlas of Algeria
located along the Africa–Eurasia convergent plate boundary. The active tectonics of this region is associated
with large shallow earthquakes (M≥6.5), numerous thrust mechanisms and surface fault-related fold. We
conducted a detailed levelling survey of late Pleistocene and Holocene marine notches in the Algiers region
that experienced 0.50 m coastal uplift during the 2003 Zemmouri earthquake (Mw 6.8). East of Algiers,
Holocene marine indicators show three pre-2003 main notch levels formed in the last 21.9 ka. West of Algiers
on the Sahel anticline, the levelling of uplifted marine terraces shows a distinct staircase morphology with
successive notches that document the incremental folding uplift during the late Pleistocene and Holocene.
The timing of successive uplifts related to past coseismic movements along this coastal region indicates
episodic activity during the late Holocene. Modelling of surface deformation in the Zemmouri earthquake area
implies a 50-km-long, 20-km-wide, NE–SW trending, SE dipping fault rupture and an average 1.3 mcoseismic
slip at depth. Further west, the 70-km-long Sahel fold is subdivided in 3 sub-segments and shows ~0.84–
1.2 mm/yr uplift rate in the last 120–140 ka. The homogeneous Holocene uplift of marine terraces and the
anticline dimensions imply the possible occurrence of large earthquakes with Mw≥7 in the past. The surface
deformation and related successive uplifts are modelled to infer the size and characteristics of probable future
earthquakes and their seismic hazard implications for the Algiers region.
© 2011 Elsevier

Resumo
Este estudo tem como objetivo fundamental, apresentar uma análise da evolução do relevo da Serra da Malcata sobretudo em termos estruturais. A apresentação deste trabalho justifica-se sobretudo pelo fato da análise desta elevação permanecer uma lacuna nos estudos de Geomorfologia. Deste modo procurámos desenvolver uma explicação da evolução da unidade geomorfológica da Serra da Malcata. Esperamos que a apresentação desta análise possa promover uma fundamentação geomorfológica da evolução da Serra da Malcata, procurando sobretudo lançar importantes elementos de explicação da evolução deste relevo e que os dados agora apresentados possam colmatar de momento o vazio existente nos conhecimentos de geomorfologia relativamente à Serra da Malcata. Palavras-chave: Serra da Malcata; Geomorfologia estrutural; Evolução tetónica; Basculamento;

Abstract:
The evolution of Serra da Malcata – Geomorphology study.
This study has as primary aim to present an analysis of the evolution from the relief in Serra da Malcata, especially when speaking in structural terms. This work’s presentation is mainly justified by the fact that this uplift analysis is still an omission in geomorphologic studies. Thus, we aimed to develop an explanation of the evolution from Serra da
Malcata’s geomorphologic unit. We hope that this analysis presentation might promote a geomorphologic backing of Serra da Malcata’s evolution, seeking above all to mount important explanation elements of this particular relief, hoping that the data now being presented may be able to fill in, at present time, the existing hollow in the geomorphologic knowledge regarding Serra da Malcata.
Keywords: Serra da Malcata; Structural Geomorphology; Tectonic Evolution;

This study shows the neotectonic deformation occurred in the southern piedmont of the Cumbres Calchaquíes, in the Amaicha and Tafí valleys. Neotectonic deformation manifests itself through faults, folds and diversions of drainage channels. The Amaicha valley is bounded to the north by the Tafí del Valle fault and to the south by the Los Cardones fault. The Cumbres Calchaquíes ride over the Sierra de Aconquija through the Los Cardones and Carapunco faults. The Carapunco fault also has a synestral component, responsible for generating an imbricated system of contractional fractures. In the study region many earthquakes of ≥ 3 and ≥ 4 magnitude coincide with regional faults evidencing its neotectonic activity. The seismic energy dissipated through materials with less cohesion that form the fill of the valleys, generating discrete fault scarps and strongly folded conglomerate strata. The foothills deposits of the Cumbres Calchaquíes absorbed most of the seismic energy released during the reactivation of the faults. Tectonic activity is deforming 630 a BP deposits in the Cumbres Calchaquíes piedmont.

In order to better understand the activity of the Akşehir normal fault in SW Turkey and the associated seismic hazard, we investigated the tectonic geomorphology of a 60-km stretch of the 100-km-long Akşehir fault block. The fault can be separated into seven geomorphic segments (1 to 7 from NW to SE) along the mountain front. Segment length varies from about 9 to 14 km, and relief of the horst block varies from about 0.6 km in the SE to 1.0 km in the NW. Analysis of the tectonic geomorphology of 32 drainage basins and mountain front facets using a combination of geomorphic indices reveals a general pattern of high slip rates in the northern and central segments and low slip rates in the southern, probably older, segments. We show that mountain front sinuosity varies from about 1.1 to 1.4 on segments S1-S6 to 2.4 on segment S7, suggesting that the six northern segments are more active than the southernmost segment. Similarly, χ analysis and slope-area analysis of streams reveal a pattern of steepest channels draining the central and northern segments of the horst. The ratio of valley floor width to valley height varies from 0.2 to 0.6, which are typical values for tectonically active mountain fronts; and alluvial fans along segments S1, S2, and S4 are back-tilted. Finally, we show that (1) shapes of the ~ 100–900m high mountain front facets are mostly triangular (~ 80%) and partly trapezoidal (~ 20%); (2) facet slopes range from 6 to 22°; (3) facets at the NW and SE segment ends are larger than the intervening facets; and (4) steepest facets occur along the central segments. Uplift rates estimated from the slope of mountain front facets range from about 0.06 m/ky on the southernmost fault segment (S7) to 0.23 m/ky on the more central S5 and 0.16 m/ky on the northern segment (S1). The estimated pattern of uplift is consistent with the pattern of geomorphic indices. The vertical relief of the facets suggests that uplift of the mountain front initiated in the late Miocene-early Pliocene and continues to the present, with the earliest surface-rupturing faults on the southern-most fault segment (S7). Large normal faults with a similar slip rate of 0.2–0.3 m/ky typically have strong earthquakes every few thousand years. Therefore, the many moderate to strong earthquakes on the Akşehir fault in the past few hundred years may be misleading. A paleoseismic evaluation could answer questions concerning the area's earthquake hazard. The tectonic geomorphology suggests that the Akşehir fault is active, and larger earthquakes than those of the historic period are a potential threat.

Soil development can significantly influence the topographic evolution of a tectonically
deforming mountain piedmont. Faults and folds associated with the North Frontal thrust
system deform piedmont sediments of variable compositions along the north flank of the
San Bernardino Mountains. The topographic expressions of folds with similar structural
characteristics diverge appreciably, primarily as a function of differences in sediment
composition and associated soil development. Soils with petrocalcic horizons in limestonerich
deposits are resistant to erosion, and anticlinal folds form prominent ridges. Folds
forming in granite-derived deposits with argillic soil horizons are eroded and/or buried
and are therefore topographically less pronounced. We propose that these landform contrasts
can be explained by differences in soil-controlled hydrologic and erosion characteristics
of deposits without calling upon changes in tectonic style along the mountain front

Partitioning of horizontal deformation between localized and distributed modes in regions of oblique tectonic convergence is, in many cases, hard to quantify. Here we use the geometry of river basins and numerical modeling to evaluate modes and rates of horizontal deformation associated with the Arabia-Sinai relative plate motion in Lebanon. We focus on river basins that drain Mount Lebanon to the west and are bounded by the Yammouneh fault, a segment of the Dead Sea fault system that transfers left-lateral deformation across the Lebanese restraining bend. We quantify a systematic counterclockwise rotation of these basins and evaluate drainage area disequilibrium using the c metric. The analysis indicates a systematic spatial pattern whereby tributaries of the rotated basins appear to experience drainage area loss or gain with respect to channel length. A kinematic model reveals that since the late Mio-cene, 23%–31% of the relative plate motion parallel to the plate boundary has been distributed along a wide band of deformation to the west of the Yammouneh fault. Taken together with previous, shorter-term estimates, the model indicates little variation of slip rate along the Yammouneh fault since the late Miocene. Kinematic model results are compatible with late Miocene paleomagnetic rotations in western Mount Lebanon. A numerical landscape evolution experiment demonstrates the emergence of a similar pattern of drainage area disequilib-rium in response to progressive distributed shear deformation of river basins with relatively minor drainage network reorganization.

Several Mesozoic limestone elevations of E-W elongated shape rise up in the central region of the Algarve Barrocal (Portuguese southwestern margin). Tectonic geomorphology suggests that these reliefs correspond to right lateral strike-slip contractional duplexes of a large, NW-SE trending, shear zone, with a pronounced topographic expression, whose southern boundary, located southeast of the Serra de Monchique hill, is defined by the São Marcos–Quarteira Fault Zone.

The Bengal Basin is one of the largest peripheral collisional foreland basins at the juncture of three converging lithospheric plates (Indian Plate, Eurasian Plate and Burma Plate), carrying signatures of regional scale sesimogenic faults, which is conducive for the frequent and recurrent earthquakes. The recent earthquakes occurred with a magnitude range (M w) of 3.6-5.7 in the western shelf zone of the Bengal Basin and the seismologists have predicted an event of potential earthquake of M w 8.2-9.0 due to locked mega thrust. Such activeness of seismic events reflects the vulnerability of densely populated towns and cities located in the Ganga-Brahmaputra-Megna Delta. The main point of research interest is the anomalous fluvial responses to active tectonics in the shelf zone of the Bengal Basin to explore the relative perkiness of regional tectonic uplift or subsidence. Since Palaeogene time, the peninsular river system (viz., Brahmani, Dwarka, Mayurakshi, Ajay, Damodar, Dwarkeswar, Silai and Kasai river basins) was directly influenced by the underlying structure and en echelon faults, and several landforms, channel morphology and morphostratigraphical units were distorted and deformed due to seismic shocks. The present study tries to document and understand the significant tectonic elements, geomorphometric anomalies and soft-sediment deformation structures on the alluvial river valleys and Quaternary floodplains using seismic information, proxy data, geomorphic indices of active tectonics, thematic mapping and stratigraphic analysis of depositional facies.

The left-lateral strike-slip Adıyaman fault is located in eastern Turkey within the plate boundary deformation
zone between Arabia and Anatolia. The Adıyaman fault is a major splay from the East Anatolian Fault (EAF),
one of the most important tectonic structures in the Eastern Mediterranean region. These faults are consequence
of the collision between the Arabian and Anatolian plates and the resulting westward tectonic escape of Anatolia.
Although the EAF has been intensively studied since its discovery in the late 1960s, little is known about the
Adıyaman fault and its tectonic activity. In this study, we extract geomorphic indices including mountain-front
sinuosity (Smf), valley floor width-to-height ratio (Vf), stream length-gradient (SL), catchment Asymmetry Factor
(AF) and hypsometric integrals and curves (HI and HC) to evaluate the relative tectonic activity of the Adıyaman
fault. These three geomorphic indices (AF, HI, and HC) are averaged to define an index for Relative Tectonic
Activity (RTA) that allows the Adıyaman fault to be divided into categories of low, moderate and high RTA.
The results confirm that the Adıyaman fault is an active fault with high to moderate Quaternary tectonic activity.
However, this fault is of minor importance on accommodating plate boundary deformation, as evidenced by the
recent crustal motions determined by GPS studies. Nevertheless, it is worthwhile to note that the Adıyaman fault
still poses a significant seismic hazard for the region despite its relatively moderate tectonic activity.