Book Reviewed in this article: Development and Environment in Peninsular Malaysia . S. Robert Aiken, Colin H. Leigh, Thomas R. Leinbach, Michael R. Moss. The Rural-Urban Fringe: Canadian Perspectives . Ken B. Beesley and Lorne H. Russwurm, eds. Women and Development . Lourdes Benería, ed. The Border that Joins: Mexican Migrants and U.S. Responsibility . Peter G. Brown and Henry Shue, eds. Cities of the World: World Regional Urban Development . Stanley D. Brunn and Jack L. Williams, eds. Time Resources, Society, and Ecology: On the Capacity for Human Interaction in Space and Time (Vol. I, Preindustrial Societies). Tommy Carlstein. Urban Geography . David Clark. Spanish City Planning in North America . Dora P. Crouch, Daniel J. Garr, and Axel I. Mundigo. Not On Our Street: Community Attitudes to Mental Health Care . M. J. Dear and S. M. Taylor Unequal growth: Urban and Regional Employment Change in the U.K. Stephen Fothergill and Graham Gudgin. Agricultural Land in an Urban Society . Owen J. Furuseth and John T. Pierce. The Petroleum Industry in Oil-Importing Developing Countries . Fariborz Ghadar. Historical Understanding in Geography, An Idealist Approach . Leonard Guelke. Regional Planning in Europe . R. Hudson and J. R. Lewis, eds. Remote Sensing for Resource Management . Chris J. Johannsen and James L. Sanders, eds. Geography and The State . R. J. Johnston. Texas Graveyards: a Cultural Legacy . Tlrry G. Jordan. The Politics of Location: An Introduction . Andrew Kirby. A Social Geography of the City . David Ley. Energy and the Future . Douglas MacLean and Peter Brown, eds. The Natural Environment of Newfoundland Past and Present . A. G. Macpherson and J. B. Macpherson, eds. Tourism: Economic, Physical and Social Impacts . Alister Mathieson and Geoffrey Wall. Railroads and Land Grant Policy: A Study in Government Intervention . Lloyd J. Mercer. Progress in Rural Geography . Michael Pacione, ed. Progress in Urban Geography . Michael Pacione, ed. Models of Spatial Inequality: Settlement Patterns in Historical Archaeology . Robert Paynter. Natural Hazard Risk Assessment and Public Policy, Anticipating the Unexpected . William J. Petak and Arthur A. Atkisson. The Nature of Geomorphology . Alistair F. Pitty. Regional Conflict and National Policy . Kent A. Price Women and Spatial Change: Learning Resources for Social Science Courses . Arlene C. Rengert and Janice J. Monk, eds. Urban and Regional Analysis for Development Planning . Richard Rhoda. Rivers: Form and Process in Alluvial Channels . Keith Richards. This Remarkable Continent: An Atlas of United States and Canadian Society and Culture . John F. Rooney, Jr., Wilbur Zelinsky, and Dean R. Louder, gen. eds. The Origins of Open-Field Agriculture . Trevor Rowley, ed. Residential Location Determinants of the Older Population . Gundars Rudzitis. Borderland Sourcebook: A Guide to the Literature on Northern Mexico and the American Southwest . Ellwyn R. Stoddard, Richard L. Nostrand, and Jonathan P. West, eds. Arctic and Antarctic . David Sugden. Tall Timbers Ecology and Management Conference, February 22–24, 1979, Proceedings No. 16 . Graphic Communication and Design in Contemporary Cartography (Progress in Contemporary Cartography , Vol. II). D. R. Fraser Taylor, ed. Living with Energy Shortfall: A Future for American Towns and Cities . Jon Van Til. The United States: Habitation of Hope . J. Wreford Watson. Air Photo Interpretation for Archaeologists . D. R. Wilson. Urban and Rural Change in West Germany . Trevor Wild, ed. Population and Resources . Harry Robinson. 相似文献
Subvolcanic ring complexes are unusual in that they preserve a rapidly frozen record of intrusive events. This sequential history is generally lost or complicated in plutons owing to mixing and mingling in a dynamic state. Thus, subvolcanic ring complexes are more like erupted rocks in their preservation of instantaneous events, but the self-contained nature of the complexes allows detailed structural and chemical work to be conducted in environments where the relative timing between individual magmatic events is commonly well preserved.
We suggest that development of subvolcanic ring complexes in the western Peninsular Ranges Batholith (PRB) involved the following three-stage generalized sequence: (1) fracturing of the roof above a buoyant or overpressured magma chamber, which resulted in moderately inward-dipping conical fractures that locally hosted cone sheets; (2) subsequent loss of magma from the chamber, combined with degassing of the melt, which facilitated collapse of the roof along near-vertical ring faults that locally hosted ring dikes; and (3) resurgence of the chamber, and/or intrusion of a broadly cogenetic nested pluton, which locally destroyed evidence for the earlier history of the system. This sequence has been repeated twice in one of the ring complexes that we have identified, which resulted in nested intrusive centers.
Calderas, subvolcanic ring complexes and plutons may represent progressively deeper sections through linked magma plumbing systems, and the systematic occurrences of these features in the western PRB are consistent with progressively deeper along-strike exposures of the batholith from south to north over a distance greater than 250 km.
In addition to subvolcanic complexes in the western PRB, deeper crustal levels exposed in the transition zone between eastern and western parts of the batholith preserve ring complexes emplaced at depths of up to 18 km. Occurrence of these deeper-level complexes suggests either that caldera subsidence can extend to mid-crustal levels or that other processes can produce ring complexes. 相似文献
The supracrustal enclave within the Peninsular Gneiss in the Honakere arm of the Chitradurga-Karighatta belt comprises tremolite-chlorite
schists within which occur two bands of quartzite coalescing east of Jakkanahalli(12°39′N; 76°41′E), with an amphibolite band
in the core. Very tight to isoclinal mesoscopic folds on compositional bands cut across in the hinge zones by an axial planar
schistosity, and the nearly orthogonal relation between compositional bands and this schistosity at the termination of the
tremolite-chlorite schist band near Javanahalli, points to the presence of a hinge of a large-scale, isoclinal early fold
(F1). That the map pattern, with an NNE-plunging upright antiform and a complementary synform of macroscopic scale, traces folds
'er generation (F2),is proved by the varying attitude of both compositional bands (S0) and axial pranar schistosity (S1), which are effectively parallel in a major part of the area. A crenulation cleavage (S2) has developed parallel to the axial planes of theF2 folds at places. TheF2 folds range usually from open to rarely isoclinal style, with theF1 andF2 axes nearly parallel. Evidence of type 3 fold interference is also provided by the map pattern of a quartzite band in the
Borikoppalu area to the north, coupled with younging directions from current bedding andS0-S1 inter-relation.
Although statistically theF1 andF2 linear structures have the same orientation, detailed studies of outcrops and hand specimens indicate that the two may make
as high an angle as 90°. Usually, in these instances, theF1 lineations are unreliable around theF2 axes, implying that theF2 folding was by flexural slip. In zones with very tight to almost isoclinalF2 folding, however, buckling attendant with flattening has caused a spread of theF1 lineations almost in a plane. Initial divergence in orientation of theF1 lineations due to extreme flattening duringF1 folding has also resulted in a variation in the angle between theF1 andF2lineations in some instances. Upright later folding (F3) with nearly E-W strike of axial planes has led to warps on schistosity, plunge reversals of theF1 andF2 axes, and increase in the angle between theF1 andF2 lineations at some places. Large-scale mapping in the Borikoppalu sector, where the supposed Sargur rocks with ENE ‘trend’
abut against the N-‘trending’ rocks of the Dharwar Supergroup, shows a continuity of rock formations and structures across
the hinge of a large-scaleF2 fold. This observation renders the notion, that there is an angular unconformity here between the rocks of the Sargur Group
and the Dharwar Supergroup, untenable. 相似文献
The Mesozoic paleomagnetic pole positions from the Indochina block and South China block are not consistent with each other in that the formers are displaced with respect to the latters westward in longitude and southward in latitude. The displacement is here interpreted as to be related to the India-Eurasia collision in such a way that after the collision the Indochina block was rotated clockwise by 8° about the Assam syntaxis, followed by an eastward translation of the South China bl.. 相似文献
CO2 concentrations at depths of 15,30, and 50 cm were determined over a one-year period in six karst soils in the Malay peninsula. Evidence suggests that the highest single CO2 value (MAXCO2, per cent) recorded at each site/depth provides the best estimate of conditions during groundwater recharge events. Soil depth (cm) and bulk density (BDEN) are the best predictors of MAXCO2, with the equation loglo(MAXCO2) = 1·146 (BDEN) + 0·00698 (DEPTH) - 1·227 accounting for 86 per cent of the variation. This equation is used to model MAXCO2 at seven, more remote sites. Soil throughflow patterns and groundwater recharge points are estimated from slope pantometer and soil depth surveys in order to assess the CO2 concentration with which soil waters ultimately equilibrate before entering the limestone. Limestone weathering seems to be predominantly of the open system type, the overall mean MAXCO2 of 1·65 per cent corresponding with a weathering potential of 167 ppm CaCO3. Weathering potentials vary markedly, ranging from 62–82 ppm on rocky hilltops to more than 280 ppm on certain tower karst footslopes in Selangor and the Kinta Valley and on moderate hillslopes developed in impure limestones in the Boundary Range. 相似文献
Calcrete profiles developed on Precambrian silicate rocks in south peninsular India are studied and compared in terms of mineralogical, chemical and isotopic composition. The aim of this study is to determine the origin of calcium and the processes governing the development of a minor economic deposit in different geomorphic settings. The investigation integrates observations from an outcrop to a microfabric scale and reveals that the origin of calcium is local and linked with the weathering of the minerals of the surrounding rocks. The CaCO3 precipitation occurs after vertical and lateral translocation in the slope system. 相似文献
Peninsular India (PI), which lies south of 24°N latitude, has experienced several devastating earthquakes in the past. However,
very few strong motion records are available for developing attenuation relations for ground acceleration, required by engineers
to arrive at rational design response spectra for construction sites and cities in PI. Based on a well-known seismological
model, the present paper statistically simulates ground motion in PI to arrive at an empirical relation for estimating 5%
damped response spectra, as a function of magnitude and source to site distance, covering bedrock and soil conditions. The
standard error in the proposed relationship is reported as a function of the frequency, for further use of the results in
probabilistic seismic hazard analysis. 相似文献