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A number of studies have shown that the conservation and protection of significant geoheritage sites are crucial for scientific expeditions, education, and cultural viewpoint. Such geosites include places of geological, geomorphological, structural, palaeontological, stratigraphic, mineralogical, and/or archaeological significance. The values for bio-tourism, geotourism, and archaeo-tourism with distinguished geological features can be considered geoheritage in particular. The rocks of the Kumaun Himalaya (North India) ranging from the Proterozoic to Cenozoic periods are ideally preserved in various geographic domains and comprise a large number of geosites. These rock units have enormous potential to implement the concept of geopark and geotourism in the Kumaun Himalaya. In this paper, we have highlighted significant geosites of Kumaun Himalaya by describing their geology and related aspects along with their educational value. The conservation of proposed geosites is especially crucial to preserve them for posterity. Government agencies and educational institutes can promote the existing and potential sites of geotourism which will ultimately enhance the economy of the region and certainly help to develop and conserve important geosites in the rugged Himalaya terrain. Therefore, it is proposed that the geosites of Kumaun Himalaya, preserved in different geographical domains, should be conserved as national geoparks in India. [ABSTRACT FROM AUTHOR]

Himalaya is one of the youngest mountain systems with a fragile ecosystem due to continued collision tectonics. The endogenic and exogenic processes in the Himalaya have made landslide one of the critical surface processes continually sculpting the Himalaya. Constituting the hanging wall of the Main Boundary Thrust (MBT), the south-facing slope of the Mussoorie Syncline is prone to various slope movements. Several old and active landslides are taking place along the Dehradun-Bhitarli Chhoti-Mussoorie road section. The main causative factors for landslides are tectonics, slopes, and human interference. The highly sheared bedrocks and high numbers of joint sets in the bedrocks are the signatures of the successive phases of tectonic uplift along the MBT imprinted on the bedrocks. The intersecting joint sets developed in the bedrocks have formed wedges, and these wedges have facilitated the recurrence of several landslides. Wedge failure, sliding (bedrock and debris), and toppling are the primary types of failure mechanisms, of which wedge failure-induced landslides accounts for the maximum. The south-facing slopes are very steep and are also one of the contributing factors to the instability of the hill slope. Anthropogenic activities have further aggravated slope stability as the roads are constructed across steep slopes and highly sheared rocks. The onslaught of rains easily destabilizes the weak rocks during monsoon, where the region receives a good amount of rainfall. The landslides occur primarily during or right after monsoon when the slope-forming materials become saturated with water. Recent tectonic activity along the MBT is evident from tectonic landforms such are uplifted terraces, linear fault traces along the MBT, and triangular facet cones. [ABSTRACT FROM AUTHOR]

In the present study, we are reporting an unnamed glacier located (30.28089N-80.69344E) in the upper Kali Ganga valley, Pithoragarh district, Uttarakhand, India, which has been affected by active fault and climate change. Recent tectonic activity and change in climatic conditions have changed the course and morphology of this glacier. An active fault has produced a fault scarp that measures about 250 m in height with a northerly dip, the fault trace is 6.2 km in length and trend towards NW-SE. The observation is based on the satellite image, toposheet and Google Earth images. We observed that the 5 km long unnamed glacier, which covered ∼4 km2 area in Kuthi Yankti valley (Tributary of Kali River) has abruptly changed its main course. The NE moving glacier has been abruptly truncated and forced to move towards SE and ultimately merges with the adjacent glacier named Sumzurkchanki as a result of tectonic forcing. It is one of the unique behaviors of the glacier, which is for the first time reported from the Himalayan glacier as no such observation have so far been reported on this type of glacier kinematics. The study will help to understand the glacial-tectonic interaction and provides key information for future studies. [ABSTRACT FROM AUTHOR]

Here a report of a lake of about one km in length that resulted from damming of a river by landslide near Kuwari village at the altitude of 1733 m asl and located between N 30° 5′ 16″–30° 5′ 16″ and E 79° 48′ 30″–79° 48′ 29″. On the basis of Google Earth images, it has been observed that a huge landslide took place from 16th to 17th June, 2013 and also in 2019 (as per the local sources) that blocked the Shambhu Gad (Baura Gad) in Bageshwar district and formed a huge lake, which covered ∼15666 m2 area. It was also observed that an old landslide was reactivated due to cloud burst or toe erosion and affected an area ∼862913 m2 between 2664 and 1761 m asl. The area affected by the landslide is ∼4 km, the maximum width is about 650 m. In the vicinity of Kuwari village the impact of this Kuwari landslide also observed in the Jhaliya village (district Chamoli) established over south facing slope in the right bank of Pinder river. Both the villages are separated by E-W trending ridge (3700 m asl). [ABSTRACT FROM AUTHOR]

This paper documents the various factors contributing to the evolution of landforms in the Kosi River valley, Ukhaldhunga area of the Kumaun Himalaya, Uttarakhand. The area falls in the major tectonic boundary between the Lesser Himalaya and the sub-Himalaya. Passing through the Parewa-Ukhaldhunga-Dabara area, this tectonic contact is known as the Main Boundary Thrust (MBT), which is characterized by presence of varied landforms. Study of the development of geomorphology, particularly those evolved in the MBT zone, suggests that the morphological features are intimately associated with the tectonic activities related to the movement of rocks along the MBT and the surface processes such as fluvial and mass movement. The various landforms observed in the MBT zone include strath terraces, fill terraces, paleochannels and V-shaped valley that pertain to fluvial genesis; gravity induced landforms such as landslide debris and colluvial fans; and tectonic landforms such as linear fault traces, swerving/swing of river course and linear depressions. Signature of recent tectonic activity along the MBT is observed between Dabara and Khakrakot. The activity is evident in the form of 8-km-long active fault trace trending NW-SE. Normal fault related landforms are observed in the hanging wall block of the MBT. Neotectonic strath terraces and fill terraces are well developed in the MBT zone. Multiple events of recurrence of landslides are evident from exposed section of landslide debris fans. The bedrocks are highly sheared, suggesting successive tectonic movements along the MBT. As a consequence, tectonic wedges have developed in the bedrocks. These wedges have facilitated for the recurrence of a number of landslides. The anthropogenic activities have also aggravated the slope stability. Truncation of older debris fan surfaces by an erosional/fault scarp is observed and the scarp separates the older fans from the youngest debris fan deposit. The scarp runs parallel to the MBT and Kosi River. Swerving of the Kosi River is as a result of the tectonic forcing along active lineaments/faults. The trend of lineaments of the maximum and high density is NE-SW, which is transverse to the trend of the NW-SE trending Himalayan fold-thrust belt. [ABSTRACT FROM AUTHOR]

A portion of the Kosi River in the outer Kumaun Lesser Himalaya is characterized by wide river course situated south of the Ramgarh Thrust, where huge thickness (~200 m) of the landslide deposits and two to three levels of unpaired fan terraces are present. Brittle normal faults, suggesting extensional tectonics, are recognized in the Quaternary deposits and bedrocks as further supported by surface morphology. Trending E-W, these faults measure from 3 to 5 km in length and are traced as discontinuous linear mini-horst and fault scarps (sackungen) exposed due to cutting across by streams. Active normal faults have displaced the coarsely laminated debris fan deposits at two sites located 550 m apart. At one of the sites, the faults look like bookshelf faulting with the maximum displacement of ~2 m and rotation of the Quaternary boulders along the fault plane is observed. At another site, the maximum displacement measures about 0.60 cm. Thick mud units deposited due to blocking of the streams by landslides are observed within and above the fan deposit. Landslide debris fans and terrace landforms are widely developed; the highest level of fan is observed ~1240 m above mean sea level. At some places, the reworking of the debris fans by streams is characterized by thick laminated sand body. Along the South Almora Thrust and Ramgarh Thrust zones, the valleys are narrow and V-shaped where Quaternary deposits are sparse due to relatively rapid uplift across these thrusts. Along the South Almora Thrust zone, three to four levels of fluvial terraces are observed and have been incised by river exposing the bedrocks due to recent movement along the RT and SAT. Abandoned channel, tilted mud deposits, incised meandering, deep-cut V-shaped valleys and strath terraces indicate rapid uplift of the area. Thick mud sequences in the Quaternary columns indicate damming of streams. A ~10-km-long north-south trending transverse Garampani Fault has offset the Ramgarh Thrust producing tectonic landforms. [ABSTRACT FROM AUTHOR]

The present study incorporates quantitative analysis of drainage of the Ramganga basin, Garhwal Himalaya, Uttarakhand. The drainage parameters (linear, areal and relief) of the Ramganga basin from Dudhatolidhar peak its point of origin to Kalagarh from where the river Ramganga enter into the plain, are covered. The impact of the morphological characters on the terrain is reflected by the drainage basin of the area. The calculated values of all the morphometric parameter of 38 V order intrabasins for different lithotectonic units were computed under four sectors viz., NE of NAT, between NAT and SAT, between SAT and MBT and downstream of MBT. In the lower reaches of Ramganga basin the various morphometric parameters shows existence of proportionality between stream length and catchment area while such proportionality is non-existence in the crystalline zone. Structural control on the drainage patterns of the Ramganga river and its tributaries are observed in the form of straight course, wide valleys with thick fluvial deposits and relatively gentle stream gradient along the transverse faults to incised valleys; less fluvial deposits in the banks and steeper stream gradient with knick points in the hanging wall of thrusts. [ABSTRACT FROM AUTHOR]

Main Boundary Thrust (MBT) zone is constituted of some of the landslide prone areas in southeastern part of Kumaun Sub-Himalaya. Role of landslides as natural hazard and hill slope modifying agent is well documented from various part of Himalayan region and southern hills of Kumaun particularly in the MBT zone, which are susceptible to various type of mass movement. The rocks making up the slopes has been put to a number of brittle deformation phases during the movement along the MBT, and are traversed by number of joint sets. In the open slope these intersecting joint sets forms wedges and are the most favorable site for initiation of rockfalls and other types of landslides. Landslides are taking place primarily due to high angle slopes, formation of structural wedges along the free steep slopes, sheared nature of the rocks due to proximity to the MBT and neotectonic activities along the MBT and other transverse faults. Wedge failure is a common type of landslides in rock slopes characterized by multiple joints and acts as sliding planes for the failed blocks. Field observations and wedge failure analysis indicates most of the landslides taking place in MBT zone of Kumaun Sub-Himalaya are joint controlled. Safety Factor analysis suggests MBT zone of Kumaun Sub-Himalayan region is prone to landslides and related mass movements. This zone is also neotectonically active as indicated by various geomorphic signatures such as structurally controlled drainage pattern, offsetting of fan by MBT and formation of number of small lakes. [ABSTRACT FROM AUTHOR]

The Churachandpur-Mao Fault (CMF), trending NNE-SSW, is morphogenic in nature and can be traced for ~ 300 km. It is defined by straight valleys; most prominent being between Kangpokpi and Maram. The fault takes a north-easterly trend from Maram where the fault zone is characterized by active landslides during the monsoon. At Puni Pfosemai, which represents the hanging wall of the fault, extensional tectonics of local extent is observed. This is designated the Puni Pfosemai Fault that trends NNE-SSW and is about 2.5 km in length. The downthrown block is characterized by single-order streams with steep gradients. In the downstream, the fault scarp facing SE developed in the footwall block is more than 100 m in height. The upper portion of the Barak River is tectonically controlled. The SW flowing Barak River takes an almost 360° turn at Karong to flow NNE, before changing course again towards the northwest near Maram. The immediate hanging wall of the CMF is characterized by a narrow valley with relatively high stream-gradient index and steepness index values. A strath terrace of 11 m height is observed on the hanging wall block of the CMF. The straight river valley and concavity (θ) of 0.64 for the Barak River are indicative of active tectonics. [ABSTRACT FROM AUTHOR]