太古代

A forof single zircon U-Pb dating and whole rock isochron of Sm-Nd dating suggested that thePalooproterosoic rock in Chthaysia Bfork is formed in the time span from 2 400 Ma to 2000 Ma,Mesoproterocoic frOIn 1 400 Ma to 1000 Ma and the latest formdfrom 740 Ma to 430 Ma.

该区变质基底的时代划分、区域对比、基底结构和性质一直存在较大的分歧和争论，最早Grabau（1924）认为中国东南沿海存在太古代的基底，提出华夏古陆的概念匕］。

After crystallization basement was formed in Tai Shan group in the end of Archaean, it suffered long term denudation and deposited to marine and land interbedded formation with stable lithology and thickness. Buried Hill is a large size fold nappe which was uplifted, compressed, folded, denudated and settled in Indosinian period, deposited in Mesozoic formation, then wholly advanced to the west in the late of Yan Shan movement. The force acting on internal structure of buried hill was complicated, and fault block was broken up.

本文通过物探、测井二次解释和钻井等大量资料的研究认为：桩西古潜山在太古代末期泰山群形成结晶基底后，遭受长期剥蚀，在古生代沉积一套岩性、厚度稳定的海陆交互相地层，是一个经印支期抬升、挤压、褶皱、剥蚀、沉降接受中生界地层沉积之后，在燕山运动后期，整体向西推移的大型褶皱推覆体。

Many crustal zircons have the age (up to 2770Ma) that is much earlier than the formation of ophiolite considered by previous researchers, indicated the abundant subduction crust components occur in the zircons separated, which was preserved in the mantle, and outcropped with the mantle cycle process.

纯橄岩样品四个测点得到加权平均值为130.0±2.8Ma，属早白垩世，代表了纯橄岩的结晶年龄；研究中发现许多地壳成因的古老锆石(最老可达太古代2770Ma)，远远早于目前主流观点中蛇绿岩的形成时间中生代晚期，综合考虑认为所选锆石有大量俯冲地壳成分，在地幔中保存，后随地幔循环运移出露地表。

Based on the a series of research carried in typical gold lodes in Linglong, Jiapigou, Dongfeng and Xiaoqinling and related data, it is suggested that the deposit type is concentrated in the circumference of the North China Platform, occurring in the Archean granite-greenstone belts, being adjacent to deep-cut faults and being accompanied by the Mesozoic, remelted l-type granites. The spatial distribution features of the deposit type indicate that the deposits are closely related to the multiple evolution of the mantle plumes.

通过对玲珑、夹皮沟、东风和小秦岭等典型中深脉状金矿及相关资料的研究表明：中深脉状金矿主要分布于华北地台的周边，位于太古代花岗—绿岩带中，与深大断裂相邻，同中生代重熔I型花岗岩伴生，这种空间展布特征与地幔的多级演化有关。

The model showed that a partial pressure of only 2.9 millibars of CO2 would have been needed during the late Archaean and early Proterozoic periods in order to bring the surface temperature of the Earth above freezing.

模拟显示：在太古代末期和原生代初期，要想使地球表面温度升高到凝点以上，只需要二氧化碳的局部压力达到2.9毫巴。

Millibars of CO2 would have been needed during the late Archaean and early Proterozoic periods in order to bring the su rface temperature of the Earth above freezing.

模拟显示：在太古代末期和原生代初期，要想使地球表面温度升高到凝点以上，只需要二氧化碳的局部压力达到2。 9毫巴。

In the space, along with increased distance from the main ore-controlling structures, the frequency of P type of pyrite and their thermoelectricity also decreased gradually. Within one lode, from the upper to the lower parts of an ore body, the vertical change of pyrite in thermoelectricity as the follows:① when the ore body is stable, that is when the ore body is uniformly and continuously mineralized, the Dp andαvalues keep increased from shallow to deeper parts;② when an ore body is discontinuously mineralized, the Dp andαvalues have a wavy increasing tendency from the shallow to the deeper;③ when the deeper part of an ore body contains abundant, Co and Ni high mafic dykes, the Dp andαvalues of pyrite decreased from the shallow to the deeper parts of an ore body, that is, an reversed zoning of pyrite thermoelectricity occurs for pyrite in this situation contain more Ni and Co and belongs to N type.④ For the deposits hosted in the Archean metamorphic rocks, because all of the pyrite in this case is N-type, the vertical change of pyrite is not featured by the transition of pyrite type, but by the increased values of Vnp and α from the shallow to deeper parts of an ore body.

在空间域上，水平分带规律为：随远离主干断裂，矿脉中P型的出现频率逐渐降低或热电系数值逐渐变小；在同一条矿脉中，这是由于矿化不均匀性及脉岩的影响，由矿体的上部到下部，它的垂向变化特征可以有如下几种变化形式：①由矿体的浅部到深部，黄铁矿的Dp值、或α值呈稳定升高的趋势时，矿体往往表现为矿化均匀，连续性好、延伸稳定；②由浅部到深部，黄铁矿的Dp值、α值呈波状变化，但总体又具有增大的趋势时，所在的矿体连续性差；③当矿脉的下部发育有大量的基性脉岩时，由于基性脉岩中常含有较高的Co、Ni，使其中黄铁矿的Co、Ni含量较高而呈N型导电，由矿体的上部到下部，黄铁矿的Dp值、α值呈减少的趋势，而造成黄铁矿热电性特征的逆向分带，④产于太古代变质岩中的中深脉状金矿，由于其中的黄铁矿均为N型导电，所以垂向变化规律并不表现为导型的改变，只是Vnp值或α值从矿体的上部到下部由小变大。

He says by examining oxidation rates they have shown the mantle has cooled several hundred degrees since the Archaean.

丹尤柴夫斯基说，通过检测氧化的速度，他们证明了自从太古代以来，地幔冷却了好几百度。

On the basis of detailed studies on structures and metamorphism in YantaiPonglai-Qixia area, deformation and metamorphic evolution of the Jiaobei region since Archaean and their implications are analysed in this paper.

本文依据在烟台－蓬莱－栖霞地区的详细构造与变质研究，分析胶北地区太古代以来的变形与变质演化历史及其意义。

Fe isotope compositions, major and rare earth elements of Archaean banded iron formations from Anshan-Benxi area, Liaoning Province have been studied.

通过Fe同位素、稀土元素与主量元素相结合的方法，对辽宁省鞍山－本溪地区新太古代条带状铁建造的成矿物质来源提出了有效制约。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。