以三角图表示石炭成分

除去灰份将炭(定炭)烟(挥发份)及水(水份)三者之百分率重行计算各在三角图中定其位置,则每种石炭可以三角图中之一点代表之.上图即以此法表示中国二十馀种著名石炭之位置,及其相互关系.以此可为石炭分类之根据。     

A PETROGRAPHICAL STUDY OF THE WURMKALK(With two Plates)

I. GENERAL DESCRIPTION. Wurmkalk is the term given by von Richthofen to Conglomeraticlimestone in the Cambrain beds in North China. It is widely distributed is thenorthern provinces, vis., Fengtien, Shantung. Chihli, Shansi, Honan, etc. The     

ON A NEW GENUS OF SYRINGOPOROID CORAL FROM THE CARBONIFEROUS OF CHIHLI AND FENGTIEN PROVINCES.

In the course of my study on the Chihsia Corals from Central China, Mr. Y. T. Chao my collegue of the Geological Survey was so kind as to hand over to me two specimens of tube corals which he personally found in a limes-     

A GRAPHIC METHOD TO AID SPECIFIC DETERMINATION OF FUSULINOIDS AND SOME RESULTS OF ITS APPLICATION TO THE FUSULIN?E FROM N. CHINA.——WITH 2 PLATES AND 20 TEXT-FIGURES.

本篇分为三节:第一节论研究(竹廷)蜗之方法及其各部分之名称;并猎取古生物学家迄今历史之结果而加以批评。第二节专述中国北部已发见之(竹廷)蜗。第三节讨论本篇所述各种(竹廷)蜗生存之时代及其棲息流徙之情形。     

STRATIGRAPHY AND PALEONTOLOGY OF THE SINIAN ROCKS OF NANKOU

INTRODUCTION The Sinian rocks in China as far as we know are most well developedin Chihli and Shansi provinces. In Chihli, they are usually restricted to theupper part, as in Ta Yang, Pei Yu, Hsia Ma Ling, Ching Pei Kou and other     

REPORT ON THE EXCAVATION OF THE LOCALITY 13 IN CHOUKOUTIEN~1

1. INTRODUCTION When inspecting the Choukoutien area in October 1933, under the direction of the late Dr. Davidson Black, the workmen brought to the attention of the members of the Cenozoic Laboratory a fossiliferous site which had     

REPORT ON THE EXCAVATION OF THE LOCALITY 13 IN CHOUKOUTIEN~1

1. INTRODUCTION When inspecting the Choukoutien area in October 1933, under the direction of the late Dr. Davidson Black, the workmen brought to the attention of the members of the Cenozoic Laboratory a fossiliferous site which had     

Anatomy of a submarine pyroclastic flow and associated turbidity current: July 2003 dome collapse, Soufrière Hills volcano, Montserrat, West Indies

The 12 to 13 July 2003 andesite lava dome collapse at the Soufrière Hills volcano, Montserrat, provides the first opportunity to document comprehensively both the sub‐aerial and submarine sequence of events for an eruption. Numerous pyroclastic flows entered the ocean during the collapse, depositing approximately 90% of the total material into the submarine environment. During peak collapse conditions, as the main flow penetrated the air–ocean interface, phreatic explosions were observed and a surge cloud decoupled from the main flow body to travel 2 to 3 km over the ocean surface before settling. The bulk of the flow was submerged and rapidly mixed with sea water forming a water‐saturated mass flow. Efficient sorting and physical differentiation occurred within the flow before initial deposition at 500 m water depth. The coarsest components (～60% of the total volume) were deposited proximally from a dense granular flow, while the finer components (～40%) were efficiently elutriated into the overlying part of the flow, which evolved into a far‐reaching turbidity current.     

Deep channel sedimentation in the Lower Cretaceous McMurray Formation, Athabasca Oil Sands, Alberta

ABSTRACT In the region of the Athabasca Oil Sands, Alberta, the Lower Cretaceous McMurray Formation comprises 50-80 m of uncemented quartz sand and associated shale, saturated throughout by bitumen. The sediments are dominantly of continental origin, except in the uppermost parts of the formation where sedimentation was influenced by the encroaching boreal sea.
In most outcrop and mine face exposures of the McMurray Formation, a sequence of three facies is recognized. In ascending order these are: (1) an erosionally based thick-bedded sand facies, 2-20 m thick, dominated by large-scale trough cross-beds; (2) an epsilon cross-stratified facies with solitary sets up to 25 m in thickness, consisting of decimetre to metre thick couplets of sand/mud, with depositional slopes of 8-12° and palaeocurrent indications parallel to the strike of the epsilon cross-set; and (3) a horizontally bedded argillaceous sand facies up to a few metres thick. The three-fold sequence is interpreted as a single upward-fining cycle of channel sedimentation, the trough cross-bedded sands resulting from channel bottom deposition, the epsilon cross-strata accumulating by lateral accretion of channel point bars, and the upper argillaceous sand representing floodplain sedimentation. Where the McMurray Formation is relatively thin (less than 50 m), virtually the entire formation is commonly composed of a single upward-fining channel deposit.
Details of the size and physiographic setting of the channels are somewhat uncertain, but the present evidence suggests that the epsilon-dominated McMurray Formation sequence in the Athabasca Deposit region represents the coastal plain culmination of a very large fluvial drainage system.     

Closed-system marine burial diagenesis: isotopic data from the Austin Chalk and its components

ABSTRACT
The carbon and oxygen isotopic composition of the Austin Chalk was examined in cores representing a range of depths from surface to 3000 m in order to document the effects of burial diagenesis on carbon and oxygen isotopic composition. Low magnesium calcite oysters were separated (from 500 um wide areas) and analysed to estimate the starting composition of Cretaceous marine sediment. These gave an average value of -2·5%δ¹⁸O; + 2·0%δ¹³C (PDB). The compositions of micrite, intergranular cement, and fracture cement were analysed, and their deviation from this original marine composition was evaluated to document the progression of chalk diagenesis. Interestingly, micrite exhibits only minor variation in composition from marine values despite present burial depth ranges in excess of 3000 m. The average deviation from δ18O marine is less than 1·5. Furthermore, intergranular cement and particularly fracture cements, which occur only in the deepest cores and which clearly post-date micrite lithification, are generally indistinguishable from micrite in composition. Isotopic compositions exhibit no correlation with depth of burial despite abundant petrographic evidence of deep burial diagenesis. This uniformity in composition is interpreted as reflecting a closed, rock-dominated diagenetic system in which the compositions of precipitated carbonate cements were controlled by the composition of dissolving carbonates during lithification. As such, the composition of burial cement is not representative of the rock-water temperatures during precipitation.
Thus, in the context of isotopic analyses from other carbonate systems, unless the degree of openness of the diagenetic system is known, oxygen isotopic signatures of cements cannot directly be converted to the rock-water temperatures at which they were precipitated unless the composition of the ambient porefluid is also known.