An In-Situ Melting Model of Granite Formation: Geological Evidence from Southeast China

2003 ◽  
Vol 45 (7) ◽  
pp. 611-622 ◽  
Author(s):  
Guoneng Chen ◽  
Rodney Grapes
Keyword(s):  
Geological Evidence ◽  
Southeast China ◽  
Granite Formation

scholarly journals Effects of Tidal Scenarios on the Methane Emission Dynamics in the Subtropical Tidal Marshes of the Min River Estuary in Southeast China

2019 ◽  
Vol 16 (15) ◽  
pp. 2790 ◽  
Author(s):  
Jiafang Huang ◽  
Min Luo ◽  
Yuxiu Liu ◽  
Yuxue Zhang ◽  
Ji Tan
Keyword(s):  
High Tide ◽  
River Estuary ◽  
Tidal Marshes ◽  
Tidal Wetlands ◽  
Ch4 Emission ◽  
Air Exposure ◽  
Southeast China ◽  
Min River ◽  
Min River Estuary

In order to accurately estimate the effects of tidal scenarios on the CH4 emission from tidal wetlands, we examined the CH4 effluxes, dissolved CH4 concentrations, and environmental factors (including in situ pH, Eh and electrical conductivity, porewater SO42−, NO3−, and NH4+) during inundation and air-exposure periods in high- and low-tide seasons in the Min River Estuary in southeast China. By applying static and floating chambers, our results showed that the CH4 effluxes during the inundation periods were relatively constant and generally lower than those during the air-exposed periods in both seasons. When compared, the CH4 effluxes during the air-exposed periods were significantly higher in the high-tide season than those in the low-tide season. In contrast, CH4 effluxes during the inundation periods were significantly lower in the high-tide season than those in the low-tide season. During the inundation periods, dissolved CH4 concentrations were inversely proportional to in situ Eh. Under air-exposed conditions, CH4 effluxes were proportional to in situ pH in both seasons, while the dissolved CH4 concentrations were negatively correlated with the porewater SO42− concentrations in both seasons. Our results highlighted that CH4 effluxes were more dynamic between inundation and air-exposure periods compared to low- and high-tide seasons.

Climatic Changes in South-East India during Early Palaeolithic Times

1932 ◽  
Vol 69 (5) ◽  
pp. 193-205 ◽  
Author(s):  
F. J. Richards ◽  
L. A. Cammiade ◽  
M. C. Burkitt
Keyword(s):  
East Africa ◽  
Climatic Changes ◽  
East African ◽  
Geological Evidence ◽  
Arid Conditions ◽  
Lower Palaeolithic

HUMAN artifacts can often be very useful to the geologist. When they occur in sufficient numbers and are characteristic, prehistorians can be definite in assigning the industries to a certain culture or cultures, and they can then be utilized by the geologist in the same way as are fossils. In Europe during a part of Quaternary times Lower Palaeolithic cultures flourished. Now Quaternary times in Europe can, of course, be readily subdivided into glacial and interglacial periods, but these naturally did not occur further south. In East Africa geological evidence has been adduced to show that intense pluvial periods took the place of our European glaciations, while during the interglacial phases the African areas suffered from arid conditions. Lower Palaeolithic industries are found at certain levels in East Africa and they enable the geologist to correlate the East African and European sequences. South-East India (Madras) is also not an area where glaciations ever occurred: but, we ask, can geological evidence be adduced to demonstrate climatic changes corresponding to those found to have occurred in East Africa ? Lower Palaeolithic industries occur in great numbers in South-East India; whereas most of them have been merely collected from the surface, and are therefore useless for the purposes of exact dating, a number of finds in situ in definite layers have been made, and as in East Africa these can be used as datum lines for correlating purposes.

scholarly journals Analysis of potential field anomalies in Lavrion mining area, Greece

Geophysics ◽  
1998 ◽  
Vol 63 (6) ◽  
pp. 1965-1970 ◽  
Author(s):  
Gregory N. Tsokas ◽  
Alexandros Stampolidis ◽  
Antonis D. Angelopoulos ◽  
Stefanos Kilias
Keyword(s):  
Gravity Anomaly ◽  
Three Dimensional ◽  
Mining Area ◽  
Geological Evidence ◽  
Long Wavelength ◽  
Ancient Athens ◽  
First Millennium ◽  
Anomaly Map ◽  
Three Dimensional Models

Mining activities in Lavrion began during the first millennium B.C. after the decline of ancient Athens and then restarted more deliberately during the nineteenth century. Aeromagnetic data from a 1967 survey of the mining area was recompiled, processed, and interpreted for the present study. The original flight lines were digitized and leveled, and the international geomagnetic reference field (IGRF) was removed. The data were inverted by means of a terracing technique that defines separate domains of uniform distribution of physical properties that cause the magnetic anomalies. The log power spectrum was computed; along with the results of terracing, it suggested the existence of two sources of the magnetic anomaly. The long‐wavelength anomaly reflects a large, concealed body that is most probably a granitic intrusion, consistent with local geological evidence. The source of the short‐wavelength anomaly is a strongly magnetized body attributed to the net effect of various thin, magnetite‐bearing sulfide zones. The anomalies were then separated in the wavenumber domain. Magnetic susceptibility measurements were made in situ on the exposed parts of the local formations. Three‐dimensional models whose effect simulates the observed anomalies were calculated. Results of the modeling show that the large magnetic body is buried at 0.68 km depth. The small, relatively shallow body is about 0.035 km thick and buried at 0.6 km depth. The bodies do not show any corresponding gravity anomaly on the regional Bouguer gravity anomaly map.

Some Hampshire and Dorset handaxes and the question of ‘Early Acheulian’ in Britain

1975 ◽  
Vol 41 ◽  
pp. 1-9
Author(s):  
Derek Roe
Keyword(s):  
Geological Evidence ◽  
Christ Church ◽  
The Hill ◽  
Lower Palaeolithic

SummaryA Lower Palaeolithic handaxe found a few years ago at St Catherine's Hill, Christ church, is described. Various aspects of its technology and morphology appear archaic, and although it was found in a secondary context, with no clear geological evidence for its true age, relatively old Pleistocene gravels do occur at the summit of the hill. At the Ballast Hole, Corfe Mullen, a few miles west, J. B. Calkin and J. F. N. Green recorded some 25 years ago a number of handaxes very similar to this one, in a hill-wash deposit below bluff gravels; they suggested that the implements had originally been dropped on the surface of the Sleight (170 ft) terrace while the 130 ft terrace was forming nearby. These implements were demonstrably older than the well-made later Acheulian ovate handaxes from the same pit. They were called Middle Acheulian by Calkin and Green, but it is suggested that Earlier Acheulian would be a better description. Their likely context in the British sequence is briefly discussed. Early Acheulian occurrences in situ in early deposits are rare in Britain and Europe.

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