Holocene Floral and Faunal Remains Revealed Concealed Neotectonic Disturbance (Saria Tal, Kumaun Himalaya, India)

Palynological and paleontological investigations supported by the radiocarbon dates of the lacustrine sediments of two profiles from the temperate lake Saria Tal, in Naini Tal District, Kumaun Himalaya, have revealed the presence of a concealed fold at the region. The profile from bore cores represents the upper part of the Late Holocene and the profile from exposed sections from the Middle Holocene to the over middle part of the Late Holocene. The data generated from different investigations have uniformly indicated that the former profile represents normal superposition, while the latter represents the reverse order. The contemporary pollen as well as molluscan zones of both profiles are situated at different elevations but consist of similar bioremains - indicating continuation of the same strata in two profiles. The presence of reverse order of superposition, continuation of the same strata in two profiles at different elevations, and the orientation of biozones, have indicated that the revealed folding is of syncline type. The present study has also given an idea about the origin of this lake.

Crustal Deformation Revealed by GPS in Kumaun Himalaya,India

The foremost Global Positioning System(GPS) derived measurements in the Kumaun Himalaya indicate that most of the crustal motion of the Indian plate is accommodating towards the base as well as on the hanging wall of Main Central Thrust(MCT).Deformation pattern within the Kumaun Himalaya varies from south to north and indicates maximum deformation rate near MCT.Our study,based on the campaign mode GPS survey during 2003- 2006,reveals that the area between north of North Almora Thrust(NAT) and at the base of Great Himalaya registers maximum strain rate,which is lowered towards the Trans Himadri Fault(THF).The GAMIT-GLOBK processed campaign data of the area show that currently,the Himalayan Frontal Fault(HFF) and Main Boundary Thrust(MBT) are locked with the Indian plate,and a 6.7 ± 2.5 mm/yr of horizontal shortening is taking place between the Lesser Himalaya and Peninsular India.

Magnetic fabric and geomorphic characteristic of Neotectonic activity along strike direction of North Almora Thrust,Kumaun Lesser Himalaya,India

Structurally,the North Almora Thrust(NAT),is placed in the northern proximity of the Almora Nappe(AN)in the Kumaun Lesser Himalaya.The NAT is characterized by the presence of a zone of mylonitic rocks of basal Saryu Formation(1800±100 Ma)in the hanging wall and the metasedimentaries of Inner Lesser Himalayan rocks as the footwall block.The NAT has been dextrally offset by two estabilished maj or faults i.e.Saryu River Fault(SRF)in Saryu Valley and Dwarahat-Chaukhutia Fault(DCF)in Ramganga valley.In present study,we identified four new faults,based on field study,geomorphic landform and magnetic fabric analysis.These faults are N-S trending Pancheshwar Fault,NE-SW Rameshwer Fault,NNE-SSW trending Kosi Fault,and NNE-SSW trending Gagas Fault(GF).Our results show that the zone is bound by cross cutting relation with NAT and these fault zones are comparatively more active than other regions.Furthermore,we suggest that the steep and NW-SE orientation of magnetic foliation within the NAT zone is a result of NE-SW oriented progressive regional compression.The magnetic foliations represent the unseen internal foliations in the rocks developed due to preferred alignment of magnetic minerals and can be found through the Anisotropy of magnetic susceptibility(AMS)study.Variation in the alignment of the field and magnetic foliations are developed due to superimposed brittle deformation along the faults over the pre-existing field foliations.Magnetic foliations represent the impact of last stage deformation and significant to find brittle deformation and finite strain in the rocks of the study area.The lowering of anisotropy(Pj)away from the fault zone represents distribution of strain across the NAT zone.AMS fabric confirms the presence of faults developed across the NAT zone and also explains the deformation pattern along these faults.The geomorphic anomalies and steepness changes across the NAT zone are correlated with active deformation along the NAT and associated transverse faults.

Mineralogy, Geochemistry and Palaeomagnetism of Mafic Dykes from Kumaun Lesser Himalaya: Implication on Petrogenesis, Tectonic Setting and Timing of Mafic Magmatism in Northern Part of Indian Lithosphere

Occurrence of mafic dykes in Himalaya has been intriguing and debated since long because of its difficulty to ascent and emplacement through a thickened crust.Mafic dykes in Kumaun Lesser Himalaya(KLH)of central Indian

Ecological variables influencing the diversity and distribution of macrolichens colonizing Quercus leucotrichophora in Uttarakhand forest

Ecological variables play a significant role in determining the diversity and distribution of any living organism on earth. Lichens are not exceptional and are quite sensitive in comparison to other organisms; hence the present study focuses on the impact of ecological variables on the diversity and distribution of epiphytic macrolichens colonizing Quercus leucotrichophora across eight different sites(50 m × 50 m) in Thal Ke Dhar forest, Kumaun Himalaya, Uttarakhand, India. For sampling of macrolichens, 200 trees(25 trees from each site) of Q.leucotrichophora were selected from each site and five quadrats of 5 cm × 10 cm(1000 quadrats in totality) were drawn at the tree trunk. From all the sampled trees, a total of 54 species of epiphytic macrolichens belonging to 18 genera and five families were recorded. Various ecological variables, namely altitude, aspect, slope, diameter at breast height(DBH), and lopping percent(partial cutting of the twigs as disturbance), were also analyzed to investigate their influence on macrolichen species composition and distribution pattern in the study area. For the determination of relationships between these variables, statistical analysis, namely Pearson's Correlation Coefficient, Polynomial regression analysis and Principal Component Analysis(PCA)were performed. Out of all variables, lopping was significantly correlated to species richness of epiphytic macrolichens(0.712~*, p<0.05) and it was confirmed by Pearson's Correlation Coefficient.Despite of having high anthropogenic pressure or impact through lopping, the maximum number of macrolichen species was recorded at elevation 2267 meter above sea level(m asl). The present study revealed that besides other ecological variables,lopping practices can act as a key parameter incontrolling the diversity and distribution not only of epiphytic macrolichens but also of other life forms such as bryophytes, pteridophytes, insects, birds etc.and can be either negatively or positively correlated.

印度库茂恩喜马拉雅纳尼塔尔温带地区晚全新世古植被和古气候(英文)

根据从印度库茂恩(Kumaun)喜马拉雅纳尼塔尔(Naini Tal)温带地区获得的85 cm钻井的孢粉资料,恢复了1720+/-130年以来晚全新世古植被演变史,并推测了当地的古气候。当前孢粉资料说明了该地区当时发育有栎树混交林和波动的温暖湿润气候。孢粉组合序列的初始阶段,森林距沉积盆地较远。但是,由于气候变得更加温暖潮湿,森林也很快茂密起来。约1200年前,因气候恶化,森林变得稀疏。而在约124年前,气候再次转好。麦类及其他作物花粉资料证明农耕活动大约开始于1460年前左右。